loggerhead
A sudden increase in the number of turtle deaths washing ashore on the beaches of the Algarve in Portugal had raised concerns over the health of the population. At least 35 turtles had died during late July and August – 9 times the normal amount. The Institute for Nature Conservation and Biodiversity (ICNB) investigated the deaths and came to the conclusion that human activities had caused the deaths. They believe that warming waters due climate change is encouraging turtles to swim closer to the shoreline which increases interaction with humans.
Most of the dead turtles have been washed up along the eastern section of Algarve and are predominately loggerhead turtles which are common in the region. The situation appears to be very localised although Portuguese authorities are liaising with their Spanish counterparts to determine if the problem is more widespread. While no turtles have yet been washed up on Spanish beaches the authorities have reported higher than normal numbers of turtles in their waters. Climate change and warming seas are thought to be changing the habits of turtles and encouraging them into shore which brings them into contact with human activities such as boating, sailing and fishing.
When the bodies of turtles first started appearing their were concerns that a virus or disease may have been causing the deaths and there were fears of an epidemic in the species. The Portuguese conservation organisation ICNB were called in to undertake further studies and investigate the cause of the deaths. While results of some tests are still be awaited the initial findings are that all the deaths have been caused by human interaction. Physical wounds on the turtles show evidence of either entanglement with fishing gear or collision with boats.
“The significant rise in sea water temperature experienced this summer is, in itself, explanatory for the turtles coming closer to the coastline, where involvement with fishing activities easily accounts for the number of washed-up animals” said the ICNB. “There were also some cases that showed wounds compatible with a run-in with recreational boats”
It concluded “The ICNB, from first observations, considers that there are no indications that these wash-ups are the consequence of a natural epidemiological outbreak, but have originated due to a change in the turtles’ habitat”.
One of the biggest concerns is that while most of the turtles affected have been loggerheads there have also been a case of the critically endangered leatherback turtle being washed ashore. There has also been an incident of a dolphin and whale washing ashore in the region.
photo credit: coda
