Isolation and cross-species amplification of novel microsatellite loci in a charismatic marine mammal species, the northern elephant seal (Mirounga angustirostris)

Methylmercury (MeHg) is a potent neurotoxin that is biomagnified approximately 1–10 million-fold in aquatic carnivores such as the Northern elephant seal (Mirounga angustirostris), whose excreta and molted pelage, in turn, constitute a source of environmental MeHg contamination at the base of marine food chains. The potential for this top-down contamination is greatest in coastal areas with productive marine ecosystems that provide ideal habitats for large marine mammal colonies that can number in the thousands. This recycling of MeHg was evidenced by comparing total mercury (HgT) and MeHg concentrations in seawater, and HgT in molted pelage of M. angustirostris, at the Año Nuevo State Reserve pinniped rookery with concentrations at neighboring coastal sites in Central California. Seawater MeHg concentrations around the rookery (average = 2.5 pM) were markedly higher than those at the comparison coastal sites (average = 0.30 pM), and were as high as 9.5 pM during the M. angustirostris molting season. As a consequence, excreta and molts from this marine mammal colony, and presumably other marine predator populations, constitute a major source of MeHg at the base of the local marine food chain.

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Click-evoked potentials in a large marine mammal, the adult male northern elephant seal (Mirounga angustirostris)

The Journal of the Acoustical Society of America ◽

10.1121/1.2932063 ◽

2008 ◽

Vol 124 (1) ◽

pp. 44-47 ◽

Cited By ~ 8

Author(s):

Dorian S. Houser ◽

Daniel E. Crocker ◽

James J. Finneran

Keyword(s):

Evoked Potentials ◽

Adult Male ◽

Marine Mammal ◽

Elephant Seal ◽

Mirounga Angustirostris ◽

Northern Elephant Seal

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In-air hearing in Hawaiian monk seals: implications for understanding the auditory biology of Monachinae seals

Journal of Comparative Physiology A ◽

10.1007/s00359-021-01498-y ◽

2021 ◽

Author(s):

Brandi Ruscher ◽

Jillian M. Sills ◽

Beau P. Richter ◽

Colleen Reichmuth

Keyword(s):

Marine Mammals ◽

Elephant Seal ◽

Critical Ratio ◽

Mirounga Angustirostris ◽

Northern Elephant Seal ◽

Hearing Ability ◽

Highly Sensitive ◽

Monk Seals ◽

Management And Conservation ◽

Hearing Abilities

AbstractThe auditory biology of Monachinae seals is poorly understood. Limited audiometric data and certain anatomical features suggest that these seals may have reduced sensitivity to airborne sounds compared to related species. Here, we describe the in-air hearing abilities of a Hawaiian monk seal (Neomonachus schauinslandi) trained to participate in a psychophysical paradigm. We report absolute (unmasked) thresholds for narrowband signals measured in quiet conditions across the range of hearing and masked thresholds measured in the presence of octave-band noise at two frequencies. The behavioral audiogram indicates a functional hearing range from 0.1 to 33 kHz and poor sensitivity, with detection thresholds above 40 dB re 20 µPa. Critical ratio measurements are elevated compared to those of other seals. The apparently reduced terrestrial hearing ability of this individual—considered with available auditory data for a northern elephant seal (Mirounga angustirostris)—suggests that hearing in Monachinae seals differs from that of the highly sensitive Phocinae seals. Exploration of phylogenetic relationships and anatomical traits support this claim. This work advances understanding of the evolution of hearing in amphibious marine mammals and provides updated information that can be used for management and conservation of endangered Hawaiian monk seals.

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