| Summary: | Tese de doutoramento em Biociências, na especialidade de Ecologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra The impacts of human-based environmental change on the global oceans have been increasing exponentially in the last decades. The main environmental change factors affecting marine ecosystems are those related to climate change and fishery activities, whose impacts are widely distributed and have profound effects in the marine biodiversity. Top-predators, like seabirds, experience the effects of those changes in many different levels, from the individual – affecting behaviour, movement, body condition and breeding success – up to the community level – species shifts and change in species interaction with cascading consequences through the food webs. In this thesis, I explored the risks imposed by changing environmental conditions triggered by fisheries and climate change over the spatial distribution of seabird species, and pointed out ways to minimize the impacts of those risks on seabirds. I used year-round geolocator tracking data from 14 seabird species breeding in Islands of the South and North Atlantic Ocean: Wandering Albatross (Diomedea exulans), Tristan Albatross (D. dabbenena), Black-browed Albatross (Thalassarche melanophris), Grey-headed Albatross (T. chrysostoma), Southern (Macronectes giganteus) and Northern (M. halli) Giant Petrels, White-chinned Petrel (Procellaria aequinoctialis), Trindade (Pterodroma arminjoniana) and Deserta’s (P. deserta) Petrels, Antarctic Prion (Pachyptila desolata), Cory’s (Calonectris borealis), Cape Verde (C. edwardsii), Manx (Puffinus puffinus) and Great (Ardenna gravis) Shearwaters. Such data were used to quantify home range, ecological niches, overlap with fisheries, and to project distribution towards different scenarios of climate change and fishing activities. The main findings of this thesis are: 1) there is a potential causal link between seabirds’ individual features and overlap with ...
|
|---|