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horseshoe crab  (Source: web.rollins.edu)
Sea-level rise and ocean temperatures are affecting horseshoe crab breeding

New research from the U.S. Geological Survey (USGS) reveals that horseshoe crab populations may be declining due to changes in the climate

Horseshoe crabs are arthropods that have lived on the planet for approximately 450 million years. These ancient creatures have declined in population in more recent years, and the main reason is because of overharvesting (for fertilizer and bait) and coastal habitat destruction. But now, climate change may have some part in the dwindling numbers as well.

"Using genetic variation, we determined the trends between past and present population sizes of horseshoe crabs found that a clear decline in the number of horseshoe crabs has occurred that parallels climate change associated with the end of the last Ice Age," said Tim King, lead author of the study and a scientist with the USGS.

According to research by the USGS, accompanying water temperature fluctuations and sea-level rise have contributed to limited horseshoe crab interbreeding and distribution. This leads to a reduction in population, which is what happened when temperatures rose after the last Ice Age.  

Horseshoe crabs are not the only creatures affected by their decline, though. Migrating sea birds like the Red Knot depend on horseshoe crab eggs for food each spring. Red Knots usually eat horseshoe crab eggs at Delaware Bay during migration, but severe population declines in horseshoe crabs have occurred all along the eastern seaboard of the United States. Significant declines have also occurred in the eastern Gulf of Mexico. 

In addition, Atlantic loggerhead turtles have experienced a change in population due to the lack of adult horseshoe crabs in Chesapeake Bay. 

Now, conservation managers are using certain findings, such as the fact that adult male horseshoe crabs travel from bay to bay while females stay in one place, to create both local and regional strategies to help sustain the horseshoe crab populations, and help them to continue reproducing.  

"Consequently, harvest limitations on females in populations with low numbers may be a useful management strategy, as well as relocating females from adjacent bays to help restore certain populations," said King. "Both studies highlight the importance of considering both climatic change and other human-caused factors such as overharvest in understanding the population dynamics of this and other species."

This study was published in Molecular Ecology in August of this year.




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450 million years
By ZachDontScare on 9/3/2010 3:22:56 PM , Rating: 4
So basically, this species which has survived 450 million years - which is 200 times longer than human-kind has walked the earth, includes countless ice-ages and warm-ups, and at least one planet-killer asteroid impact... cant handle a supposed 1 degree F temperature increase over 100 years.

And then these 'climate scientists' wonder why people dont buy their crap anymore.




RE: 450 million years
By phxfreddy on 9/4/2010 12:40:47 AM , Rating: 2
You have to give it to these climate snake oil salesmen. Al Gore and company took this scam and filled their bank accounts to the tune of 1 billion dollars and more.

All the while the liberal fools felt more important and relevant in their lives because they were "helping the planet".....should have gotten technical degrees instead of liberal arts and "social justice" degrees. Then they could have REALLY been relevant!


RE: 450 million years
By celticbrewer on 9/7/2010 9:06:07 AM , Rating: 3
THANK YOU!

Obviously it's over-fishing and loss of habitat that's more to blame than the global warming boogeyman.


RE: 450 million years
By kattanna on 9/7/2010 10:25:01 AM , Rating: 1
exactly, but that doesnt produce the scary headlines to bring in those page views


RE: 450 million years
By Grabo on 9/9/2010 4:32:28 AM , Rating: 1
Right, or:

It has survived for 450 million years, through countless natural variations and disasters, and is now in the blink of an eye(over the course of a hundred years or less) facing extinction. In the same tiny window of time, the most disruptive species on the planet has more members and means of disruption than ever. Coincidence?

Mightn't be rising temps but the odds are through the roof that humans are to blame.


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