Tag Archives: predators

Louisiana’s crab bans spurred by changes in climate and habitat

South Louisiana’s blue crab population is on the decline, pummeled by environmental and man-made threats. Increased trapping, less rainfall, no recent hurricanes, wetlands loss, predators, oil spills, closing of the Mississippi River-Gulf Outlet Canal and river-water diversions have taken their tolls. In response, Louisiana’s Wildlife and Fisheries Commission last summer decided to ban crabbing and trap use for thirty days, starting on February 20 of this year.,, The state’s diversions of Mississippi River water to fend off oil from the BP spill, and separately as a way to rebuild wetlands, have pushed crab larvae and babies into the sea where predators loom, Lively said. At this point, it’s unclear which factors are most to blame for a decline in the state’s blue crabs, Jeffrey Marx, LDWF marine biologist and crab program manager, said last week. Less rainfall and ongoing predation on crabs are negatives, he noted. Predators include red and black drum, sea catfish, sheepshead and spotted sea trout. (very interesting) Read the article here 17:47

Study says predators may play major role in chinook salmon declines

A new study shows that increased populations of seals and sea lions are eating far more of Puget Sound’s threatened chinook than previously known, potentially hampering recovery efforts for both salmon and endangered killer whales.  Seals and sea lions are eating about 1.4 million pounds of Puget Sound chinook each year — about nine times more than they were eating in 1970, according to the report, published online this month in the Canadian Journal of Fisheries and Aquatic Sciences. Most of these chinook are small fish migrating to the ocean, which ultimately reduces the number of adults returning to Puget Sound. The study estimates that seals and sea lions are decreasing potential returns by about 162,000 adult chinook each year. That’s twice the number eaten by killer whales and roughly six times as many as caught in Puget Sound by tribal, commercial and recreational fishers combined. Read the rest of the story here 21:16