How Fisheries Work

By: Jonathan Strickland
Retro style child outdoors togetherness amidst war.
Fishing Image Gallery Heading down to the old fishing hole. See more pictures of fishing.
CBS Photo Archive/Getty Images

For many ­people, there's nothing more relaxing than taking a stroll down to a local lake or river, baiting a hook, casting a line out into the water and waiting for a bite from a fish. It seems like such a relaxing, simple activity. But upon closer examination, fishing -- even recreational fishing -- is a complex subject that has political, economic and biological implications. At the heart of this issue are fisheries.

The word fishery has several meanings. It can refer to a place or facility where people breed fish, also known as a hatchery. It can also mean the geographic location in which fish are caught, such as off the coast of New England. The word fishery also refers to the occupation of capturing and processing fish for profit. Finally, the word has a legal meaning as well: a fishery is the legal right to catch fish in a specific area during a specific time.


Many countries have large fishing industries. Among the world leaders are the United States, Japan, China, Russia, South Korea, Peru and India [source: Encyclopedia Britannica]. These countries aren't just impacting fish stocks within their own borders and off their own coasts -- they're also affecting other nations. Some countries depend on fishing for their prim­ary source of food.

­Fishing is lucrative. The industry generates billions of dollars of commerce every year. But with this economic boom comes the potential for overfishing, which can deplete fish stocks to dangerous levels. To make matters more complicated, some fishermen feel that people who obey fishing guidelines and stay within limits suffer, while unscrupulous fishermen who ignore rules and regulations profit.

In this article, we'll concentrate on the fishing industry and the geographic areas known as fisheries. We'll also learn how fishing practices affect fish populations and the environment. While some of the news is disturbing, it's not all doom and gloom. There are coalitions of scientists, politicians and fishermen who are working hard to ensure that fish stocks around the world maintain sustainable populations.



Fishery Basics

U.S. Coast Guard boat
The U.S. Coast Guard has many duties -- one of them is making sure fishing boats are following the laws of the United States.
­U.S. Coast Guard

In the United ­States, the governme­nt has play­ed an instrumental role in the development of the fishing industry. In 1871, Congress debated a bill that would create the Commission of Fish and Fisheries. The bill didn't receive universal approval -- some members of Congress openly questioned the usefulness of such an office. But those voices were in the minority and President Ulysses S. Grant signed the bill, which officially created the office. The first Commissioner was Spencer Fullerton Baird from the Smithsonian Institution. Baird was concerned that the fishing industry was depleting both fresh and saltwater fish stocks.

The government established the office's headquarters in Woods Hole, Mass. Today, Woods Hole is still known as one of the world's leading marine research centers. Throughout the years, the government has shuffled the office from one department to another through a series of reorganizations. In fact, the office has changed names more than once during the process. Today, we call it the National Marine Fisheries Service (NMFS), which is part of the Department of Commerce's National Oceanic and Atmospheric Administration (NOAA).


­The most important piece of legislation relating to fishing within the United States is the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006. This law establishes fishing limits and creates enforceable measures to protect against overfishing. The United States Coast Guard regularly inspects fishing boats to make sure the crew has the proper safety equipment and is operating within the parameters established by the Magnuson-Stevens Act.

The Magnuson-Stevens Act is the latest in a long line of laws that regulate the fishing industry in the U.S. Others include the original Magnuson-Stevens Fishery Conservation and Management Act and the Sustainable Fisheries Act. Other nations have similar laws to regulate the fishing industry, although some countries either have very lax regulatory guidelines or lack the means to enforce existing laws.

NOAA oversees marine (or saltwater) fishing activities, but freshwater fisheries and fish hatcheries are another story entirely. The U.S. Fish and Wildlife Service is in charge of authorizing fish hatcheries in the U.S. The department oversees 70 national fish hatcheries in the United States. Every state has its own fishery office to oversee and regulate fishing in that state's lakes and rivers.

Like the NOAA, the U.S. Fish and Wildlife Service's goal is to maintain a sustainable fish population that maximizes yield without depleting fish stocks or damaging the environment. This federal office partners with states, tribes and other federal organizations.

Next, we'll take a look at the role of wild fisheries.


