Ocean conservation is essential to fight climate chaos and the seas should be left alone to recover, an environmental campaigner says.
Photo: Supplied / Mattias Klum
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British journalist Charles Clover's recently published book Rewilding the Sea argues that, left to its own devices, the sea’s biodiversity can recover from and counter the devastating effects of climate change.
In the case of whales, he tells Nine to Noon if the creatures were allowed to rebuild to pre-whaling numbers, they would remove the same amount of carbon from the atmosphere as we pump into it, just with their poop.
He says oysters too are worth their weight in ecological gold and far exceed the economics benefits of harvesting these as food. Oysters can filter well over 100 litres of water a day.
Clover says whales are coming back in huge numbers and there is hope that endangered species like the northern right whale will recover. Whale numbers in the southern ocean in particular have seen a significant boost.
“They feed at depth and pull on the surface, thereby putting nutrients into the upper layers and feeding plankton - the plankton in turn lives and then dies, drop into the depths,” he says.
“So, this is what they what we call them whale pump, whereby carbon is taken from the surface and and ends up with the abyssal depths and takes co2 out of the atmosphere.”
The whale is one very obvious example of the potential for carbon capture. One great whale does as much for carbon capture as about 1000 trees.
The modest oyster also has huge regenerative capabilities, Clover says.
"The oyster is an amazing ecosystem engineer. It takes carbon out of the atmosphere it takes algae and muck out of the water. It clarifies the water as you said it, the European oyster - I'm not sure about the Kiwi oyster - but the European oyster can filter 140 litres of seawater a day.
“In places which have been rather overused, like parts of the New Zealand coast, I suspect, and certainly on the south coast of England, what we are lacking and what the sea badly needs is to reintroduce the oyster, because it not only is a single species treater of the water. It is also an eco-system and an astonishing 400-plus species are associated with the European native oyster.
“I'm sure the same thing is true in New Zealand,”.
He says the oyster is associated with regeneration in other, more mysterious ways, with eels, seahorses and other species being found inside cages suspended beneath marina platforms where oysters had migrated to, documented in his book.
“It’s one of the one of the great mysteries why so many other species are associated with oysters and are attracted by oysters. If you want to restore the ecosystem, where we have taken too much out - and the story of the oyster across all of the world is one of over fishing- we want to put the oysters back to serve their ecosystem function.”
About 25 percent of co2 emissions are captured by the ocean, but slowly the salinity of the ocean is changing as a result of those emissions.
Kelp Photo: Kelp Blue - Sunny Sanderson
“If we want to cap tackle climate change, why aren't we using the ocean? There are so many things we can do to enhance the capacity of the ocean, to absorb carbon.
“We can restore salt marshes, we can restore seagrass, and we can look at the disturbance of the seabed by trawling,” he says.
Trawling by fishing boats is a huge problem, causing disturbance and destruction in seabed habitats and the health of the ocean. There should be more laws restricting such practices across the globe, he says.
“I'm not saying that people shouldn't fish, I'm just saying that we should factor that in to what we allow to happen in the fishing environment, because we can catch fish many ways. And do we need to do it in ways that don't damage the habitat on the seabed.”
Clover points to what he calls an astonishing recovery of kelp on the south coast of England, where a recent trawling and dredging ban was introduced off Sussex.
“The initial results are pretty amazing,” he says. “The recovery of organisms, and the recovery of the kelp itself, is amazing. We haven't actually quantified these enormous ecosystems’ ability to soak up carbon, but clearly they are doing it."
Photo: 123RF
Blue fin tuna numbers off the coast of Scotland have also been lifted and an example of what happens when you simply leave the ocean alone, he says.
“The blue fin tuna in the whole of the Northeast Atlantic is one of the great success stories that I write about in my book, which I called 'tendrils of hope'. There's some virtuous examples of what we should do and could do that would actually bring back our oceans to rude health. We are struggling with the climate, but we know what to do with the oceans, you just leave it alone enough.”
Some nations remain stubbornly resistant to change however, he says, and commercial fishing interests remain powerful, lobbying governments to drop environmental protection initiatives.
In the UK cod remains over fished, with 65 percent of the catch limits set significantly over what scientists have recommended as a sustainable number.
“It's a very depressing picture, but there are these examples like the blue fin tuna, of what you can do, and what we should be doing,” he says.
A sign of hope was the World Trade Organization agreeing to limit harmful subsidies for fishing vessels by member states, including China. General international treaties on conservation are important as countries can’t create legally-binding marine reserves outside national boundaries, he says. But better fishing management at nation-state level is key in the absence of these treaties.
Bill Ballantine at Goat Island Bay, New Zealand's first marine reserve. Photo: Kennedy Warne
“The Americans are very good. I believe that New Zealand is very good at it,” he says. “There are nations which manage their fish stocks, which of course are carbon too, like the whales. They manage them better than others. So there's a virtuous path, and a not-so-virtuous path, which we can follow within our own territorial waters within our 200 mile limits.”
He acknowledges the work of Bill Ballantine, the late ocean conservation pioneer in New Zealand who fought to create the world's first no take marine reserve at Leigh, north of Auckland.
“Bill was a great hero of mine and taught me a lot. He was determined that we should have more no take zones. And that he was also confident that no take zones will produce economic value for fishermen, as well as benefits for biodiversity. I think that the years since I met him in New Zealand, nearly 20 years ago, have been full of examples of exactly that being the case.”