arctic marine science curriculum · external food supply are called zooplankton. most of the...

ARCTIC MARINE SCIENCE CURRICULUM

MODULE 3 LIVING ORGANISMS

STUDENT GUIDE 2001

Prepared for: Fisheries and Oceans Canada

Northwest Territories Dept. of Education, Culture and Employment Nunavut Department of Education Yukon Department of Education

Prepared by: AIMM North Heritage Tourism Consulting

with Prairie Sea Services, Bufo Incorporated and Adrian Schimnowski

MODULE 3 STUDENT GUIDE

MODULE 3 - LIVING ORGANISMS STUDENT GUIDE

TABLE OF CONTENTS

INTRODUCTION............................................................................................. 1 1.1 CLASSIFICATION SYSTEMS ..................................................................... 2 1.2 KINGDOM MONERA ................................................................................ 9 1.3 KINGDOM PROTISTA .............................................................................12 1.4 KINGDOM PLANTAE ..............................................................................17 1.5 KINGDOM ANIMALIA .............................................................................18 GLOSSARY .................................................................................................57


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MODULE 3 – LIVING ORGANISMS

Try This: 1. Invite Elders into the

classroom or interview Elders in their home or on the land to identify special rituals that are used for particular animals to show respect and ensure successful future hunts.

2. Why was it so important for Aboriginal people to show respect to the animals they hunted?

3. Is it still important for hunters to show respect for the animals that are killed? Explain your answer.

INTRODUCTION In this module you will investigate the living organisms that inhabit the Arctic region and the importance of these organisms to the people that live there.

The Inuit have prevailed over the centuries because of their extraordinary ability to draw sustenance from the vast lands and frozen seas over which they have roamed in a difficult struggle for survival. They share these lands with many creatures. The frigid climate and the absence of arable soils render the land incapable of yielding grains or fruits suitable for human consumption. To meet basic needs for food and warmth, Inuit have traditionally been compelled to turn almost exclusively to animals-whether fish, fowl or mammals. This reliance has helped engender a deep integration with nature. The Inuit hold a profound relationship with fellow beings of the Arctic and an abiding respect for them. In the Inuit way of seeing the world, each living thing has a soul and a spirit that endures even after life has left the body. The Inuit hunter is grateful for the food, clothing and other necessities these creatures provide. He seeks to protect their spirits so that others will come and the hunt can be renewed. Special rituals are observed to show respect for the soul of a fallen animal, for example, placing fresh water, obtained from melted snow, in the mouth of a slain seal to help slake its thirst.

Source: Seals and Nunavut:

Our Tradition, Our Future


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"I am going to talk about two things They have differences between them. For instance there are the puijiit, the bases of human sustenance, the sea animals. And there are nunatuttiit, the planteating animals. I just want to make it clear about the differences, and also because I need to be understood. Puijiit, the sea animals, are what they are called by the Inuit, those sea animals that are fit for human consumption. Then polar bears, caribou, hares and foxes are called pisutiit, walking animals."

1.1 CLASSIFICATION SYSTEMS

Describing, naming, and grouping the many different kinds of living things on the earth and in the waters of the earth has been both a necessity and a pastime for centuries. Think of all the different ways you can describe and group organisms. For example, field guides, such as "Barrenland Beauties", group organisms based on where they are found. Hunters will also know what types of organisms can be found where, at what type of year. It is often useful to group organisms by what they do. For example, Inuit describe certain species of shrimp as the ocean's "cleaners" because they eat any decaying matter. Ecological Knowledge The following information describes and example of the Ecological Knowledge held by the Inuit.

Nunatuttiit are land creatures that breathe but do not fly, such as caribou, fox, rabbit and lemming. Puijiit are animals that surface in the sea to breathe and are layered thickly with fat. Polar bears occupy a position between the two categories, for they are not exclusively of the land nor of the sea, but of both. Larger birds are collectively termed tingmiat, the fliers. Many varieties of fish are named, but there is no generic term for fish. The term iqaluk is often used to mean fish in general, but usually by younger people. For our elders, iqaluk is used to indicate Arctic char, but other terms, such as tisuajuk, ivisarak and nutilliajuk, are more specific. We understand that all large marine and land mammals, fish and birds that we depend on for food are themselves dependent on the many varieties of smaller plants, animals and insects found on the land and in the sea. Some of these have specific names as well. A number of insects are named: bee is iguta; spider, ausivaq;


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Kingdom Phylum

Class Order Family Genus Species

Figure 1: Taxonomic Classification Hierarchy

mosquito, qitturiak and butterfly, takalikituak. Our knowledge identifies these different creatures, and it also identifies many other factors that help us understand the behavior of resources we depend on directly for food and indirectly as the food of our food. The relationship between living things, and between the environment and living things, contributes to a very complex web of life. Our identification of these relationships and of the complexity of the web demonstrates our ecological understanding.

Source: Inuit Tapirisat

www.tapirisat.ca The start of the scientific classification system began with an early grouping of organisms on the basis of structural similarities. The Greeks and Romans who grouped plants and animals into basic categories such as dogs, oaks and horses, etc. This method of grouping into categories was expanded into a simple classification system. Eventually, each unit of classification was called a genus, the Latin word for 'group'. Seventeenth century European naturalists made this system very complicated by giving plants and animals descriptive Latin names, sometimes five or six words long. In the mid nineteenth century, a Swedish biologist named Carolus Linnaeus simplified the problem of categorizing life's diversity by assigning every organism then known to science to a series of increasingly specific groups, depending on the number of structural traits shared by group members. The science of classifying organisms is called taxonomy. The hierarchy of taxonomic classifications starts with the broad category of Kingdom, then descends with ever-increasing specificity as outlined in Figure 1.

"When we think of something or discover a new fact, we also think of all the interconnections between that fact and everything else. And so it is with our science: it is going to be connected to everything within our culture. If scientists have trouble with this idea, they should take time to understand it better. I think we have something important to teach them that will make them much better researchers and help them solve problems more easily."


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For many years, taxonomy was based on physical structures such as the number and arrangement of toes or the shape of the skull. In recent years, however, a branch of taxonomy known as phylogenetics has dramatically changed the way we look at species, at families and at orders. Phylogeneticists classify organisms through their genetic similarity, as evidenced by DNA sequences. As a result, the evolutionary relationships are better understood, and new species may be recognized. For example, some taxonomists no longer classify crocodilians (alligators, crocodiles and their relatives) as reptiles and instead link them to birds and dinosaurs. Figure 2 provides two examples of how the scientific classification system works.

Taxonomic Level Example Kingdom Animalia Phylum Chordata Class Mammalia HUMAN Order Primates Family Hominidae Genus Homo Species sapiens

Taxonomic Level Example Kingdom Animalia

Phylum Chordata WHITE WHALE Class Mammalia (Beluga) Order Cetacea Family Delphinidae Genus Delphinapterus Species leucas

Figure 2: Scientific Classificaiton Breakdown for Human and Whales


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Ε Check Your Understanding Discuss the following questions with a classmate and then answer them in your notebook. Be prepared to discuss these questions in class.

1. What are two reasons why scientists needed a classification system?

2. Why are there so many levels to the system?

3. Briefly describe a classification system similar to taxonomy.

4. List the taxonomic levels.

There are at least 30 million different species of plants and animals alive today. Many of these have no common name (e.g. beluga). When biologists and scientists discuss an animal, they usually refer to the scientific name which is identified by the genus and species, to avoid any possible confusion; for example the common name herring is used in the Tuktoyaktuk for Coregonus autumnalis, in Yellowknife for Coregonus artedii and in Vancouver for Clupea harengus all three are different species. Scientists only use a common name if it is referenced to a scientific name.


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Figure 3: Taxonomic Classification System

Figure 3 summarizes the taxonomic classification system. As you can see, there is a general separation between the Prokaryotes and Eukaryotes. The prokaryotes are among the simplest, most primitive forms of life. In this type of cell, there are no cell organelles as there are in the eukaryotes.


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Figure 4: Ocean Zones

OTHER WAYS TO LOOK AT LIVING THINGS IN THE OCEAN The study of oceans is so vast and complex that one person cannot hope to become an expert on everything. Marine biologists and oceanographers often focus their studies on one part of the ocean. To simplify terminology, scientists have agreed to give certain names to the different parts of the ocean. Figure 4 contains the names given – some of which you will be familiar with. Bookmark this page so you can refer back to it when a new term is introduced and you need to see where it fits in the total profile of the ocean. Organisms found in the ocean can be grouped according to three fundamental life styles: planktonic, nektonic and benthic.


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Planktonic Plankton are organisms that drift with the ocean currents. Many such organisms have some ability to move but usually only in a vertical direction. Autotrophs that follow this drifting life style in the upper layers of the ocean are called phytoplankton. Planktonic heterotrophic organisms that depend on external food supply are called zooplankton. Most of the biomass of the earth is found adrift in the oceans as plankton. Many of the nekton organisms and almost all of the benthic organisms make their home in the plankton community during their larval stages. As adults, benthos sink to the bottom and nekton begin to swim freely. Nektonic Nekton include all animals that can move independently of ocean currents. Included are most adult fish and squid, marine mammals, and most marine reptiles. These animals are limited in their movement by invisible barriers created by gradual changes in temperature, salinity. Vertical range may be determined by water pressure, temperature or other factors. Benthic Benthic organisms live on or in the ocean bottom. They may live in mud, sand, or buried shells. They may also attach themselves to rocks or move over the surface of the bottom.


