Save Our Sponges . . . they could save us

A valuable source of marine organisms, which could have a major impact on the development of new medicines, is under threat from deep sea fishing and engineering works and could be lost before their properties can be captured.

Ocean sponges from shallower waters have already been shown to be valuable sources for new medicinal drugs to treat cancers and for antibiotics, and it is expected that deepwater sponges will be equally valuable, if not more so.

Area dominated by 'lollipop' sponges of the genus Stylocordyla. The sponges are stalked and their bodies lifted 10-30 cm above the sediment surface. The species is typical for a later succession stage in the recolonisation after iceberg disturbance. Depth 250 m.

But a groundbreaking report from leading experts (led by the Centre for Marine Biodiversity and Biotechnology at Heriot-Watt University) shows that ancient sponge grounds, dating back up to 9,000 years, containing individual sponges with life spans of over 100 years, are being destroyed by deep sea trawling.

The report, 'Deep Sea Sponge Grounds: Reservoirs of Biodiversity' will be unveiled at the European Marine Biology Symposium, starting today at Heriot-Watt University in Edinburgh. It highlights deep-sea sponge science and conservation and contributes towards the escalating international efforts to understand and protect critical marine habitats. Its launch also coincides with the 2010 UN International Year of Biodiversity, of which UNEP-WCMC and a number of the contributing institutions are partners.

As Murray Roberts, Reader in Biodiversity at Heriot-Watt University, points out, it's in all our interests to maintain these marine habitats which are potential underwater treasure chests of future medical discoveries. "People might think of natural sponges as just a bit of a bath time luxury, but they are potentially vitally important to future medical developments.

We already know that some sponges contain substances that are being used to treat cancers, but there are many other species in our own waters that we simply don't know about.

Murray Roberts, Reader in Biodiversity

"We already know that some sponges contain substances that are being used to treat cancers, but there are so many other species in our own UK and Scottish deep waters that we simply don't know about. We found a hundred sponge species at Scotland's only inshore cold-water coral reef near Mingulay, and over the next few years we will be investigating other sites around Scotland where we hope to find many more. But meanwhile we have also shown that deepwater bottom trawling is causing carnage among these slow-growing but potentially invaluable colonies."

But why do these marine organisms have such potential? Murray explains: "Sponges grow fixed in place and have to compete for space with many neighbouring animals. This goes some way to explain why over millions of years they have evolved so many powerful chemicals €“ known as secondary metabolites €“ to defend themselves. It's these complex chemicals that are showing such promise as a new generation of drugs. To make sure that this potential isn't lost to us we need to take steps to protect deep-water sponges on our doorstep and further afield.

"Appreciation of deep sea sponge grounds and consideration of them in conservation and management decision-making is only just beginning and the report launched today provides an excellent foundation upon which to build this work."

Main image courtesy of Art Howard  of Artworks.

Inset image from the south-eastern Weddell Sea, Antarctica, courtesy of J. Gutt, University of Bremen.