Aquaculture of FishesBiology of Fishes

11.6.12

Presentation Guidelines Syllabus Revisions Guest Lecture 2 – Dr. Charles Madenjian – USGS Great Lakes

Science Center Aquaculture – related to fish ecology & diversity

Overview

Guidelines online All groups submit written reports 11.27.2012 Attendance required at all student presentations Student Presentations material will be on Final Exam

Presentation Guidelines

November 13 – Biogeography, conservation, genetics

November 15 – Conservation ecology case study synthesis

November 20 – Exam 2 November 22 – Thanksgiving Break November 27 – Student Presentations

November 29 – Guest Lecture 3

December 4, 6, 11 – Student Presentations

Syllabus Revisions

Dr. Charles Madenjian – USGS Great Lakes Science Center Dynamics of the Lake Michigan Food Web 1979-2000 Assignment Part 1 hard copy due at start of class

Guest Lecture 2

Aquaculture – the farming of aquatic organisms under controlled conditions (fishes, crustaceans, mollusks, aquatics plants, etc).

Farming of fishes is the most common form (what we will focus on).

2 Primary categories we will focus on (often overlap) Grow-out aquaculture for direct human consumption Hatchery and stocking operations – release fishes into wild

to supplement exploited or declining stocks

Aquaculture

Aquaculture – example types Mariculture – cultivation of marine organisms in seawater Polyculture – cultivation of multiple species Integrated Multi-Trophic Aquaculture – by-products of one

species are recycled as inputs for another species

Aquaculture

Aquaculture – example types Extensive – utilizes cages/pens, but relies on natural food

supply Semi-intensive – feeding supplements or fertilizer to

encourage feed production Intensive – highly subsidized, large inputs of feed; highest

yields, but highest ecological impacts

Aquaculture

Aquaculture – the farming of aquatic organisms under controlled conditions

Practiced by humans for thousands of years 6000 BC Australia – eel culture via landlocked ponds 2500 BC China – carp aquaculture 1000 years ago in Hawaii – oceanic ponds

Aquaculture

Aquaculture

Global harvest of aquatic organisms in million tons, 1950–2010, (Food & Agriculture Organization of UN)

Fisheries provide 16-19% of human animal protein consumption

~1 billion people rely on fish for most of their protein (especially in developing nations)

Increased pressure on fisheries with increasing population Wild supply/CPUE leveled off at 90 MMT in late 1980s Yields increased in recent years to 120 MMT largely due to

aquaculture Aquaculture expanded from 5 MMT (1950) to 30 MMT (1990s)

Aquaculture will be needed, but can it be done sustainably?

Aquaculture

Pros Economically important Access to animal protein Relieve pressure of overfishing Restocking wild populations, conservation (captive

propagation) Cons

Ecological efficiency (lack thereof) Pollution (disease, parasites, nutrient loading) Escapes

Aquaculture

Usually done to enhance growth rate Highly debated, lack of solid research Growth hormones Antifreeze genes

Genetically Modified Organisms (GMOs)

Pros Increased growth & feeding efficiency (market size faster)

tilapia +60-80% faster growth, 2.9x feed conversion, 3.6x less food Chinook salmon – 10-30x growth rate w/ hormone & antifreeze

genes

Increased disease resistance Potential health benefits (lower cholesterol)

Genetically Modified Organisms (GMOs)

Cons Deformities Non-adaptive characteristics (feeding behavior, swimming

ability) Perceived potential health hazards (not well-supported*)

Genetically Modified Organisms (GMOs)

Example species/systems Atlantic salmon – sea ranching Bluefin tuna – sea ranching Tilapia – intensive aquaculture Carps – polyculture Air-breathing fishes – sustainable aquaculture

Aquaculture

“Sea Ranching” - process of growing out salmon in net pens until market size.

Atlantic salmon (Salmo salar) most common species International scale practice (Norway, Chile, Canada = ~85%

production in 2005) 1.3 million metric tons (2005), 90% S. salar; $4-5 billion USD Pros: increased economic activity; healthy animal protein at

reasonable price; pressure off wild stocks Cons: low ecological efficiency, 2.5 kg fishmeal: 1 kg salmon

Aquaculture

Cons Low ecological efficiency Socioeconomic hardships (compare to wild-stock fisheries) Pollution (high density – high waste, nutrient pollution,

organic sewage of 40 salmon ~ 1 person) Parasites, disease, antibiotics, pesticides (although

debatable in some comparisons to wild fish) Escapes (disease, hybridization, competition)

Sea Ranching

Cons

Sea Ranching

Bluefin tuna (Thunnus thynnus) Very early stages, minimal success Large species, special requirements May contribute to current overfishing Valuable species ($396,000 for one fish)

Aquaculture

Bluefin tuna (Thunnus thynnus)

Aquaculture

Tilapia (Oreochromis spp.)

Aquaculture

Carps (various cyprinid species), commonly polycultured Grass, silver, bighead, common carps Cultured primarily in Asia Introduced in US and elsewhere

Aquaculture

Air-breathing fishes – several species (Channa, Clarias, Osphronemus, Arapaima, Protopterus, Atractosteus)

Numerous advantages over other fishes

Aquaculture

Air-breathing fishes – several species (Channa, Clarias, Osphronemus, Arapaima, Protopterus, Atractosteus)

Numerous advantages over other fishes Tolerant of lower water quality (conducive to high-density culture) Lower technology required for culture Most species exhibit rapid growth and readily accept artificial feed May be more adaptive options for culture in the face of climate

change

Aquaculture

Air-breathing Fishes

Air-breathing Fishes

Will likely be a necessity to meet future fish & seafood supply and demand

Sustainable practices necessary to reduce negative impacts

High economic potential Much further research is necessary

Aquaculture