Overfishing is one of the few large-scale environmental problems with a proven fix. When fisheries run on science-based limits and steady enforcement, fish populations recover. In the Northeast Pacific, 92.7% of assessed stocks are fished sustainably, according to the Food and Agriculture Organization of the United Nations (FAO). Worldwide, FAO’s State of World Fisheries and Aquaculture 2026 classifies 37.6% of assessed marine stocks as overfished.
The gap between those numbers comes down to management, and management comes down to trained people: the biologists who count fish, the managers who set catch limits, and the officers who enforce them. At Unity Environmental University, the Bachelor of Science in Marine Biology and Sustainable Aquaculture prepares students for that work through coursework in fish biology, sustainable harvest, and aquaculture.
Learn how to make fishing more sustainable with a degree in wildlife and fisheries biology.
What Is Overfishing, and Why Is Overfishing a Problem?
Overfishing is catching too many fish before they can reproduce, which depletes fish populations over time. Overfishing is one form of overharvesting, which the National Wildlife Federation describes more broadly as the overexploitation of wild plants and animals, from timber trees to birds.
Fisheries scientists draw a sharper line between two related terms. To NOAA Fisheries, part of the National Oceanic and Atmospheric Administration (NOAA), a stock is subject to overfishing when the annual catch rate is too high and overfished when the population has fallen too low. The first is about how hard a stock is being fished right now. The second measures damage already done, and pollution or a warming ocean can deepen it even after fishing eases. A fishery can end overfishing and still need years to stop being overfished.
Most overfishing traces back to four human pressures:
- Increased demand for seafood
- Technologies that make fishing easier
- Lack of fishing regulations or lack of enforcement
- Government subsidies that keep more boats fishing than a stock can support
What are the effects of overfishing? Overfishing affects entire ecosystems. It reduces biodiversity and can push some fish species toward extinction. Seabirds, otters, and orcas that feed on fish can go hungry, and species that cannot switch to other prey may become endangered. Reefs suffer too, as many reef fish graze on algae, and when fishers remove them, algae can overgrow and smother the coral.
6 Solutions To Overfishing
No single solution stops overfishing on its own. Fisheries that have recovered usually combined several at once: firm catch limits, protected habitat, better gear, and research to show whether any of it is working. The first three solutions act directly on the water, and the last three shape the markets, laws, and science behind them.
Science-Based Catch Limits and Regulations
The first solution to overfishing is the one most people know: regulations on how many fish can be caught, what size a fish must be to keep, when they can be caught, and who needs a permit. The goal is to keep fish populations large enough to reproduce, protect their breeding grounds, and keep them available as a sustainable food source. Some seasonal closures do both, keeping boats off the water while fish spawn.
In the United States, the Magnuson-Stevens Fishery Conservation and Management Act requires those limits to follow scientific stock assessments and directs managers to protect essential fish habitat, including spawning grounds. Since 2000, 51 overfished U.S. stocks have been rebuilt, according to NOAA’s Status of Stocks 2024 report. At the end of 2024, 23 stocks were still subject to overfishing and 42 remained overfished.
Recreational fishing counts too. Along the Atlantic coast, NOAA collects that data through the Access Point Angler Intercept Survey (APAIS), which interviews anglers about their catch, and separate surveys for highly migratory species (HMS) like tuna and sharks.
Marine Protected Areas (MPAs)
Marine protected areas (MPAs) are areas where fishing is prohibited or greatly restricted. Some also restrict other activities that harm habitat. Within these boundaries, fish can grow, spawn, and replenish nearby waters.
One of the best-documented overfishing examples comes from Georges Bank off New England, where a closure helped some species but not others. Cod, haddock, and other groundfish had declined sharply by 1994, and in December managers closed large sections of the bank year-round to any gear that could catch them. Sea scallops responded fastest. Their biomass inside the closed areas rose 14-fold between 1994 and 1998, according to a 2000 study in the Bulletin of Marine Science.
Closures do the most for species that stay put, such as shellfish and many reef fish, while wide-ranging species need protected areas paired with catch limits. Protected areas on land work the same way to reduce overharvesting and wildlife poaching.
Selective Fishing Gear and Bycatch Reduction
Destructive fishing practices such as bottom trawling cause extensive habitat damage and unintended catch. Bottom trawling involves dragging a large net across the ocean floor, picking up all sea life in its path.
Fishers call that unintended catch bycatch, and it includes juvenile fish, sea turtles, marine mammals, and sharks. Selective gear reduces it. Larger or reshaped mesh lets young fish slip through the net while modified hooks and escape panels keep many non-target animals out of the catch. Selective fishing also makes it easier to stay within quotas, since what comes aboard matches what a permit allows.
Sustainable Seafood Choices, Stock by Stock
Preventing overfishing at the seafood counter starts with one fact: the same species can be well managed in one ocean and overfished in another. Tuna is the clearest case: more than 90% of assessed tuna stocks are fished sustainably, according to FAO’s 2026 report, so the better question is which stock it came from. Sharks are a different story: 43.5% of assessed highly migratory shark stocks are fished unsustainably, often as bycatch in tuna fisheries, according to FAO’s 2025 review.