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Figure 5: Shapes of Marine Bacteria

1.2 KINGDOM MONERA This Kingdom includes bacteria and the Blue -Green Algae (cyanobacteria). The members of this kingdom are prokaryotic which means that they are the most primitive of all one-celled organisms. They contain no nucleus nor do they contain mitochondria or chloroplasts. BACTERIA Bacteria are found everywhere in the marine environment including deep-sea vents, volcanic vents, the Arctic and the Antarctic. Bacteria grow best when they can attach to a substrate. Consequently marine bacteria are more common in bottom sediments than in the water column. However in estuaries, such as the Mackenzie River estuary, which contain a lot of suspended solids, bacteria can also be abundant in the water column as the bacteria can attach themselves to these suspended particles. The taxonomy of marine bacteria is poorly known. Scientists have found that bacterial cells often change with their environment, which makes classification difficult. Figure 5 illustrates the ability of some bacteria to change their classical shape of rods, spheres and spirals. You will do an activity in the lab where you will see the various shapes of bacteria. There are fewer marine bacteria than terrestrial forms but this does not lessen their importance to the marine food chain. There are three groups of marine bacteria: saprobic (decomposers), autotrophic(producers), and pathogenic / parasitic.


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Saprobic bacteria are important in the decomposition of organic matter. They reduce dead tissue, feces, and other remains of marine organisms to the inorganic compounds of CO2, nitrate (NO 3- ) , and phosphate ( PO4 3- ). As decomposers, saprobic bacteria are the key link in detritus-based food webs, which are so important to benthic marine organisms. An interesting characteristic is their ability to use most organic molecules as a source of energy. They have also been found to slowly degrade petroleum products released into the environment from oil spills or from community pollution. Autotrophic or chemosynthetic bacteria are important because they can produce complex organic molecules where photosynthesis is not possible due to the lack of light energy. Pathogenic/parasitic bacteria in the marine environment are not as well known as in the terrestrial world. However, some diseases found in marine mammals, fish, and invertebrates are caused by bacterial infections. BLUE-GREEN ALGAE Blue-Green Algae are believed to be among the first photosynthetic organisms on earth. Many species are marine and can tolerate wide ranges of salinity and temperature. They are found almost everywhere including the least expected places like the hair of polar bears! In the Arctic marine environment, blue-green algae are limited by low temperatures and occur only in low abundance. Their occurrence is a biological marker for areas where warm southern waters reach during the summer.


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Ε Check Your Understanding 1. Look at the profile of the ocean and explain the difference between

benthic and pelagic organisms.

2. List the major kingdoms.

3. What is the difference between a prokaryote and a eukaryote cell?

4. Describe an importance characteristic of saprobic bacteria.

5. Theorize another use for saprobic bacteria.


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1.3 KINGDOM PROTISTA

PHYTOPLANKTON This kingdom and all others are eukaryotic which means they have a full complement of cell organelles with a nucleus that contains the genetic material. Members of this kingdom include: diatoms, dinoflagellates, algae and protists. They are collectively called phytoplankton (drifting plant). A diagram of a typical eukaryotic can be seen in Figure 6.

Figure 6: Typical Eukaryotic Cell

The phytoplankton of the ocean are often referred to as the 'pastures of the sea'. The role of phytoplankton in capturing the sun's energy in the marine environment is very important to all marine life. They are mainly small unicellular (single-celled) plants known as algae. Each planktonic cell is an independent, photosynthesizing individual. They can occur either as single cells or as long chains. At least 90% of the photosynthesis in the marine environment is due to phytoplankton. The remaining 10% is from littoral (see the ocean profile for this zone) and shallow water algae and sea grasses. The phytoplankton at any given location is generally a mixed population of species belonging to a number of groups. Diatom (Figure 8) and dinoflagellates (Figure 7) are two


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Figure 7: Dinoglagellates

major groups of organisms belonging to the phytoplankton. Figure 7 is of a selection of dinoflagellates. They usually have two whip-like appendages or flagella that give the cells limited swimming movement. The two organisms in the middle of the right diagram produce toxic red tides and paralytic shellfish poisoning. Primarily diatoms and dinoflagellates dominate Arctic marine phytoplankton.

Stephanodiscus niagrae

A. valve view B. girdle view


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Figure 9 - Green Algae

ALGAE Algae is the term used for marine and freshwater plants, including most seaweeds. They can be single-celled, colonial, or multi-celled, with chlorophyll but not true roots, stems, leaves, and with no flowers or seeds. There are three distinct types of eukaryotic sea algae: green, brown and red. Each has its own distinct structure and reproductive cycle. Green algae can be quite small in relation to other forms of algae. They appear in the shape of sheets or tubules. Although growth in green algae is usually vegetative, there is a well-defined sexual reproductive cycle. Using the species Ulva we will follow the cycle.

The two stages illustrated in Figure 9, differ only in the number of chromosomes in each cell. The sporophyte stage is diploid (having a double set of chromosome: 2n), The sporophyte produces spores through meiosis at the margin of the blade. These are released and grow up as a gametophyte. The gametophyte stage is haploid (having a single set of chromosomes: 1n ). The gametophyte releases the male and female isogametes which fuse to produce a 2n zygote that develops into the sporophyte stage.


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Brown algae among the largest and most complex algae grow to lengths of up to 50 m. This species includes a number of large plants generally called kelp. Most species of kelp can be divided into three parts: holdfast, stipe and frond. Many brown algae have floats, or pneumatocysts, located either on the fronds or stipe. Pneumatocysts are filled with gases that help the algae float. Commonly these gases are those that are dissolved in water like oxygen, nitrogen and carbon dioxide. Reproduction in brown algae is characterized by alternating generations. In some species like the one shown, the haploid, or gametophyte generation is a single cell. Only the sporophyte is multicellular. Specialized cells on the frond called sporangia produce flagellated microscopic zoospores. These zoospores, which are haploid, swim to the bottom and grow into the small gametophyte stage. Brown algae occur on the Arctic Ocean bottom. Many small invertebrates live among the blades of kelp and “Devil’s apron’, a seaweed of big, flat brown sheets. Initially attached to rocks, these seaweeds are often torn loose by storms and drift to the surface with numerous small animals attached to them. They freeze into the ice and in spring melt first because they are dark. In the pools around them you may find the remains of creatures from the bottom such as clams, sea urchins, sea stars and sometimes the hollow shells of amphipods. These gametophytes are either male or female. The male gametophyte produces mobile sperm cells that swim to the female that has already produced nonmotile eggs. After fertilization, the diploid zygote attaches to the bottom and grows into the larger sporophyte stage.


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Red Algae are mostly filamentous or sheet-like macro algae. Their name comes from the presence of a red photosynthetic pigments that usually mask the chlorophyll of green plants found on land. Most species are marine and are found in the benthos attached by a holdfast. There are no motile red algae and even the reproductive stages cannot swim. Their reproductive cycles involve the alternation of generations like the other algae species but in patterns that are often complex. These open water areas are ideal habitat for microorganisms at the bottom of the food chain (for all trophic levels). In addition to the open water, there is a steady supply of nutrients (especially nitrogen and phosphorus) brought to the surface by upwelling currents. Ice algae are one-celled plants that live and breed in the pores in the underside of the ice. Ice algae live on the underside of ice near holes, cracks, leads, under thin ice and/or with or no snow cover. Ice algae is common in first year ice. They give the bottom of the ice a yellowish brown colour and are grazed upon by zooplankton. A special species of ice algae called Helosira forms very long strands under the ice. These strands can be a few meters in length although the algae is a phytoplankton = 1 cell (only a few 1/10 of mm length). Ice algae is mainly made of diatoms that grow between the ice crystals on the underside of sea ice. The light that reaches the algae and the nutrients it receives from the water below the ice determines the abundance of ice algae. The amount of available light is controlled mainly by the thickness of the snow cover, whereas water currents and diffusion control nutrient availability. At high abundance, the bottom of the ice can turn dark greenish brown in color. Ice algae are very important to productivity of the Arctic Ocean by providing a kick-start to spring. They allow the growing season or season of maximum productivity to begin earlier than it would otherwise. A community develops in association with the ice algae which includes zooplankton, (in particular amphipods and copepods), Arctic cod etc.


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Ε Check Your Understanding (sections 1.3 to 1.5) 1. What organisms are included as phytoplankton?

2. Diatoms and dinoflagellates are microorganisms. Sketch a food chain to show their importance.

3. Sketch a diagram of a green algae to show its three basic structures.

4. What is the primary function of marine fungi?

5. What is the principal difference between land plants and marine plants?

Did You Know… Much of the Arctic coastal area is very inhospitable to plants as a result of ice scouring and exposure. But a few do make a living there:

• Sheltered beaches - seashore starwort

• Shingle or cobble beaches – scurvy grass, sea lungwort

• Sandy beaches - sea-purslane

• Beaches, barrier islands, dunes - lyme grass

1.4 KINGDOM PLANTAE Plants are the primary source of food energy through photosynthesis on land but in the marine world, that responsibility has been left to the organisms that we have already discussed. The explanation for this lies in the functioning of the vascular system. Plants rely on the evaporation of water from the leaf surface to provide the force that draws water from the roots and through the stems to the leaves. For plants that are only partially submerged in seawater, such as saltwater marshes, this evapotranspiration system can still work, although these plants must use up a lot of energy to desalinate the salty water coming into their root system. Salt marsh plants can stand only periodic submergence in seawater and are found in the intertidal zone between high tide level and low tide level.


