Protecting 5% more of the oceans would boost fish catches by 20%

Fishermen - Mediterranean

A study by the University Of California and the National Geographic Society has shown that by banning fishing in 5% more of the oceans there would be at least a 20% increase in fish catches in the future. This should encourage international cooperation in expanding marine protected areas and it goes against the suggestion that such an expansion would harm developing countries.

Fishermen - Mediterranean

Fishermen – Mediterranean. Screenshot from video on this page.


The UK is helping to lead a campaign to provide protection in some form or other to 30% of the seas within 10 years. Presently 7.5% of the oceans are protected but fishing is allowed in most of these areas. Fishing is banned in only 2.5% of the oceans.

The scientists used computer modelling based on data for 1,338 commercially important fish stocks to make the prediction. A 20% increase in catches equates to an additional 9 million to 12 million tonnes of fish a year. An increased area of protection also improves conservation at least potentially, it is said.

Enric Sala an author of the study published in Proceedings of the National Academy Of Sciences said that if humankind wanted to fish more it needs to fish less and “close key areas to fishing, so stocks have a chance to replenish”. Fairly common sense stuff it has to be said.

Never in the history of humanity has the health of the oceans been more threatened, and more important to our wellbeing. – WWF

The fishermen in the video want drastic measures to save their way of life for their sons and grandsons. I should add daughters and granddaughters to be politically correct.

What happens is, the larger female fish produce a disproportionately larger number of eggs in those protected areas. To this you add spillover of adult fish which helps to replenish adjoining areas.

Internationally, the right areas need to be protected to increase the spillover effect. Financially the proposal makes sense. The proposal should be applied to Dogger Bank which is still fished because of the UK government’s failure to enforce environmental law. Greenpeace have dumped large rocks on Dogger Bank to physically stop European (non-UK) trawlers dredging the bottom.

The protection of areas need to be enforced properly for the scheme to be effective. As mentioned previously, a lot of the protected areas in UK waters are described as “paper parks” because their protected status is unenforced. The UK government’s funding of agencies involved in these matters has dropped dramatically over recent years. The coronavirus pandemic has been catastrophic economically so even less money is available in the future. The chief executive of the National Federation of Fishermen’s Organisations appears to disagree and they suggested that setting limits on total catch and the size of fish are better options.