Wild Fisheries

San Francisco Fish Company
Wild and farmed salmon fish filets at the San Francisco Fish Company.
Justin Sullivan/Getty Images

Wild fisheries refer to ­geographic regions rather than organizations or structures. The two broad categories of fisheries are marine (or saltwater) fisheries and freshwater fisheries. There ­are three major kinds of fishing: subsistence, commercial and recreational fishing.

Subsistence fishing refers to customary fishing practices that certain communities within the United States depend on either as a means of survival or to preserve cultural traditions. Commercial fishing refers to harvesting fish for profit and recreational fishing refers to sport fishing and hobbyists.


Let's look at marine and freshwater fisheries in turn. The United States organizes marine fisheries by geographic regions. Those regions include:

  • Alaska
  • Northeast
  • Northwest
  • Pacific Island
  • Southeast
  • Southwest

The United States defines the commercial fishing region of marine fisheries for most of the country as between 3 and 200 miles (5 and 322 kilometers) off the U.S. coast. The only exception is the region off the coast of Texas and western Florida, which extends from 9 to 200 miles (15 to 322 kilometers) offshore [source: NOAA]. Each region has its own regional office in charge of monitoring fish populations, fishing activity, fishing regulations and regulation enforcement. These offices report to NOAA. The offices partner with fishermen, scientists, environmentalists and law enforcement to ensure the integrity of fish stocks and the environment.

Each region has its own fish management plan (FMP) for each fish stock or stock complex. This plan takes multiple factors into account. The end result is a series of regulations that tell fishermen when and where they can fish as well as how much fish they can harvest during a season. There are many different ways to regulate the number of fish a fisherman is allowed to catch -- we'll take a closer look later on.

As for freshwater fisheries, each state has its own office that oversees fishing activity within that state's waters. Laws, regulations and enforcement vary from state to state. If you plan on spending a quiet day at the lake with rod and reel, you should look into your local laws and regulations first. You will need to apply for a fishing license and there could be strict limits on the kind of fish you are allowed to catch and keep.

Wild fisheries around the world are in danger of deteriorating for many reasons, including damage from pollution, environmental disasters and climate change. But the biggest threat to many fisheries comes from overfishing. We'll take a closer look at this threat in the next section.




Fishing boats in the harbor
Fishing boats at San Francisco harbor
Justin Sullivan/Getty Images


NOAA­ de­termines if a fish stock has been overfished by looking at the fish population's biomass and comparing it to the biomass that supports the maximum sustainable yield. The maximum sustainable yield is the largest yield (or harvest) that fishermen can take from a fish population without reducing the population to a dangerous level. As long as the fish population is large enough to replenish its numbers year after year, fishermen are not overfishing.


To determine if a particular stock is in danger, the NOAA takes the estimated biomass of the stock (B) and divides it by the biomass of the maximum sustainable yield (BMSY). After multiplying this figure by 100, you get a percentage of the current biomass compared to the ideal one. The equation looks like this:

B/ BMSY * 100 = Percentage

The NOAA relies on the Fish Stock Sustainability Index (FSSI), which says that 80 percent or more is within the threshold of sustainability. A lower percentage is an indicator of overfishing.

According to the NOAA's 2007 report to Congress, the organization had enough data to determine the overfishing status of 244 different fish stocks. Of those, the NOAA said 41 are being overfished and 203 are fished responsibly. But the NOAA doesn't have enough data to determine the status of 284 other fish stocks.

Just a sample of the fish stocks that the NOAA says are overfished include:

  • Atlantic salmon
  • Bigeye tuna
  • Black sea bass
  • Blue king crab
  • Bluefin tuna
  • Cod
  • Greater amberjack
  • Haddock
  • Marlin
  • Pink shrimp
  • Red snapper
  • Sailfish
  • Yellowtail flounder

It's important to remember that most commercial fishermen want to avoid overfishing as much as environmentalists do. They rely upon fish stocks to make their living. But the cycle of overfishing is self-perpetuating. We'll use bluefin tuna as an example.


Bluefin tuna is a very popular fish and commands a high market price. Because it's so valuable, some fishermen will capture more fish than their legal allotment in order to cash in. However, the price drops as the supply of bluefin tuna to the market increases. In order to make the same amount of money as before, fishermen have to capture even more bluefin tuna to make up the difference. Before long, the fish stock can become irreparably depleted.

