Macroparasites in stranded and bycaught harbour porpoises from German and Norwegian waters

Abstract

Parasitological investigations were carried out on harbour porpoises Phocoena phocoena originating from 3 different areas: the German North Sea (28), the German Baltic (18) and Norwegian waters (22). The individuals were bycaught in gill-nets or found stranded during the period 1997 to 2000. A total of 7 species of parasites was identified from the investigated organs. These originated mainly from the respiratory tract and comprised 1 ascaridoid nematode (Anisakis simplex), 4 pseudaliid nematodes (Pseudalius inflexus, Torynurus convolutus, Halocercus invaginatus, Stenurus minor) and 2 trematodes (Campula oblonga, Pholeter gastrophilus). This is the first geographic record of H. invaginatus from German waters. Differences were found in the severity of the parasitic infection between stranded and bycaught animals as well as between porpoises from different areas. A correlation was shown between parasitic infection and observed lesions.

Parasites in harbour seals (Phoca vitulina) from the German Wadden Sea between two Phocine Distemper Virus epidemics

“…In contrast, the harbour porpoise (Phocoena phocoena) calving in the same habitat does not exhibit strong age-dependent lungworm infections (Lehnert et al 2005), although lungworm species of harbour porpoises and harbour seals are quite closely related (Carreno and Nadler 2003) and the lifecycles therefore may be similar (K. Lehnert et al unpublished data). The diVerences might be due to the longer lactation period of porpoises of about 8 months (Møhl-Hansen 1954).…”

Pulmonary Vascular Proliferation and Lungworm (Stenurus ovatus) in a Bottlenose Dolphin (Tursiops turncatus)

“…Infection with lungworm has been commonly found in the European countries and cause subacute to chronic bronchitis and bronchiolitis [2,6,8,10]. Parasitologically, Stenurus ovatus was found in the esophagus and stomach of the bottlenose dolphin.…”

“…The cause of angiomatosis has not been clarified, and a broad field defect of vascular endothelium has been speculated [9]. On the other hand, nematode infection of the bronchial tract was commonly found in harbor porpoises stranded in United Kingdom, Belgium and Germany [2,6,8,10]. In the bottlenose dolphin, 2 species of lungworms have been reported: Halocercus lagenorhynchus [3,4] and Stenurus ovatus [1,5].…”

Eighteen-Year Study of South Australian Dolphins Shows Variation in Lung Nematodes by Season, Year, Age Class, and Location

“…Of the cetaceans, the harbor porpoise (Phocoena phocoena) has been particularly well studied, with studies in the Baltic Sea finding a relationship between water pollution and lung nematode infections (Siebert et al, 2001). A difference in severity of parasite infections was observed between stranded and by-caught harbor porpoises from German and Norwegian waters (Lehnert et al, 2005). Baker (1992) and Gibson et al (1998) investigated mortality and incidental lesions in a range of dolphins and whales from British waters.…”

“…Studies have been conducted in Europe, the USA, Japan, and Hong Kong (Measures, 2001) but these locations are likely to be areas of high observer effort rather than true hot spots of nematode infection in marine mammals. Most studies have concentrated on the taxonomy of the nematodes (Baylis and Daubney, 1925;Johnston and Mawson, 1941;Arnold and Gaskin, 1975;Raga et al, 1987;Balbuena et al, 1994;Gibson et al, 1998;Lehnert et al, 2005) or the pathology of host species (Testi and Pilleri, 1969;Woodard et al, 1969;Dailey and Stroud, 1978;Viale, 1981;Tsocheva et al, 1992;Parsons et al, 1999;Siebert et al, 2001;Bossart et al, 2003;Kuwamura et al, 2007). Of the cetaceans, the harbor porpoise (Phocoena phocoena) has been particularly well studied, with studies in the Baltic Sea finding a relationship between water pollution and lung nematode infections (Siebert et al, 2001).…”