Who’ll care for the otters’ habitat after Brexit?

SIR – As Boris Johnson points out, it is gratifying that otters have returned to the Exe (Comment, August 20). However, the improvements in our river life did not happen spontaneously.

Membership of the EU compelled us to implement the Urban Waste Water Treatment and Water Framework directives, which required water companies and other parties to clean up their discharges into rivers. Compliance with the directives enabled fish stocks to recover and water quality to improve so that otters could thrive.

Let us hope we are as zealous in the future about cleaning up the natural environment, without the EU to compel us to do it. Dr Michael Doble

London SE23

SIR – Mr Johnson draws attention to the accelerating depletion of the natural environment, which he rightly attributes to the necessity to feed the ever increasing world population. However, it is the increasing trend towards the Western diet of meat and dairy which is placing the most strain on farming resources.

Half of the world’s cultivated land is devoted to growing vegetable protein which is processed and used for animal feed. As only a fraction of this is converted into the animal protein we consume, it amounts to a terribly wasteful and polluting process.

Meat and fish can now be grown in factories from specific animal cells, thereby eliminating the need for raising and slaughtering the animals themselves. Millions of dollars worldwide has been invested in developing this process and millions more are currently being invested in the commercial production process. We are rapidly developing the means which will enable us to transform millions of acres of farmland back to its wild state. Peter Land

Hitchin, Hertfordshire