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Figure 10: Copepods

1.5 KINGDOM ANIMALIA ZOOPLANKTON Let us first look at the smallest form of animals that make up an important part of all food chains. This group of organisms is referred to as zooplankton. Most large epipelagic animals cannot feed directly on the tiny phytoplankton. They rely on herbivores that can. Of all the herbivores in the epipelagic zone, zooplankton are far the most important. They belong to almost every food chain in the ocean. Zooplankton are weak swimmers – enough for them to catch a floating phytoplankton – and are carried around by the currents. By far the most abundant of the zooplankton are protozoa. Copepods are very small crustaceans and are usually the largest component of the more visible zooplankton. A sample of zooplankton collected with a net can contain about 95% copepods. In the Arctic and Antarctic, the euphausiids are often the krill, usually Euphausia superba, occurring in such large numbers that they provide the main food for the giant baleen whales such as the bowhead whale in the Arctic. Figure 10 contains two types of copepod. The lower form is found in the Arctic and the other in temperate waters. The following account of whale growth in the Arctic will show you why small organisms that we can hardly see are so important to the North. To illustrate the great productivity that occurs during the short summer season in Polar Regions, consider the growth rate of baby whales. The bowhead whale is able to develop and support calves during a gestation (development within the womb) of 13-14 months. The calves reach 4.3 metres in length and weigh approximately 907 kilograms.


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By the end of the first year, the young whales grow to 8 metres in length. This phenomenal growth rate gives some indication of the great biomass of copepods and krill that these large mammals feed upon. Epipelagic food webs tend to be long and complex because they contain many species and different trophic levels. The following is such an example of this kind of food web. INVERTEBRATES Invertebrates dominate the animal kingdom. There are about 30 phyla in the animal kingdom of which all but one are invertebrates, and one major group, the arthropods, consist of over a million species (85% of all animal species). Arthropods are the most abundant phylum on the planet and if you traveled to the deepest ocean trenches, highest mountaintops or could even swim in a geothermal pool you would find a member of this phylum waiting to greet you. As a group they are easy to recognize with their hard outer cuticle, unique compound eyes, and a pair of legs on each segment of the body that are grouped into functional tagma. Due to the incredible number of species, it has always been a problem to identify them. We will only discuss those groups that occur in the benthos of the Arctic marine environment. Few studies have been done on benthic invertebrates in the Arctic because of the difficulties in doing so and the lack of commercial potential. Benthic invertebrates depend on the availability of plankton and decaying organic material. Many are scavengers. The most common benthic invertebrates are amphipods. Amphipods are crustaceans, typically ranging in size from 2 to 50 mm, although a few may be larger. Amphipods are common in aquatic ecosystems throughout many parts of the world, inhabiting marine, brackish, and freshwater environments. The order Amphipoda contains nearly


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Figure 11: A Typical Amphipod

7,000 described species. Some groups live their lives attached to marine mammals. These whale-lice are ectoparasites that cling firmly to, and feed on, the skin of whales. Unlike other amphipods, whale-lice cannot swim so once the juveniles leave the brood chamber of the female they attach themselves close by. Another example of an amphipod is sea lice. Many fishermen will recognize these if they leave their nets in too long. A Typical Amphipod Comb jellies or ctenophores are very abundant in the Arctic. They have radial symmetry and have a gelatinous body. They are carnivores with a great appetite. Swarms of comb jellies may consume large numbers of fish larvae. Many capture their prey using two long tentacles armed with sticky cells named colloblasts. Other groups of invertebrates are present but are less common and diverse:

• Polychaetes are segmented worms and are among the most common marine organisms. They can be found living in the depths of the ocean, floating free near the surface, or burrowing in the mud and sand of the beach. Some, such as Eunice gigantea, may reach three meters long.

• Polychaetes are known by many names: lugworms, clam worms, bristleworms, fire worms, etc., but all possess an array of bristles on their many leg-like parapodia. The name polychaete, in fact, means "many bristles". The many common names reflect the wide array of body forms found in this group, unlike the related earthworms and leeches which all have the same general appearance. Many small polychaetes dwell in the bottom ice.

• Gastropod (also called univalves) are a type of mollusk that have a single valve (a shell, which is sometimes reduced or even absent) and a muscular foot. There are over 90,000


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species of gastropods worldwide, both in the water and on land. Some gastropods include snails, whelks, and slugs.

• Brittle stars, sea urchins, sand dollars, sea cucumbers, sea stars, basketstars and feather stars are commonly found in the Arctic. These and many other organisms make up the Echinodermata, the largest phylum to lack any freshwater or land representatives. Most echinoderms have five-fold symmetry, with rays or arms in fives, or multiples of five. Echinoderms have a system of internal water-filled canals, which in many echinoderms form suckered "tube feet", with which the animal may move or grip objects.

• The decapod, 10 legs, crustaceans are amongst the most familiar as they include the lobsters, crab and shrimp that are often harvested for food. Shrimp occur both in the benthic Arctic environment as well as pelagic and like most of its kind, are primarily scavengers.

FISH Fish are part of the kingdom Animalia. The phylum to which they belong is chordata. Chordates have the following characteristics:

• Central spinal cord • Notochord or backbone • Tail (at some stage of life) • Muscle blocks • Gill slits (at some stage of life)

Ask your teacher to show you diagrams of the human stage where all these characteristics are present. You probably didn't know you had gills and a tail at one stage of your life! There are two classes of fish that we will look at: the bony fish called Osteichthyes and the cartilaginous fish called Chondrichthyes. Both of these classes can be found in the Arctic.


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Scientists believe that fish were the first vertebrates to evolve. And from them all other forms of vertebrate life developed. Unlike mammals and birds, they have no lungs, taking oxygen from the water directly into the blood stream by means of gills. The hard flaps covering the gills are called the operculum. Bony fish have an air bladder that is used to regulate buoyancy. Scales are often but not always present. For many species, scales can be used to determine age by counting growth rings. We will do a fish lab in which we will determine the age of fish by examining their scales and the otolith – a bone-like structure found in a fish’s inner ear. Fish have an extremely well developed sense of smell. They also have senses of sight, hearing and taste. Their sense of touch is generally poor, except in those fish that have barbels, which help locate food by touch. They also have 'skin senses' such as the lateral line system seen in many fishes. This is a line of pores along each side of the body used for detecting changes in pressure and temperature. Some fish can also detect electromagnetic fields, a skill that may be useful for finding prey, avoiding predators, and for navigation. The tuna fish shown in Figure 12 has a more muscular body and a large powerful caudal fin for increased speed. Most fish have similar fin structure. The caudal fin thrusts from side to side to propel the fish forward. The dorsal fins prevent the fish from rolling as it swims, and a ventral anal fin keeps the fish from slipping sideways. Paired pectoral and pelvic fins act to assist the fish in moving up or down, in turning and in stopping. The distribution and diversity of fishes is determined by a number of conditions, including: temperature, light, and salinity. Some species are benthic (bottom -dwelling) while others are pelagic (swimming about freely). Most fishes inhabit either freshwater or seawater but some can live in both environments.

Village Science

Over thirty years ago, right after freeze-up, I helped Jack Ingatti make a fish trap. We spent hours splitting spruce for the fence, chopping poles to support the fence and many more hours picking river ice to set the trap. The first time we checked the fish trap was an eye-opener. Hundreds of lush (burbot) flopped on the ice until the cold air silenced their efforts. Every day the trap produced a harvest for the village. One of my partners and I had a dog team that was a composite of all the rejects in the village-dogs people didn't want to feed and didn't want to shoot. They were slow but adequate for our needs. The old-timers told us not to feed fresh lush to our dogs but to freeze them for several nights first. We thought about it and decided that they were giving us some superstition because we could see that the lush were fat and good dog feed. When it was our turn to check the fish trap, the dogs agreed with us as they ate the fresh lush on the spot. We didn't say anything, not wanting to hurt people's feelings by exposing the local superstition. Within two weeks our dogs were totally lifeless. We had to rest them halfway to the store and it was only two miles from the village. Occasionally, someone mumbled, "fresh lush." We didn't make the connection for quite a while.

(continued on next page)


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Fish that live in salt water but migrate up rivers to spawn are called anadromous. There has been much information collected about freshwater fishes that live in the Northwest Territories, Yukon and Nunavut but marine fishes are less well known. This is generally because fresh water fishes are more easily accessible to catch and study. Figure 13 is the anatomy of a bony fish showing its main organs.

(…cont’d) We fed our dogs tremendous amounts of dog feed, but they remained skinny and lazy. Finally, the tapeworms started dangling from the dogs' posterior and we got it. Fresh lush have tapeworms! If we had frozen or cooked the lush, our dogs could have made it to the store without a break halfway. Superstition? Hardly. That was science.

Village Science Sharing Our Pathways

Vol. 4, Issue 3 Summer 1999

by Alan Dick

Figure 12: Arctic Charr


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Anadromous Fish This characteristic of some fish is a remarkable example of animal adaptation to their life style and the environment. The following information on anadromous fish is taken from a presentation made by Dr. Jim Reist at Oceans Day 1996 in Churchill, Manitoba. Most fish occupy either freshwater (e.g. lakes, rivers) or marine (e.g. oceans) habitats at all times of their life. Some examples of freshwater fish are:

• Walleye Stizostedion vitreum • Burbot Lota Iota • Northern Pike Esox lucius

Some examples of marine fish are:

• Capelin Mallotus villosus • Arctic Cod Boreogadus saida

However, some fish switch between freshwater and marine habitats at different times of their life. These are called diadromous fish (from the Latin di = two, and drorn = to run). There are about 20,000 species of fish and about 160 of these (0.80 %) exhibit diadromy. Diadromous Fish Diadromous fish can be grouped into three types:

1. Anadramous (ana = up & drom = to run) These fish migrate to the sea as sexually immature fish and then migrate back to freshwater to breed. For example: Pacific salmon Oncorhynchus spp and Arctic char Salvelinus alpinus. Most char return to freshwater every year not always for spawning, but to spend the winter.

