Spare a thought for the World’s Smallest Turtle

Posted on Sep 7, 2012 Guest blogs, Network News | Comments Off on Spare a thought for the World’s Smallest Turtle

At just 2 feet in shell length and weighing up to 100 pounds, the Olive Ridley turtle is one of the world’s smallest species of sea turtles. They are solitary species and prefer the open water, however come together once a year when females return to the beaches where they hatched to nest, this is known as an “arribada”.

This turtle is listed as vulnerable (VU) on the IUCN Red List.  Whilst it is one of the more abundant of the marine turtle populations with approximately 800,000 nesting females, their numbers are still dwindling.  On the other hand these declines do vary in severity in different regions, for example in the United States; the western Atlantic Olive Ridley population is described as endangered (EN).

Many governments which have nesting females have protection action plans in place; however problems for this species are still persisting.  Natural pressures such as beach erosion, climate change and predators both on land and in the sea have always decreased surviving hatchling numbers.  Couple this with anthropogenic threats such as directly harvesting the adults at sea for commercial sales of both the meat and hides, and indirectly drowning turtles through by catches, means populations are spiraling downhill. Another major threat which has significantly impacted their population size is mortality associated with boat collisions and incidental takes in fisheries. During 1993–2003, it was estimated that more than 100,000 turtles were reported dead in Orissa, India from fishery-related practices.

However, it appears the greatest threat this species faces is from unsustainable egg nesting.  Large groups of turtles gather off shore near nesting beaches, this amount of nest sites can cause confusion leading to nests being inadvertently dug up and destroyed by other nesting females. In some cases nests become cross-contaminated by bacteria or pathogens of rotting nests. For example, in Playa Nancite, Costa Rica, only 0.2% of the 11.5 million eggs produced in a single arribadas event are successfully hatched.  Many believe that the massive reproductive output of these nesting events are critical to maintaining populations, while others maintain that traditional arribada beaches fall far short of their reproductive potential and are most likely not sustaining population levels.

By Eleanor Smith