Abundance of Sea Kraits Correlates with Precipitation

Abstract

Recent studies have shown that sea kraits (Laticauda spp.) – amphibious sea snakes – dehydrate without a source of fresh water, drink only fresh water or very dilute brackish water, and have a spatial distribution of abundance that correlates with freshwater sites in Taiwan. Here we report six years of longitudinal data on the abundance of sea kraits related to precipitation at these sites in the coastal waters of Orchid Island, Taiwan. The abundance of sea kraits varies from year to year and correlates positively with previous 6‐mo cumulative rainfall, which is an inverse index of drought. Grouped data for snake counts indicate that mean abundance in wet years is nearly 3X greater than in dry years. These data complement previous findings and suggest that freshwater dependence influences the abundance of sea kraits on both spatial and temporal scales. Increasing evidence for freshwater dependence in these and other marine species have important implications for the possible impact of climatic change on sea snake distributions. Funding was provided by the National Geographic Society (CER grant #8058‐06 to HBL), the U.S. National Science Foundation grant IOS‐0926802 to HBL, and Taiwan NSC grant 97‐2621‐B‐003‐004‐MY3 to M‐C Tu.