2. Catadromous (cata = down & drom = to nm):These fish migrate to freshwater as sexually immature fish and then migrate to the seawater as adults to breed. For example: American eel Anguilla rostrata.


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Ε Check Your Understanding Discuss the following questions with a classmate and then answer them in your notebook. Be prepared to discuss these questions in class.

1. It is possible for fish to drown. Speculate on the conditions that would make this happen.

2. What structures in fishes enable them to adapt to their environment?

3. How do scientists determine the age of fishes?

4. Explain why it is necessary that anadromous fishes return to fresh water for the winter.

5. Using a map identify areas that the class members have caught anadromous fish.

3. Amphidromous (amphi = both & drom = to run) These fish migrate between freshwater and sea water for purposes other than breeding. For example: some of the southern hemisphere fishes.

In the Arctic, the only diadromous fish we observe are anadromous species. Marine water does not freeze until about -1 .80C. Fish freeze at 00C. Therefore, to survive in cold Arctic waters, the fish must have anti-freeze in its tissues. Arctic anadromous fish do not have this adaptation therefore they must leave the sea every fall. We see movement back into freshwater as an upstream migration of large numbers of fish of many sizes, ages, and maturities. Some populations of Arctic char remain in freshwater all their lives, but most are anadromous. Within most populations of Arctic char, some fish become adult without ever going to sea. The further north, the greater the likelihood that the char population never goes to sea.


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Figure 13: Anatomy of a Fish


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Ε Check Your Understanding 1. Why didn't the old man just explain how to free the fish more easily?

2. Have you ever had a similar experience with learning a new thing? Share the experience with a classmate.

Village Science: A Fish Story

By the time they arrive in the headwaters, male dog salmon have large teeth that become badly enmeshed in a net. I spent hours and hours carefully extracting them, trying not to tear the net. I told the old man about my frustrations. "You have to know how," was all he said. A few days later, I was very tired, having worked at a mine all day and having fished all night. I spent more time wearily taking fish out of the net than I did with the net in the water. I always keep a wooden club in the boat to dispatch the livelier fish so they don't flop and tangle the net once it is hauled into the boat. I took the club and angrily pounded the dog salmon's teeth in abject frustration. To my utter amazement, the teeth easily fell off the jaw, and the net was released. Within minutes, club in hand, I removed the rest of the fish from the net. The next morning I told the old man of my discovery. He said, "That's how."

Sharing Our Pathways Vol. 3: Issue 4 Sept/Oct 1998

by Alan Dick


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Biological Importance of Arctic Cod Like other marine environments, Arctic waters support complex ecosystems of organisms (including humans) that are connected by food chains. The Arctic is different from more temperate environments because there is less diversification of species as well as a lower level of productivity. The loss of a single species might seriously disrupt the food chain, resulting in severe changes at all levels of the chain. The loss of the Arctic cod in northern areas by over fishing, from disease, from an imbalance in the ecology or from all of these factors would be serious as it is an important food in the diet of many species of marine mammals, sea birds other fish and humans. Narwhals, for example, feed on predominantly Arctic cod. The remains of as many as 64 Arctic cod have been found in a single narwhal stomach. Belugas and ringed seals also feed on this fish. Seabirds, especially murres, depend heavily on Arctic cod as a source of food. In one study, it was estimated that over a 35-day period, at least 1.4 million Arctic cod were eaten by a line of seabirds stationed along the edge of 125 km of fast ice. Arctic cod have still other predators. Atlantic cod have been reported feeding on large numbers of Arctic cod off northeastern Newfoundland. Arctic char, Greenland halibut and Atlantic salmon also feed on Arctic cod at various times. And changes in the abundance of the different species in only one situation that could change the Arctic ecosystem. While there is always change in any environment, some changes can be catastrophic for some species. Natural cycles can be easily displaced by biotic and abiotic changes such as temperature, pollutants, increased shipping, increased eco-tourism, the establishment of new communities, commercial fishing, etc.


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Figure 14

GENERALIZED LIFE CYCLE OF AN ANADROMOUS FISH ARCTIC CHAR


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ARCTIC MARINE MAMMALS Traditionally, few cultures in the world were more dependent on the animals of the sea than the Inuit. In a land where resources were often scarce, the Arctic seas with their vast populations of fish and marine mammals provided the raw materials that helped Inuit society survive in one of the world's harshest climates. Even today, as massive material changes continue to reshape Aboriginal society, the people use marine mammals as important sources of food, clothing, and increasingly, revenue in the from of whalebone sculptures. WHALES The largest group of marine mammals is the cetaceans (order Cetacea), the whales, dolphins and porpoises. Of all marine mammals, the cetaceans have made the most complete transition to aquatic life. While most other marine mammals return to land at least part of the time, cetaceans spend their entire lives in the water. Their bodies are streamlined and look remarkably fish-like. Though they resemble fishes, cetaceans’ breath air and will drown if trapped below the surface. They are "warm-blooded,” have hair (though not much) and produce milk for their young. Cetaceans have a pair of front flippers, but the rear pair of limbs has all but disappeared. The rear limbs are present during the embryo stage but fail to develop. Like fishes, many cetaceans have a dorsal fin although it is often small. The muscular tail ends in a pair of fin-like, horizontal flukes. Blubber provides insulation and buoyancy. Cetacean nostrils differ from those of other mammals. Rather than being on the front of the head, they are on the top, forming a single or double opening called the blowhole.


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Figure 15: Baleen Feeding Apparatus

There are about 90 species of cetaceans, all of which are marine except for five species of freshwater dolphins. Cetaceans are divided into two groups:

(1) the toothless, filter feeders, that include the bowhead

(2) the toothed, carnivores, a group that includes the narwhal and beluga.

The toothless whales are better known as baleen whales. Instead of teeth they have rows of flexible, fibrous plates named baleen. Baleen is made of the same material as our hair and nails. The inner edge of each plate consists of hair-like bristles that overlap and form a dense mat in the roof of the mouth. The whale filter feeds by taking a mouthful of water and then squeezing it out through the bristles. Baleen whales are not only the largest whales but they are the largest animals that have ever lived on the earth. There are 11 species of these majestic creatures. They were once common in all the oceans, but commercial over-hunting has brought many species to the edge of extinction. Figure 15 provides a look at the process by which a baleen whale (bowhead) feeds.


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Belugas, narwhals, and bowheads are the three true Arctic whales, although others are occasionally spotted here in summer. Of the three Arctic whales, belugas are the most numerous and widely distributed. More than 60,000 and perhaps as many as 100,000 live in the Arctic and the sub-arctic. The Bowhead whale - Balaena mysticetus (arviq ) belongs to the right whale family, which received its name in early whaling days. Being slow swimmers and floating (rather than sinking ) when killed, as well as providing a large amount of oil, they were the " right " whales to hunt.

Figure 16: Bowhead Whale

Bowhead whales have very large heads compared to their body size. This is because they have the longest baleen of any living species reaching up to 4 m. Bowheads may grow up to 20 m long and weigh about 50 tonnes. They are dark black or bluish gray in colour with a pale throat and underbelly. Bowhead whales have been observed to feed cooperatively in U-shaped groups taking advantage of dense gatherings of invertebrates. Breaching and leaping is also a common site.


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Did You Know … Bowheads feed on:

iglirait/copepods… …they feed on them by opening their mouths and waiting, the mouth is full of suqqaw/baleen and they are just like hair… (in this way) the bowhead collects its food; I guess when they feel that they have collected enough (on the hairy fringes of the baleen) then they close their mouths and eat it. …the tips of the baleen are quite hairy, and they stand up like teeth all the way to the back of the mouth…

Nauja Tassugat, Clyde River

Did You Know … Their food, the krill or the copepods, when they are more plentiful during some springs and summers, the whales are around in greater numbers, and in some summers they are less; so people would know that there are more bowhead whales if they have seen a lot more krill or copepods.

Jacobie Panipak,

Clyde River

This species is the only baleen whale to inhabit polar waters year round. In summer they are found in Lancaster Sound, Davis Strait and northern Hudson Bay. They winter in the loose ice or open water of Greenland, and may venture as far south as northern Labrador. They are not restricted to ice-free areas as they can use their heads and bodies to push through half a meter or more of solid ice. Most bowhead whales live in the Bering, Chukchi and Beaufort Seas along areas of pack ice. The bowhead has been designated an endangered species in both the eastern and western Arctic. Eastern Arctic populations are estimated to include only 700 individuals, while the western population totals 8200 individuals. Bowhead whales exhibit sexual dimorphism, with females being larger than males. Unlike its close relative the right whale, this rather rotund creature has a smooth skin, with no callosities and supports the longest baleen of any whalebone cetacean. They are thought to be the world's oldest mammals with some individuals living for at least more than 100 years as evidenced by the presence of 19th century whaling harpoons found in their flesh. The bowhead whale is both a surface skim-feeder, a bottom-feeder and a water column feeder. It consumes krill, amphipods (tiny shrimp-like crustaceans) and copepods (tiny planktonic crustaceans). The bowhead inhabits Arctic waters, where pack ice occasionally causes them to get trapped, or stranded. The bowhead ordinarily overcomes these challenges by being able to hold its breath for up to an hour, and by being able to fracture ice up to 12 inches thick to create breathing holes! Other whales that travel in heavy ice-choked waters, such as the beluga, are often found associated with bowheads as they take advantage the larger whales’ breathing holes.


