Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A dichotomy in migration patterns found for sea turtles in east Atlantic

23.05.2006
Newfound differences in turtle behavior pose a conservation challenge

Studying members of a large population of loggerhead sea turtles that nest on the Cape Verde islands off of West Africa, researchers have found an unexpected dichotomy in turtle behavior: While some turtles leave the nesting grounds to feed on bottom-dwelling sea life in shallow coastal waters, others leave Cape Verde to roam the much deeper open ocean along the African coast and exhibit a distinct feeding strategy. Interestingly, while adults compose both groups, the coastal feeding strategy correlates with larger animal size. These new findings revise our understanding of the turtle’s life history and indicate that a multifaceted approach to fishing regulation--in both coastal and oceanic waters--will be required to effectively conserve these animals.

The findings are reported by Brendan Godley and colleagues at the Marine Turtle Research Group at the University of Exeter in Cornwall, Michael Coyne of the Marine Geospatial Ecology Lab at Duke University, and other members of an international team of researchers. The paper appears in the May 23rd issue of Current Biology.

Past studies had indicated that the loggerhead sea turtle (Caretta caretta), which reaches sexual maturity at about 30 years of age, typically undergoes a shift from an oceanic juvenile stage to a shallow-water, coastal adult stage. But the new findings--obtained by newly-improved methods for satellite tracking of the adult turtles’ geographical movements and diving patterns--show that the sexually mature adult population also includes oceanic animals and thereby reveal that adults in the eastern Atlantic occupy very different habitats and undertake two distinct foraging strategies.

The differing strategies correlate with body size, which may be linked to the different diets of the two groups. Turtles migrating to shallow coastal waters-the so-called neritic environment-were larger, and they feed on the arthropods and mollusks that are normally abundant in this food-rich ecosystem. In contrast, adults foraging in the open ocean are smaller, have a more limited capacity for diving, and most likely feed on a somewhat different set of prey that includes small, floating plants and animals.

Importantly, the correlations in animal size and foraging strategy suggest that the majority of adults in the Cape Verde population may undertake the oceanic strategy, rather than the primarily coastal existence previously thought to characterize adulthood. This means that two adult populations will need to be monitored for conservation efforts. And critically--because commercial and artisanal fishing occur in both the open ocean and coastal waters--the findings indicate that appropriate measures will be needed to regulate fishing efforts to reduce by-catch in the different environments. The fact that the oceanic adults were found in a large area, including international waters and waters from Mauritania to Guinea Bissau, indicates that efforts toward regulation and population monitoring will need to take place on a large scale.

Heidi Hardman | EurekAlert!
Further information:
http://www.cell.com
http://www.current-biology.com

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>