Wayward giant

A gray whale seen off the coast of Namibia in early May was the first one ever sighted south of the equator. The species, extinct in the Atlantic since the 18th century, has been mainly confined to the North Pacific. A separate one was sighted in the Mediterranean in May 2010. Experts say this could suggest the leviathan is recovering from the whaling hunts that ended in the 20th century, or it could mean changing climate is disrupting its feeding habits. Another possibility is that the increasing population could be allowing it to regain some of its ancient migratory routes. Gray whales grow up to 45 feet long and complete a round trip of over 18,000 miles between their summer feeding grounds in the high Arctic and winter breeding area off the coast of Mexico. jellyfish population boom, a new study claims. Published in the Bulletin of Marine Science, the report argues that the unrestricted fishing of small open-water fish, such as sardines and herring, has reduced the number of creatures that jellyfish compete with for plankton and other forms of food. Thinning out these rivals, many of which also feed on jellyfish eggs, has eliminated the main checks on explosive jellyfish population growth. Over the past decade, the jellyfish have been showing up where they had never before been a problem, such as the Sea of Japan and the Mediterranean, clogging fishing nets and driving away swimmers.