Please note: This video was one of a number of presentations from the webinar, and in order to allow each video to be watched individually, they all have the same 30 second introduction to provide the required context. If you have already seen this introduction in another video from the webinar, please skip to 0:31.
Read the video transcript:
The subject of the webinar today is animating the carbon cycle. It really explores the very important link between biodiversity and climate. And the goal of this webinar is to launch a new global initiative to launch nature and climate, and set the first global target for restoration and rewilding to address this accelerating climate breakdown.
We’re going right now to really look at specifically the marine environment. Steven Lutz is senior programme officer and the Blue Carbon lead for Grid Arendelle, which is a Norwegian foundation and a collaborating centre for UNEP. His work in Norway includes the development and management of the Abu Dhabi Blue Carbon demonstration project and the GEF Blue Forest project. Prior to being there with grid Arendelle in Norway, Stephen worked on us lobbying and legislation related to climate change and barbarian areas. He has really moved the whole concept of blue carbon really, really well, and we’re very honoured to have you, Steve, please speak to us.
Thank you. Can you see my slide? All good. All good. Okay, so I’d like to thank the organisers and my fellow presenters. Rewilding is kind of a new subject for me and I’m finding it very interesting and definitely related to my work. Well, I’ll start with the ocean. The ocean is vital to life as we know it on this planet. It provides half of the oxygen we breathe and holds over 50 times more carbon than the atmosphere. Understanding how the ocean absorbs and stores carbon can help identify ways to mitigate for climate change. One of these ways is something that we’re exploring on behalf of the United Nations Environment Programme. It involves how coastal marine ecosystems, such as mangroves, can store and sequester carbon in their biomass and sediments, locking it away from the atmosphere.
Through UNEP’s Blue Forest project, we’ve been able to harness this blue carbon value on the voluntary carbon market. International buyers can offset their carbon emissions by paying for carbon credits. These carbon credits then support mangrove conservation and restoration activities that would not normally occur. One such project is in Kenya, pictured here on the right and left. And it has been able to use the excess profit from carbon finance to support the building of wells, bringing fresh water to three villages and coastal Kenya. Locally restored mangroves also help to protect these villages from storms and are supporting enhanced fish stocks through the habitat they provide. But even with the multiple benefits that a host of the ocean provides us, they face many severe threats. Ocean impacts include coral bleaching, which is when corals are heat stressed, and they respond by expelling the algae living in their tissues, causing the coral to turn white. These algae are the coral’s primary food source and give them their food colour.
This is a reef I visited in Sri Lanka. I was expecting to find a pristine and vibrant coral community. Instead, we found coral skeletons and a severely stressed reef. Researchers have also found plastic trash in the deepest part of the ocean, in the
Marianas trench in the Pacific. Yes, we can find plastic bags, even at a depth of over
10,000 metres. Sadly, our fingerprint and our impacts on the ocean stretches across the seas from the shallowest waters, the deepest depths. So in the face of these impacts and more, we can ask, can ocean rewilding actually work? Well, we may get that answer from the fishermen themselves. Throughout the world, a fishing tactic called fishing the line is commonly employed. This is where no take. Marine reserves are targeted by fishers. They fish right up to the very boundaries of the of the marine protected area because these areas provide refuge for targeted species. Fish inside these boundaries or these areas have time to grow larger than their counterparts outside of the area. I’ve actually seen this in the Florida Keys, where some no take areas are not much larger in size than a small apartment, or not much larger in size than the room I’m in. And it’s not uncommon on the weekends to see boats fishing right up to the line of their boundaries. Research has shown that the biomass of fish within a metre of a marine reserve is, on average, six to seven times greater than in nearby unprotected areas. By fishing the line fishermen are actually demonstrating that ocean rewilding is possible and effective.
And here is the so what? Well, it turns out that ocean rewilding is potential climate change mitigation. Marine life not only serves as a resource to be fished from the ocean, keeping fish and other marine life in the ocean may actually benefit us and the planet. Carbon is fixed in the marine waters through primary production, which includes the growth of plants such as phytoplankton up on the corner here, like plants on land, phytoplankton need nutrients to grow. The more nutrients in sunny surface waters, the more phytoplankton can grow by absorbing carbon dioxide. Phytoplankton play a central role in the global carbon cycle. They also form the basis of the marine food web. Through their feeding activities and other life processes, all marine animals can help remove carbon from the atmosphere. We call this oceanic blue carbon.
