Cetáceos na Zona Económica Exclusiva Continental Portuguesa: distribuição espaço-temporal e registo de novas ocorrências
Gil, A. (2018). Cetáceos na Zona Económica Exclusiva Continental Portuguesa: distribuição espaço-temporal e registo de novas ocorrências. MA Thesis. Faculdade de Ciências da Universidade do Porto (FCUP): Porto. 86 pp.
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| Keyword |
Phocoena phocoena (Linnaeus, 1758) [WoRMS]
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| Author keywords |
observational platforms of opportunity, relative abundance, habitat preferences, mouth of Douro river |
| Abstract |
Cetaceans are key species in marine ecosystems, and the knowledge of their distribution patterns is fundamental for the conservation and management of the Ocean. In the portuguese continental waters, 24 species of cetaceans are known, however data on their occurrence along the coast is fragmented and scarce. As a Member-State of the European Union, covered by the Marine Strategy Framework Directive, Portugal has the obligation to evaluate its level of environmental monitoring, which, as recommended by the Directive, implies that information on several descriptors associated with cetaceans are presented. Moreover, specifically for the species Phocoena phocoena (harbour porpoise), included in the Annex II of the European Habitats Directive, Member-States are requested to designate special areas of conservation. Hence, this thesis aimed at presenting: 1) the spatio-temporal patterns of distribution for cetacean species in the continental Economic Exclusive Zone (EEZ) of Portugal; 2) the first records of a group of harbour porpoises in the mouth of Douro river. Data on occurrence in the continental EEZ was collected within CETUS Project, since 2012, using platforms of opportunity; and in the mouth of Douro river, monitoring was performed from a fixed station in land, since 2017. The use of platforms of opportunity resulted in 43243 Km surveyed in the portuguese continental EEZ, in the identification of 19 species and the register of 962 sightings of cetaceans, 686 on-effort, totaling an encounter rate of 1,59 sightings per 100 Km. Delphinus delphis (common dolphin) was the most frequently sighted species, which is in line with data previously published. In the mouth of Douro river, 26 surveys were performed, resulting in 22 sightings of a group of harbour porpoises with, at least, four individuals. One of the animals is leucistic, a rare condition worldwide. These registers are the first in the region and the most recent presented in estuarine areas of Portugal. Several priorities for research were defined: 1) year-round surveys to assess/confirm the degree of occurrence and seasonality of the species; 2) dedicated surveys in the coastal waters of the North of Portugal and in the Gorringe, areas pointed by the results as preferable for several species; 3) dedicated study of the group of harbour porpoises in the mouth of Douro river, through several methodologies. |
| Dataset |
- Correia, A.M., Oliveira-Rodrigues, C., Gandra, M., Liberal, M., Valente, R., Gil, A., Rosso, M., Pierce, G.J. & Sousa-Pinto, I., CIIMAR - UP. (2022). CETUS: Cetacean monitoring surveys in the Eastern North Atlantic. Marine Data Archive., more
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