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Pack ice is not the only hazard that the bowhead whale faces. Because of its slow speed and non-aggressive behavior, young bowhead may be attacked by killer whales. In the past humans have greatly affected bowhead populations. The whaling industry brought the bowhead whale to the brink of extinction. Inuit still hunt the bowhead, but the harvest is tightly controlled. Bowheads mature at 4 years of age and mate from April to June. The gestation period is 12 months and calves are born in April or May. Nursing lasts for a year with additional births occurring every 2 years. The behaviour of the bowhead whale is hard to study because of the harsh environment that it inhabits. Observations suggest that although migratory, their movements are dictated by the seasonal advance and retreat of ice. Bowheads typically travel alone, or in groups of no more than six individuals. During migration, the whales segregate themselves according to age and sex. The bowhead is a slow moving whale, commonly travelling at speeds of 3-4 knots, although when in flight, speeds of 7-9 knots may be reached. It is not aggressive and often shows curiosity toward small boats. Little is known of bowhead whale reproduction. It is thought that mating occurs from February to March and gestation takes about 13 to 14 months. These gentle giants were hunted by European commercial hunters to near extinction in the 1800s and early 1900s. To this day, their populations in the eastern Arctic remains dangerously low, thus their endangered status. There were once more than 11,000 bowheads in these waters. Today, most biologists agree there are no more than 1,000. The Beluga Whale- Delphinapterus leucas (qinalugaq or qilalugaq ) stands out conspicuously in dark waters. Belugas are circumpolar in their distribution. They are found in Arctic and Subarctic waters along the northern coasts of Canada, Alaska,


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Russia, Norway and Greenland. It is estimated that between 40,000 and 60,000 belugas live in Canadian waters. Sexual maturity occurs at 8 years of age in males and 5 years in females. Mating takes place in April-May. The mating system remains unknown but there are indications that males are polygamous, breeding with several females. Gestation lasts for 14.5 months and birth occurs in May and June. The gestation period and the lactation period of some 18 months results in females only being able to produce young approximately every 3 years. Belugas belong to the suborder of toothed whales (Odontoceti) and, together with narwhal, make up the family Monodontidae. The beluga is an opportunistic feeder with a diverse diet. Food items very according to seasonal availability and consist of many fish species, such as capelin, Arctic cod, and herring, but also invertebrates such as shrimp, squid and marine worms. As with most marine mammals, there is a seasonal change in the storage of blubber reserves. During their summer return to estuaries, they do not appear to eat at all. Belugas have a well-developed sense of hearing and refined echolocation. They are also a very vocal species emitting not only echolocation clicks but a wide variety of modulated whistles which probably serve in social communication. Congregating in large numbers in the same area every summer, these small-toothed whales are also the most gregarious and most vocal of the Arctic whales, spending hours rollicking in shallow waters, chirping, trilling, and clicking to one another in apparent delight. Early whalers actually dubbed them " sea canaries ". Their ability to discriminate using echolocation appears to be superior to the much-studied oceanic bottlenose dolphin and is probably related to their navigation in ice-filled winter habitats and their use of shallow water in the summer.


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CONTAMINANTS

There is evidence of significant decline in both PCBs and DDT in some marine mammals in the last 10 years. Yet, because of the high consumption of marine mammals fat by Aboriginal people, there is a concern about the effect of PCBs on human health. The flooding of large amounts of land by the development of future hydroelectric projects could also result in significant amounts of methyl mercury being transported to the coastal marine environment. The following account of contamination by toxic substances comes from the Proceedings of the Workshop on Traditional and Contemporary Knowledge of Nunavik Belugas, held in November 1994 at the Maurice Lamontagne Institute (Quebec).

A presentation was made on the sources of contaminants in belugas, trends in their concentrations, and their biological consequences for humans and animals. The principal heavy metals of concern in Arctic mammals are mercury, cadmium, lead, and arsenic. The man-made chlorinated organics include PCBs, DDT, toxaphene, chlordane, endosultphins, and lindane. The hydrocarbons recorded in Arctic mammals include PAHs and alkane, while radionuclides include cesium, strontium, plutonium, lead, and polonium. The most important source of hydrocarbons and radionuclides in the Canadian Arctic may be ocean dumping off the coast of the former Soviet Union. The Canadian Arctic receives high concentrations of heavy metals and chlorinated organics, especially in winter, primarily from atmospheric transportation. These chemicals travel to the Canadian Arctic, principally in the form of gas or dust, and they can enter marine and freshwater ecosystems and travel through the food web, eventually reaching marine mammals and the


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humans who eat them. Mercury

concentrations in the muscle and liver tissues of belugas from different areas is increasing. Belugas from eastern Hudson Bay have highest concentration of mercury in liver tissue. Because of its hydroelectric developments, the La Grande River might be an important source of contaminants in the foods consumed by Inuit, since the current in eastern Hudson Bay flows from south to north.

TECHNOLOGY’S IMPACTS During a study of Inuit knowledge of the Southeast Baffin Beluga the impact of technology on eastern beluga populations was noted:

• Since 1960's, when motorized boats were first introduced to the North and they began to be used for hunting whales, changes in their behaviour have been observed. Hunters chasing whales along the floe-edge with snowmobiles has also affected their behaviour.

• Initially, whales were curious about the noise. Today whales (who can hear from great distances) avoid areas where motorized boats are heard.

• Whales are now scattered in areas where they were once densely concentrated.

• Whales detour by great distances and have been known to travel within ice packs to avoid hunters.

• At the floe edge the behaviour has changed. They no longer stay close to the ice when feeding nor do they float still after feeding. Many whales have learned to avoid hunters at the floe-edge.


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Ε Check Your Understanding 1. Summarize the impacts that technology has had on the behaviour and

health of beluga whales.

2. Identify and describe other ways that technology has impacted on hunting methods, and possible implications of these changes.

• Elders in Pangnirtung have noticed a slight decrease in the thickness of the whales' fat and suspect this is due to whales needing to travel faster and farther to avoid motorized boats.

Source: Final Report on A Study of

Inuit Knowledge of the Southeast Baffin Beluga, Nunavut Wildlife Management Board, 1998.


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In order to deal with the changing nature of the hunt, elders have recommended that a set of Hunters Guidelines be established. These would help address concerns related to the current competitiveness amongst hunters because of quotas and help in the renewal of traditional hunting methods. The guidelines for hunting Belugas would ensure hunters use the right equipment, use nets properly, butcher whales properly, make safety a priority, use the proper calibre rifles, use proper harpoons and floats, practice proper hunting techniques, etc. Other topics suggested as guidelines include:

1) distribution of catch (traditional distribution methods),

2) chasing of whales, including steering of whales,

3) safe hunting practices,

4) hunt leaders, 5) traditional laws, i.e. leaders to take first shot,

etc. The Narwhal - Monodon monoceros (tuugaalik or allanguaq ), the mysterious unicorn of the sea, also boasts significant Nunavut populations, though its range is more restricted that the beluga. The majority of narwhals winter in northern Davis Strait and southern Baffin Bay. Toward the end of June they head for the fertile waters of Lancaster Sound and the deep bays and fiords of northern Baffin Island and beyond. A distinct population spends the winter in Hudson Strait, moving into northwestern Hudson Bay in spring. Narwhals average four meters in length and weigh nearly two tonnes. This species is remarkable for its ivory tusk that twists from its upper jaw like the overgrown tooth that it is. While narwhal belong with the toothed whales, its small, narrow mouth is toothless and the only two adult teeth it has are in the upper right and left sides of the jaw, either embedded in the jaw or, in males, extending out as a tusk. Narwhal produce clicks and other sounds though not as diverse a repertoire as beluga.


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Hundreds of years ago, reports of the existence of unicorns were told by imaginative European whalers. The large majority of tusked narwhals are male, although females occasionally grow them as well. The purpose of this tusk is still unknown, although different theories have been presented for centuries. Most often, the tusk is used in displays of aggressive behavior. Scientists believe that they may be used to determine social rank, much like the antlers of a moose. The following information is from the Final Report of the Inuit Bowhead Knowledge Study, Nunavut, March 2000 The Inuit were convinced that wildlife populations would remain healthy and abundant only if they were harvested and treated with respect. Species that are harvested in a disrespectful manner, or not harvested at all (a sign of disrespect), may decline in numbers or disappear altogether. Arguing and fighting over wildlife, or talking badly about wildlife in any way, are considered as being offensive to the wildlife; this also includes harming, mistreating, and abusing wildlife, or causing wildlife to suffer. Such displays of disrespect may also lead to the disappearance of wildlife. It was also stipulated that harvested animals must be utilized to the maximum extent possible, with minimal waste; this is another means of respecting wildlife. In the Inuit traditional way of living, everything was utilized and nothing was thrown away. Anything from the animal that was left over would be cached for later use, and Inuit would harvest only what they needed. Failure to share wildlife with other members of the community also constituted disrespectful treatment of wildlife. Sharing of food is one of the basic and vital foundations of Inuit society. Harvested wildlife must be shared with family and community.


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Ε Check Your Understanding 1. Why do you think whale stories attract the interest of the media?