Additionally, keeping carbon out of the atmosphere for as long as possible is key to addressing climate change in the ocean. The deeper that carbon sinks, the longer it will remain out of contact with the atmosphere. Carbon that sinks to waters over 1000 metres deep, or thousands of metres deep, can be stored hundreds to thousands of years. Carbon that finds its way into marine sediments and the deep sea floor can be stored for millions of years, just like this fossilised ichthyosaur that was a carbon unit of its day. These timescales are far greater than carbon stored in terrestrial forests. So far, researchers have identified nine oceanic blue carbon processes, or mechanisms, and I’ll talk about a couple now.
So, four of these mechanisms relate to the role of whales in the oceanic carbon cycle. When whales feed at depth, they bring nutrients up to the ocean surface through their vertical movement. The waste products of whales. Yes, the whale poo contains exactly what phytoplankton needs to grow, notably iron and nitrogen. Through their annual migrations, they also transport the nutrients across the oceans. This natural ocean fertilisation activity can potentially significantly enhance phytoplankton growth in the habitats that whales frequent during their lifetimes. Whales store carbon in our bodies and upon natural exploration, they bring that carbon down to the sea floor. And as you may remember, that’s exactly where we want the carbon to be. Researchers recently, two years ago at the International Monetary Fund, estimated that in terms of carbon sequestration and climate mitigation, each great whale, the larger whales, sequester an estimated 33 tonnes of carbon. Essentially, one whale is worth a thousand trees in terms of carbon absorption. When combined with other economic contributions, such as fishery enhancement and ecotourism, that whales support one whale is worth $2 million. And the global whale population is worth trillions of dollars to the global good, at least according to the researchers from the IMF. But it’s not just whales.
Researchers have found that selective grazing by sea turtles stimulates regenerative growth and maintains diverse seagrass ecosystems. This promotes healthy and seagrasses with high biomass and therefore carbon sequestration, because the seagrass is absorbent. However, when sea turtles are overfished, or when their predators, such as sharks, are removed, it creates an unbalanced ecosystem and reduced carbon sequestration. Additionally, fish in the ocean’s twilight zone, such as this lanternfish, play a role in oceanic carbon function. These animals live in the deep, dark waters and at nighttime they come up to the surface to feed on phytoplankton and zooplankton. They do this in order to avoid predation. They don’t want to be eaten because at night it’s difficult for them to be spotted by the predators that prey on them. After feeding, they take this organic carbon back down with them, inside them, and release it as fish poo in waters hundreds of metres deep, these twilight zone fish actually act as carbon elevators, constantly drawing down carbon from the surface every day.
Researchers estimate that the global biomass of twilight zone fish at over 1000 million tonnes, representing one of the largest marine ecosystems on earth. Or one of the largest ecosystems on earth. Here’s a personal note. A few years ago, when I was based out of the University of southern California, I found myself on a purse seine fishing boat at night. Fishing for anchovy purse seines are gigantic nets that the fishermen used to encircle and scoop up large schools of little fish. At night, I could see the fish in the net illuminated by a searchlight. I noticed lots of little bits of. Of lots of little reflecting particles sinking down around the fish. I asked the captain about this. He said, they eat, they defecate, they do it all the time, just like us. I now see that gigantic school of anchovy as a gigantic swimming natural factory of carbon sequestration. But oceanic blue carbon is not what it used to be. We have overfished much of our oceans, and whales are at historically low levels of abundance. In the 1950s, only 1% of the high seas was fished and 0% of species identified as exploited, overexploited or collapsed.
Can you imagine the oceanic blue carbon sequestration ability or potential of the 1950s compared with that of today? And historical references can give us a reflection on the true rewilding potential or what we are missing. For example, cod were reported larger as individuals and so commonplace in the sea around Newfoundland that it was difficult to row a boat through a school of them. At the time of Christopher Columbus, there were so many green sea turtles in the Caribbean that the sounds of their breathing and bumping of their shells against the wooden ship hulls were signals used by sailors for navigation when visibility was proved poor. One account from the early 15 hundreds reads, on Wednesday, May 10, we were in sight of two very small, low islands full of tortoises, as was all the sea about insomuch that they looked like little rocks, whence these islands were called la Tortugas, the turtles. Researchers have estimated that between 33,000,030 9 million adult green sea turtles existed in the Caribbean before the time of Columbus. As of 2011, an estimated fewer than 10 million of all sea turtle species exist globally. For green sea turtles alone in the Caribbean, that’s only 300,000. So, saving the whales, sea turtles, ocean conservation and rewilding our ocean is not only good for marine life, it may help reanimate oceanic blue carbon function and save us from climate change. Thank you.
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