Understanding the Patterns and Causes of Variability in Distribution, Habitat Use, Abundance, Survival and Reproductive Rates of Three Species of Cetacean in the Alboran Sea, Western Mediterranean.

摘要

The question of how environmental variability affects populations of marine top predators is an important one because of their role within ecosystems and their potential to influence community structure and biodiversity (Heithaus et al. 2008). An understanding of the patterns of distribution and abundance and particularly the causes of that variation is critical to making informed assessments of the importance of anthropogenic activities to marine mammal populations. This project aimed at quantifying changes in distribution, habitat use, abundance, survival and reproductive rates of three species of cetacean in the Albor n Sea (western Mediterranean) in relation to variation in the physical and biological environment and human activities, based on 18 years of data. The study species, bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus delphis) and long-finned pilot whale (Globicephala melas) occupy different oceanographic niches off southern Spain. The Albor n Sea is a highly productive and distinct ecosystem that plays an important role in the oceanography of the Mediterranean basin, and has experienced marked changes in climatic and oceanographic conditions. We attempted to relate features of a species biology to environmental change, particularly climate change, focusing on distribution, abundance and estimated reproductive and survival rates. The two last ones provide information on the mechanisms that cause distribution and abundance to change. Knowledge of these relationships will help us to predict the future impacts of environmental change in a way that studies of distribution and abundance alone cannot. This project aimed at doing this using a two decades dataset on bottlenose and common dolphin and pilot whale in the Albor n Sea and the time series of environmental changes generated by NOAA OceanWatch.