chapter 16 fisheries and agricultuire fish in a warehouse?

CHAPTER 16 FISHERIES AND AGRICULTUIRE

FISH IN A WAREHOUSE?How one Baltimore fish scientist could change the

way we eat

FISH IN A WAREHOUSE?How one Baltimore fish scientist could change the way we eat

At the end of this chapter you will know:• The pros, cons, and importance to

human of fish and fish hatcheries.• The history and status of declining

fish hatcheries.• How the “Tragedy of the Commons”

has jeopardized global fish takings.• How we can protect fish hatcheries

Learning Outcomes

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Despite the vastness of our oceans, fisheries are in jeopardy. Aquaculture may offer part of a solution.

Main Concept


Case: Huge fisheries supported towns all along the northeastern coast of North America until

the early 1990s.

As a result of over-fishing and using unsustainable practices, the fisheries collapsed and have yet to recover—even after a 30-year

ban on fishing.

In an effort to bring the industry back, fishermen are becoming fish farmers.

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Case: Huge fisheries supported towns all along the northeastern coast of North America until

the early 1990s.

As a result of over-fishing and using unsustainable practices, the fisheries collapsed and have yet to recover—even after a 30-year

ban on fishing.

In an effort to bring the industry back, fishermen are becoming fish farmers.

Cod inhabit cold coastal waters in the North Atlantic. They live approximately 200m deep near the ocean floor and depend on protection from a diverse community and complex structure. Through trawler fishing, their habitat became so severely degraded that the populations crashed.

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The fish industry has declined throughout the Atlantic range, especially in the Grand Banks of the Newfoundland–Labrador Shelf region.

Adult cod can be more than six feet long and weigh 200 pounds or

more. Spawning schools have been recorded at more than 100 million

fish and the average female can spawn millions of eggs.

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How one Baltimore fish scientist could change the way we eat16

When large nets are dragged behind trawler ships, the result is capture of target and non-target species. Capture of non-target species has threatened many species, including sea turtles, birds, seals, sea lions, and otters. Bottom trawlers are also devastating the sea floor—destroying habitat for coral, sponges, starfish, and other invertebrates.

Humans rely on protein from fish16TERMS TO KNOW:

BycatchMaximum sustainable yield

Overexploited fisheriesDepleted fisheries

Humans consume more seafood every year than beef, pork, and chicken combined.

Wealthy countries take advantage of the health benefits while poorer nations get an inexpensive source of protein.More than 200 million people make their livings in the fishing industry, which generates about $130 billion annually.

Humans rely on protein from fish16TERMS TO KNOW:Maximum sustainable yieldOverexploited fisheriesDepleted fisheries

Unbalanced food webs may be irreversibly changing the ocean ecosystem. Loss of the high-order predators is especially disruptive.

“Fishing down the food chain” reduces apex predators like cod and tuna, leaving the lower-trophic-level species unchecked and in competition with the young of more desirable species.


One obstacle to recovery of cod and other large predatory fish is the loss of their own prey. When cod are depleted, fishers pursue the herring, crabs, and other low-order species, reducing the cod’s food supply.

The Marine Trophic Index (MTI) is a measure of the average trophic level (TL) of fish taken in a given year and is an indicator of the status of marine ecosystems.


The Marine Trophic Index (MTI) is a measure of the average trophic level (TL) of fish taken in a given year and is an indicator of the status of marine ecosystems.

One obstacle to recovery of cod and other large predatory fish is the loss of their own prey. When cod are depleted, fishers pursue the herring, crabs, and other low order species, reducing the cod’s food supply.

Humans rely on protein from fish16

More than half the world’s fisheries are at their maximum

sustainable yield—fully exploited, the amount that can

be harvested without decreasing the yield in future years.

Another 30% are overexploited or depleted, meaning there are

not enough fish left to support a fishery.

One obstacle to recovery of cod and other large predatory fish is the loss of their own prey. When cod are depleted, fishers pursue the herring, crabs, and other low-order species, reducing the cod’s food supply.

TERMS TO KNOW:Maximum sustainable yieldOverexploited fisheriesDepleted fisheries


Fish catches in the Newfoundland-Labrador Shelf area of the North Atlantic show a distinct shift in the species and amounts taken over the years. Fishery managers called for a 50% reduction in allowable catch of cod in 1988, but political officials only reduced the amount by 10%. The cod fishery was closed in 1992.


