Marine Mammals as Environmental Sentinels Focusing on Mercury Contamination

The Strait of Messina is located at the centre of the Mediterranean Sea and is considered a biodiversity hotspot and an obligatory seasonal passage for different pelagic species such as sharks, marine mammals, and billfishes. For the first time, in the Strait of Messina, our research group tagged a Mediterranean spearfish (Tetrapturus belone) using a pop-up satellite archival tag (PSAT). The observation of abiotic parameters (depth, light, and temperature) recorded by the PSAT confirmed that the tagged specimen was predated after about nine hours. The tag was then regurgitated 14 days after the tag deployment date. The analysis of collected data seems to indicate that the predator may be an ectothermic shark, most likely the bluntnose sixgill shark (Hexanchus griseus).

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Marine mammals are natural hosts of Oceanivirga salmonicida, a bacterial pathogen of Atlantic salmon

Diseases of Aquatic Organisms ◽

10.3354/dao03478 ◽

2020 ◽

Vol 139 ◽

pp. 161-174

Author(s):

R Palmer ◽

GTA Fleming ◽

S Glaeser ◽

T Semmler ◽

A Flamm ◽

...

Keyword(s):

16S Rrna ◽

Atlantic Salmon ◽

16S Rrna Gene ◽

Marine Mammals ◽

Rrna Gene ◽

Bacterial Disease ◽

Common Dolphin ◽

Stenella Coeruleoalba ◽

Striped Dolphin ◽

Natural Hosts

During 1992 and 1993, a bacterial disease occurred in a seawater Atlantic salmon Salmo salar farm, causing serious mortalities. The causative agent was subsequently named as Oceanivirga salmonicida, a member of the Leptotrichiaceae. Searches of 16S rRNA gene sequence databases have shown sequence similarities between O. salmonicida and uncultured bacterial clones from the digestive tracts of marine mammals. In the current study, oral samples were taken from stranded dolphins (common dolphin Delphinus delphis, striped dolphin Stenella coeruleoalba) and healthy harbour seals Phoca vitulina. A bacterium with growth characteristics consistent with O. salmonicida was isolated from a common dolphin. The isolate was confirmed as O. salmonicida, by comparisons to the type strain, using 16S rRNA gene, gyrB, groEL, and recA sequence analyses, average nucleotide identity analysis, and MALDI-TOF mass spectrometry. Metagenomic analysis indicated that the genus Oceanivirga represented a significant component of the oral bacterial microbiomes of the dolphins and seals. However, sequences consistent with O. salmonicida were only found in the dolphin samples. Analyses of marine mammal microbiome studies in the NCBI databases showed sequences consistent with O. salmonicida from the common dolphin, striped dolphin, bottlenose dolphin Tursiops truncatus, humpback whale Megaptera novaeangliae, and harbour seal. Sequences from marine environmental studies in the NCBI databases showed no sequences consistent with O. salmonicida. The findings suggest that several species of marine mammals are natural hosts of O. salmonicida.

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First in situ passive acoustic monitoring for marine mammals during operation of a tidal turbine in Ramsey Sound, Wales

Marine Ecology Progress Series ◽

10.3354/meps12467 ◽

2018 ◽

Vol 590 ◽

pp. 247-266 ◽

Cited By ~ 8

Author(s):

CE Malinka ◽

DM Gillespie ◽

JDJ Macaulay ◽

R Joy ◽

CE Sparling

Keyword(s):

Marine Mammals ◽

Acoustic Monitoring ◽

Passive Acoustic Monitoring ◽

Tidal Turbine ◽

Passive Acoustic

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Reply to Comment on Grahl-Nielsen et al. (2003): sampling, data treatment and predictions in investigations on fatty acids in marine mammals

Marine Ecology Progress Series ◽

10.3354/meps281303 ◽

2004 ◽

Vol 281 ◽

pp. 303-306 ◽

Cited By ~ 8

Author(s):

O Grahl-Nielsen ◽

M Andersen ◽

AE Derocher ◽

C Lydersen ◽

Ø Wiig ◽

...

Keyword(s):

Fatty Acids ◽

Marine Mammals ◽

Data Treatment

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Ecology and biogeography in the introduction to “De bestiis marinis” by Georg Wilhelm Steller

Archives of Natural History ◽

10.3366/anh.2019.0554 ◽

2019 ◽

Vol 46 (1) ◽

pp. 63-74

Author(s):

Stefano Mattioli

Keyword(s):

Body Size ◽

Phenotypic Plasticity ◽

Geographical Distribution ◽

Functional Traits ◽

Marine Mammals ◽

Main Part ◽

Wide Distribution ◽

Restricted Range ◽

Direct Influence ◽

Modern Biology

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.

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