Fish Fish
Conservation and Research

Commercial Fisheries

The Food and Agriculture Organization of the United Nations (FAO) reports that for 2002, commercial ocean fisheries captured more than 84 million metric tons of fish and shellfish; inland fisheries captured and harvested more than 9 million metric tons of fish and shellfish. While these numbers include sharks, rays, mollusks and crustaceans, about 82% of the total is bony fishes.

  • About 73 percent of the fisheries harvest is food for human consumption. Most of rest goes to feed livestock that are then used for human consumption.
  • Demand for fish is projected to increase in the future. Yet the FAO estimates that about 52% of the oceans' wild fish stocks are fully exploited, 17% are overexploited and 8% have been depleted. Thus, only about 23% of the world's marine fisheries stocks offer opportunity for further fisheries expansion.
  • U.S. commercial fishing operations accounted for about 3.7 million metric tons of the bony fish catch in 2003.

Most commercial fishing operations aren't able to perfectly select only the kind of fish that they want (specimens for which there is a market). Non-targeted catch is called bycatch. Bycatch is discarded, often dead or dying.

  • A 1996 study by the FAO estimated that the amount of bycatch for that year was somewhere between 18 and 39 million metric tons.
  • Shrimp trawl fisheries generate more discards than any other fishery type and account for just over one-third of global total bycatch.
  • Fisheries strive to reduce bycatch. Gear modifications and operation modifications have been somewhat successful in reducing bycatch.
  • Another goal of fisheries is to utilize the non-targeted specimens to fulfill demand for food.

With the goal of ensuring effective conservation, management and development of living aquatic resources, the FAO has developed a "Code of Conduct for Responsible Fisheries". The Code sets out principles and international standards for responsible fishing practices. In 1997 the United States National Marine Fisheries Service/National Oceanic and Atmospheric Administration (NMFS/NOAA) set forth an implementation plan for compliance with the Code.

Recreational Fishing

Various species of marine and freshwater bony fishes are targeted for small scale fishing for food and recreation.

In 2003, about 100,000 metric tons of bony fishes were caught by recreational anglers in the U.S.

Aquarium Collection

Some of the marine fishes sold in pet and aquarium stores are collected using methods that destroy other marine animals (including other fish) and habitats.

The Marine Aquarium Council (MAC) is an international organization that certifies collection areas and collected organisms as well as industry professionals who adhere to best practices for the marine aquarium industry. MAC promotes sustainable, environmentally sound trade and conservation of natural resources.

SeaWorld encourages aquarium enthusiasts to purchase "hand-caught" or captive-bred fishes, and to look for MAC-certified sources of aquarium fish.

Invasive Species

A non-native species introduced into a habitat can alter the ecology of that habitat.

Some invasive species have devastating results on native species.

  • A popular aquarium fish, the goldfish (Carassius auratus) is native to Asia. It has been released - both intentionally and inadvertently - and has formed wild populations. In some areas goldfish prey on native fish.
  • A strain of Caulerpa taxifolia, a marine algae cultured for use in aquariums, is an invasive seaweed that was inadvertently introduced into the Mediterranean Sea, where it grows in dense beds that prevent native plants from growing, thus eliminating habitat for native species. In 2003, experts were alarmed to find this invasive species in California.

Habitat Modification

Damming, channelization, and stream diversion alter aquatic habitats. Without assistance, hydroelectric dams would make migration impossible for anadromous fishes (those that hatch in freshwater and travel downriver to the sea to complete their life cycle).
  • Young fish headed toward the ocean can be barged downriver, sent over the dam, or guided to a bypass channel.
  • After spending several years at sea, anadromous fishes must travel upriver to spawn. A fish ladder next to a dam provides a way for these fish to travel upriver.

Silting can result from deforestation or agriculture, and can change an aquatic habitat significantly.

The loss of wetlands due to coastal development threatens fish populations. Wetlands are important nursery grounds for many species of ocean fishes.


Chemicals that are used on land can eventually end up in freshwater systems and oceans as pollution. Such chemical contaminants can enter the food chain and become concentrated in the bodies of fishes.

  • Pesticides may enter waterways through agricultural runoff.
  • Household and garden pesticides can enter waterways, too - through sewers and storm drains.

Small amounts of heavy metals occur naturally in the ocean, but industrial pollution has increased the amount of heavy metals in many aquatic environments. Heavy metals may also enter waterways when people illegally empty household chemicals, such as paints, into sewers and storm drains.

  • Heavy metals accumulate in the tissues of organisms that ingest them and are passed up the food chain. Thus, large carnivorous fishes are most susceptible to high levels of heavy metals.
  • The effects of heavy metals on fishes are not well known, but we do know that more than minute amounts of heavy metals are poisonous to humans. The best known heavy metal poisoning associated with fish is from mercury. The U.S. Department of Agriculture (USDA) has set a maximum acceptable level for mercury in fish. Any fish with more than 0.5 ppm (parts per million) mercury may not be sold as food.

Acid rain results when the emissions of fossil fuels combine with moisture in the atmosphere to form droplets of sulfuric or nitric acids. The droplets fall as rain or snow and can reduce the pH level in lakes and streams to the point where the pH is inhospitable to native species.

Oil spills are harmful for fish populations.


The FAO reports that worldwide aquaculture operations harvested more than 39 million metric tons of fish and shellfish in 2002. While this number includes mollusks and crustaceans, about 66% is bony fishes.

According to FAO calculations, aquaculture operations worldwide have grown at a rate of 9% per year since 1970. In comparison, the worldwide annual growth of ocean fisheries has been only about 1% per year, and worldwide terrestrial farmed-meat operations growth has been just 3% per year.

Worldwide, the most commonly farmed fish are various species of carps, salmons, trouts, smelts, and tilapias. In the United States, catfish farming leads the aquaculture industry.

