Heartworm and seal louse: Trends in prevalence, characterisation of impact and transmission pathways in a unique parasite assembly on seals in the North and Baltic Sea.

The ectoparasitic seal louse, infects harbour () and grey seals () in the North and Baltic Sea. The endoparasitic heartworm parasitizes the right heart and blood vessels of harbour seals. The complete lifecycle of the heartworm is not entirely understood although the seal louse is assumed to serve as vector for its transmission.

Attachment performance of the ectoparasitic seal louse Echinophthirius horridus.

Marine mammals host a great variety of parasites, which usually co-evolved in evolutionary arms races. However, little is known about the biology of marine mammal insect parasites, and even less about physical aspects of their life in such a challenging environment. One of 13 insect species that manage to endure long diving periods in the open sea is the seal louse, Echinophthirius horridus, parasitising true seals.

Heartworms in : first records of (Onchocercidae; Filarioidea) in 2 grey seals from the North Sea.

The assumed definitive host of the heartworm (Onchocerdidae; Filarioidea) is the harbour seal (). This filaroid nematode parasitizing in cardiac ventricles and blood vessel lumina of harbour seals () has a low prevalence and seldom causes severe health impacts. The seal louse () is the assumed intermediate host for transmission of filariae between seals, comprising a unique parasite assembly conveyed from the terrestrial ancestors of pinnipeds.

Variation of blubber thickness for three marine mammal species in the southern Baltic Sea.

Evaluating populational trends of health condition has become an important topic for marine mammal populations under the Marine Strategy Framework Directive (MSFD). In the Baltic Sea, under the recommendation of Helsinki Commission (HELCOM), efforts have been undertaken to use blubber thickness as an indicator of energy reserves in marine mammals. Current values lack geographical representation from the entire Baltic Sea area and a large dataset is only available for grey seals () from Sweden and Finland.

Deciphering Eurasian otter (Lutra lutra L.) and seal (Phoca vitulina L.; Halichoerus grypus F.) diet: Metabarcoding tailored for fresh and saltwater fish species.

Long-lived top predators shape biodiversity structure in their ecosystems and predator-prey interactions are critical in decoding how communities function. Studies on the foraging ecology of seals and Eurasian otters in Western Europe are outdated and most studies solely performed traditional hard part analysis. Molecular metabarcoding can be used as an innovative noninvasive diet analysis tool, which has proven efficient and complementary to hard part analysis, however, lacking application in the wider North Sea area.

Whale lice ( & ; Cyamidae) prevalence in odontocetes off the German and Dutch coasts - morphological and molecular characterization and health implications.

Whale lice (Cyamidae; Amphipoda) are ectoparasitic crustaceans adapted to the marine environment with cetaceans as their host. There are few reports of cyamids occurring in odontocetes from the North Sea, and long-term studies are lacking. Marine mammal health was monitored along the German and Dutch coasts in the past decades, with extensive post mortem investigations conducted.

Lungworm infections in harbour porpoises () in the German Wadden Sea between 2006 and 2018, and serodiagnostic tests.

Pseudaliid lungworm (Metastrongyloidea) infections and associated secondary bacterial infections may severely affect the health status of harbour porpoises () in German waters. The presented retrospective analysis including data from 259 harbour porpoises stranded between 2006 and 2018 on the German federal state of Schleswig-Holstein's North Sea coast showed that 118 (46%) of these stranded individuals harboured a lungworm infection. During this 13-year period, a significant difference in annual lungworm prevalence was only observed between the years 2006 and 2016.

Preliminary study of oxidative stress biomarkers and trace elements in North Sea Harbour Seals.

This preliminary study investigated the potential correlations between trace elements (mercury, zinc, cadmium, copper, selenium, lead, nickel, chromium, lithium and vanadium) concentrations, measured in red blood cells, and oxidative stress biomarkers (total thiols, total glutathione, total and selenium-dependent glutathione peroxidases, triglycerides, malondialdehyde) assessed in the respective serum, in males and females P. vitulina, sampled in the Wadden Sea in spring and autumn 2015. Only concentrations of total mercury and zinc showed significant differences by sex, and only lipid peroxidation was different by season.

Pathological Findings in White-Beaked Dolphins () and Atlantic White-Sided Dolphins () From the South-Eastern North Sea.

In the North Sea, white-beaked dolphins () occur regularly and are the second most common cetacean in the area, while their close relative, the Atlantic white-sided dolphin (), prefers the deeper waters of the northern North Sea and adjacent Atlantic Ocean. Though strandings of both species have occurred regularly in the past three decades, they have decreased in the southern North Sea during the last years. Studies describing necropsy findings in stranded spp.

Anisakid nematode species identification in harbour porpoises () from the North Sea, Baltic Sea and North Atlantic using RFLP analysis.

