effects of overfishing

Effects of Overfishing on Ocean Health

Jane Marsh - August 30, 2018

We are reader-supported. When you buy through links on our site, we may earn affiliate commission.

Fish is a staple on restaurant menus all over the world. You might eat this protein-rich food every week or more.

Humans consuming fish for nutrition is certainly not a new trend. It’s been happening for at least 164,000 years, and researchers found fishhooks dating back to 40,000 B.C.

In modern times, we have to be concerned about the effects of overfishing on local marine populations and overall ocean health. Technology and large-scale fishing operations allow people to catch vast quantities of fish while exerting relatively low effort.

Overfishing happens when people catch fish at a rate faster than natural replenishment occurs. Let’s look at some of the effects of overfishing on our oceans’ ability to thrive.

The Threat to the Shark Population

Sharks have been on the planet for 450 million years — even before dinosaurs. However, estimates suggest humans kill nearly 200 sharks per minute. Sometimes that’s because people prey on sharks for their fins, but in other cases, sharks come too close to fishing vessels.

Sharks help keep the ocean’s ecosystem in balance and protect coral reefs by managing the populations of herbivorous fish eating algae. Without sharks, predators threaten the fish that feast on that algae, potentially causing it to overpopulate the reef.

Scientists are building a database that tracks how sharks interact with fishing vessels. As part of the project, the researchers tagged blue sharks. That species doesn’t have commercial value, but it’s found all over the world. In some areas, blue sharks make up 90 percent of the sharks mistakenly caught by fishing vessels.

Thanks to this database, fishery managers could have the data they need to figure out the best ways to catch fish without causing extraordinary danger to sharks. Then, the effects of overfishing on sharks may minimize.

Too Much Fishing Decreases Biodiversity

Marine experts know biodiversity — the variety of species and functions in an ecosystem — protects oceans against the effects of climate change and makes them more resilient against potential extinction issues. They also discovered losing a vital component of an ecosystem has a spiral effect that impacts all the plants and animals in an area.

Humans substantially disrupt biodiversity through their activities, and that’s one of the effects of overfishing.

Rare Freshwater Stingrays at Risk

The problems also span beyond oceans and into rivers. Overfishing especially threatens massive freshwater stingrays living in South America’s waterways. South America features an incredible assortment of stingrays, comprising 32 species.

However, researchers found five species declined in number by up to 25 percent per year. When they looked at the matter more closely, they saw many of the stingrays had missing tails. When people fish in South America and catch them, they typically cut off the tail to make it safer to handle the creatures.

An investigation revealed the comparatively smaller populations had more stingrays with missing tails. So, the research team concluded overfishing was to blame.

Scientists know people are negatively affecting saltwater stingrays. Research from 2014 indicated hundreds of species of stingrays and sharks are at risk of extinction from frequent fishing. However, the South American research was the first study that focused on freshwater stingrays and the resultant impact.

The Seafood Industry Contributes to Overfishing

People in the United States love seafood so much, they’ve helped turn it into a $5.5 billion industry. If you like fish but care about reducing the effects of overfishing, look for fish caught by sustainable operations. Some fisheries are even distributing natural feed to the fish populations, replacing previously used unsustainable foods.

Before feasting on fish, be mindful of which varieties are already scarce. A global report found 35 percent of fish caught get wasted because they’re unwanted kinds or even because people don’t know how to preserve the fish properly before they make it to diners’ plates.

Instead of immediately ordering a seafood dish that’s causing a buzz in foodie culture, research it. See if whether, by eating it, you’re contributing to the effects of overfishing.

A new visual identification method could cut down on unsustainable levels of fishing in certain areas. Scientists say fish caught in specific areas have distinct body types, even if those locations are only three miles apart. They’ve devised a method of finding out where fish came from that’s 80 percent accurate.

Using it could show warning signs that some fishing populations are getting overrun by members of the seafood sector, and it’s time to relocate.

Excessive Fishing by European Operations Hurts Seabirds

So far, we’ve examined how overfishing affects the things that live under the ocean’s surface, but what about the birds that fly above it? Research that pinpointed the effects of overfishing on the European seabird population found that 200,000 birds perish every year when they get caught in fishing nets.Plus, many of the fishing vessels that operate in Europe and cause that problem don’t only stick to that continent. They often venture to Africa and have similarly devastating effects.

Dolphins Could Get Caught in the Nets, Too

When looking at the effects of overfishing, we also have to be aware of how the decreasing fish population affects the marine animals that have to eat them to survive. Surprisingly, dolphins in Cyprus are reportedly breaking into nets full of fish and eating some of what’s caught.

Researchers say the phenomenon is damaging fishing nets. Unfortunately, it’s also risking the lives of dolphins who could get trapped in the nets while indulging in their feeding frenzies.

The Far-Reaching Effects of Fishing Operations

The information here emphasizes that the effects of overfishing reach into all aspects of the marine ecosystem, its creatures and its overall health. We can help minimize the adverse effects by being more aware of the fish we eat and where it comes from.

Share on

Like what you read? Join other Environment.co readers!

Get the latest updates on our planet by subscribing to the Environment.co newsletter!

About the author

Jane Marsh

Starting from an early age, Jane Marsh loved all animals and became a budding environmentalist. Now, Jane works as the Editor-in-Chief of Environment.co where she covers topics related to climate policy, renewable energy, the food industry, and more.