2. Describe the process by which a baleen whale collects food.

3. Research more about echolocation.

4. How do scientists arrive at the conclusion that whales are very social animals?

SEALS, SEA LIONS AND WALRUSES Seals and other related forms are marine mammals that have paddle-shaped flippers for swimming, but still need to return to land or ice at regular intervals. They belong to the Order Pinnipedia, which means “wing-foot.” Pinnipeds are predators, feeding mostly on fish, squid and other invertebrates. Most pinnipeds live in cold water. To keep warm they have a thick layer of blubber like whales. They also have bristly hair for added protection against the cold. Many of them are quite large, which helps conserve body heat because large animals have less surface area for their size and therefore lose less body heat. The largest group of pinnipeds is the “true” seals (family Phocidae) that are characterized by having rear flippers that cannot be rotated forward. On land they must move by pulling themselves along with their front flippers. However, they are powerful swimmers propelled by strokes of their rear flippers. There are three families of Pinnipeds: Phocidae or true seals as they are called, Otariidae which included fur seals and sea lions (these can rotate their back flippers and are very agile on land), and Odobenidae or the walrus. Seals are hunted for their skin, meat, and for the oil extracted from their blubber.


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Five species of true seals are found in the Arctic Ocean: ringed seal (Phoca hispida), harp seal (Phoca groenlandica), bearded seal Erignathus barbatus, harbour seal (Phoca vitulina), and hooded seal (Cystophora cristato). However, the most numerous are the ringed, harp, and bearded seals. The Ringed Seal (Phoca hispida) is the most abundant, widespread and important seal to the socio-economy of many Arctic communities. The common name refers to the circular markings on the back of the adult. The scientific name refers to the seal's bristly coat. Traditionally, this seal was the main diet of the Inuit; its skin was used as clothing, its blubber fuelled the soapstone lamps, qulliit, that provided both light and warmth, and its intestines - a delicacy to Inuit - were also used as containers and igloo windows. The skin was made into the upper parts of boots and clothing. While the animal is no longer used to this extent today, the ringed seal is still an important food source for the people living along the Arctic coast, who also use the skin for boots and mitts, and, less frequently, for parkas, pants, and artwork. A wide array of Inuit names describes their various age classes, sex and condition. Some of these include: "netsiak" (white coat), "netsiavinerk" (silver jar), "netsilak" (adult), and "tiggak" (breeding male). The name, Bearded Seal (Erignathus barbatus), refers to its obvious moustache of long, white whiskers. The alternate name of " square-flipper" describes the shape of its front limbs. In Inuktitut, it is called "ugjuk". Lacking distinctive coloration, the pelt is dark gray on the back and lighter gray on the belly. The sexes are similar in colour. An annual molt occurs between March and August. Annual growth rings in the teeth and fore claws indicate age. The oldest seal that had been found was 31 years old. This seal is one of the largest seals found in the Northwest Territories. The average weight of adults is 250 kg and the length averages 235 cm. The blubber and hide layers account for 29 to 39 percent of its weight. There are about 300,000 bearded


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seals in Canada. They are permanent residents of the Arctic and are generally found as solitary individuals in areas associated with moving pack ice, such as leads and polynyas, however, they can maintain breathing holes in areas of thin ice by breaking it with their heads. Their diet consists of benthic (bottom dwelling ) organisms found in the shallower waters of the continental shelf. These include worms, clams, crabs and fish, such as Arctic cod, sculpin and flounder. Feeding dives as deep as 220 m have been reported. An undisturbed seal swims with its head and back above the water. When sleeping, it floats vertically. The senses of sight and hearing are good while its ability to smell is only fair. They sing long musical underwater songs. Singing activity peaks in April and May. Bearded seals have a large variety of songs that form part of a complex social structure that is not well understood. It may be related to claims of territory and breeding. Mating occurs in mid-May with a delayed implantation of two months resulting in a total gestation period of 11 months and an active gestation period of 9 months. A single pup is born on the ice at the end of April to early May. Bearded seals are the only northern seals with four mammae rather than two. The mother-pup bond is strong during the relatively short 12 to 18 days of the nursing period a recent study in Svalbaard suggests the lactation period may be longer – approximately 24 days. The pups are then left on their own. A female may give birth every one or two years. Sexual maturity is attained as six years of age. Bearded seals have always been important to the Inuit of the Arctic. The tough, flexible hide is valued for general uses like lines, traces, kayak coverings, and kamik (boot) soles. The meat is suitable for human and dog food: however, the liver may contain toxic levels of vitamin A and accumulated residues of mercury, DDT, DDE and dieldrin. The roundworm Trichinella may be transmitted to people who eat raw or frozen bearded seal meat.


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The Harp Seal (Phoca groenlandica) is one of Canada's most controversial wildlife species. A commercial hunt used to be conducted in the Gulf of St. Lawrence in March before the seals migrated north. This hunt focused largely on "white coats” – newborn seals. Emotional campaigns promoted by animal right groups brought an end to this hunt in the 1980s. These groups claimed that the hunt was inhumane and that the seals were declining in numbers. Due to lobbying in 1983, the European Economic Community banned the import of harp and hooded sealskins. Though aimed at stopping the killing of seal pups by Newfoundlanders, it also had a damaging effect on the market for Inuit seals. Slightly larger than the ringed seal, harp seals go through a series of coats with different patterns beginning with the white coat pup and ending with the adult coat which is distinguished by the black, harp-shaped saddle on their backs. These seals have never been as vital to Inuit as ringed seals mainly because they don't over-winter in the Arctic and also because they were harder to capture. About 500,000 of them summer in Nunavut, migrating north when the sea ice finally breaks up in the spring. They return south to warmer waters with the coming of autumn. Inuit in the Hudson Bay Bioregion call the harp seal qairulik This species has a fondness for porpoising and frolicking in Arctic waters. They are found mostly in the eastern part of the territory, ranging throughout Foxe Basin, northern and eastern Hudson Bay, Hudson and Davis straits, and the northern parts of Baffin Bay as well as Lancaster Sound. Walrus Odobenus rosmarus aiviq can often be found packed like sardines on ice floes. On land these massive animals (adult males can grow to 3.5 meters and 1,400 kg ) appear clumsy and move about with great difficulty but in the water they are masterful swimmers. Walruses dine primarily on clams, using their sensitive whiskers to detect the mollusks on the sea floor. An adult walrus may eat as many as 3,000


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Ε Check Your Understanding 1. What kind of seals do you have in your community? Estimate how many

there are. How has this number changed over the last 10 years?

2. What are the traditional names for the seals in your community?

3. How important to your community are seals today?

4. Speculate why nature delays the implantation of the embryo in the uterus of ringed and Bearded seal.

clams in a day, although they also eat other bottom-dwelling creatures such as fish, crabs, and sea cucumbers. There are reports that some old bulls will kill ringed seals. Because they rarely dive deeper than 75 m, walruses stay in or near shallow waters. The most distinguishing feature of both males and females of this species is its tremendous overbite. Despite their Latin name odobenidae ("those that walk with their teeth"), walruses do not use their teeth for walking. In fact their tusks are used for feeding, as a symbol of dominance or social rank and occasionally to help lift themselves from the water. In the Canadian Arctic, Atlantic walruses are only found in the Hudson Bay area, the waters around Baffin Island and the High Arctic. The much larger Pacific walrus is found in Alaskan waters and only occasionally is see in the Canadian portion of the Beaufort Sea.


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Polar bears Ursus maritimus Nanuq – are the largest of all bears. Females generally weigh up to 300 kg whereas males can attain weights of 450 - 600 kg and lengths of 2.5 - 3.5 m from nose to tail. This species is the most carnivorous of all bears. More than 90% of their diet is seal, most of which is ringed seal (70 %) with the remainder being bearded seal. Occasionally, walrus, beluga and narwhal are eaten, although these species are rarely killed by bears, but rather are found as carrion along the shore. Polar bears range throughout the Arctic and subarctic from the permanent ice pack of the Arctic Ocean to southern James Bay. In summer, they seek out areas of permanent ice, drift about on ice flows, or come ashore at traditional retreats. To avoid overheating, they are less active during the warmer summer. They prey on birds and rodents, consume vegetation, and scavenge the beaches. When the sea ice forms again, they move on to it to resume hunting seals. Unlike other species of bears, only pregnant females den up during the winter. Mating occurs in spring, but the embryo does not begin to develop until September. In November or December, the female excavates a snow den, often on a south-facing hill near the coast. Some of the best-known denning areas are southern Banks Island, Simpson Peninsula, Southampton Island, Yukon coast and eastern Baffin Island. Cubs, usually twins, are born sometime between late November and January. In March or April they leave their dens and usually accompany their mother for at least two and a half years. Females are not sexually mature until about 4 years of age, which results in polar bears having the lowest birth rate of any Arctic animals. Earlier in this century when polar bear populations were thought to be declining, government took the first step toward conservation by limiting the annual


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Did you know … Like us, birds need to breathe air in and out of their lungs in order to fulfill the cycle of bringing oxygen into the body to be used in metabolism, and to rid themselves of the waste carbon dioxide away from the body. However, unlike us, when a bird breathes the air does not go simply in and out of the lungs in a simple u-shaped path. Instead birds' have a number of large extensions called 'air sacs' and hollow bones all interconnected to their lungs. These allows the air to flow around in a grand circle meaning birds can have fresh oxygen rich air in their lungs all the time Also unlike we mammals, a bird's breath is not driven into and out of the lungs by means of a diaphragm. In birds, breathing is controlled by muscular contractions of the ribcage, which reduce or increase the overall size of the body cavity and thus force air out of the various air sacs.

hunting season in 1935, and by restricting hunting to Aboriginal people in 1949. Community quotas were fixed in 1967, and in 1976 an international agreement to conserve polar bears came into effect. The agreement binds all five countries where polar bears are found: Canada, Greenland, Norway, Russia, and the United States. The status of polar bear populations is closely monitored. In the Canadian Arctic, where most of the world's polar bears are found, annual research is carried out to determine numbers and distribution. This information is used to adjust community quotas, which total about 600 bears per year. When entering the polar bear's domain, one is well advised not to be deceived by the animal's customary shambling slow movement. This is an animal of enormous strength, perseverance and ingenuity; it is also capable of exceptional bursts of speed. Visitors must always remain alert and not invite harm by carelessly storing food or garbage. ARCTIC BIRDS

