However, while this is obviously worrying for a species that is categorized as critically endangered, there is one important factor that needs to be taken into consideration when reviewing these numbers — leatherbacks, unlike most species of sea turtles, often move between different nesting beaches, sometimes even within a single nesting season. We have discovered these movements from tag returns reported by other turtle conservation projects in Costa Rica and Panama. Researchers have encountered turtles with tags from Tortuguero nesting on their beaches, and vice versa. What this means is that the leatherback females nesting at these different beaches are all part of the same population. Therefore, we can’t look at the situation at Tortuguero in isolation; we need to consider how leatherbacks are doing at the other nesting beaches along the coast.
STC also runs a sea turtle conservation program at Chiriquí Beach, Panama, so we can compare the leatherback nesting trend there with what we are seeing at Tortuguero. Fortunately, what we have found since the start of monitoring activities at Chiriquí Beach is the opposite of what we’re seeing at Tortuguero. There has been an overall increase in the number of leatherback nests, with some annual variation. Every year, between 3,000 – 7,000 leatherback nests are reported at this beach, making it one of the most important leatherback nesting beaches in Central America.
What does this mean for leatherbacks and efforts to conserve them? First, it’s not a straightforward situation of looking at trends at individual beaches; the situation is far more complex. Second, it is important to communicate with other organizations running sea turtle monitoring programs at nesting beaches in Costa Rica and Panama, to gather valuable information about leatherback movements. And third, we need to find out if there has been a general shift in nesting patterns due to something that may be happening at Tortuguero beach, making it less attractive as a nesting site for this species.
All of which means we definitely have our work cut out for us to make sure we can effectively conserve these magnificent creatures.
To end on a positive note, this year’s Leatherback Monitoring Program has been running since the beginning of March in Tortuguero, and from the data collected so far it looks as if the 2012 nesting season may be better than in the last few years. Already, 161 leatherback nests have been recorded along the 18 miles of Tortuguero beach. In 2011, a total of just 319 nests were counted for the entire season, and we still have the peak months to come. STC remains hopeful that our sustained conservation efforts at Tortuguero will eventually produce a positive trend for leatherbacks at this famed beach, as we are seeing at our project site in Panama.