We need to protect the ocean, our biggest ally in the fight against climate change.
On a hot sunny day, there are few things more pleasurable than diving into the cool aquamarine Mediterranean Sea. Armed with a snorkel and flippers, I can spend quite a long time quietly exploring the rocky walls and little caves around Ibiza where I live.
Sometimes I can spot an octopus creeping into a hidey hole, or even the quicksilver of a barracuda.
There are groupers, corvinas, mullets, lobsters, scorpion fish, conger eels, moray eels, anemones and sponges; even seahorses I hear, although I haven’t unearthed one yet!
But sadly, some areas have been pretty degraded over time by human pressures; sewage, trawling, anchoring and pollution are all having a big impact on our coastlines. In my lifetime, I have noticed a real degradation in many of the marine habitats that I’ve been lucky enough to swim in and that’s what encouraged me to get involved in marine conservation.
We need to take threats to the ocean seriously because (according to the United Nations) the ocean is the world’s greatest ally in the fight against climate change. It is estimated to have absorbed at least one third of the excess carbon dioxide we’ve emitted since the industrial revolution, but its ability to do so is being diminished by continually raising temperatures.
The highest sea temperatures ever were recorded last summer; the western Mediterranean reached levels of up to 4 degrees above normal, with particularly significant heat waves here in the Balearic Islands. Much of the research on marine heatwaves finds that they affect certain habitats particularly strongly, including coral reefs, seagrasses and seaweeds. Marine heatwaves were found to be responsible for the loss of up to 80% of the population of some Mediterranean species between 2015 and 2019.
One of the reasons that the ocean is such an effective carbon sink is that when fish die, they sink rapidly and most of the carbon they contain is then sequestered at the bottom of the sea.
Whales are also particularly good carbon sinks; each great whale sequesters 30 metric tons of CO2 on average, taking that carbon out of the atmosphere for centuries.
That is about 6 times the annual emission of someone in the United Kingdom per year.
However global production of fish and seafood has quadrupled over the past 50 years, greatly reducing the amount of carbon resting on the seabed. Not only has the world population more than doubled over this period, the average person now eats almost twice as much seafood as half a century ago. This has unsustainably increased pressure on many fish stocks. Many commercial fishing methods such as longlines, purse seine, and bottom trawling are indiscriminate in what they catch, so they also produce a massive amount of unintended bycatch such as sharks, turtles, marine mammals, and unwanted fish. For example, shrimp trawlers in the Gulf of Mexico kill more than 50,000 sea turtles each year (that’s 150 per day!).
Not only this, the weighted nets of trawlers destroy any seagrasses, corals and seafans leaving a wake of rubble on the ocean floor. Referring to the “carbon reservoir” on the seabed I mentioned earlier, trawling disturbs this, releasing that carbon back into the atmosphere. Some estimates approximate that this pumps out over a gigaton of carbon every year, which is roughly the same emissions as the entire global aviation industry.
Plastics are also a huge bugbear of mine. The quantity is notoriously difficult to measure, but it is estimated that between 500,000 and 1m tons a year of plastics tumble into the sea.
Over 75% of plastic in Great Pacific Garbage Patch originates from fishing.
Ghost gear – which is what marine waste comprises fishing nets, ropes, line and traps- can also sadly entangle and kill marine life.
Despite a global commitment to protect 30 per cent of our oceans by 2030, only about 8 per cent is currently under some level of protection and only 2.1 per cent of the world’s oceans are fully protected from all damaging activities such as bottom trawling. So whilst fishing is an essential part of modern life (fish is the largest traded food commodity in the world, and more than 3 billion people rely on wild-caught and farmed seafood as a significant source of their animal protein), many marine conservationists are calling for it to be banned in marine protected areas, known as MPAs.
Securing MPAs - specified areas of ocean where fishing and other extractive activities are restricted or regulated – and ensuring they are effectively managed rather than just paper parks and developing models of sustainable fishing is key to the global mission of protecting 30 per cent of the world’s ocean by 2030. MPAs help provide climate change resilience, allow stocks to recover from overfishing and in many cases support sustainable fisheries in tandem with biodiversity protection.
This is just one of the things we work towards at Blue Marine Foundation, you can find out more about the work we do on our website. But in the interim, when you dive into the deep blue this summer, remember all the things it does for us. It will make your plunge even more fulfilling, I promise.
Photography: Manu San Felix
August, 2023
