IN A TIME of such hyperconnectivity, a population of seven and a half billion souls, and space probes that relay information from beyond our solar system, you might expect that we’d have a pretty fair idea about the number of species in our oceans. The truth of the matter is, scientists are still discovering hundreds of new species each year – unsurprisingly, given that undiscovered species are believed to account for 70-80 percent of all marine species. As the first generation with the ability to freely explore the oceans using scuba, our community has made a huge contribution to the discovery of new species.

With the ease of capturing digital images, the rate of new discoveries made by recreational divers has skyrocketed. It is an exciting time to be diving the Coral Triangle.

Where have all these species come from?

Marine animals are fundamentally different to their terrestrial counterparts. More often than not, marine creatures have a pelagic larval stage in their life cycle, during which time their babies can float far and wide at the whim of ocean currents. As a result they are distributed across huge distances.

Land-living animals on the other hand are constrained by oceans, mountains, rivers and other physical barriers that they are unable to cross. Even birds can be scared to cross narrow stretches of sea; Wilson’s and red birds of paradise are found only on Waigeo and Batanta Islands in Raja Ampat, despite Salawati being the other side of a strait just a few kilometres wide. As a result of marine creature’s pelagic stage, there are very few barriers to prevent marine animals from reaching even the most remote atolls. Many coral reef fish species are found all the way from the east coast of Africa to the mid Pacific.

How do new species evolve in the ocean?

Although much less common in the ocean, evolution through geographic isolation does occur in our seas. From Triton and Cenderawasih Bays in remote West Papua, to the Calamian Island group in the Philippines, isolated areas of the ocean have contributed disproportionately to recent new marine discoveries.

Read the rest of this article in 2017 Issue 2 Volume 146 of Asian Diver magazine by subscribing here or check out all of our publications here.

Post a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.