Up to 1 million marine species, with most yet to be discovered

Grace Chua Straits Times 20 Nov 12;


Prof Ng says many parts of the undersea world are still poorly explored. -- ST FILE PHOTO

AN INTERNATIONAL team of researchers has estimated that the oceans may harbour up to a million marine species.

That figure includes the tiniest crustaceans to the largest whales.

The estimate is based on the rate at which species were discovered in the past and also on a range of expert opinion.

These were backed up by the World Register of Marine Species, an open online database of marine species around the world.

About 226,000 of those species have so far been "described", which means studying a specimen's physical characteristics, showing that it is indeed new and giving it a formal scientific name.

There are estimated to be another 65,000 species awaiting description in specimen collections, researchers reckon.

The work, led by Mr Ward Appeltans of the Unesco Intergovernmental Oceanographic Commission, was published online last week in the journal Current Biology.

National University of Singapore crab expert Peter Ng, who contributed to the crustacean section of the work, said that for crabs alone, 50 to 60 new species are named every year.

He said it is important to know how many species there are. "People keep talking about conservation, biodiversity crisis, extinction crisis and so on. All these mean we need to know the scale of the work at hand," he said.

But many parts of the undersea world are still poorly explored, he added, such as deep reefs, sea cliffs and rubble zones. And collecting animals in the sea, with its depths and currents, is even more expensive and difficult to do than on land.

While plenty of scientists work on "charismatic" types of corals, fish and turtles, there are few who work on the small animals that live in the sand or mud, or worms - a group so diverse "there are too few experts alive to work on them", Professor Ng said.

Mr Giam Xingli, a Singaporean ecology and evolutionary biology graduate student at Princeton University who was not involved in the research, said:

"Numbers are useful to remind private citizens, concerned NGOs (non-governmental organisations) and governments about what we know and what we don't, as well as the scale of the problems.

"If we could go one step further and identify the likely hot spots of undescribed marine species, then we will know which areas to conserve and which areas to focus on for species discoveries."

Besides the number of species, scientists also need to know how each species responds to disturbance - which are the most sensitive or resilient, how long the impacts last and whether ecosystems or communities can bounce back, he added.