One way to limit overfishing is to institute a catch-share quota system. Under some quota systems, a fishing boat has a specific limit to the number of fish it can harvest during a season. There's no incentive to rush out and gather as many fish as possible. Sometimes, fishermen are allowed to trade or sell fishing permits, which can increase or decrease the individual boat's quota. Fisheries may choose to auction off quotas to the highest bidder.

Some fishery organizations have strict weight and size requirements for caught fish. Any fish under those limits cannot be sold at market. The purpose for these requirements is to give juvenile fish the chance to mature and produce offspring.

Another way to alleviate overfishing is to rely on farmed fisheries. We'll take a closer look in the next section.


Farmed Fisheries

Fishing boat in the Yangtze River
The Yangtze River is important for China's fishery industry, but water levels have dropped and pollution has increased in recent years.
China Photos/Getty Images

Not all fish are caught in the wild. ­In fact, according to the 2006 report from the Food and Agriculture Org­anization of the United Nations (FAO), fish farms produced more than 45 million tons of fish in 2004 [source: FAO]. Fish farms are a type of aquaculture. Aquaculture is the growing and harvesting of aquatic organisms and can apply to both freshwater and saltwater plants and animals.

These cultivated fisheries come in many shapes and sizes. Some are manmade ponds or lakes. Others are large tanks filled with hundreds or thousands of fish. Another kind uses nets or other barriers to fence off part of a natural waterway. The most common types of fish you'd find in fish farms include catfish, tilapia, salmon, carp, cod and trout.


Fish farmers have to know a lot about the type of fish they wish to raise, including understanding the conditions in which the fish reproduce. Because fish farms often group thousands of fish into a relatively small environment, farmers have to be sure the type of fish they cultivate can cope with crowded conditions. Farmers also need to understand the feeding habits of the fish to maximize their return on investment.

­The most obvious advantage to relying on fish farms is that the farmer has complete control over how many fish he or she harvests at any one time. Through careful management, the fish farmer can keep the stock population at a sustainable level.

But there are other factors the farmer must keep in mind. Some fish farms group large populations of fish in relatively small areas. Disease and infection are a constant threat. A diseased fish can infect dozens of others as it rubs up against them in the enclosure. Before long, infection can corrupt an entire harvest.

Parasites are another problem. Sea lice are a kind of parasite that attack fish like Atlantic salmon. If the fish farm connects to natural waterways, the parasites can spread from the wild fish to farmed fish.

Another concern for fish farmers is pollution, both from within the farm itself and from outside sources. The waste from the fish can pollute the waters of a fish farm. Some farmers collect the waste and sell it as fertilizer. Other farmers will release waste water into the environment. The chemicals, drugs and waste in the water can be very harmful to the surrounding area. Fish farms that rely on natural water sources are also vulnerable to external pollution. Chemicals from pesticides or fertilizers can harm the fish.

Together, wild fisheries and aquaculture are a big business. Let's take a closer look at the numbers in the next section.



Fishery Economics

Fish market in the Maldives
Nations like the Maldives rely heavily on a national fishing industry.
Lakruwan Wanniarachchi/AFP/Getty Images

According to a 2008 press release from NOAA, the fisheries in the United States contribute approximately $35 billion a year to the economy. An additional $20 billion comes from recreational fishing.

Globally, it's even more impressive. The FAO's report on the state of global fisheries and aquaculture said that capture fisheries -- another name for wild fisheries -- generated more than $84.9 billion in 2004. Aquaculture of fish stocks created an additional $63 billion in revenues. Not bad for a fishy business!


But there are still some major problems with the fishery industry worldwide. The FAO estimates the world fishing fleet at around 4 million units. Of those units, 2.7 million are open water boats (the rest are stationary facilities, most of which are in Asia). According to the FAO and other experts, the fleet is far too large. In fact, in an article for National Geographic, journalist Fen Montaigne goes so far as to say the fleet is nearly twice the size it needs to be.

Some governments have tried to reduce the size of their respective nation's fleets. China instituted a program designed to reduce its own fleet by 7 percent. The government provided incentives to fishermen to retire their boats. The measure was completely voluntary and appealed mainly to fishermen with smaller operations.

