Preliminary data on the occurrence of marine turtles in the Laje de Santos Marine State Park (SP, Brazil)

Abstract Although marine turtles have always been observed by divers, there are few scientific works on marine turtles in the Laje de Santos Marine State Park (PEMLS). Diurnal (bimonthly) and nocturnal (biannual) surveys were conducted between 2013 and 2015 for a more comprehensive study, totalizing 42 hours of diurnal observations and the capture of 41 turtles during nocturnal dives. During the diurnal surveys, visual observations were made from two land based sites (Paredão da Face Sul and Portinho). The numbers of heads (heads observed whether they are of the same turtle or not) and turtles (individuals observed in groups) were counted. The results showed the presence of marine turtles throughout the year. More turtles were observed from Paredão da Face Sul than from Portinho, the latter being a more sheltered point and a site preferred by divers. The nocturnal surveys consisted of the capture of turtles through scuba diving so they could be measured and weighed and tagged according to the guide-lines of the TAMAR project. Four nocturnal surveys were conducted and in the last survey three tagged turtles were captured, two of them having been tagged during this study. The measurements of these turtles indicated their growth during the study period.The present survey also highlighted the importance of the PEMLS as a feeding area for juvenile marine turtles.

摘要 尽管潜水员长期以来均有观测到海龟，但针对圣多斯礁海洋州立公园（Laje de Santos Marine State Park，以下简称PEMLS）内海龟的学术研究仍较为匮乏。为开展更全面的研究，研究团队于2013至2015年间开展了日间（每两月一次）与夜间（每年两次）调查，累计完成42小时日间观测，并在夜间潜水过程中捕获41只海龟。日间调查依托两个陆基观测点（南崖观测点Paredão da Face Sul与波蒂纽港Portinho）开展目视观测，统计指标包括露头频次（无论是否为同一只海龟，仅统计单次露头记录）与海龟个体数（集群观测到的独立个体数量）。结果显示，该区域全年均有海龟活动；南崖观测点记录到的海龟数量多于波蒂纽港，后者水域更为隐蔽，是潜水员青睐的观测点位。夜间调查采用水肺潜水方式捕获海龟，随后依据TAMAR项目（TAMAR Project）的操作规范对其进行测量、称重并加装生物标记。本次研究共开展4次夜间调查，末次调查中捕获3只已标记海龟，其中2只为本次研究期间完成标记的个体。对这些海龟的测量数据表明，其在研究周期内实现了生长。本项调查同时证实了PEMLS作为幼年海龟觅食栖息地的重要价值。