May 2011

Insights can inform urgently needed shark conservation strategies

New research reveals shark super highways

The world’s sharks are disappearing. These fearsome yet charismatic fish continue to fall victim to overfishing and many are now at risk of extinction as a result. New research shows that open-ocean sharks are particularly threatened from overfishing, and other work shows that the deeper sharks live, the longer it takes for their populations to recover. Yet researchers are just now learning critical details of their behavior, including the fact that some species migrate quickly along “superhighway” routes and congregate at established “stepping stone” sites.

Space Diving: European Astronaut Centre in Cologne

To simulate work in space, astronauts practice maneuvering equipment and gear underwater

At the European Astronaut Centre (EAC) where astronauts train for ESA’s manned space missions, trainee astronauts undergo a 16-month basic training program, and an integral part of this is to dive. Astronauts need to be underwater to practice spacewalks, also known as Extra-Vehicular Activities (EVA). Diver and underwater photographer, Christian Skauge, paid ESA’s Neutral Buoyancy Facility a visit.

Tide pool sea stars feast on Dungeness crabs that suffocated in the low oxygen waters of a dead zone.
Tide pool sea stars feast on Dungeness crabs that suffocated in the low oxygen waters of a dead zone.

'Dead Zones' off US west coast may be irreversible

Dead zones form where microscopic plants, known as phytoplankton, are fertilized by excess nutrients, such as fertilizers and sewage, that are generated by human activities and dumped into the ocean by rivers, or more rarely, where they are fertilized by naturally occurring nutrients. The result: blooms of organic matter that ultimately decompose through processes that rob the ocean of life-sustaining oxygen. Animals that fail to flee dead zones either suffocate or suffer severe stress.

Algae and Porites: Seaweed overgrowing a massive coral on an inshore reef of the Great Barrier Reef.
Algae and Porites: Seaweed overgrowing a massive coral on an inshore reef of the Great Barrier Reef.

Weed-eating fish "key to reef survival"

For some years, researchers have pinned their hopes on the ability of weed-eating fish to keep the weeds at bay while the corals recover following a major setback like bleaching, a dump of sediment from the land, or a violent cyclone.

However, the latest work by Dr Andrew Hoey and Professor David Bellwood at CoECRS and James Cook University shows that once the weeds reach a certain density, the fish no longer control them, and prefer to graze less weedy areas. “As a result, the whole system tips from being coral-dominated to weed-dominated,” said Dr Hoey..

Viscount Melbourne ca 1841 William John Huggins (artist & publisher) Charles Rosenberg (engraver)
Viscount Melbourne ca 1841 William John Huggins (artist & publisher) Charles Rosenberg (engraver)

19th Century Shipwreck found off Borneo

Part-time marine archaeologists Hans and Roz Berekoven - who are married to each other - said their find was unlikely to yield any treasures as the ship had been a British cargo vessel, but it could add to knowledge of trade then, the Jakarta Globe reports

Newspapers in the region reported on its loss at the time but interest faded and the wreck was abandoned to its fate.

Then in 1950, The Straits Times published a series of articles on the survivors' struggle to reach Borneo. The series, titled 'A perilous sea voyage', gave the Berekovens the key to finding the wreck.