Harbour porpoises () are the only native cetacean species in the German North and Baltic Seas and the final host of (.) , which infects their first and second gastric compartments and may cause chronic ulcerative gastritis. belongs to the family Anisakidae (Ascaridoidea, Rhabditida) as well as the phocine gastric nematode species (.

Health effects from contaminant exposure in Baltic Sea birds and marine mammals: A review.

Here we review contaminant exposure and related health effects in six selected Baltic key species. Sentinel species included are common eider, white-tailed eagle, harbour porpoise, harbour seal, ringed seal and grey seal. The review represents the first attempt of summarizing available information and baseline data for these biomonitoring key species exposed to industrial hazardous substances focusing on anthropogenic persistent organic pollutants (POPs).

Novel infections of Corynosoma enhydri and Profilicollis sp. (Acanthocephala: Polymorphidae) identified in sea otters Enhydra lutris.

Infectious disease is a major cause of mortality for sea otters Enhydra lutris, a keystone species of continued concern for conservationists. Parasitic infection has long been identified as a cause of mortality in otters in both Alaska and California, USA. Corynosoma enhydri (Acanthocephala) is the only parasite that uses sea otters as its primary definitive host and is highly prevalent in otter populations; however, it is generally considered unimportant both pathologically and ecologically, although this assumption is based on limited empirical knowledge.

Pathological findings in North Sea and Baltic grey seal and harbour seal intestines associated with acanthocephalan infections.

Grey seals Halichoerus grypus and harbour seals Phoca vitulina are common seal species in the North and Baltic seas and final hosts of Corynosoma acanthocephalans. C. strumosum and C.

A review of pathogens in selected Baltic Sea indicator species.

Here we review the state-of-the-art of pathogens in select marine and terrestrial key species of the Baltic Sea, i.e. ringed seal (Pusa hispida), harbour seal (Phoca vitulina), grey seal (Halichoerus grypus), harbour porpoise (Phocoena phocoena), common eider (Somateria mollissima), pink-footed goose (Anser brachyrhynchus) and white-tailed eagle (Haliaeetus albicilla).

Phylogenomic insights to the origin and spread of phocine distemper virus in European harbour seals in 1988 and 2002.

The 1988 and 2002 phocine distemper virus (PDV) outbreaks in European harbour seals Phoca vitulina are among the largest mass mortality events recorded in marine mammals. Despite its large impact on harbour seal population numbers, and 3 decades of studies, many questions regarding the spread and temporal origin of PDV remain unanswered. Here, we sequenced and analysed 7123 bp of the PDV genome, including the coding and non-coding regions of the entire P, M, F and H genes in tissues from 44 harbour seals to shed new light on the origin and spread of PDV in 1988 and 2002.

There and back again - The return of the nasal mite to seals in German waters.

The nasal mite (Acari; Halarachnidae) is adapted to live in the marine environment with pinnipeds as its primary host and can cause different levels of upper respiratory disease in both harbour seals () and grey seals (). Historical reports of occurring in seals from German waters date back to the end of the 19th century. However, with the disappearance of the grey seal from German waters as a consequence of human over-exploitation, the mite vanished from the records and the fauna found in Germany for more than a century.

Cytokine expression and lymphocyte proliferative capacity in diseased harbor porpoises (Phocoena phocoena) - Biomarkers for health assessment in wildlife cetaceans.

Harbor porpoises (Phocoena phocoena) in the North and Baltic Seas are exposed to anthropogenic influences including acoustic stress and environmental contaminants. In order to evaluate immune responses in healthy and diseased harbor porpoise cells, cytokine expression analyses and lymphocyte proliferation assays, together with toxicological analyses were performed in stranded and bycaught animals as well as in animals kept in permanent human care. Severely diseased harbor porpoises showed a reduced proliferative capacity of peripheral blood lymphocytes together with diminished transcription of transforming growth factor-β and tumor necrosis factor-α compared to healthy controls.

CRYPTOSPORIDIUM SPECIES AND GIARDIA SPECIES PREVALENCE IN MARINE MAMMAL SPECIES PRESENT IN THE GERMAN NORTH AND BALTIC SEAS.

Marine mammals are known to harbor Cryptosporidium spp. and Giardia spp., especially species or genotypes commonly associated with humans.

Beached bachelors: An extensive study on the largest recorded sperm whale Physeter macrocephalus mortality event in the North Sea.

Between the 8th January and the 25th February 2016, the largest sperm whale Physeter macrocephalus mortality event ever recorded in the North Sea occurred with 30 sperm whales stranding in five countries within six weeks. All sperm whales were immature males. Groups were stratified by size, with the smaller animals stranding in the Netherlands, and the largest in England.