A few habits help you buy from stocks that can handle the demand:
- Ask where and how the fish was caught. A good seafood counter or server can tell you.
- Check a U.S. species against NOAA Fisheries’ stock status updates.
- Look up the species in the Monterey Bay Aquarium’s Seafood Watch, which rates seafood by where and how it was caught or farmed.
- Look for a third-party sustainability label when the package doesn’t name the source.
- Buy local species in season, since they come from fisheries held to your state’s size and catch limits.
International Cooperation and Limits on Harmful Subsidies
Many commercial fish cross national borders, so no single country can manage them alone. Beyond the 200-nautical-mile zones that nations control, regional fisheries management organizations (RFMOs) manage shared stocks such as tuna. These treaty bodies set catch limits and monitoring rules for their member countries, and their work is a major reason tuna stocks have improved.
Countries also regulate their own fleets wherever they fish. The U.S. requires permits for all commercial fishing vessels in international waters. Subsidies, one of the causes listed earlier, now face the first binding global limits. The World Trade Organization (WTO) Agreement on Fisheries Subsidies took effect September 15, 2025. It bans subsidies for illegal, unreported, and unregulated (IUU) fishing, for catching overfished stocks, and for fishing on high seas that no RFMO manages.
Fishery Management and Research
Fish populations improve where governments invest in management and research, according to a study in the Proceedings of the National Academy of Sciences (PNAS).
Every other solution on this list depends on that research. Each catch limit rests on a stock assessment, which combines survey data and population models to gauge a stock’s size and how much harvest it can absorb. FAO Director-General Qu Dongyu calls effective management “the most powerful tool for conserving fisheries resources.” Catch shares divide a fishery’s total allowed catch among fishers or groups, so no one has to race for fish before the season’s limit is reached.
Love the ocean? Find a marine career that matches your passion at Unity Environmental University.
Can Aquaculture Take Pressure Off Wild Fish?
Partly, and the answer depends on how a farm is run. Fish and shellfish farms now supply 53% of the world’s aquatic animal production, according to FAO’s 2026 report. Since the late 1980s, nearly all growth in seafood supply has come from farms, while the wild catch has held roughly level.
Two caveats keep aquaculture from being a simple fix. Many farmed fish eat feed made partly from wild-caught fish, so a farm can shift pressure onto other stocks instead of removing it. Poorly sited or managed farms can also spread disease and escaped animals into wild populations. Shellfish and seaweed farms need no added feed, so they avoid the first problem. Disease screening and escape-proof pens address the second, and Unity’s BS in Marine Biology and Sustainable Aquaculture teaches those farm controls alongside wild fisheries science.
Careers That Help Stop Overfishing
Each solution above is someone’s job. Most fisheries and marine biologists work for government, and the U.S. Bureau of Labor Statistics (BLS) counts them among the nation’s 19,500 zoologists and wildlife biologists.
A bachelor’s degree in biology or natural resources opens most of these roles. Higher-level research jobs often call for a master’s degree, and leading independent research usually takes a Ph.D. Each role targets a different part of the problem, and national median pay runs from about $74,000 to nearly $90,000.
| Role | How It Reduces Overfishing | Median Pay (May 2025) |
| Fisheries biologist | Runs the field surveys and sampling that feed stock assessments | $76,780 |
| Fisheries management specialist | Turns assessment results into seasons, size limits, and quotas | $76,780 |
| Fisheries officer or game warden | Checks permits, catches, and gear on patrol and at the dock; many are sworn officers who complete an academy | Set by state agency pay scales |
| Marine biologist | Studies fish populations, bycatch, and habitat to show which measures are working | $76,780 |
| Coastal resources manager | Plans protected areas and balances fishing with other coastal uses | $73,920 (conservation scientists) |
| Aquaculture farm manager | Runs fish and shellfish farms, managing stock health, feed, and escape prevention | $89,900 (agricultural managers, including aquaculture) |
Many people start as technicians or fisheries observers collecting data at sea, then move into assessment or management roles as they gain experience.
Build a Career in Sustainable Fisheries at Unity Environmental University
If the science behind these solutions interests you, the next step is training that covers both wild fisheries and fish farming.
Unity Environmental University’s BS in Marine Biology and Sustainable Aquaculture is built around both halves of that work. Global Diversity of Freshwater and Marine Resources Used in Sustainable Harvest grounds you in the science of how much a wild population can give up. Ichthyology and Fish Health adds the biology that fisheries managers and fish farmers both rely on, and Field Research in Marine Biology and Aquaculture puts those methods to use. Among the instructors guiding that coursework is Dr. Kafayat Fakoya, who has taught fisheries science at the university level for more than 20 years.
The degree is 120 credits, taught through remote learning with eight terms a year, a schedule designed for the life you’re already living. Credits you’ve already earned can cover up to 90 of those 120, and Distance Education tuition stays locked through 2030, keeping costs predictable as you plan. If you already hold a bachelor’s degree, the MS in Marine Conservation Biology is the more direct route, with a focus on research design and conservation strategy.
Talk with Unity Environmental University about how the B.S. fits around your schedule and which of the eight yearly terms works for your first course.
