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Chapter Introduction

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CHAPTER 8

Sustaining Aquatic Resources

(Bill Dewey, Taylor Shellfish Farms)

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Central Question: Can we sustainably manage fisheries and aquaculture?

SCIENCE

Describe the ways in which fish and shellfish are harvested and how the physical environment influences the availability of aquatic resources.

ISSUES

Analyze the impacts of humans on aquatic resources.

SOLUTIONS

Discuss approaches for developing more sustainable aquaculture and fisheries.

A Tale of Overharvesting and Fishery Collapse

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When Europeans first began fishing for Atlantic cod off North America, they encountered an astonishing abundance of fish. Now, five centuries later, that natural wealth is nearly gone.

Historical images of the cod fishery of the northwest Atlantic, a fishery that produced abundant harvests for five centuries and then collapsed. (Data from Lilly et al., 2006; cited in Stares et al., 2007)

(Library of Congress Prints and Photographs Division, LC-USZ62-117909) (AP Photo/Robert F. Bukaty)

The Atlantic cod (Gadus morhua) is a bottom-dwelling, predatory fish that can reach 200 pounds. It is a top, or apex, predator that prowls the ocean floor, hunting for smaller fish and crustaceans. Beginning in the 15th century, people began to prize it for its flaky, white flesh and for the fact that it could be preserved for long periods of time by drying and salting. It didn’t take long before cod became the focus of one of largest and most valuable fisheries on the planet. The worldwide cod harvest peaked in the 1960s, when massive bottom trawlers—nets dragged along the sea floor—scooped up 3.9 million tons of codfish in a single year. The ocean’s bounty seemed endless.

fishery A population of fish or shellfish, and the economic system involved in harvesting the population, often identified by the geographic area where the fish or shellfish are harvested.

But in the spring of 1992, fishing boats returned to ports from New Bedford, Massachusetts, to Halifax, Nova Scotia, with their hulls nearly empty. Cod stocks dropped to less than 1% of historic levels, and regulators shut down the prime fishing grounds on Georges Bank, an elevated plateau off the Atlantic coast of the United States and Canada. Retailers everywhere switched white fish recipes from cod to Alaskan pollock and New Zealand hoki. The cod fishery had collapsed.

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“If the oceans don’t make it, neither will we.”

Jackson Browne, “If I Could Be Anywhere,” 2010

fisheries collapse The decline in a certain species’ annual catch below 10% of its historic catch.

Fisheries collapse occurs when annual catches of the species in question decline below 10% of the historic catch. Today, following the collapse of the cod fishery in the northwest Atlantic and the subsequent closing of the fishing grounds, the fishing fleets that harvested hundreds of thousands of tons of cod each year now sit idle. What factors led to the collapse of this, and other, fisheries in the United States? What, if anything, can be done to restore valuable fisheries here and around the world? In this chapter, we will explore the science behind fisheries and what steps we need to take to restore them to their former health.

The collapse of the rich cod fishery off New England and Canada is not unique. Similar crashes have occurred in other fisheries around the world due to the rise of industrial fishing in the 20th century. In the United States, the National Oceanic and Atmospheric Administration (NOAA) considers 40 fish stocks to be overfished and 28 subject to continued overfishing. Once a major fish exporter, the United States now imports the majority of its seafood. These fishery declines threaten marine species with extinction, as well as the food webs and productivity of marine ecosystems, which in turn affects the human communities that depend on them for ecosystem services and economic livelihood.

Central Question

Can we sustainably manage fisheries and aquaculture?