scholarly journals The Sea Otter

Oryx ◽  
1957 ◽  
Vol 4 (3) ◽  
pp. 153-158 ◽  
Author(s):  
Karl W. Kenyon
Keyword(s):  
Marine Mammals ◽  
Sea Urchins ◽  
Sea Otter ◽  
River Otter ◽  
Dry Land ◽  
Insulating Layer ◽  
Marine Life ◽  
Open Sea ◽  
Pacific Waters ◽  
Fur Seal

In general form the sea otter, Enhydra lutris resembles the weasel and river otter, of which animals it is a large relative. The male attains a weight of 85 pounds, the female about 65 pounds; the young at birth weigh from 3 to 5 pounds. It is peculiar among members of its family, the Mustelidae, in having deserted dry land and fresh water to take up a marine life. Among marine mammals it is peculiar in its adaptation to the sea. It does not possess an insulating layer of blubber but is protected from the chill of North Pacific waters by a blanket of air trapped among the fine and closely packed fibres of its inch-long delicate fur. Unlike the river otter and fur seal, the sea otter has but little protective coating of guard hair. The fine guard hairs present add to its beauty but do not offer much protection to the soft under-fur. Unlike other maring mammals, the sea otter has never taken to the open sea. It usually feeds in shallow water from 5 to 50 feet in depth. Its food consist primarily of such sedentary forms as sea urchins, rock oysters, mussels, a variety of snail-like molluscs and, in California, abalones. Occasionally fish and octopus are eaten.

Biology and epidemiology ofToxoplasma gondiiin man and animals

2005 ◽  
Vol 6 (1) ◽  
pp. 41-61 ◽  
Author(s):  
Dolores E. Hill ◽  
Sreekumar Chirukandoth ◽  
J. P. Dubey
Keyword(s):  
Toxoplasma Gondii ◽  
Intermediate Host ◽  
Host Range ◽  
Marine Mammals ◽  
Parasitic Infections ◽  
Sea Otter ◽  
Coccidian Parasite ◽  
Wild Carnivores ◽  
Southern Sea Otter

AbstractToxoplasma gondiiis a coccidian parasite which utilizes felids as definitive hosts, and which has an unusually wide intermediate host range. The parasite was initially described by Nicolle and Manceaux in 1908 from the rodent,Ctenodactylus gundi. Infection withT. gondiiis one of the most common parasitic infections of man and other warm-blooded animals. It has been found worldwide from Alaska to Australia. Nearly one-third of humanity has been exposed to this parasite; serologic surveys indicate thatT. gondiiinfections are common in wild carnivores, including pigs, bears, felids, fox, raccoons, and skunks. Clinical and subclinical toxoplasmosis has been reported from wild cervids, ungulates, marsupials, monkeys, and marine mammals. Southern sea otter populations have been severely impacted byToxoplasmainfections.

Tourist Disturbance On New Zealand Fur Seals (Arctophalus Forsteri)

2002 ◽  
Vol 24 (1) ◽  
pp. 85 ◽  
Author(s):  
LJ Boren ◽  
NJ Gemmell ◽  
KJ Barton
Keyword(s):  
New Zealand ◽  
Marine Mammals ◽  
Effective Management ◽  
Negative Effects ◽  
Management Guidelines ◽  
Tourist Attractions ◽  
Fur Seals ◽  
Fur Seal ◽  
Current Minimum ◽  
The Impact

Marine mammals are significant tourist attractions around New Zealand, however, the impact of eco-tourism on these species is poorly documented. Effective management to mitigate any negative effects requires an understanding of target species? reactions to tourist activities. We have studied the effects of tourist activities on New Zealand fur seals (Arctocephalus forsteri) using a novel combination of observations and controlled approaches. Three study areas were selected reflecting a range of visitor density, type of tourism, and the anticipated sensitivity of fur seals to disturbance. Behaviour was observed using instantaneous scan sampling and attributes of tourist approaches were tested experimentally by controlled approaches. Approaches were made on land, by kayak, and motorboat. Fur seal responses and the distance at which the seal responded were recorded. Our results indicate that A. forsteri behaviour was being modified by tourist activities. Habituation was occurring at study areas with high levels of tourist activity. Approachers following current minimum approach distances still caused some animals to modify their behaviour and new minimum approach distances are recommended based on controlled approaches to seals at all study areas. Our work demonstrated that controlled approaches can be a useful tool to develop effective management guidelines to lessen impacts from eco-tourism activities.

