Navigation Links
Seals quickly respond to gain and loss of habitat under climate change
Date:7/9/2009

Southern Elephant seals responded rapidly to climate and habitat change and established a new breeding site thousands of kilometres from existing breeding grounds, according to new research.

An international research team, including post-doctorate Dr Mark de Bruyn and collaborators from the US, South Africa and Italy, led by Professor Rus Hoelzel from the School of Biological and Biomedical Sciences, Durham University, found that when the Antarctic ice sheets of the Ross Sea Embayment retreated in the Holocene period 8,000 years ago, elephant seals, Mirounga leonina, adopted the emergent habitat and established a new population which flourished.

DNA sequences from the ancient remains of seals from the now extinct Antarctic colony showed high levels of genetic diversity, probably due to the very large population size sustained there. The study, published in the academic journal PLoS Genetics, and funded by the US National Science Foundation, shows how environmental change can drive the demographic and evolutionary processes that determine diversity within and among species.

Tracking these processes during periods of change reveals mechanisms for the establishment of populations, and provides predictive data on response to potential future impacts, including those caused by climate change.

Professor Rus Hoelzel said: "In general, this approach of looking to the past to understand what might happen in the future, has good potential for predicting the impact of environmental change in both marine and terrestrial systems.

"We've shown how a highly mobile marine species responded to the gain and loss of new breeding habitat. The new habitat was quickly adopted, probably because seals migrate annually into Antarctic waters to feed. However, when the ice returned and the habitat was lost, only a small proportion returned to the original source population. The Antarctic population crashed and much diversity was lost."

This habitat was released after the retreat of the grounded ice sheet in the Ross Sea Embayment 7,500-8,000 years ago, and is within the range of modern foraging excursions from the Macquarie Island colony. Using ancient mtDNA and evolutionary models, the research team tracked the population dynamics of the now extinct colony and the connectivity between this and modern breeding sites.

The team found clear signs of rapid expansion in the new colony 8,000 years ago. This was followed by directional migration away, coupled with a loss of diversity 1,000 years ago, when the sea ice is thought to have expanded. The data suggest that the new colony seals came initially from Macquarie Island, and that some returned there, but in much smaller numbers, when the new colony habitat was lost 7,000 years later.

In order to understand how biodiversity is generated and maintained over time, the team has set out to understand the process by which the seal populations formed and diverged. They analysed data from ancient DNA to show how elephant seal populations responded when new breeding habitat was gained and then lost over the course of approximately 7,000 years.

Professor Rus Hoelzel said: "Using ancient DNA, we were able to track the dynamics and diversity of a population from its foundation, through to its extinction, in the context of Holocene climate change. We learned that new habitat emerging within the species' migratory range could be quickly taken advantage of, but that the reverse was not true. The movement patterns of seals from this Antarctic breeding site would have been unlikely to take them near other potential breeding sites, and so when their breeding site was lost, their numbers crashed.

"The seals that discovered the new breeding site had things good, because food was abundant and nearby, however when the ice returned, the new colony collapsed and only a few seals made it back to their original home.

"This illustrates the importance of understanding the behaviour and life history of a species, in order to model how it may be able to respond to rapid change."

The key factors in the expansion of the new colony were likely to be the abundant local food resource and extensive physical habitat that allowed rapid expansion after the initial founder event, and a tendency for females to return to annual breeding sites in this species.

When the ice expanded again 1,000 years ago, the seals returned to their origins but in much smaller numbers.


'/>"/>

Contact: Carl Stiansen
media.relations@durham.ac.uk
44-191-334-6077
Durham University
Source:Eurekalert

Related biology news :

1. Fossil evidence of missing link in the origin of seals, sea lions, walruses found in Canadian Arctic
2. NTU seals global partnerships on environmental sciences R&D
3. Mercury pollution causes immune damage to harbor seals
4. Southern Ocean seals dive deep for climate data
5. TGen spin-off MedTrust Online enables cancer doctors to quickly obtain best-available information
6. Portable device quickly detects early Alzheimers
7. Scripps scientists develop new tests that identify lethal prion strains quickly and accurately
8. UF botanists: Flowering plants evolved very quickly into 5 groups
9. Simple reason helps males evolve more quickly
10. Twinkle after-effect can help retinal patients detect vision loss quickly and cheaply
11. International team shows mercury concentrations in fish respond quickly to increased deposition
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/13/2017)... According to a new market research report "Consumer IAM Market by Solution ... Authentication Type, Deployment Mode, Vertical, and Region - Global Forecast to 2022", ... 14.30 Billion in 2017 to USD 31.75 Billion by 2022, at a ... ... MarketsandMarkets Logo ...
(Date:4/11/2017)... 2017 Research and Markets has announced the ... to their offering. ... eye tracking market to grow at a CAGR of 30.37% during ... Market 2017-2021, has been prepared based on an in-depth market analysis ... and its growth prospects over the coming years. The report also ...
(Date:4/11/2017)... MELBOURNE, Florida , April 11, 2017 ... "Company"), a security technology company, announces the appointment of independent ... John Bendheim to its Board of Directors, furthering the ... ... behalf of NXT-ID, we look forward to their guidance and ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... ... launched Rosalind™, the first-ever genomics analysis platform specifically designed for life science ... in honor of pioneering researcher Rosalind Franklin, who made a major contribution ...
(Date:10/11/2017)... CA, USA (PRWEB) , ... October 11, 2017 , ... ... to take place on 7th and 8th June 2018 in San Francisco, CA. The ... influencers as well as several distinguished CEOs, board directors and government officials from around ...
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased emissions are the main ... people each year. Especially those living in larger cities are affected by air pollution ... of the most pollution-affected countries globally - decided to take action. , “I knew ...
(Date:10/10/2017)... , ... October 10, 2017 ... ... cancer-focused pharmaceutical company advancing targeted antibody-drug conjugate (ADC) therapeutics, today confirmed licensing ... HPLN (Hybrid Polymerized Liposomal Nanoparticle), a technology developed in collaboration with Children’s ...
Breaking Biology Technology: