Sustainable Fish

It’s not just plastic pollution that threatens life in our oceans – overfishing and illegal fishing are also major threats to many species. Since the 1970s the marine population has declined by almost half, which means that the future of numerous species is looking uncertain.


Sustainable fishing means leaving enough fish in the ocean, respecting habitats and ensuring people who depend on fishing can maintain their livelihoods.

Not only is overfishing a problem for us humans, it also has a major impact on other species that live in the sea and also eat the fish. Natural predators such as penguins, polar bears and dolphins are struggling. They are trying to find food in areas that no longer contain enough fish to sustain them and therefore face starvation.

Even if they do have a sustainable source of fish, harmful fishing techniques can also be a major threat. Animals can become tangled in nets or fishing lines, and some fishing boats may also leak fuel and other pollutants which may damage their habitat.

This is all taken into consideration when assessing the sustainability of a fishery. They look into:

  • Sustainable fish stocks – is there enough fish left in the ocean to continue indefinitely
  • Minimising environmental impact – are other species and habitats in the ecosystem able to remain healthy?
  • Effective fishery management – can fisheries comply with relevant laws and adapt to changing environmental circumstances?


  • Working with the Marine Conservation Society to highlight fish stocks which are most at threat and suggesting alternative species which people can shop for and eat
  • Promoting sustainable fishing at our daily penguin talks
  • Working with fisheries to make sure that the fish we feed our animals and also sell in our catering outlets is sustainably sourced


If you are buying fish from a supermarket keep an eye out for the Marine Stewardship Council (MSC) or the Aquaculture Stewardship Council logos on the products. The MSC logo certifies wild fish stocks that are fished in a sustainable way, and the ASC logo certifies that farmed fish have been produced in an environmentally and socially responsible manner.

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