What is Overfishing?
Overfishing occurs when more fish are caught than the population can replace through reproduction. There are different types of overfishing, such as growth overfishing, where young fish are caught before they reach their optimum marketable size or are allowed to reproduce before they are caught. Recruitment overfishing occurs when the reproduction rate of fish stocks is too low to replace loss from fish naturally dying or from being caught. This results from disproportionately large reproductive fish, mainly females being targeted. There is also economic overfishing when the revenue generated from increases in fishing efforts is less than the cost of this effort.
Adverse impacts of overfishing
- A Threat to Fish Stocks – Causes substantial depletion of many fish stocks, loss of breeders, declines in average sizes of fish, and reduces the fish population of many age groups to a few, making it more vulnerable to natural fluctuations in years where the survival of young is poor. Intense fishing can lead to changes in genetic diversity and genetic change toward less desirable characteristics like smaller size potential.
- Increase Bycatch – Many tropical fisheries are multi-species. Increases in the capture of target species mean more of the bycatch is also caught and in many cases simply discarded.
- Fishing down the food chain – As large predators get fewer in numbers, smaller fish from different trophic levels are taken, which can result in changes to food chains and food webs
- Degraded Ecosystems – When too many fish are taken out of the ocean, it creates an imbalance that can erode food webs and lead to the loss of other important marine life, including vulnerable species like sea turtles and corals.
- Unhealthy Coral Reefs – Overfishing of many species leads to functional loss of species or species groups. Keystone species are those whose removal causes a chain or cascade of ecological effects. For example, the removal of algae-eating fishes such as parrotfish can cause smothering and eventual death of corals reefs to be killed by algae overgrowth, a large problem in many tropical regions.
- Lives and Livelihoods – The damage caused by overfishing goes beyond the aquatic environment. It can adversely affect livelihoods, jobs, and food security, and lead to a decline in economic growth in economies where fishing is a mainstay of the GDP. The well-being of coastal communities is also at stake, as the mores and culture of many such communities revolve around fishing and associated activities.
Overfishing is made worse from illegal and unregulated fishing practices as a result of poor fisheries management.
Listen to the podcast titled ‘Illegal, Unreported, and Unregulated Fishing in our waters, part of the Republic Bank’s/IMA’s Beyond the Blue – from the Ocean to Our Tables Radio Broadcast series, which was hosted by the Institute’s Chief Information Officer, Alicia Carter-Fisher. For more information, follow the link: https://www.ima.gov.tt/2023/01/06/beyond-the-blue-season-4-episode-20/
Take in all twenty podcasts and ten video vignettes at the link: Click here
And relive the prize-giving ceremony for students and adults who participated in the campaign’s competition here: https://www.ima.gov.tt/2023/03/01/new-fisheries-legislation-poised-to-promote-sector-growth-and-protection/