The fates of some of our oldest and most mysterious natural treasures will hang in the balance tomorrow as members of the European Parliament's committee on fisheries vote on a future deep-sea fishing regulation for the northeast Atlantic. It is a game-changing moment for the deep ocean. The EU has the world's biggest deep-sea fishing fleet. If it adopts a strong new deep-sea access regime that protects vulnerable marine creatures and habitats, and stops the horrendous by-catch of more than 100 of non-target species, it will be a turning point in the fight for sustainable fishing and ocean conservation.

The EU can choose to lead the world in preserving the unique, and largely unexplored, wonders of the deep sea. Or it can allow a relatively small number of fishing vessels to continue to crush millennia-old ecosystems with giant nets and steel plates for very little or no profit.

UK MEPs are at the centre of this decision. Of the 25 members of the committee on fisheries, five from the UK: Struan Stevenson, John Stuart Agnew, Chris Davies, Diane Dodds and Ian Hudghton could make or break the result. UK citizens should be watching very closely and demand that our representatives support a healthy ocean, and a sustainable and viable fishing industry.

Everyone has a stake in this vote, not only those directly involved in the fishing sector. It goes to the heart – the very depths – of our shared natural heritage and the legacy we will leave. The deep ocean houses a vast reservoir of biodiversity, an unimaginable wealth of genetic material with the potential to enable breakthroughs in medical and other vital fields. Deep-sea species are already being studied for their potential role in cures to fight cancer, diabetes and a host of other conditions. Our exploration of these organisms is only just beginning. Who knows what miraculous solutions may emerge from the ocean, if we protect it.

The future is ours to decide and this vote is a key step. It is time to call for a halt to the practices that we know cause irreversible damage to ocean biodiversity, namely deep-sea bottom trawling and gill-netting. In reality, most deep-sea fishing is all pain for little gain. EU-wide, deep-sea fishing accounts for just over 1% of the value of the total catch and many experts claim that it would not be financially viable at all without government subsidies. Voting to end damaging deep-sea fishing is not anti-business or anti-fishing; it is good business and good for the fishing industry. It would protect our valuable marine assets from permanent and unprofitable destruction.

The UK has traditionally been a champion of the deep sea. Tomorrow, it is vital that our MEPs do not bow to the pressure of a very small section of the fishing industry over a matter that affects everyone. Ninety percent of the EU's northeast Atlantic deep-sea catch is taken by vessels from just three countries: Spain, Portugal and France, with most of the Spanish and French catch taken by bottom trawlers. MEPs from Spain and France have worked to gut the proposed regulation and have proposed amendments that oppose the phase-out of deep-sea bottom trawling and gillnet fishing. They have also called for large areas where deep-water trawlers already operate to be exempt from conservation measures. These amendments are unacceptable and fly in the face of both the original recommendations of the European Commission and scientific evidence.

Until a strong deep-sea fishing regulation is implemented, bottom trawlers are free to engage in an unrestricted "buffalo hunt" that every year reduces hundreds of square kilometres of the vibrant sea-floor to barren wastelands, including 4,000-year-old corals that have been alive since the pyramids were built.

Our elected representatives have a responsibility to vote in favour of a forward-thinking regulation that will promote sustainable fisheries and maintain jobs in the long term. The UK is also influential on the EU Council of Ministers, which must also approve the deep-sea regulation. Our new fisheries minister, George Eustice, should build on the positive legacy of his predecessors and be a leading voice for sustainable fisheries – both in Brussels and during the UN negotiations.

This is a key moment for the ocean. By voting for a strong deep-sea access regime, the EU can help lead the world down the right path. Who in their right mind would clear-cut an ancient forest to catch a few mammals? Yet that is exactly what we are allowing to happen in the deep sea, and corals take a lot longer than trees to grow back, if they ever do. It is high time we came to our senses and stood up for our ancient marine heritage, for the ocean and for everyone's future.

Sir Richard Branson is an Ocean Elder, an international maritime conservation group