Monday, 16 July 2012

Why Sockeye Salmon Are in Trouble


Every year, millions of adult salmon return from the ocean to their home streams, where they lay eggs and produce the next generation of fish. But far fewer sockeye salmon are making it back to their freshwater mating grounds compared to a few decades ago, and that’s seriously affecting population sizes of the species throughout the Northwest, from Alaska to Washington State.

The discovery suggests that changing ocean conditions may be making life harder for some groups of wild salmon -- possibly by reducing their food supply or increasing populations of predators.

By zeroing in on what, exactly, is causing the widespread decline, researchers hope to help managers figure out what to do about the problem.


“We found that substantial reductions in productivity of over 50 percent have occurred in the last two decades in a wide geographical area,” said Randall Peterman, a fisheries scientist at Simon Fraser University in Burnaby, Canada. “We were quite stunned to see these results.”


“We’re telling researchers that in order to really explain the decline in a give population, you should be looking at what is causing the decline in productivity in other populations,” he added. “Depending on which mechanism is the cause of the decline, we may or may not be able to do anything about it.”


Continued:  http://www.livescience.com/21517-sockeye-salmon.html

No comments:

Post a comment

You only need to enter your comment once! Comments will appear once they have been moderated. This is so as to stop the would-be comedian who has been spamming the comments here with inane and often offensive remarks. You know who you are!

Related Posts with Thumbnails

ShareThis