scholarly journals Ecological studies of marine mammals using a seabed-mounted echosounder

2009 ◽  
Vol 66 (6) ◽  
pp. 1029-1036 ◽  
Author(s):  
Lise Doksæter ◽  
Olav R. Godø ◽  
Erik Olsen ◽  
Leif Nøttestad ◽  
Ruben Patel
Keyword(s):  
Marine Mammals ◽  
Principal Component ◽  
Dive Depth ◽  
Trophic Levels ◽  
Target Strength ◽  
Spatial Proximity ◽  
Ecological Studies ◽  
Marine Life ◽  
Deep Scattering Layer ◽  
Temporal And Spatial

Abstract Doksæter, L., Godø, O. R., Olsen, E., Nøttestad, L., and Patel, R. 2009. Ecological studies of marine mammals using a seabed-mounted echosounder. – ICES Journal of Marine Science, 66: 1029–1036. A seabed-mounted, upward-looking, 38 kHz echosounder (Simrad EK60) was used to monitor cetaceans for 128 d between July 2004 and June 2005. The echosounder was placed at 52°N 30°W at a depth of 910 m, in a frontal area with continuous upwelling creating a hotspot of marine life at all trophic levels. Echo tracks were observed, apparently resulting from one or more animals in close temporal and spatial proximity. The 69 “acoustic detections” were examined with a principal component analysis (PCA) considering mean target strength (TS), group size, and maximum dive depth and duration. The PCA conservatively classified 45 of the acoustic detections as “cetaceans”. Their mean TS values varied between −5 and −36 dB, in agreement with earlier TS measurements of whales and dolphins. Several of the supposed cetaceans were apparently feeding in the “deep-scattering layer” when this ascended at night. This study demonstrates that cetacean behaviour, including swimming, feeding, and vocalizing, can be observed and monitored with stationary active-acoustic instrumentation.

scholarly journals Reframing Habitat

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Larry Asakawa ◽  
Jhalak Kara Miller
Keyword(s):  
Marine Mammals ◽  
Visual Media ◽  
The Body ◽  
Video Recordings ◽  
Marine Habitats ◽  
Pacific Waters ◽  
Scientific Analysis ◽  
Human Perceptions ◽  
And Performance ◽  
A Site

In 2016, filmmaker Larry Asakawa and dancer/media artist Jhalak Kara Miller collaborated in Hawai‘i to create a video dance installation and performance called Habitat. Asakawa and Miller, conceived and then subsequently joined with other artists to produce a performance score for the installation, based on solo dances and video recordings that each undertook, produced, and filmed. Habitat explored the interconnections among humans and marine mammals as they relate to the controversial sonar testing activities in Pacific waters. The Habitat performance modalities included visual media, sound, and movement as tools for an embodiment process that might offer human communities a deeper awareness and understanding of the body in a holistic ecosystem. Somatic disciplines that include meditation and dance offer theoretical paradigms to understand the body as a site of knowledge production. Throughout the creative process, the artists ask how personal experiences in these marine habitats may be effectively translated through live embodied performance captured on digital video and then reframed in a gallery video dance installation? Grounded in movement practice, the artists also inquire how the blurry edges of somatic intelligence, feeling, and sensing through the body might focus our human perceptions, go beyond scientific analysis, and inform our intellectual minds to remember to care for the planet we live on?

scholarly journals The Great Global Fish Count (GGFC): A Potential Project of the UN Ocean Decade

2021 ◽  
Vol 55 (3) ◽  
pp. 116-117
Author(s):  
Jesse H. Ausubel ◽  
Mark Y. Stoeckle
Keyword(s):  
Public Interest ◽  
Marine Mammals ◽  
Geographical Information Systems ◽  
Mobile App ◽  
Geographical Information ◽  
Access To Information ◽  
Reference Library ◽  
Web Based ◽  
Marine Life ◽  
Community Science