The arrival of birds is greeted with great joy by Inuit. The songs and beauty of birds are appreciated by everyone. I am not sure everyone enjoys them. Birds signal a renewal of life and Inuit are thankful that the winter is over, the first sighting of a snow bunting is considered to be an important event, indicating that other birds will follow shortly. There are many beliefs about birds. The Inuit also made full use of the birds they caught. Some examples include:

• the ptarmigans red eyebrow was used for decorating the atigi

• crane or loon heads were used for dancing headgear

• in Sanikiluaq, they make beautiful duck clothing

• bird tendons were used as alternate thread

• feathers were used as dusters, to wipe hands with and as brooms


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• bird feathers were attached to arrows • loon skins were used as bags to keep

things dry or to carry embers while travelling

• the large bone on the swan's wing was used as the stem of a pipe

• the bills and other parts of birds were often used as talismans or amulets

• women's work bags were sewn from the skin of swan's feet

• windows were made from the swan's gullet

• loon and swan skins were used as bags for rope when whale hunting

Source: Inuuquatigiit ,

The Curriculum From An Inuit Perspective,

Northwest Territories Education, Culture and Employment, 1996.

Ε Check Your Understanding

1. Create a list of the types of things that birds were used for (e.g. decoration).

2. Why was it so important to make full use of the birds that were caught? (had to supply all needs from what they hunted, also it is a form of respect not to waste anything).

3. Observe and describe examples of some of the products made from birds that are found in your community. If possible, bring them together for a community showing.


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Birds arose from one of the dinosaur lineages and if you look closely at the legs and toes of a bird you'll see scaly reptilian-like skin. The vertebrate class Aves includes an estimated 9000 species of birds worldwide. Although descended from the dinosaurs, birds have evolved remarkable specializations for flight: a unique "one-way" breathing system, light yet strong hollow bones, a skeleton in which many bones are fused or lost, powerful flight muscles, and – most importantly – feathers. Over 100 species of birds from a dozen different families can be seen in the arctic during the summer but only 11 species spend the whole year in the north. In most cases, it is food that draws them north and sends them flying south again. For the hardy birds that remain, there is no secret body form or lifestyle that ensures survival; the amazing eleven represent seven different families. The tundra and the innumerable shallow, fish-free bodies of water that result, is a perfect breeding ground for insects. Many of the small perching birds and shorebirds are drawn to the Arctic by the abundance of these insects on the tundra and the long days for gathering food for the nestlings. Birds of prey may be drawn specifically by the abundance of these small birds and for the numerous rodents that are also reproducing at a rapid rate during the summer. The marine environment with its annual summer explosion of plankton draws other species. Birds that live most of their live at sea are collectively referred to as “seabirds” but this term includes a number of different body forms and life histories. And some species are seabirds for a major part of the year and land birds for the rest. Although there is a broad overlap of food amongst different species and families, there are certain body types in birds that give us a good idea of what they feed on.


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Waterfowl are common in the Arctic in summer. Tundra swans, geese and many ducks feed on fresh, green water plants. Most Arctic marine ducks such as the eiders and long-tailed ducks are “diving ducks” or “sea ducks” and they feed on aquatic invertebrates such as krill, which they dive underwater for. All of these must migrate when the days start to shorten and the ice starts to form. All ducks must nest on the ground in the Arctic. As is often the case with birds, the females are drably coloured to help them hide while on the nest. The common eider, one of the most widespread sea ducks in the north, lines its nest with down from its body. Like all ducks, eider ducklings are able to move about and feed themselves almost as soon as they hatch. Female eiders leave their ducklings for care by “aunties,” non-breeding females who take over as soon as the eggs hatch. They protect the youngsters from attacks by gulls and jaegers. This babysitting is probably very important for the female who goes without food for a month while incubating the eggs. This may be the reason that many species of ducks establish “crèches” where several mothers will combine their broods and leave them to the care of one or two adults. Shorebirds are distinguished by their long slender legs and relatively thin bills. They frequent open shoreline environments where they probe or pick while looking for small aquatic insects, worms and other small animals. Bill shape, body proportions, and habitat are important clues to identification. For example, the semipalmated plover has a relatively short bill, bright orange legs and a black necklace that contrasts with its white breast and throat. They are found on mudflats and beaches across the Arctic. All plovers perform a “broken wing” display to distract predators or people who get too near their nest. They are imitating injured and therefore easy prey. The black-bellied plover goes even further – it will carefully arrange itself on the eggs where there is no nest.


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Four species of loons breed in the Arctic. The long, powerful, pointed bill of the loon is the trademark of a fish eater. The red-throated loon is the commonest and most widespread of the loons in the Arctic and it occurs along the entire coast. The red throat and upturned bill is distinctive of this species. Loons are excellent swimmers and divers and can even control their buoyancy in the water by flattening their feathers and expelling air from their lungs. In this way they can simple sink out of sight. Loons pair for life and both mother and father help with feeding and caring for the youngsters. They sometimes swim with their chicks riding on their back. Only one representative of the Shearwater and Fulmar family (Procellariidae) occurs in the Arctic. The northern fulmar is a true seabird spending, except for the breeding season, their whole life at sea either flying or swimming. They look similar to gulls but can be distinguished by their great wingspan and by the long tubes that enclose their noses. Their “tubenoses excrete the salt they absorb from drinking seawater. Fulmars breed in colonies on the same towering cliffs as do some other seabirds. They are capable of defending themselves by forcefully vomiting their stomach oil at an intruder. Ivory gull is one of eleven species of the family Laridae that includes gulls, terns and jaegers. It is also the only member of the family that lives year-round in the north. It is easy to recognize as it is snow white with black legs; the only other white gull is the glaucous gull, which is much larger and has pink legs and feet. Little is known about the ivory gull as they are true marine birds most often seen flying out to sea or perched on ice floes. They are probably the bird equivalent of the Arctic fox as they seem skilled at scavenging the kills of other predators. They also catch small fish. In winter, they may follow polar bears or stay near the polynyas where food is available.


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Long-tailed Jaegers are a member of the very large gull family. They feature dramatically contrasting colours, a very long tail, and a large, menacing, hooked beak. Long-tailed jaegers are both predator and parasite. Much of their food, they catch for themselves including eggs, nestlings, birds, mammals and fish. But they also steal food from other birds either by harassing them in flight until they drop it (then catching it in mid-air) or by snatching it directly from the other birds bill. Jaegers only come to land to breed and spend the winter in the warmer portions of the Atlantic and Pacific. Black guillemot belong to the same family as the long-extinct great auk and together with the other members of the family Alcidae are probably most truly deserving of the term seabird. They are the northern hemisphere’s equivalent of penguins but guillemots and other auks can fly – both above and below the water. They are adapted for marine life and feed primarily on small fishes and small crustaceans, which they pursue underwater. Black guillemots are distinctive with their narrow pointed bill, white wing patches, and bright orange feet. They can dive to a depth of 30 metres. They breed in small colonies on rocky shores, coastal cliffs and at the base of boulders. Black guillemots are found in the eastern Arctic; a close relative, the pigeon guillemot, occurs in the western Arctic. This species is the only auk that remains at high Arctic polynyas throughout the winter. Thick-billed murres are the largest and most common of the auk family in the Arctic. They breed in a few huge and very crowded colonies on rocky cliffs. The sound and smell of the thousands of birds living on these colonies is incredible. The female of each pair of murres lays a single conical egg on a ledge on the cliff. The egg’s shape helps prevent it from rolling off. Timing of the egg laying is very important as the adults may have to fly up to one hundred kilometers to find food for the youngsters. The youngsters leave their cliffside home before they can fly: they simply jump or fall into the water. They are than tended by the male for several weeks.


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While the chicks are mostly fed on fish, the adults often take crustaceans, worms and mollusks, which they will dive as deep as 100 metres to find. Ravens are aggressive, clever, and inquisitive and another of the few bird species that spend their entire life in the Arctic. Ravens are the largest members of the family Corvidae that includes crows and gray jays (“whiskey jacks”). This family is also thought to be the most intelligent. Ravens can be found all over the Northern Hemisphere. In Canada, they are chiefly restricted to the more uninhabited areas of the country, but range throughout much of North America, Europe, Asia, and northern Africa. The raven is omnivorous, but it tends to be predatory, and its diet embraces a wide variety of animal and vegetable matter. Northern ravens are much larger than their southern cousins and have been observed acting as a team to kill baby seals. In the north they are often called “crows”; crows are much smaller and do not occur in the Arctic. Specialized Adaptations Birds have many types of structural adaptations that enable them to live in a given habitat and play a specific role in a food chain. The following paragraphs highlight some of these adaptations. Diving ducks including eiders and long-tailed ducks, and loons are very good underwater swimmers. They can dive to great depths and use their powerful, webbed hind feet to propel themselves. To aid in swimming underwater, their feet are set well back on their body. This makes it difficult for them to maneuver on land and most only come ashore to nest. They also have smaller wings than do the “puddle ducks”. As a result, they need a long stretch of open water in which to take off. The shape of the bill gives a good clue as to what it feeds on. The broad bill of a dabbling duck is for straining out vegetation. The bills of some diving ducks such as eiders are designed for straining amphipods from the water. Seabirds that eat fish usually have long slender pointed bills that can be turned very quickly when trying to grasp an agile fish.


