Protecting nature starts with science. Here’s a roundup of recent scientific research published by Conservation International experts.
1. Reforesting the tropics is essential for protecting life on land
Reforesting the tropics could be an effective strategy for conserving threatened wildlife while slowing climate change, according to a new study.
A 2019 UN report revealed that more than 1 million terrestrial species across the globe are at risk of extinction, driven largely by habitat loss and climate change. In this new study, Conservation International scientists Pamela Collins and David Hole in partnership with Arizona State University explored how reforestation could minimize this species loss.
To do this, the scientists compared global maps of degraded forests that have restoration potential to maps of the geographic ranges of threatened species.
The results were promising.
Nearly half of the area on these maps overlapped, meaning that reforestation could help conserve an array of wildlife that is at risk of extinction. Together, the more than 3.69 million square km (more than 1.424 million square miles) — strewn across South America, Africa and Asia — are the size of India and Vietnam combined.
“This overlap represents around 15 percent of the total land area that harbors threatened vertebrate species worldwide,” Collins explained. “While reforestation is not a substitute for conserving existing forests, this study shows that, in the right places, forest restoration can be a crucial part of the strategy for protecting Earth’s biodiversity.”
In addition to protecting animal species, reforestation across this area of tropical land could absorb nearly half the amount of greenhouse gas emissions currently being released by human activities such as logging, agriculture, mining and urban development.
“Deforestation skyrocketed across the globe in 2019. We need 2020 to be the year that we protect and restore tropical forests,” said Hole, Conservation International’s vice president of global solutions.
2. Reef manta rays break deep-diving record
A recent study documented the deepest dive by a reef manta ray ever recorded, shattering the previous world record by more than 200 meters (656 feet). During the historic dive, the reef manta ray — which is smaller than the giant oceanic manta ray — reached a maximum depth of 672 meters (2,204 feet).
An elusive and highly mobile species, the reef manta ray’s behavior has never been recorded in the South Pacific islands of New Caledonia — until now.
Using satellite tags attached to the backs of the manta rays, a team of researchers, including Conservation International scientist Mark Erdmann, was able to track nine of these aquatic giants in the waters of New Caledonia. This information gives valuable insight into the behavior of reef manta rays — vital for protecting them.
“Reef manta ray populations are declining worldwide, largely due to fisheries that target the species for their gills, which are used in traditional Asian medicines,” Erdmann says. “Not only is this bad for the manta rays, this impacts local economies across Indonesia, Australia and the rest of the South Pacific that rely on these charismatic creatures for their ecotourism value.”
Although manta rays in New Caledonia are not yet threatened by fishing, the authors of this study hypothesized that the reef manta rays are likely diving deeper due to insufficient food supplies on the water’s surface.
The deep-diving behavior of the manta rays reaffirms that countries must ensure that deep waters adjacent to coral reefs are protected to conserve this iconic species, according to François Tron, country director of Conservation International’s New Caledonia program.
"Marine protected areas designed to protect manta rays typically focus on coastal and reef areas, and rarely extend into deeper offshore waters,” explained Tron in a recent statement. “This research shows that reef mantas regularly utilize these deeper waters, where we already know other ocean voyaging species such as whales, sharks and turtles are also present. To ensure we do not lose these emblematic species, this broader habitat needs to be included in ocean conservation efforts.”
3. A new plan to protect rapidly vanishing freshwater ecosystems
A recent study offers the first global framework to protect Earth’s freshwater ecosystems, some of which are vanishing three times faster than forests.
Although they cover less than 1 percent of Earth’s surface, freshwater ecosystems — such as rivers, lakes and wetlands — are home to around 10 percent of the planet’s species. However, populations of freshwater vertebrate species such as turtles and sturgeons have fallen by more than 80 percent, and nearly one-third of wetland ecosystems have been lost since 1970 due to human activities that destroy habitats and decrease water quality.
Informed by global data and successful conservation examples from around the world, Conservation International scientists Robin Abell and Ian Harrison worked with other freshwater experts to provide a plan for reversing the rapid decline of freshwater species and habitats — and the services they provide.
“Freshwater ecosystems underpin human society, providing water security, offering flood protection and ensuring food security to vulnerable communities around the world,” said Abell, who leads Conservation International’s freshwater work. “With competing demands for land and water use, we know that freshwater biodiversity conservation isn’t easy — if it were, we wouldn’t be facing such extreme imperilment of fish, invertebrates and other species.”
The paper proposes six strategies to protect freshwater biodiversity, including improving water quality by reducing pollution, preventing and controlling invasive species and managing overfishing.
“It would be easy to interpret this work as a further message of freshwater doom, but it is in fact the opposite,” said Harrison, Conservation International’s director of freshwater science and policy. “It is a forward-looking plan, with specific areas of action, for how to address the 21st century challenges that our freshwater ecosystems face. It presents an opportunity for us to change the trajectory of biodiversity decline in turn supporting the health of the planet and the livelihoods of people.”
Cover image: A reef manta ray in New Caledonia (© Mark Erdmann)
Funding for the reforestation research was provided by Arizona State University; the manta ray satellite tagging research was a collaboration between the University of New Caledonia, Aquarium des Lagons, Manta Trust and Conservation International; support for the freshwater research initiative was provided by WWF-UK.