Navigation Links
Climate change implicated in decline of horseshoe crabs

LEETOWN, W. Va. A distinct decline in horseshoe crab numbers has occurred that parallels climate change associated with the end of the last Ice Age, according to a study that used genomics to assess historical trends in population sizes.

The new research also indicates that horseshoe crabs numbers may continue to decline in the future because of predicted climate change, said Tim King, a scientist with the U.S. Geological Survey and a lead author on the new study published in Molecular Ecology.

While the current decline in horseshoe crabs is attributed in great part to overharvest for fishing bait and for the pharmaceutical industry, the new research indicates that climate change also appears to have historically played a role in altering the numbers of successfully reproducing horseshoe crabs. More importantly, said King, predicted future climate change, with its accompanying sea-level rise and water temperature fluctuations, may well limit horseshoe crab distribution and interbreeding, resulting in distributional changes and localized and regional population declines, such as happened after the last Ice Age.

"Using genetic variation, we determined the trends between past and present population sizes of horseshoe crabs and 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 King.

The research substantiated recent significant declines in all areas where horseshoe crabs occur along the West Atlantic Coast from Maine to Florida and the eastern Gulf of Mexico, with the possible exception of a distinct population along the Yucatan Peninsula of Mexico

These findings, combined with the results of a 2005 study by King and colleagues, have important implications for the welfare of wildlife that rely on nutrient-rich horseshoe crab eggs for food each spring.

For example, Atlantic loggerhead sea turtles, which used to feed mainly on adult horseshoe crabs and blue crabs in Chesapeake Bay, already have been forced to find other less suitable sources of food, perhaps contributing to declines in Virginia's sea turtle abundance. Additionally, horseshoe crab eggs are an important source of food for millions of migrating shorebirds. This is particularly true for the red knot, an at-risk shorebird that uses horseshoe crab eggs at Delaware Bay to refuel during its marathon migration of some 10,000 miles. Since the late 1990s, both horseshoe crabs and red knot populations in the Delaware Bay area have declined, although census numbers for horseshoe crabs have increased incrementally recently.

"Population size decreases of these ancient mariners have implications beyond the obvious," King said. "Genetic diversity is the most fundamental level of biodiversity, providing the raw material for evolutionary processes to act upon and affording populations the opportunity to adapt to their surroundings. For this reason, the low effective population sizes indicated in the new study give one pause."

These studies should help conservation managers make better-informed decisions about protecting horseshoe crabs and other species with a similar evolutionary history. For example, the 2005 study indicated males moved between bays but females did not, suggesting management efforts may best be targeted at local populations instead of regional ones since an absence of enough females may result in local extinctions.

"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," King said. "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."


Contact: Catherine Puckett
United States Geological Survey

Related biology news :

1. Genetic structure of first animal to show evolutionary response to climate change determined
2. Study offers historic buildings protection from climate change
3. Climate change affects geographical range of plants
4. Too hot to handle: Impacts of climate change on mussels
5. NOAA awards grant to investigate impacts of land use and climate change on hypoxia in Green Bay
6. Common orchid gives scientists hope in face of climate change
7. The worst impact of climate change may be how humanity reacts to it
8. A crystal ball for predicting the effects of global climate change
9. Ancient Hawaiian glaciers reveal clues to global climate impacts
10. American Chemical Society to hold forum on climate change on Aug. 23
11. Reconciliation ecology: The fun way to adapt to climate change
Post Your Comments:
(Date:10/29/2015)...  The J. Craig Venter Institute (JCVI) policy group ... Biosecurity: Lessons Learned and Options for the Future," which ... Services guidance for synthetic biology providers has worked since ... --> --> Synthetic biology promises great ... pose unique biosecurity threats. It now is easier than ...
(Date:10/29/2015)... Oct. 29, 2015 Today, LifeBEAM ... partnership with 2XU, a global leader in technical ... smart hat with advanced bio-sensing technology. The hat ... to monitor key biometrics to improve overall training ... the two companies will bring together the most advanced ...
(Date:10/26/2015)... and LAS VEGAS , Oct. ... Labs , an innovator in modern authentication and a ... announced the launch of its latest version of the ... enabling organizations to use standards-based authentication that supports existing ... S3 Authentication Suite is ideal for organizations deploying customer-facing ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... ... November 24, 2015 , ... ... But unless it is bound to proteins, copper is also toxic to cells. ... at Worcester Polytechnic Institute (WPI) will conduct a systematic study of copper in ...
(Date:11/24/2015)... ... ... This fall, global software solutions leader SAP and AdVenture Capital brought together dozens ... BIG ideas to improve health and wellness in their schools. , Now, the top ... of SAP's Teen Innovator, an all-expenses paid trip to Super Bowl 50, and an ...
(Date:11/24/2015)... 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS) ... remaining 11,000 post-share consolidation (or 1,100,000 pre-share consolidation) ... B Warrants") subject to the previously disclosed November ... 2015, which will result in the issuance of ... the issuance of such shares, there will be ...
(Date:11/24/2015)... , Nov. 24, 2015 /CNW Telbec/ - ProMetic Life ... announced today that Mr. Pierre Laurin , President and ... presentation at the upcoming Piper Jaffray 27 th Annual ... Hotel, on December 1-2, 2015. st , ... for one-on-one meetings throughout the day. The presentation will be ...
Breaking Biology Technology: