It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Saturday, December 10, 2022
New study highlights urgent need to safeguard deep reefs - one of the largest and least protected ecosystems
IMAGE: RECOMMENDATIONS FOR COP15 ON DEEP REEF CONSERVATION. (C) NEKTON 2022.view more
CREDIT: CAN BE USED WITH CREDIT NEKTON 2022.
Scientists call for urgent conservation of deep reefs, one of the planet’s largest and least protected ecosystems
As world leaders, government negotiators, scientists and conservationists gather at the UN Biodiversity Conference, COP15, to agree to halt and reverse nature loss, an international team of marine scientists and conservationists have made an impassioned plea for the urgent conservation of deep reefs.
Their calls are based on a new study, recently published in the journal Conservation Letters, led byscientists from Nekton, the Western Indian Ocean (WIO) and the University of Oxford. This confirms for the first time that deep reef habitats, notably in the WIO, are largely unprotected despite being under threat from a multitude of stressors, including overfishing, pollution, climate change and, in the near future, seabed mining.
Their calls follow COP27 in Egypt, where many scientists, politicians and campaigners concluded that the 1.5C climate goal died, signing the death warrant on the vast majority of shallow reefs.
Deep reefs (found below 30 m) provide essential ecosystem services for climate change resilience, ocean health, and food security whilst also acting as a refugia for organisms threatened in shallow water, including commercially important species. Despite this, deep reefs are barely protected, even though they have a larger geographic footprint than their shallower counterparts. Furthermore, the scarcity of fish in shallow waters combined with modern deep sea fishing technologies is resulting in deep reefs being increasingly exploited by coastal communities who need fish for their food security.
“We strongly encourage deep reefs to be included in conservation and sustainable management action to complement global targets, notably 30% protection of the global ocean by 2030” said the study’s lead author, Dr Paris Stefanoudis, a marine biologist at the University of Oxford’s Department of Biology and a Research Scientist at Nekton. “Deep reefs are critical to a healthy marine ecosystem and face similar threats from overfishing, pollution and climate change faced by the much-imperilled shallow reef system.”
Covering over 8% of the global ocean, the Western Indian Ocean is one of the least known, least protected, and most threatened marine regions of our planet. Shallow and deep coral reefs of the WIO are marine biodiversity hotspots with high numbers of species that are found nowhere else on Earth. They are essential to the region’s 100 million people living within 100km of the coastline, including over three million people who are directly dependent on artisanal fishing for their livelihoods. The population is projected to double over the next 30 years, driving greater stressors on the ocean’s biological capacity to support lives and livelihoods.
The scientific team has co-developed a new framework for conserving deep reefs including practical recommendations and specific actions for regional policy-makers, conservationists and scientists. This has been published in the journal Conservation Letters.
The researchers urge policy makers to use the COP15 summit to agree to the following:
Highly protect 30% of ecosystems by 2030 (‘30 by 30’), and include deep reefs in this target.
Conserve deep reef ecosystems and their resources by specifically including them in fishery regulations, marine protected areas, and marine spatial planning.
Extend current management efforts on shallow reefs to include deep reefs as these ecosystems are often connected.
Invest in foundational, fundamental, and applied research on deep reef biodiversity, ecosystem functioning and provided services.
Develop national, international, transnational cross-stakeholder collaborations to survey and conserve deep reefs in national and international (High Seas) waters
“To halt and reverse nature loss, the UN Biodiversity Conference, COP15 must prioritise the conservation of unique ecosystems such as deep reefs, one of the least protected ecosystems on Earth” stated co-author Professor Lucy Woodall, Professor of Marine Biology at the University of Oxford, Nekton Principal Scientist, “We hope our recommendations and actions will be useful for decision makers in the WIO, be applied within the new Western Indian Ocean regional policy and provide the springboard for deep reefs to become protected across the global ocean”, continued Professor Woodall.
Co-author Melita Samoilys, CORDIO East Africa explains: “Our framework was jointly developed with a range of stakeholders from academia, research, management and government, and provides a list of actions across three themes: capacity, information collection, and information sharing. Given the scale of the issue, we have also identified which parties – such as funding agencies, government, Institutions or the research community - are needed to work together to realise those actions”.
“To ensure a prosperous and resilient Western Indian Ocean, it is essential that deep reefs are no longer ignored by scientists and policy makers, and they must be specifically considered in conservation and management strategies”, shared co-author Athur Tuda, Executive Director of the Western Indian Ocean Marine Science Association, WIOMSA.
A video summary of the findings and proposals is available at https://www.youtube.com/watch?v=lz1Tm2wo2JU&t=2s
Notes for Editors
The Publication
‘Stakeholder-derived recommendations and actions to support deep-reef conservation in the Western Indian Ocean’ published in Conservation Letters, co-authored by 18 scientists representing 18 different organisations including from South Africa, Tanzania, Seychelles, Kenya, Mozambique, UK and USA. https://conbio.onlinelibrary.wiley.com/doi/epdf/10.1111/conl.12924
WIO Conservation Framework: The UNEP’s Nairobi Convention provides the regional framework for governments, civil society and the private sector to strengthen the health and resilience of the Indian Ocean. At the Nairobi Convention’s COP10 in November 2021, the WIO nations unanimously agreed to co-create an ambitious new regional ocean strategy and accompanying policies to support sustainable ocean development underpinned by science-based management. ‘The Western Indian Ocean – Resilience & Prosperity Initiative’ (WIO-RPI), as it’s known includes establishing a just, equitably designed and managed connected network of ecologically and culturally representative protected areas in national and international waters, complementing global targets. Nekton and University of Oxford scientists are the technical partners supporting the implementation of the WIO-RPI.
