Functional Traits For Fish Biodiversity Assessment Offer New Opportunity In Conservation

An interesting idea put forward by a research study has redefined the ways biodiversity assessment may be taken up in future.

Traditionally, biodiversity of a place is determined by identifying number of different species or “species richness” as the basis global diversity pattern since the times of Darwin and Linnaeus. This has also constituted as the biological basis for management of threatened ecosystems.

However, a  study conducted by a global team studying reef fishes has revealed that by considering a species’ role in an ecosystem and the number of  individuals within a species, new hot spots of biodiversity can be identified.

The study, led by Dr. Rick Stuart-Smith of the University ofTasmania’s Institute for Marine and Antarctic Studies, includes researchers, Jon Lefcheck and Professor Emmett Duffy of the Virginia Institute of MarineSciences, and scientists from Spain, and researchers from other places.

The study is based on information collected through the Reef Life Survey program, which is a “citizen science” initia­tive developed in Tasmania. The RLS program operates worldwide training recreational SCUBA divers to survey numbers of reef animals and supporting their research endeavors.

Over 100 dedicated divers have contributed to the project by looking at ecological patterns and processes impossible for scientific dive teams to cover.

As pointed out by Lefcheck, counting species is a really coarse way of understanding diversity. Gathering information, instead, on other animal’s traits—what they eat, how they move, where they live— can provide understanding of their dissimilarity, the very essence of diversity.

The study provides a fresh look at biodiversity assessment. Unlike biodiversity censuses which count species, collecting information on species role in ecosys­tems, which needs to know, how abundant they are and what they’re doing, is difficult to get.

The study is based on analysis of data from 4,357 standardized surveys, spanned over 133 degrees of latitude finding 2,473 different species of fish by RLS divers at 1,844 coral and rocky reef sites worldwide. This study is claimed to the first comprehensive study with new approach, and this  undoubtedly offers a different perspective of global diversity map.

The research team noted how the members of each of these species make a living, using a detailed matrix of “functional traits”,  which included what the fishes eat (plankton, inver­tebrates, algae, other fish, or a combination), how they eat (browsing, scraping, or predation), where they live (in, on, or near the bottom or free-swimming), weather active at night or during the day, and how gregarious they are (solitary, paired, or schooling).

By determining the biology and ecology of these fishes—noting what they do and how they do it—alters hotspots of diversity. Though coral reefs are the most species-rich habitats on earth, the trait-based view identifies new areas where the diversity of ways in which fishes function is even higher.

The study reveals that functional biodiversity is highest in places like the Galápagos with only moderate species counts, whereas functional biodiversity is low in many classical hotspots with high species counts, such as the iconic coral triangle of the west Pacific.

It is interesting to note that in coral reefs having lots of species, many are doing largely the same thing, whereas in temperate reefs with many fewer species, species tend to spread individuals out among species doing different things.

The study findings have important implications for planning and management, because 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.