MONITORING REPORT CALIFORNIA: Researchers believe California blue whales have recovered in numbers and the population has returned to sustainable levels; they say this is the only population of blue whales to have rebounded from the ravages of whaling.
According to the research team there are now 2,200 of these giant creatures on the eastern side of the Pacific Ocean. But concerns remain about their vulnerability to being struck by ships. At up to 33m in length and weighing in at up to 190 tons, blue whales are the largest animals on the planet.
The numbers of blue whales caught in the Pacific was much lower, approximately 3,400 between 1905 and 1971. Much of this hunting was carried out by Russian fleets.
However most of the data on the catches was kept secret under the Soviet regime. Scientists have only recently been able to get access to this information in the archives. However the location and size of the catches didnt give any clues to the types of blue whales that had been caught.
“We tried to separate the catches into east and west, but we didnt know the boundary between the two,” said Dr Trevor Branch from the University of Washington.
Now back at 97pc of their past numbers, the team believes that a rise in population has slowed down as these whales have reached the capacity of what the ocean system can support. One concern for the scientists at present are ship strikes.