Though 68% of global marine fisheries are sustainably fished, the percentage that is overfished (31%) has increased threefold since the 1970s and is a major concern for fishers and fishery managers.

Laws exist to protect and manage fisheries16TERMS TO KNOW:Exclusive economic zone (EEZs)Marine protected areas (MPAS)Marine reserves

Lawmakers and scientists around the world are struggling to undo the damage that’s been done to our oceans and fisheries. Laws were not in place to limit the reach of fishing vessels beyond the 12-mile mark, nor were there rules about how long a vessel could stay in any one spot or how much they could take.No fishery could withstand this kind of stress.

Marine protected areas (MPAs) provide varying degrees of protection for different species, depending on the area and need. Exclusive economic zones (EEZs) extend 200 nautical miles from the coastline of any given nation, giving that nation exclusive rights over marine resources.

Laws exist to protect and manage fisheries16In addition to the MPAs and EEZs, the country with rights to the fishery also has strictly enforced limits as to the amount of fish they can take. Once the vessel has reached the catch limit, it is done for the season.Some MPAs are considered marine reserves and are “no take” zones—absolutely nothing can be disturbed by human hands in these areas.

TERMS TO KNOW:Exclusive economic zone (EEZs)Marine protected areas (MPAS)Marine reserves


Laws exist to protect and manage fisheries16Magnuson-Stevens Fishery Conservation and Management Act (1976)

Primary law governingmarine fisheries in U.S. federal waters.

Amended in 1996 to focus on rebuilding fisheries, protecting ecosystems, and reducing bycatch.

Amended in 2006 to add market-based programs like cap-and-trade.

TERMS TO KNOW:Exclusive economic zone (EEZs)Marine protected areas (MPAS)Marine reserves


Scientists study the possibility of growing marine fish indoors16

Dr. Yonathon Zohar at COMB in Baltimore

Center of Marine Biotechnology (COMB) at the University of Maryland

Using a recirculating aquaculture system (RAS) to raise Mediterranean bass from eggs to table.

Using examples of generations-old, small-scale fish farms and freshwater fish farms, Dr. Zohar is attempting to grow marine fish at levels with the potential to serve cities rather than families.


TERMS TO KNOW:Sustainable fisheryaquaculture

Sea bream fish farm, Shikoku, Japan


Sea bream fish farm, Shikoku, Japan

In 2009, more than half of the global fish landings were being produced through aquaculture.

China produces over 60% of the farmed fish.

Problems are inevitable—depletion of feeder fish from the wild, clearing tropical mangrove forests to make room for shrimp ponds.

Aquaculture presents environmental challenges16

The aquapod is a submersible net pen for open-ocean aquaculture.

Aquapods are designed to be located away from the marine coast to reduce environmental impact and optimize growing conditions for fish.

Problems and possible solutions for net pen and aquaculture

Aquaculture presents environmental challenges16

The Aquapod is a submersible net pen for open ocean aquaculture.

Aquapods are designed to be located away from the marine coast to reduce environmental impact and optimize growing conditions for fish.

Problems and possible solutions for net pen and aquaculture

Indoor fish farming may provide a solution16Seawater is created in the lab from tap water to which a precise mix of salts and trace elements has been added.

Each critical factor in the gigantic swimming pool ocean—temperature, salinity, pH, CO2, and oxygen concentrations can all be controlled through a series of computers, pipes, and hoses.

Feed conversion is higher, and bacteria are being used to help process waste products into fuel-grade methane.

Microbes in the RAS manage the waste in the water.

Indoor fish farming may provide a solution16Today, 85% of the fish

consumed in the United State are

imported from great distances. Not only does that mean the

fish are less fresh, but also that fossil fuels

are required for transportation and

refrigeration.

By reducing the distance through locally grown fish, even in land-locked areas, the footprint associated with fish consumption is reduced.

How about flavor? Five Baltimore chefs prepared two plates or five different dishes—

one using wild-caught fish and the other using laboratory-grown fish. According to chef

Damon Hersh, “You couldn’t tell them apart.”

PERSONAL CHOICES THAT HELP16

UNDERSTANDING THE ISSUE16

ANALYZING THE SCIENCE16

EVALUATING NEW INFORMATION16

www.montereybayaquarium.org/cr/seafoodwatch.aspx

MAKING CONNECTIONS16

chapter 16 fisheries and agricultuire fish in a warehouse?

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