Corals Tutorial: Fishing Impacts on Coral Reef Ecosystems

There are many ways that fishing impacts coral reef ecosystems. Click the images to view a larger image and a description of these impacts.

Small fish

Coral reefs serve as nurseries for many fish and shellfish species. The reefs offer small growing fish food, like algae and zooplankton, and places for them to hide from bigger fish and other predators. Catching young fish before they can mature and have their own young reduces the amount of fish available to replenish the population.

Fishing for undersized, immature fish is illegal and results in fines and jail time for offenders. This picture shows undersized fish caught by a fisher that was stopped by local enforcement officers. The middle line of fish lays on top of a metal ruler used to measure the fish and determine whether it is below the legal size to be caught.

All the fish in this picture are below the legal catch size. *Photo credit: Florida Fish and Wildlife Conservation Commission*

Large fish

Large fish produce more young that are likely to survive to adulthood. Bans on fishing some large, slow-growing species can help their populations rebound. *Photo credit: sablin - stock.adobe.com (Standard license)*

Aggregating fish

Some fish species gather in large numbers at known times and locations on the reef. This makes them susceptible to overfishing. *Photo credit: R.J Hamilton/The Nature Conservancy*

Non-selective fishing gear

Nets and traps are examples of non-selective gear. They often catch many kinds of herbivorous fish (fish that eat algae and other plants) and invertebrates (like crabs and sea urchins) from reefs that fishers do not intend to catch when they lay their nets out. Ensuring these animals are present on the reef at levels that can control algal growth, and provide space for corals to grow and thrive, is key to a healthy reef. When caught, these animals may be kept, but are often just thrown away, depleting the reef ecosystem of an important resource. Fishing lines and hooks are examples of selective gear, which are designed to draw in and catch specific types of fish.Photo credit: Smithsonian Institution

Collecting fish

Collecting fish from the wild for the aquarium trade reduces the overall population of wild fish on and around the reef. In some parts of the world fishers squirt cyanide and other chemicals to stun the fish before collecting them. This can kill the fish and be destructive to the corals themselves. The marine aquarium trade is a global industry valued at billions of dollars annually. *Photo credit: NOAA.*

Marine debris

Marine debris, such as ghost traps, lost nets, monofilament, and lines, can damage coral reefs, which take a long time to recover. *Photo credit: NOAA*

Scientists and resource managers use different tools to address unsustainable fishing practices. These include:

Regularly evaluating fish populations,
Incorporating indigenous and local knowledge about different fish species and fishing practices,
Restricting the use of certain types of fishing gear,
Enforcing a limit to the number and types of fish that can be caught during a fishing season, and
Working to protect and restore the habitats where the fish live.

NOAA Fisheries, regional fishery management councils, and state and territorial fishery management agencies are responsible for the sustainable management of coral reef fisheries in the U.S. They work with each other and the public to ensure the best available knowledge is used to protect coral reef ecosystems and the fish that call them home.