Why worry about the size of the fleet? It has an impact not only on overfishing, but also on the economy. Back in 1992, the FAO estimated that the global revenue generated by capture fisheries was $70 billion. But the cost of operating and maintaining the global fishing fleet amounted to $85 billion. That meant the entire fishing industry, when viewed from a global perspective, was operating at a loss [source: Somma].

Why is the fleet so large in the first place? Part of the reason is that the fishing industry generates a lot of money. Another is that many countries offer subsidies to fishermen. Over the last decade, several countries have begun to cut back on subsidies as a way to address the fleet's overcapacity issue. According to a report from the U.S. Director for Trade and Environmental Policy Planning, governments around the world spend between $10 billion and $15 billion on subsidizing the fishing industry. Organizations such as the FAO and the World Wildlife Fund (WWF) have called for the complete elimination of subsidies as part of a strategy to revitalize fish populations and reduce the strain on the environment.

Japanese Fish Market
Japan's fish markets may be partially responsible for depleted tuna populations in the Mediteranean Sea.
AFP/Getty Images

It's important to remember that fishing is a global industry. For instance, fish caught in the Mediterranean Sea may end up on the table in a fancy sushi restaurant in Japan. If one nation offers high prices for a certain kind of fish, it's a safe bet that hundreds of fishermen will compete to meet the demand. Government regulation and enforcement may be the only way to keep the industry from spiraling out of control.

In the end, restraint benefits everyone. The fishing fleet will put less stress on the environment. Fish stocks will have the opportunity to reach a sustainable population. Fishermen will still be able to make a living harvesting fish. And you'll be able to enjoy a tasty tuna tartar. But the world's fisheries still have a long way to go before we can relax.

To learn more about fisheries and other topics, plot a course for the links on the next page.



Lots More Information

Rel­ated HowStuff­Works Articles

More Great Links

  • Allen, Monica. "NOAA Outlines Annual Catch Limits to End Overfishing." News from NOAA. June 5, 2008. (Nov. 4, 2008)
  • Balsiger, James W. "The Status of U.S. Fisheries." National Marine Fisheries Service. June, 2008.
  • Chambers, LantArea. "Ensuring a Future for Fisheries." Coast Guard Magazine. June 2005. pp. 14-16.
  • Economist. "Fishy Business." Oct. 11, 2008. Vol. 397, Issue 8601, pp. 52-53.
  • Encyclopedia Britannica. "Fishery." 2008. (Nov. 4, 2008)
  • ­Food and Agricultural Organization of the United Nations. "The State of World Fisheries and Aquaculture 2006." United Nations. 2007.
  • Gill, Martin. "Agriculture and Fisheries." Encyclopedia Britannica. 2008. (Nov. 4, 2008)
  • Gill, Martin. "Agriculture and Food Supplies." Encyclopedia Britannica. 2008. (Nov. 4, 2008)
  • Guinan, John A. and Curtis, Ralph E. "A Century of Conservation." NMFS. April 1971. (Nov. 4, 2008)
  • Mattice, Alice. "Eliminating Fishing Subsidies as a way to Promote Conservation." Office of the U.S. Trade Representative. Jan. 2003. (Nov. 5, 2008)
  • Montaigne, Fen. "Global Fish Crisis: Still Waters." National Geographic. April 2007. Vol. 211, No. 4, pp. 42-69.
  • National Marine Fisheries Service
  • National Oceanic and Atmospheric Administration.
  • NOAA Fisheries Service. "Implementing the Magnuson-Stevens Reauthorization Act of 2006." (Nov. 4, 2008)
  • ­Somma, Angela. "The Environmental Consequences and Economic Costs of Depleting the Oceans." Economic Perspectives. Jan. 2003. pp. 14-16.
  • Taylor, Peter Shawn. "A smart new way to save the fisheries." Maclean's. Oct. 6, 2008. Vol. 121, Issue 39, p. 25.
  • Tvedten, Inge. "'If You Don't Fish, You are Not a Caprivian': Freshwater Fisheries in Caprivi, Namibia." Journal of Southern African Studies. June 2002. Vol. 28, No. 2, pp. 421-439.
  • United States Fish and Wildlife Service.
  • Walsh, Brian. "Sustainable Sushi." Time. Oct. 16, 2008. (Nov. 4, 2008),9171,1851114,00.html