Stock Replenishment

Some species of bony fishes can be reared in a controlled environment for part of their life cycle and then released in open waters to replenish natural populations.

Salmon hatcheries in the Pacific Northwest release more than 120 million young, ocean-ready fish each year and contribute between 50% and 70% of all adults caught in that region's coastal areas.

California’s Ocean Resources Enhancement Hatchery Program (OREHP) was created to counteract the depletion of California's coastal marine fisheries through stock enhancement.

  • OREHP is a partnership between California state resources agencies, public utility companies, volunteer user groups and the scientific community. An important component of OREHP is an assessment of the biological and economic impacts of its releases.
  • The Hubbs-SeaWorld Research Institute (HSWRI) has participated in the OREHP program since 1983 by breeding and rearing white seabass (Atractoscion nobilis), releasing fingerlings into Southern California waters.
    •  White seabass had virtually disappeared from California waters due to overfishing and habitat destruction.
    • To date, HSWRI has bred, tagged and released more than 650,000 seabass into Southern California waters. Nearly 1,000 of these hatchery-reared white seabass have been recovered.
    • To evaluate the hatchlings' success in the wild, researchers insert a coded wire tag into the cheek muscle of the fish. When a fish is caught, the tag allows researchers to identify its release group and helps them learn about the white seabass population as it develops.
    • HSWRI continues to develop programs to improve culture technology, evaluate population characteristics, evaluate habitat requirements, assess stocking methods, and develop methods to monitor wild populations.

Legal Protection for Fishes

Several U.S. agencies govern fishing laws and regulations, notably the National Marine Fisheries Service (NMFS), and the U.S. Fish and Wildlife Service (USFWS). Other federal agencies that have responsibility for fish management and conservation include the U.S. Forest Service, The Bureau of Land Management (BLM), the United States Geological Survey, and the National Park Service.

State agencies such as state Departments of Natural Resources (DNR), state Departments of Environmental Protection (DEP), and state Departments of Fish and Game may also enact fishing laws and regulations for the state.

The Convention in International Trade in Endangered Species of Wild Fauna and Flora (CITES) is an international treaty developed in 1973 to regulate trade in certain wildlife species. CITES prohibits or controls trade in about 80 species of bony fish.

Endangered and threatened species and populations.

  • IUCN/The World Conservation Union is a worldwide conservation organization. This organization links together government agencies, non-government agencies, and independent states to encourage a worldwide approach to conservation. As of 2005, IUCN/The World Conservation Union identified 162 "critically endangered" fish species, 140 "endangered" fish species, 429 "vulnerable" fish species, 12 "conservation-dependent" fish species, and 105 "near-threatened" fish species.
  • CITES designates species status via listing within an appendices system.
    • CITES lists the world's most endangered plants and animals in CITES Appendix I. Nine bony fishes are listed in Appendix I. One of these, the Asian bonytongue (Scleropages formosus), is on display at SeaWorld San Diego.
    • CITES Appendix II lists species that are not currently endangered, but in which trade must be controlled to avoid endangering the species. About 70 species of bony fishes are listed in Appendix II. Six of these species are displayed at SeaWorld parks: the arapaima (Arapaima gigas), the white sturgeon (Acipenser transmontanus), and four species of seahorses (Hippocampus spp.).

As of 2005, the United States Fish and Wildlife Service (USFWS) lists 114 species of native bony fishes that are endangered.

Individual U.S. states may also list fish species as endangered.


The non-profit SeaWorld & Busch Gardens Conservation Fund (SWBGCF) works on behalf of wildlife and habitats worldwide. The goal of the SWBGCF is to encourage sustainable solutions by supporting critical conservation initiatives worldwide.

  • The SWBGCF conducts grant awards twice each year and anticipates funding for 2005 to approach $700,000. Selected projects must be science-based, solution-driven and community-oriented - attributes needed to achieve effective and long-term conservation success.
    • Groups working on fish conservation projects are invited to apply for a SWBGCF grant. Projects are carefully selected by a diverse mix of wildlife experts, scientists, business leaders and educators.
    • The SWBGCF accepts donations to support conservation projects in the U.S. and around the world. 100% of donations go directly to selected projects.
  • SWBGCF supports the following programs that are related to bony fish conservation:
    • The Nature Conservancy is working to protect the Meso-American Reef, the second largest barrier reef in the world. Their goal is to build a marine reserves network, support the development of conservation policies and practices, and protect spawning grounds and reef systems of dozens of fish species. In 2004, SWBGCF provided funding to continue these efforts.
    • The University of Miami's Rosensteil School of Marine & Atmospheric Science is addressing declines in fishes and coral of the Western Atlantic coral reefs. A 2004 SWBGCF grant helps fund several teams of scuba divers to assess the health of the Western Atlantic coral reef. The results will provide answers to key questions about these impacts and will provide a baseline to evaluate future changes.
    • A 2004 SWBGCF grant to Project Seahorse (University of British Columbia Fisheries Centre) helps fund the production of an educational seahorse poster. The poster explores seahorse biology, demand for seahorses, conservation concerns, and creative solutions for managing seahorse populations.

From 1999 to 2003 - before the creation of the SWBGCF - SeaWorld and Discovery Cove supported The Nature Conservancy's Rescue the Reef® campaign to protect and preserve fragile warm-water coral reef habitats in the Florida Keys, Caribbean Basin and Asia/Pacific regions. The program enlists scores of volunteers - some of whom are SeaWorld and Discovery Cove employees - who do everything from underwater clean-ups and fish counts to outreach programs for local dive shops and fishermen.

Scientists all over the world continue to study the abundance, biology, reproduction, migration, and catch information for various bony fish species.