Water is much denser than air, so its molecules are packed tighter together. This means that sound (which relies on molecules vibrating and pushing against one another) propagates muchfurther and faster under water than in air.
Entanglements have surpassed ship strikes as a leading danger to right whales in recent years. Forty-four percent of diagnosed right whale deaths were due to ship strikes and 35 percent were due to entanglements from 1970 to 2009, the study said. From 2010 to 2015, 15 percent of diagnosed deaths were due to ship strikes and 85 percent were due to entanglements, it said.
The Gulf of Maine stretches from Cape Cod to Canada and is a key marine environment and important to commercial fishing. Blue mussels are used in seafood dishes and worth millions to the economy of some New England states, but are also important in moving bacteria and toxins out of the water.
“Historically, at this time of year, we would see nice little bunches (of orcas) swimming back and forth in front of the house,” said Ken, who lives on the west side of San Juan Island. But this year, the whales have broken up into small family groups and are traveling around in seemingly random patterns, presumably in search of whatever salmon they can find.
Each year around 650,000 whales, dolphins and other marine mammals are unintentionally caught and killed in fishing gear worldwide. Under the new rule, foreign fishermen must meet the same marine mammal protection standards applied to U.S. fishermen or their fish will be banned from the lucrative American seafood market.
In the vast and chaotic climate systems that govern our atmosphere and oceans, making sense of how one change — diminished sea ice — affects places or people thousands of miles away is a task of such extraordinary complexity that it strains even the most sophisticated supercomputers.
“Oregon is ground zero for ocean acidification impacts–the water chemistry off our coast is already changing and has changed dramatically. For a glimpse into the science, the impacts and the information gaps behind ocean acidification in Oregon, check out the… Read More ›
So the question is: Why have there been so many sightings outside late summer and early fall, the typical peak season for sharks?
The popular theory is that unseasonably warmer water has brought the change, but experts say it is much more complex than that.
“These past years have been extremely unusual off the California coast, with humpback whales closer to shore, pelagic red crabs washing up on the beaches of central California, and sportfish in higher numbers in southern California,” said Elliott Hazen of the Southwest Fisheries Science Center, a coauthor of the paper. “This paper reveals how broad scale warming influences the biology directly off our shores.”