Marine Life & Conservation
Global Study Reveals New Hotspots of Fish Biodiversity
Teeming with species, tropical coral reefs have been long thought to be the areas of greatest biodiversity for fishes and other marine life — and thus most deserving of resources for conservation.
But a new global study of reef fishes reveals a surprise: when measured by factors other than the traditional species count — instead using features such as a species’ role in an ecosystem or the number of individuals within a species — new hotspots of biodiversity emerge, including some nutrient-rich, temperate waters.
The study, by an international team of researchers including graduate student Jon Lefcheck and Professor Emmett Duffy of the Virginia Institute of Marine Science, appears in a recent issue of the journal Nature.
Led by Dr. Rick Stuart-Smith of the University of Tasmania’s Institute for Marine and Antarctic Studies, the study team also includes researchers from Stockholm University, the University of Bologna, Stanford University, the Natural Products and Agrobiology Institute in Tenerife, Spain, the Wildlife Conservation Society’s Indonesia Marine Program, the University of Dundee, the Pontifical Catholic University of Chile, and the University of Portsmouth.
The study is based on information collected through the Reef Life Survey program, a “citizen science” initiative developed in Tasmania. The RLS program now operates worldwide, training recreational SCUBA divers to survey numbers of reef animals and supporting their research endeavors.
Stuart-Smith and fellow RLS founder Graham Edgar, also a University of Tasmania professor, highlight the central role the volunteer divers played in contributing to the new study. “The assistance of over 100 dedicated divers has allowed us to look at ecological patterns and processes impossible for scientific dive teams to cover,” says Edgar.
Species richness
The number of different species in an ecosystem — what researchers call “species richness” — has dominated the scientific view of global biodiversity patterns since the days of Darwin and Linnaeus. It has also long been used as a biological basis for management of imperiled ecosystems.
But, says Lefcheck, “Just counting species is a really coarse way of understanding diversity. By gathering information on the animal’s traits — what they eat, how they move, where they live — we can understand more about how dissimilar they are. Dissimilarity is the essence of diversity.”
Lefcheck illustrates the team’s new approach to studying biodiversity by reference to a tide pool. “Consider a pool with a fish, a bird, and a crab,” he says. “Now consider one with three fishes. Which is more diverse? Intuitively, we know it’s the one with the fish, bird, and crab. But until recently, ecologists treated each of them as equally diverse, since they both have the same number of species.”
“Most biodiversity censuses simply count species because it’s relatively easy to do,” says Duffy. “But to understand how species help ecosystems work, we need to know how abundant they are and what they’re doing. That sounds obvious but such data are much harder to get. Ours is the first study to do this comprehensively, and we find that the extra knowledge paints a very different map of global diversity.”
Functional Traits
The team conducted their study by analyzing data from 4,357 standardized surveys conducted by RLS divers at 1,844 coral and rocky reef sites worldwide. The surveys spanned 133 degrees of latitude and found 2,473 different species of fish.
Moving beyond traditional species counts, the research team noted how the members of each of these species make a living, using a detailed matrix of “functional traits.” These include what the fishes eat (plankton, invertebrates, algae, other fish, or a combination), how they eat it (browsing, scraping, or predation), where they live (in, on, or near the bottom or free-swimming), whether they are active at night or during the day, and how gregarious they are (solitary, paired, or schooling).
“Determining the biology and ecology of these fishes — noting what they do and how they do it — alters hotspots of diversity,” says Lefcheck. “Coral reefs remain the most species-rich habitats on earth, but a trait-based view reveals new areas where the diversity of ways in which fishes function is even higher.”
“Functional biodiversity is highest in places like the Galápagos with only moderate species counts,” adds Duffy, “whereas functional biodiversity is low in many classical hotspots with high species counts, such as the iconic coral triangle of the west Pacific.”
Lefcheck notes that the team’s study also looked at how individuals are distributed among species — what scientists call “evenness,” and that doing so further alters global diversity patterns.
“Coral reefs have lots of species but many are doing largely the same thing, whereas temperate reefs with many fewer species tend to spread individuals out among species that are doing different things,” he explains.
Resource management
The team’s findings have important implications for planning and management. Lead author Stuart-Smith notes, “Incorporating information on functional traits into monitoring programs will add an extra dimension and greater ecological relevance to global efforts to manage and conserve marine biodiversity.”
Says Lefcheck, “Loss of species in a community in which all species are doing different things may have greater consequences, since each species plays a unique role that can’t be filled by any other species. Investing resources in conserving the most non-redundant — and therefore vulnerable — communities may have the greatest impact.”
Source: www.sciencedaily.com
Marine Life & Conservation
Leading UK-based shark conservation charity, the Shark Trust, is delighted to announce tour operator Diverse Travel as a Corporate Patron
Corporate Patrons provide a valuable boost to the work of The Shark Trust. The Trust team works globally to safeguard the future of sharks, and their close cousins, the skates and rays, engaging with a global network of scientists, policymakers, conservation professionals, businesses and supporters to further shark conservation.
