“If you're overfishing at the top of the food chain, and acidifying the ocean at the bottom, you're creating a squeeze that could conceivably collapse the whole system.”- Carl Safina 1

Fishing and Aquaculture

In 1497, an explorer named John Cabot sailed from New England and landed on the island of Newfoundland, in what is now Canada.

In his journal, Cabot noted,“The sea there is full of fish that can be taken not only with nets but with fishing-baskets.”

Another fishing captain, written over a hundred years later made a similar observation.“[The cod are] so thick by the shore that we hardly have been able to row a boat through them.”

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The Cod

The fish, Atlantic Cod, grow to be 6-7 feet in length and weighing upwards of 200 pounds at full maturity.

The cod, due to its massive size and ability to be salted and transported, was extremely valuable.

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One of the earliest forms of large-scale fishing is pole fishing, where a line is attached to a baited hook, which can catch and pull in the fish.

Of all the fishing methods, pole fishing has the lowest rate of bycatch; species of fish that are unwanted and accidentally caught.

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Pole Fishing

Pole fishing in the Maldives. Photo by Greenpeace.

Blood, Sweat, and Takeaways. Episode 1: Tuna5

As the world population grew, so did the demand for seafood.15% of the world uses seafood as a primary

source of protein.Other methods

began to takethe place of pole fishing to meet the demand.

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Fig. 11-7, p. 256

Fish farming in cage Spotter airplane

Trawler fishing

Sonar Purse-seine fishing

Long line fishing

lines with hooks

Deep sea aquaculture cage

Drift-net fishing

Float Buoy

Fish caught by gills Stepped Art

Longline fishing is a commercial fishing technique where baited hooks are attached to a single, long fishing line that trails behind a ship.

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Long Line Fishing

Compared to pole fishing, longline fishing has a much higher rate of bycatch.Sea birds are highly

vulnerable during setting of the line.

Sea turtles, sharks, and other fish are also accidentally caught.

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This goldmine of fishing off the Great Banks began to be exploited fully starting with the arrival of the Fairtry.First ship to be fully-equipped with a trawler,

processing plant, and storage freezers.10

The fastest and most efficient way to catch fish is by trawling, where a large net is dragged behind a ship.If the net actually drags along the bottom, it is

called bottom trawling.

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Trawling

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Trawling has the highest rates of bycatch, since any species big enough to be caught in the net will be trapped.

Bottom-trawling has the added side effect of damaging any habitat at the bottom of the sea floor, such as coral reefs.

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Modern Marvels, Commercial Fishing.14

The large commercial trawlers were incredibly successful in Newfoundland, harvesting over 800,000 tons of cod in 1968.In following years, harvests began to decrease.

Canada evicted the fishing fleets of other countries from its waters, but harvests continued to decline.In 1988, fisheries managers

called for a 50% reduction inallowable catch. Officialsonly reduced it by 10%.

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CBC News Broadcast, July 2, 1992.16

The majority of the world’s fisheries are at their maximum sustainable yield. This is the maximum that can be harvested

without diminishing the population for future years.

Overexploited fisheries are being harvested at unsustainable levels.Over time, these can

become depleted fisheries with stocks so low that fishing cannot be supported.

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In 1992, a complete stoppage, or moratorium, to cod fishing off Newfoundland and Labrador in Canada was announced.The moratorium was devastating to the coastal

towns, whose economies were dependent on the fisheries.

Fishermen were so angry, they tried to forcibly interrupt the press conference of Fisheries Minister John Crosbie, as he announced the moratorium.

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Cod Moratorium

CBC News Broadcast, July 2, 1992. 19

Aquatic communities are organized like those on land, with different trophic levels, or place on a food chain.

The lowest trophic level is occupied by producers.Phytoplankton and algae.

Zooplankton occupythe second level.

Small fish, crustaceans,and mollusks are on thethird level.

Medium-sized fish occupythe fourth level (Mackerel).

The highest level containsthe largest carnivorousfish, such as Atlantic cod, Sharks. 20

The Marine-Trophic Index is a measurement of the average trophic level of the total catch from a fishery.

With the loss of the cod, fishermen began pursuing herring, capelin, crabs, and other lower trophic-level organisms.

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Up to the 1960s, the only regulations on fishing were territorial waters; exclusive fishing zones that reached 12 miles off each coastline.

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Fishing Regulations

The advent of long-range industrial fishing vessels, like the Fairtry, led to the creation of exclusive economic zones, which extended 200 miles from each nation’s coastline.Each nation has exclusive rights over all marine

resources discovered within these zones.

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Many countries now establish restrictions on the amount of fish that can be harvested within their waters.

In the United States, annual catch limits have been established and enforced by the National Oceanic and Atmospheric Administration (NOAA) since 2012.These catch limits

are lower than the maximum sustainable yield, meaning the stocks are able to recover each year.

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Fully-protected marine reserves, where no living organisms can be legally harvested, have also been established to protect areas especially high in biodiversity.

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As the limits of wild seafood harvesting have become increasingly clear, industries are now beginning use aquaculture; the process of farming aquatic organisms.

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Aquaculture

The farming of saltwater organisms is called mariculture.

Most mariculture operations work by taking eggs or immature fish and raising them in long, rectangular nets called fish pens.Feed and other

supplements are added to the top of the pen.

Wastes drop out the bottom of the pen to the sea floor.

These operations are vulnerable to many of thesame issues as large animal farms, including antibioticoveruse and manure. 27

Modern Marvels, Commercial Fishing.28

Fish farming can be combined with hydroponics to create aquaponics.Waste water from fish farming is circulated

through plants, which absorb the waste as nutrients and clean the water.

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Any fish labeled as farmed was raised in a mariculture or aquaponics facility.

Wild caught fish is just that – it was caught from a body of water.

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Consumer Labels

MSC Certification is a label attached to any seafood that follows sustainable fishing practices, as established the Marine Stewardship Council.

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Fig. 12-18, p. 293

TRADE-OFFS

Aquaculture

Advantages Disadvantages

Needs large inputs of land, feed, and water

High efficiency

High yield in small volume of water

Large waste output

Can destroy mangrove forests and estuaries

Can reduce overharvesting of fisheries

Uses grain to feed some speciesLow fuel use

High profitsDense populations vulnerable to disease

Solutions: Managing Fisheries