Deep Reefs: Deep reefs include mesophotic (30-150 m), rariphotic (150-300 m), and cold-water coral reefs (>300 m) and have a great geographic
Nekton: Nekton works to accelerate the scientific exploration and conservation of the ocean for people and the planet. Nekton is an independent, not-for-profit research institute and is a UK registered charity. www.nektonmission.org
University of Oxford: Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the seventh year running, and number 2 in the QS World Rankings 2022. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer. Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions. Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 200 new companies since 1988. Over a third of these companies have been created in the past three years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.
Deep Reef Seychelles (c) Nekton 2022.
School of fish on deep reef in Seychelles (c) Nekton 2022.
Turtle glides over deep reef in Seychelles (c) Nekton 2022
In the vast oceans, one would assume their inhabitants can travel far and wide and, as a result, populations of a species would mix freely. But this doesn’t appear to be the case for a vital forage fish called the sand lance.
Sand lance are small schooling fish impressively rich in lipids, which makes them a fantastic and significant food source for at least 70 different species ranging from whales and sharks to seabirds, says UConn Associate Professor of Marine Sciences Hannes Baumann.
The Northern sand lance can be found from the waters off New Jersey all the way north to Greenland. Researchers, including Baumann and Ph.D. student Lucas Jones, were interested to see if sand lance constitute a massive, homogenous population, or whether there are genetically distinct groups. Their findings are published in the ICES Journal of Marine Science.
Baumann explains these are important questions to answer when considering conservation and sustainable management of the species, especially since the regions where sand lance live are warming faster than many areas of the planet due to climate change.
Sampling fish from such a broad range is no small task, but two years ago, Baumann and Jones began reaching out to other researchers to see if they had tissue samples to spare. Baumann credits the work to the international group of colleagues who contributed samples including co-authors from Canada and Greenland, and who helped sequence and analyze the data including co-authors from Cornell University.
In all, Baumann, Jones, and the team were able to sequence and analyze nearly 300 samples from a variety of locations across the sand lance’s range using a technique called low-coverage whole genome sequencing. They also sequenced the first reference genome for sand lance.
In a nutshell, Baumann says they found an area on the Scotian Shelf, off the coast of Nova Scotia, where a genetic break occurs. The researchers distinguished two distinct groups, one north and one south of the divide, with parts of the genome differing quite dramatically – namely on chromosomes 21 and 24. Without obvious physical barriers like a mountain range separating the groups, Baumann says it’s logical to ask how these differences are possible.
“That is the scientific conundrum,” says Baumann, and the answer, it appears, lies in the currents.
“When fish from the north reproduce and drift south, they are genetically less adapted to warmer southern waters, even if it’s five or six degrees warmer in the winter, they are just not surviving,” Baumann says. “These populations may be linked by the ocean currents, but the realized connectivity is basically zero.”
This finding is a first for the sand lance, but it has been shown in other species such as lobsters, cod, and scallops, and this research adds further evidence to an apparent temperature divide at the Scotian Shelf, and helps demonstrate that temperature is an important factor in survival.
“Example after example shows that the ocean is not as homogeneous a place as expected, and there are all kinds of things that prevent that constant mixing,”Baumann says. “We found another striking example of that.”
When researchers find adaptation in an environment where mixing is continuous, like in the ocean, Baumann says, the question is how it is possible that groups stay different, even though they are constantly encountering other genotypes. That is where powerful genomic methods, like the ones used in this paper, come in handy.
“Parts of the genome in many species have what we call a ‘genetic inversion,’ which means that the genes on the chromosome from one parent have a certain order and the genes on the same chromosome that come from the other parent that code for the same thing, and they’re the same area, but they’re flipped,” Baumann says.
These inversions mean recombination cannot occur; therefore, the genes are passed down through the generations and play an important role in adaptation.
“We discovered on chromosomes 21 and 24 there are whole regions that are completely different and that is like the trademark signature of what we call an inversion because there’s no recombination going on.”
Baumann says that knowing there are genetic and ecological barriers on the Scotian Shelf is important, because with climate change, this barrier may move north and while that may be good news for southern fish, it’s bad news for the fish currently there.
The researchers were also a little relieved in finding two clusters, because had there been many smaller clusters, it could make management and conservation more challenging, especially considering scenarios like the construction of offshore wind parks. Areas potentially well situated for wind turbines can also be habitats for sand lance, and construction disrupts habitats. If there were many, smaller population clusters, a single construction project could pose the risk of completely wiping out a cluster, whereas with more widely dispersed populations, though the local population may be temporarily disturbed, it will not be long before they are able to re-establish after construction is completed.
Baumann plans to focus further research on studying the genetic basis of the thermal divide.
“We want to make sure that this fish is productive and resilient, despite climate change, so we should make sure these areas where they are occurring are protected,” Bauman says. “These decisions should include experts to ensure if there’s an area that is very critical to sand lance, that any disturbance is temporary.”
It isn’t an unsolvable conflict, but it is something that we need to do, says Baumann, who also notes that it is possible that sand lance north of the thermal divide are already suffering more from warming because the region is warming faster.
“It could be that these two clusters have different vulnerabilities to climate change,” he says. “We don’t know that yet but that’s something that should be pursued.”
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