Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rising heat at the beach threatens largest sea turtles, climate change models show

02.07.2012
For eastern Pacific populations of leatherback turtles, the 21st century could be the last.

New research suggests that climate change could exacerbate existing threats and nearly wipe out the population. Deaths of turtle eggs and hatchlings in nests buried at hotter, drier beaches are the leading projected cause of the potential climate-related decline, according to a new study in the journal Nature Climate Change by a research team from Drexel University, Princeton University, other institutions and government agencies.


Leatherbacks are the largest species of sea turtles and are critically endangered. Heat-related deaths of turtle eggs and hatchlings in nests before they emerge and enter life at sea was identified as the leading projected cause of climate-related decline in leatherback turtles in the eastern Pacific in a new study. The study suggests that climate change could exacerbate existing threats that have already made leatherbacks critically endangered, and nearly wipe out the eastern Pacific population in the 21st century. The study, by a research team from Drexel University, Princeton University, other institutions and agencies, is published online in Nature Climate Change on July 1, 2012.

Credit: US Fish and Wildlife Service Southeast, via Flickr (http://www.flickr.com/photos/usfwssoutheast
/5839996547/in/photostream/)

Leatherbacks, the largest sea turtle species, are among the most critically endangered due to a combination of historical and ongoing threats including egg poaching at nesting beaches and juvenile and adult turtles being caught in fishing operations. The new research on climate dynamics suggests that climate change could impede this population's ability to recover. If actual climate patterns follow projections in the study, the eastern Pacific population of leatherback turtles will decline by 75 percent by the year 2100.

Modeling the Ebb and Flow of Turtle Hatching with Climate Variation

"We used three models of this leatherback population to construct a climate-forced population dynamics model. Two parts were based on the population's observed sensitivity to the nesting beach climate and one part was based on its sensitivity to the ocean climate," said the study's lead author Dr. Vincent Saba, a research fishery biologist with the NOAA National Marine Fisheries Service Northeast Fisheries Science Center, visiting research collaborator at Princeton University, and a Drexel University alumnus.

Leatherback turtle births naturally ebb and flow from year to year in response to climate variations, with more hatchlings, and rare pulses of male hatchlings, entering the eastern Pacific Ocean in cooler, rainier years. Female turtles are more likely to return to nesting beaches in Costa Rica to lay eggs in years when they have more jellyfish to eat, and jellyfish in the eastern Pacific are likely more abundant during cooler seasons. Turtle eggs and hatchlings are also more likely to survive in these cooler, rainier seasons associated with the La Niña climate phase, as this research team recently reported in the journal PLoS ONE. In addition, temperature inside the nest affects turtles' sex ratio, with most male hatchlings emerging during cooler, rainier seasons to join the predominantly-female turtle population.

The researchers applied Saba's combined model of these population dynamics to seven climate model projections assessed by the Intergovernmental Panel on Climate Change (IPCC). The climate model projections were chosen based on their ability to model El Niño Southern Oscillation (ENSO) patterns on the temperature and precipitation in the region of Costa Rica where this team has conducted long-term leatherback studies.

Hot Beaches, More Warm Years Threaten Turtles' Recovery

The resulting projections indicate that warmer, drier years will become increasingly frequent in Central America throughout this century. High egg and hatchling mortality associated with warmer, drier beach conditions was the most significant cause of the projected climate-related population decline: This nesting population of leatherbacks could decline by 7 percent per decade, or 75 percent overall by the year 2100.

The population is already critically low.

"In 1990, there were 1,500 turtles nesting on the Playa Grande beach," said Dr. James Spotila, the Betz Chair Professor of Environmental Science in the College of Arts and Sciences at Drexel. "Now, there are 30 to 40 nesting females per season."

Spotila, a co-author of the study, has been studying leatherback turtles at Playa Grande in Costa Rica, the largest leatherback nesting beach in the eastern Pacific, with colleagues and Drexel students, for 22 years.

Poaching of turtle eggs was a major cause of the initial decline, and was once such a widespread problem that virtually no turtle hatchlings would survive at Playa Grande. Spotila and colleagues worked with the local authorities in Costa Rica to protect the leatherbacks' nesting beaches so that turtle nests can hatch in safety. Bycatch of juvenile and adult turtles in fishing operations in the eastern Pacific remains a threat.

For the population to recover successfully, Spotila said, "the challenge is to produce as many good hatchlings as possible. That requires us to be hands-on and manipulate the beach to make sure that happens."

Spotila's research team is already investigating methods such as watering and shading turtle nests that could mitigate the impact of hot, dry beach conditions on hatching success.

Link to this Nature Climate Change study: http://dx.doi.org/10.1038/NCLIMATE1582

Link to recent news release about a related study by this research team in PLoS ONE: http://www.drexel.edu/now/news-media/releases/archive/2012/May/El-Nino-Climate-Change-Threaten-Leatherback-Sea-Turtles/

Dr. James Spotila recently joined the faculty of Drexel University's new Department of Biodiversity, Earth and Environmental Science (BEES), formed as a result of the University's unique affiliation with the Academy of Natural Sciences, the oldest natural history museum in the U.S. and a world leader in biodiversity and environmental research. Spotila is the author of the books Sea Turtles: A Complete Guide to Their Biology, Behavior, and Conservation (2004) and Saving Sea Turtles: Extraordinary Stories from the Battle Against Extinction (2011).

Rachel Ewing | EurekAlert!
Further information:
http://www.drexel.edu

More articles from Ecology, The Environment and Conservation:

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

nachricht The disappearance of common species
01.02.2018 | Technical University of Munich (TUM)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>