Marine Mammals

Mass Die-Offs Continue to Threaten Marine Life

Balmy temperatures can lead to conditions perfect for the spread of infectious diseases, Sanderson said. When sea ice melts too early in the season, seal pups must enter the water before they are ready to be weaned, leaving them weaker and more vulnerable to disease. Vanishing sea ice also means that seals and sea lions in cold regions will have less space to emerge from the water to rest, breed, or escape predators, forcing them to crowd more tightly together.

Southern Sea Otter Population Improves

“We believe the high count this year is partly explained by excellent viewing conditions, but it also appears to reflect increased food availability in the range center,” says Dr. Tim Tinker, a research ecologist who leads the USGS sea otter research program. “The boom in sea urchin abundance throughout northern and central California has provided a prey bonanza for sea otters, and that means more pups and juveniles are surviving to adulthood.”

“entanglements have long-term negative physical and reproductive effects (on whales)”

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.

Concern for Puget Sound Orcas

“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.