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"Astute Observers on the Sea Ice Edge: Inuit Knowledge as a Basis for Arctic Co-Management" In the late 1980's, scientists' knowledge of Hudson Bay Eiders was fragmentary, restricted to the open water period, and as biologists themselves realized, not adequate for the purposes of making management decisions. Biologists' observations were generally restricted to the traditional summer field season. Data on Hudson Bay Eiders in winter was virtually non-existent. In 1986, two scientists took on the task of piecing together scattered scientific information to estimate the Hudson Bay Eider population size. Relying primarily upon an aerial survey done seven years earlier, these scientists estimated the breeding population to be 45,000 birds. These results lead other scientists to conclude that the Hudson Bay Eider population was suffering an annual 5% decline.

(Continued next page…)

The shape of Gull and Jaeger bills seem to be a compromise between that of a predator that eats only other animals and an omnivore, which eats both vegetation and animals. The length and width of their beaks are both moderately long. Their bills are also hooked like an eagle or hawk but not as much. This enables them to feed on a greater variety of organisms unlike a loon that is restricted to a specific diet based on its physiology. Ravens may be the best example of a “generalist.” They can kill small animals on their own, rip open the carcasses of large animals that have died from other causes, or pick berries off a bush. Auks are the most specialized of seabirds. Their adaptations include:

• Thick, waterproof feathers to keep them warm

• Strong, pointed wings help them “fly” underwater

• Webbed feet that help them swim on the surface and underwater they act as rudders.

• Sharp, pointed bills for catching fish; puffins (found only in the extreme eastern Arctic during the summer) have spines on their tongues and roof of their mouths to help them hold slippery prey)

• Special gland near the eyes helps remove salt from their food and water.

• Keen eyesight for spotting food and predators at a distance. They will often head for a feeding flock and join them.

Migration The majority of Arctic marine birds depend on open water for their survival so they must migrate seasonally. Eastern auks usually migrate to open water along the Atlantic coast of Canada and the northern U.S. Western auks do the same along the Pacific coast. Loons tend to migrate to wintering grounds that are close to land as do the sea ducks such as eiders. In all cases, the journey may take a long time as all of these birds – and auks in particular – are only modest fliers. Birds may use the same wintering grounds year after year in the same way that many are loyal to the same nest site or area.


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(… cont’d) In 1985, however, ground surveys of eider nest colonies in southeastern Hudson Bay were conducted by Makivik Research, an Inuit organization, in cooperation with Inuit communities. This more exacting data provided an estimate of eider population size of 83,000 birds for eastern Hudson Bay alone, 84% larger than the scientists' estimate for all of Hudson and James Bays. Furthermore, this more recent estimate suggests that rather than declining, the Hudson Bay Eider population may be increasing annually by 7%.

by Douglas J. Nakashima,

found in Traditional Ecological Knowledge:

Concepts and Cases, 1993

Research undertaken to determine how birds navigate during migration have produced interesting, if slightly confusing results. Almost every investigation into how they orient themselves has shown positive results leading to the conclusion that birds use a variety of methods in combination. The primary sources are:

1. Topographic information including wind, which can be affected by major landforms.

2. Stars 3. Sun 4. Earth’s magnetic field 5. Odours

There are other migrations besides the major “north to Arctic” and “south to the open ocean” trips in the spring and fall. Unlike gees and swans, which molt once a year, ducks molt twice. This allows the males in particular to shed their dull summer colours for their mate-attracting winter plumage. With eiders and some other sea ducks, the males migrate in large flocks to safe “molting” areas far away from the females on the nest. This migration is to find safe tundra ponds far away from the predators that are attracted to the nesting areas. One of the busiest migration corridors in the summer is west from the Beaufort Sea to areas in western Alaska. The males will not return after the molt but will migrate south on their own. No migration story is complete without mention of the Arctic terns. Arctic terns look like finely sculpted black and white gulls with a long pointed bill and pointed wings. They are true seabirds as well, rarely coming to land except to nest. They feed primarily on crustaceans and sometimes hovering over the water before diving. But they are best known for their annual migrations, which can be as much as 18,000 kilometres long. Some Arctic terns will spend the winter at sea in the Antarctic where it is summer. Arctic terns spend more time in sunlight than do almost any other animal.


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Ε Check Your Understanding 1. Why would there be such a lack of scientific data about the Eider Duck

populations in the late 1980's?

2. What are some reasons why there are such drastically different estimates of what is happening to the Eider Duck population? Is there a right and a wrong answer to the question of what is happening to the population?

3. What did the Makivik Research organization do in their attempt to determine the Eider Duck population that scientists did not? What impact might this action have on the results?

4. The role of traditional knowledge in conjunction with scientific data in order to gain an understanding of Arctic ecosystems and make decisions of how to manage resources continues to grow in importance. Identify an example where scientists and local people are working together today to gather information and make management decisions.


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GLOSSARY FOR MODULE 3

Anadromous The term given to fish that migrate to the sea as sexually immature and then migrate back to freshwater to breed. Autotroph An organism that manufactures its own organic matter by using energy from the sun or other sources. Autotrophic Bacteria Bacteria that can produce complex organic molecules where photosynthesis is not possible. Amphidromous The term given to fish that migrate between freshwater and seawater for purposes other than breeding. Baleen The filter plates that hang from the upper jaws of baleen whales. Baleen Whale Filter feeding whales. for example bowhead whales. Benthic Belonging to the bottom of the ocean. Carnivore A mammal with teeth that that eats other animals. Carolus Linnaeus A Swedish biologist who simplified that problem of categorizing the diversity of life by assigning every organism then known to a series of increasingly specific groups. Carrion The decaying body of a dead animal. Catadromous The term given to fish that migrate to freshwater as sexually immature and then migrate to seawater as adults to breed. Cartilaginous Fishes with a skeleton made of cartilage: sharks, rays, skates and ratfish. Cetaceans Marine mammals with anterior flippers, no posterior limbs, and a dorsal fin: whales, dolphins, and porpoises. Copepods Small mostly planktonic crustaceans. Crustacean These animals are arthropods adapted to live in water. They have two pair of antennae, gills, and a calcified exoskeleton. e.g. krill, isopods, shrimp, lobsters, etc.


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DDT A powerful insecticide which is effective on contact. Its chemical organic name is Dichlorodiphenyltrichloroethane DDE The major metabolite of DDT which is 150 times less toxic than DDT Dieldrin an insecticide readily absorbed through the skin used in agriculture & forestry and also against ticks, chiggers, sand flies and some species of mosquito's Detritus Dead and decaying organic matter. Diatoms Unicellular and eukaryotic autotrophs with a silicon skeleton; mostly planktonic Dinoflagellates Unicellular, eukaryotic, mostly autotrophic organisms with two unequal flagella. Echolocation The ability of some animals to sense their surroundings by analyzing the reflection of sound waves, or clicks they emit. Embryo The earliest stage of an animals development while it is still in the uterus. Epipelagic The pelagic environment from the surface to a depth of 100 to 200 m. Eukaryotic Complex cells that subdivide their activity into cellular organelles like mitochondria. Flagella A whip-like appendage that is usually used for locomotion. Fluke The fin-like tail of cetaceans. Frond The leaf-like blade of algae. Gametophyte The haploid, gamete producing generation in many seaweeds. Gestation Period The length of time between fertilization and birth. Herbivore An animal that eats plants. Heterotrophs Animals and bacteria that depend on the organic compounds produced by other animals and plants as food; they are organisms not capable of producing their own food by photosynthesis. Holdfast The root-like base of marine algae that anchors the organisms to the substrate.


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Invertebrate Animals that lack a backbone. Kelp Brown algae characterized by their large size and complexity. Some like the giant kelp form dense kelp beds or kelp forests. Krill Planktonic crustaceans that are an important food of whales and other animals. Lactation The secretion of milk by the mammary gland. Lateral Line A system of canals and sensory cells on the sides of fishes that help them detect variations in the water. Lichens The mutualistic combination of a fungus and green algae. Littoral Zone (intertidal zone) The area between the highest and lowest tides. Mammae The name of the glandular organs in a female that secrete milk. Mitochondria The cell organelle responsible for the production of energy. Mollusk Belonging to the phylum Mollusca that includes the snails, clams, and octopuses. Mutualism A symbiotic relationship in which both participants benefit. Organelle A structure within a cell that performs one or more specialized functions. Opercula The hard flaps that cover the gills in bony fish. Otoliths These are small 'rocks' of calcium carbonate that are laid down in a fish's inner ear to maintain balance. Paralytic Causing paralysis, the stoppage of muscular motion due to neural blockage or damage. Pathogenic Bacteria Bacteria that can cause bacterial infections in mammals, fish and invertebrates. Pelagic Belonging to the water. Phykoplankton The most important community of primary producers in the ocean; photosynthetic plankton. Pinnipedia The name of the 'order' in taxonomy of seals.


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Pneumatocysts The float structures of algae that contain gas. Prokaryotic The most primitive of all one celled organisms. They have no nucleus. Protists Members of the kingdom Protista, which consists of unicellular and eukaryotic organisms. Many combine characteristics of both animal s and plants. Saprobic Bacteria Bacteria responsible for the decomposition of organic matter. They have been known to slowly degrade petroleum products. Sporophyte The diploid, spore producing generation in many seaweeds. Stipe Part of an algae plant that is similar to the stem of true plants. Taxonomy The science of classification Zygote The diploid cell that results from the fusion of an egg and a sperm cell.

arctic marine science curriculum · external food supply are called zooplankton. most of the...

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