Sustainable Fish Farming, Is It Possible?

sustainable fish farming

It’s no secret that the world’s fish stocks are in a sorry state. Overfishing, trawling, ocean pollution and climate change have all led to a severe depletion in the number of fish in our oceans.

Subsequently, the oxygen levels in our seas and waterways have also decreased. Some scientists have even speculated that by 2048 there will be no fish left at all.

So could intensively farmed fish be the solution? Does sustainable fish farming exist?

There are off-putting stories about farmed salmon being fed dye to make their flesh appear pinker. There are also environmental concerns with fish farming.

But is aquaculture, the farming of fish, really that bad?

If we want to eat fish occasionally but still want to do what’s best for the environment, what should we do? Is there a ‘best’ fish to eat?

We’ve reeled in a few of the facts about fish farming and its environmental impact. We also take a look at the best choices you can make if you want to eat fish.

boxed fish from fish farming

Fish Farms and Environmental Terrorism

While the idea of farmed fish sounds enticing and sustainable, the reality couldn’t be further from the truth. To begin with, fish are sentient creatures and the conditions on fish farms are far from palatial.

Fish farms also have debilitating effects on our oceans. These include, but are certainly not limited to, the following:

Farmed Fish Are Fed Fish

Proponents of aquaculture may like to tout fish farming as a valid alternative to large scale sea fishing. But many of the species that are farmed are predatory creatures that need to swim around freely to find their food. They also need omega-3 fatty acids in their diet – which come from the fish they eat.

This means farmed fish are fed on ocean fish. According to PETA, it takes 5lbs of ocean fish to produce 1lb of farmed fish.

The Threat of Disease Spread

In fish farms, the conditions are often overcrowded and unsanitary, much like on land farms. Because of this, farmed fish have high levels of parasites, diseases, bacterial infections and viruses.

Fish farms are therefore breeding grounds for fish diseases and a host of other transferable diseases. Because fish farms aren’t ‘sealed’, these health issues are easily passed on to wild fish in nearby waters.

To make matters worse, the pesticides and antibiotics used to prevent disease are also discharged into the environment. This also has a negative effect on wild fish.

Pollution and Fish Farming

Intensively farming fish leads to high concentrations of waste. Fish farms are often located in areas where it is easy to farm, such as rivers and inlets.

These areas start off as high quality waterways. But they don’t have the large bodies of free-flowing surrounding water needed to dilute large amounts of effluent. This jeopardises the water quality and local ecosystems, leading to a further depletion of oxygen levels.

fish farming - a catch on a boat

Are There Sustainable Fish Farming Options?

Currently there is no such thing as sustainable aquaculture. There are some options though, which work out better than others and a few forward thinkers who are coming up with solutions to the problem.

Some companies are now working on creating omega-3 fatty acids from marine algae. This could go some way towards combating the issue of overfishing to feed farmed fish. But this only addresses one of many issues.

Other aquaculture producers are trialling moving their operations further into the sea. In deeper, offshore waters there are stronger currents which would help to keep the farmed fish healthy.

The larger body of water would also mean that effluent is better dispersed. That said, it would still be dispersed into the ocean.

What About Land-Based Fish Farms?

With global demand for fish on the rise, land-based fish farms are predicted to become the future of aquaculture. Advances in technology mean that land-based Recirculating Aquaculture Systems are getting better at removing effluent and reusing water.

Land-based aquaculture has a few advantages over natural waterway farming. These include a reduced risk of farmed fish escaping and improved control of parasites and diseases. Plus, they allow for better management of water quality.

This method of farming is expensive though. It requires a lot of energy because of the number of water pumps constantly running. This means that the ecological cost of farming inland is higher than many might consider.

So, What Fish Can I Eat?

Unfortunately, if you want to make a sustainable choice when it comes to protein, fish is off the menu. If you really want to eat fish, try to do so occasionally and buy the most sustainable options.

Some retailers, like Whole Foods, are committed to only stocking sustainable fish. This could mean fish that is farmed (as sustainably as possible) or wild-caught but not at current risk of extinction.

It should be noted though, that these days, wild-caught fish and shellfish can be full of toxins, heavy metals, and even microplastics.


The Good Fish Guide

The best fresh fish to eat changes based on the current state of the given species. Before buying fish, check the Marine Conservation Society’s Good Fish Guide. This is the definitive UK guide to the most sustainable seafood and fish.

The guide offers a rating system from 1 – 5 with 1 being the best, most sustainable choice. Look for fish and shellfish that are rated either 1 or 2.

The guide lets you base your choices on whether you want farmed or fished seafood. You can also narrow your search down to method of capture and ‘most sustainable’ for all categories.

At the time of writing, the following are good options:

  • Abalone
  • Sea Bass (Farmed)
  • Gilthead Bream (Farmed)
  • Brown Crab
  • Hake
  • Mussels (Farmed)
  • Rainbow Trout
  • Skipjack Tuna

Make sure that whatever fish you buy is from a fishery that is certified as sustainable.

The future of the oceans is currently bleak as the global demand for fish continues to rise. So it can only be hoped that some truly sustainable and environmentally friendly ways to farm fish will emerge. If they could also offer hospitable conditions for the fish being bred, even better.

Time will tell what options we have with regard to eating fish, fisheries, and the future of aquaculture. So watch this space…