October 2010

Sturgeon in the Caspian Sea is critically endangered.
Sturgeon in the Caspian Sea is critically endangered.

Beluga sturgeon now listed as critically endangered

Beluga sturgeon populations have been decimated in part due to unrelenting exploitation for black caviar —the sturgeon's unfertilized eggs—considered the finest in the world.

"For those of us who have been involved in studying the rapid decline of this species over the past several decades, this reclassification of beluga sturgeon is of great significance and relief," said Dr Ellen Pikitch, Professor and Executive Director of the Institute for Ocean Conservation Science at Stony Brook University.

Long Finned Oscar (Astronotus ocellatus). The underwater environment is filled with biotic and abiotic sounds, many of which can be important for the survival and reproduction of fish

Noise pollution also a threat to fish

But in the journal Trends in Ecology and Evolution, Dr Slabbekoorn and colleagues in The Netherlands, Germany and US report how the underwater environment is anything but quiet.

"People always just assumed that the fish world was a silent one," says biologist Dr Hans Slabbekoorn of Leiden University, The Netherlands, on of the scientists who have reviewed the impact on fish species around the world of noises made by oil and gas rigs, ships, boats and sonar.

An orca's teeth are ground down to the gum.
An orca's teeth are ground down to the gum.

Shark diet bad for orca's teeth

Until the 1990s, only two kinds of orcas were seen in the inshore waters of British Columbia, says John Ford, a zoologist at the University of British Columbia and a research scientist at the Pacific Biological Station run by Fisheries and Oceans Canada.: “resident whales,” which prefer delicacies such as salmon; and “transient whales,” which prefer to eat mammals such as porpoises and seals.

Basking shark off Cornwall, UK
Basking shark off Cornwall, UK

Basking sharks trek across Atlantic

Giant basking sharks like to take tropical vacations too.

Previously thought to inhabit only temperate waters, a new study, just published in Current Biology, shows that the giant sharks make long, make vast migrations to deep, warm-water hideouts. Before the annual winter disappearance, scientists tagged 25 basking sharks off New England with floating, timed-release satellite transmitters, which showed that, like humans, the giant basking sharks like to take tropical vacations too.

Venice is getting a preview of rising sea levels by its annual flodings.
Venice is getting a preview of rising sea levels by its annual flodings.

Mediterranean Sea level could rise by 61 cm

"The most positive scenario assumes that greenhouse gas concentrations remain constant at their levels in the year 2000, and even in this case climate change still has an impact. The most negative scenario is based on diverse levels of economic development all over the world, with an ongoing increase in greenhouse gas production throughout the 21st Century," Marta Marcos, the study's lead author and a researcher at the UIB, tells SINC.