High tech helps scientists protect whales
US: Scientists are delving deep into the travels of whales -- thanks
to high-tech tracking devices -- to try to help protect them.
Except for a few species, global whale populations have been
decimated over the last few hundred years. Many are at less than 10
percent of their original population size, following aggressive hunting
in the 19th and early 20th centuries.
Today, whales are threatened by collisions with ships, getting
trapped in fishing nets and from industrial acoustic disturbances caused
by ship traffic, said Daniel Palacios at the Institute of Marine
Sciences at the University of California Santa Cruz.
To better protect them, scientists at the annual American Association
for the Advancement of Science conference in Boston said they need to
better understand how and when whales eat and breed, and where they
travel.
But that information has been difficult to obtain, Palacios said,
because scientists have only recently gotten hold of technology to track
whales for up to a year. Other sea animals have been tracked for a long
time. "But tagging and tracking such large animals has been a huge
problem over the last 25 years," said Palacios.
With the newly collected data "we have examined about 200 tracks from
(four) different species in different oceans basins," he added.
Whales can swim between 620 and 3,100 miles (1,000 and 5,000
kilometers) per year depending on the species "What we see is that is
that whales engage in sort of local restricted movements, and then they
would take off and follow very direct paths with a very high precision,"
Palacios said.
Zoologists have found that blue whales -- the largest animal on
earth, measuring up to 32 meters (105 feet) long and weighing up to 200
tonnes -- feed for several months off the coast of Santa Barbara,
California, in the middle of shipping lanes for vessels heading to the
busy port of Los Angeles.
Climate change also threatens whales, said Nicholas Pyenson, curator
at the Smithsonian's National Museum of Natural History in Washington.
AFP |
