No abstract

This study reviews and updates information on cetacean strandings in the state of Ceará, Brazil (02830 0 S 41815 0 W-04830 0 S 36845 0 W), comprising 573 km of coastline. In the years 1992-2005, there were 252 cetacean stranding events, representing 19 species: three species of Balaenopteridae, three Physeteridae, two Kogiidae, two Ziphiidae and 11 Delphinidae. Three species comprised the majority (78.9%) of stranding events: estuarine dolphin, Sotalia guianensis (61.9%); sperm whale, Physeter macrocephalus (10.3%); and rough-toothed dolphin, Steno bredanensis (6.7%). There was an increasing trend in the number of cases reported in the first five years with a highest frequency achieved in 1996. Stranding events occurred throughout the year, with the lowest frequency occurring in the autumn (March-May). Approximately 4% of the events were attributed to natural causes while 24.6% were human-related, mainly incidental captures. Meat removal for human consumption or bait was recorded in 6.7% of events. In the study area, Sotalia guianensis, P. macrocephalus and Steno bredanensis were the most abundant cetacean species, whereas Lagenodelphis hosei, Pseudorca crassidens, Orcinus orca, Kogia sima, Mesoplodon europaeus, Balaenoptera acutorostrata and Balaenoptera bonaerensis are probably rare in the area.

Manatee mortality in Ceará State (north-eastern Brazil) is analysed from twenty-five strandings between 1987 and 2002. The majority of the causes were related to the ‘dependent calf’ category (83.3%). Direct human-related causes were attributed to incidental catches in fishing gear (shrimp trawling and gill-nets) (12.5%) and direct capture (4.2%). Spatial distribution was not uniform, with the highest number of strandings on the east coast. The number of strandings has increased since 1999, and the seasonal distribution showed peaks in February, March and January, in that order. The stranding of manatee calves in Ceará State seems to be indirectly related to human activities that impact coastal nursing habitats.

This study represents the first survey of the parasitic fauna of cetaceans off the northeastern coast of Brazil. Parasites were collected from 82 animals rescued from the states of Ceará to Bahia, including the archipelago of Fernando de Noronha. A total of 14 species of cetaceans were evaluated: Sotalia guianensis, Stenella sp., Stenella clymene, Stenella longirostris, Stenella coeruleoalba, Stenella frontalis, Megaptera novaeangliae, Peponocephala electra, Steno bredanensis, Kogia breviceps, Kogia sima, Globicephala macrorhynchus, Tursiops truncatus, Physeter macrocephalus and Lagenodelphis hosei. The parasites were fixed and preserved in 70% ethanol or alcohol-formalin-acetic acid solution (AFA), clarified in phenol and mounted on slides for morphological identification. In total, 11 species and 8 genera of endo- and ectoparasites were identified: Halocercus brasiliensis, Halocercus kleinenbergi, Stenurus globicephalae, Halocercus sp., Anisakis sp., Crassicauda sp. (Nematoda), Phyllobothrium delphini, Monorygma grimaldii, Scolex pleuronectis, Strobicephalus triangularis, Tetrabothrius forsteri, Tetrabothrius sp., Trigonocotyle sp., Diphyllobothrium sp. (Cestoda), Campula sp. (Trematoda), Bolbosoma sp. (Acanthocephala), Cyamus boopis, Syncyamus pseudorcae and Xenobalanus globicipitis (Crustacea). The identification of some species represented novel records for the country and increased the occurrence of some parasites to new hosts. The use of standardized methodologies for collecting and evaluating a larger number of animals is essential for a better understanding of host-parasite relationships in cetaceans and their use as biological indicators in the region.

No abstract