Estimating life‐history traits and understanding their variation underpins the management of long‐lived, migratory animals, while knowledge of recovery dynamics can inform the management of conservation‐dependent species. Using a combination of nest counts and individual‐based life‐history data collected since 1993, we explore the drivers underlying contrasting population recovery rates of sympatrically nesting loggerhead (Caretta caretta) and green (Chelonia mydas) turtles in North Cyprus. We found that nest counts of loggerhead and green turtles from 28 beaches across the island increased by 46% and 162%, respectively over the past 27 years. A Bayesian state‐space model revealed that, at our individual‐based monitoring site, nesting of green turtles increased annually at four times the rate of that of loggerhead turtles. Furthermore, we found that loggerhead turtles nesting at the individual‐based monitoring site had stable reproductive parameters and average adult survival for the species and are the smallest breeding adults globally. Based on results from multiple matrix model scenarios, we propose that higher mortality rates of individuals in all age classes (likely driven by differences in life history and interaction with fisheries), rather than low reproductive output, are impeding the recovery of this species. While the increase in green turtles is encouraging, the Mediterranean population is estimated to have around 3,400 adults and is restricted to the Eastern Basin. The recovery of loggerhead turtles is likely to be compromised until mortality rates in the region are adequately quantified and mitigated. As survival of immature individuals is a powerful driver for sea turtle population numbers, additional efforts should target management at pelagic and neritic foraging areas. Understanding threats faced by immature life stages is crucial to accurately parameterise population models and to target conservation actions for long‐lived marine vertebrates.
30 June 2021 in Marine Science and Technology Bulletin
Blunthead puffer Sphoeroides pachygaster (Müller and Troschel, 1848) is a circumglobally distributed Tetraodontid found in temperate and tropical waters. It is believed to have colonized the Mediterranean Sea from the Atlantic Ocean. There are relatively few records of this fish in the Mediterranean Sea. On March 2020, a mature female individual was caught incidentally by a commercial fisher in Northern Cyprus. The fish was 520 mm in total length and 1200 grams in total weight. Detailed morphometrics and meristics were reported. This study is the first substantiated record of S. pachygaster from Cyprus waters, and the specimen is the largest blunthead puffer reported with a 455 mm standard length and 520 mm total length.