Specialist tour operator Diverse Travel has operated since 2014 and is committed to offering its guests high quality, sustainable scuba diving holidays worldwide. Working together with the Shark Trust will enable both organisations to widen engagement and encourage divers and snorkellers to actively get involved in shark conservation.
“Sharks are truly at the heart of every diver and at Diverse Travel, we absolutely share that passion. There is nothing like seeing a shark in the wild – it’s a moment that stays with you forever!” says Holly Bredin, Sales & Marketing Manager, Diverse Travel.
“We’re delighted to celebrate our 10th year of business by becoming a Corporate Patron of the Shark Trust. This is an exciting partnership for Diverse and our guests. We will be donating on behalf of every person who books a holiday with us to contribute towards their vital shark conservation initiatives around the world. We will also be working together with the Trust to inspire divers, snorkellers and other travellers to take an active role – at home and abroad – in citizen science projects and other activities.”
Paul Cox, CEO of The Shark Trust, said:
“It’s an exciting partnership and we’re thrilled to be working with Diverse Travel to enable more divers and travellers to get involved with sharks and shark conservation. Sharks face considerable conservation challenges but, through collaboration and collective action, we can secure a brighter future for sharks and their ocean home. This new partnership takes us one more valuable step towards that goal.”
For more information about the Shark Trust visit their website here.
For more about Diverse Travel click here.
Marine Life & Conservation
Shark Trust Asks Divers to help with Shark Sightings this Global Citizen Science Month
Whether you are stuck for ideas of what to do with the kids or are off on the dive trip of your dreams. You can get involved in Citizen Science Month and help the Shark Trust by providing vital data about sharks are rays both close to home and further afield.
In addition to reporting the sharks and rays you see on your dives, the eggcases you find on the beach, the Shark Trust is looking for some specific data from divers who are asked to report any Oceanic Whitetip and Basking Sharks.
Oceanic Whitetip Sharks
The Shark Trust are looking specifically for Oceanic Whitetip Shark sightings over the coming weeks and months. So, if you are diving anywhere in the world, please report your sightings via the website or app.
Website: https://recording.sharktrust.org/
App: Search The Shark Trust in your app store
The Oceanic Whitetip. Known for their incredibly long dorsal and pectoral fins, this species was once the most abundant oceanic-pelagic species of shark on the planet.
Large and stocky, they are grey or brown above, and white below and famous for their huge rounded first dorsal fin and paddle-like pectoral fins. The fins also highly prized within the shark fin trade. Whilst they are mostly solitary, Oceanic Whitetips do occasionally hunt in groups.
An inquisitive species, they were easy prey for fisheries. Combined with their low reproductive rate, they were inevitably at high risk of population depletion. And declines of up to 99% have been reported in certain sea areas. They are listed as Critically Endangered on the IUCN Redlist (2019).
Conservation efforts to discourage further declines include listing on CITES Appendix II and CMS Appendix I. They’re also the only species prohibited from take by all the Tuna RFMOs (Regional Fisheries Management Organisations). However, these measures do not mean that Oceanic Whitetips are not still caught – whether targeted or as bycatch – in some parts of the world. With populations declining at such a high rate, effective implementation of management measures is essential to ensure that the species can recover.
If you are lucky enough to get an image of an Oceanic Whitetip and you record your sighting on the Shark Trust app or website YOU CAN WIN! All images submitted with sightings, that also give consent to use in conservation messaging, will be in with a chance to win an Oceanic Whitetip T-shirt and mug. The competition will run until the end of “Shark Month” in July – so keep those sightings (and images) coming in.
Basking Sharks
Basking Shark (Cetorhinus maximus) season is upon us, and the Shark Trust is asking everyone to keep an eye out for these majestic giants over the summer months. If you see any, you can record your sighting to the Basking Shark Sightings database.
Each year, these mighty fish return to British waters to feed on plankton. You may see one, (or a few if you’re really lucky) from around April-October. They can be seen feeding at the surface of the water, where they look like they’re basking in the sun. Thus, their name!
Sighting hotspots around the British Isles include southwest England, Isle of Man, north coast of Ireland, and western Scotland. The Sea of the Hebrides is the most prolific sightings area in Scotland, but they have been spotted all around the coast and have even ventured into some of the sea lochs. The Shark Trust has received thousands of sightings since the Basking Shark project began, but more data is needed to truly understand what is going on with population numbers and distribution. You can help by recording your sightings this summer.
Great Eggcase Hunt
The Shark Trust has an Easter Egg Hunt with a difference for you to try. Take part in the Great Eggcase Hunt and get involved with a big citizen science project that helps shark, ray and skate conservation. And it’s an enjoyable activity for all the family.
The Shark Trust also want snorkellers and divers to record their underwater eggcase findings. Underwater records help pinpoint exactly where sharks and skates are laying their eggs and can help link to beach records. Learning the depth and substrate that they lay on also helps better understand the species.
Find out more: https://www.sharktrust.org/great-eggcase-hunt
Whether you are diving, snorkelling or exploring on the beach you can take part in Citizen Science Month and get actively involved in shark and ray conservation. Find out more: www.sharktrust.org
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