Abstract The Great Global Fish Count (GGFC) is a community science project to count fish and then other forms of marine life in coastal and later all waters using loose DNA in seawater (marine eDNA) shed by all animals. The project would distribute small filtration devices to millions of people. The devices would enable participants to take water samples, filter the water, stably preserve the filter with the sediment containing DNA, and post the filters to qualified labs for eDNA analysis. Labs would analyze samples, identify species, and upload data to a project database including Web-based geographical information systems accessible to a mobile app. The collector of each sample would learn the species and quantities of DNA in their sample(s) and have access to information from all other samples. The totality of the data would open countless opportunities for analysts to discover patterns and trends. The project would begin by targeting fish species, because of their societal importance, public interest, availability of high-quality primers to grab relevant sequences, and richness of the DNA reference library of fish sequences. Later in the decade the project could expand to all vertebrates (including marine mammals), mollusks, crustaceans, and other taxa, perhaps adding one major group each year.

scholarly journals Causes and consequences of marine mammal population declines in southwest Alaska: a food-web perspective

2009 ◽  
Vol 364 (1524) ◽  
pp. 1647-1658 ◽  
Author(s):  
J.A. Estes ◽  
D.F. Doak ◽  
A.M. Springer ◽  
T.M. Williams
Keyword(s):  
World War Ii ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Marine Ecosystem ◽  
Kelp Forests ◽  
Sea Otter ◽  
Population Declines ◽  
Killer Whales ◽  
Sea Otters ◽  
Coastal Marine

Populations of sea otters, seals and sea lions have collapsed across much of southwest Alaska over the past several decades. The sea otter decline set off a trophic cascade in which the coastal marine ecosystem underwent a phase shift from kelp forests to deforested sea urchin barrens. This interaction in turn affected the distribution, abundance and productivity of numerous other species. Ecological consequences of the pinniped declines are largely unknown. Increased predation by transient (marine mammal-eating) killer whales probably caused the sea otter declines and may have caused the pinniped declines as well. Springer et al . proposed that killer whales, which purportedly fed extensively on great whales, expanded their diets to include a higher percentage of sea otters and pinnipeds following a sharp reduction in great whale numbers from post World War II industrial whaling. Critics of this hypothesis claim that great whales are not now and probably never were an important nutritional resource for killer whales. We used demographic/energetic analyses to evaluate whether or not a predator–prey system involving killer whales and the smaller marine mammals would be sustainable without some nutritional contribution from the great whales. Our results indicate that while such a system is possible, it could only exist under a narrow range of extreme conditions and is therefore highly unlikely.

scholarly journals Harlequin Ducks (Histrionicus histrionicus) Scavenge Sea Urchin Fragments from Foraging Sea Otters (Enhydra lutris)

2016 ◽  
Vol 130 (2) ◽  
pp. 91 ◽  
Author(s):  
Erin Rechsteiner ◽  
Angeleen Olson
Keyword(s):  
Red Sea ◽  
Sea Urchins ◽  
Keystone Species ◽  
Sea Otter ◽  
Enhydra Lutris ◽  
Sea Otters ◽  
Important Prey ◽  
Histrionicus Histrionicus ◽  
Harlequin Ducks

Foraging animals may risk association with potential predators to obtain otherwise inaccessible prey. We observed this strategy in wintering Harlequin Ducks (Histrionicus histrionicus) scavenging fragments of Red Sea Urchins (Mesocentrotus franciscanus) from foraging Sea Otters (Enhydra lutris) that were re-occupying an area from which they had been ecologically absent since about 1850. Harlequin Ducks, like other sea ducks, have not previously been reported scavenging from other birds or mammals. In British columbia, Red Sea Urchins have reached large sizes and densities since the removal of Sea Otter predators by the marine fur trade in the 18th and 19th centuries. Observations of Sea Otters and Harlequin Ducks were made in 4 areas, spanning a time gradient of Sea Otter occupation from 1 to 5 years. During 3 months of observations (December 2013 – February 2014), Harlequin Ducks were associated with foraging Sea Otters only at sites that were recently occupied by Sea Otters (≤ 2 months), where the proportion of urchins in Sea Otter diets was highest and where the ducks acquired urchin fragments from foraging Sea Otters. We suggest that Sea Otters re-occupying their historic range and consuming predominantly large Red Sea Urchins provide a temporarily available prey subsidy for Harlequin Ducks. Our observations document a novel effect of Sea Otters providing important prey supplementation to a marine bird when foraging in urchin-rich habitats, contributing to the overall role of Sea Otters as a keystone species.

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