Biodiversity is often thought of as simply a species count, but when the definition is slightly changed it opens up a whole new world of ecosystem hot spots that deserve careful preservation.
Researchers took into account the species' role in the ecosystem and the number of present organisms within that species, the technique pinpointed some areas that needed more protective care, a Virginia Institute of Marine Science press release reported.
"Consider a pool with a fish, a bird, and a crab. 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," graduate student Jon Lefcheck, said.
The research team recruited volunteers to help them search for areas that fit this new definition of biodiversity.
"The assistance of over 100 dedicated divers has allowed us to look at ecological patterns and processes impossible for scientific dive teams to cover," Reef Life Survey program founder and University of Tasmania professor, Graham Edgar, said.
For decades researchers have calculated a region's biodiversity by looking its "species richness," now some scientists think it's time to update the system.
"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, said.
"Most biodiversity censuses simply count species because it's relatively easy to do," Professor Emmett Duffy, said. "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."
The team analyzed 1,844 coral and rocky reef sites across the globe that included 2,473 different species of fish.
The team delved into the "functional traits" of each species, including: what they ate, how they ate it, where they live, and their resting patterns.
"Determining the biology and ecology of these fishes-noting what they do and how they do it-alters hotspots of diversity," Lefcheck said. "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."
The researchers found that "functional biodiversity" was most present in places with only moderate species counts, such as the Galápagos. Biodiversity when looked at in this way is often low in areas that are commonly considered to be "hot spots."
"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," Lefcheck said.
