656 resultados para Marine mammals

em Aquatic Commons


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In accordance with the Marine Mammal Protection Act (MMPA, 16 U.S.c. et seq.), the National Marine Fisheries Service (NMFS) is required to publish an annual List of Fisheries (LOF) which categorizes U.S. commercial fisheries based on their level of interaction with marine mammals. The objective of this document is to provide a characterization of the six 2001 MMPA Category II commercial fisheries (i.e., those with occasional interactions with marine mammals) in North Carolina (NC). This report outlines the history, fishing method and gear configurations (using the U.S. system of measurement), primary target species, temporal and spatial characteristics including trip and landing statistics, and monthly variations in species composition for each fishery for a five-year period (1995 - 1999). (PDF contains 63 pages)

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Stranded marine mammals have long attracted public attention. Those that wash up dead are, for all their value to science, seldom seen by the public as more than curiosities. Animals that are sick, injured, orphaned or abandoned ignite a different response. Generally, public sentiment supports any effort to rescue, treat and return them to sea. Institutions displaying marine mammals showed an early interest in live-stranded animals as a source of specimens -- in 1948, Marine Studios in St. Augustine, Florida, rescued a young short-finned pilot whale (Globicephala macrorhynchus), the first ever in captivity (Kritzler 1952). Eventually, the public as well as government agencies looked to these institutions for their recognized expertise in marine mammal care and medicine. More recently, facilities have been established for the sole purpose of rehabilitating marine mammals and preparing them for return to the wild. Four such institutions are the Marine Mammal Center (Sausalito, CA), the Research Institute for Nature Management (Pieterburen, The Netherlands), the RSPCA, Norfolk Wildlife Hospital (Norfolk, United Kingdom) and the Institute for Wildlife Biology of Christian-Albrects University (Kiel, Germany).(PDF contains 68 pages.)

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During 1973-88, 3,661 marine mammals of 17 species were reported as incidental catch by U.S. fishery observers aboard foreign and joint venture trawl vessels in the U.S. Exclusive Economic Zone in the North Pacific Ocean and the Bering Sea. Northern sea lions (Eumetopias jubatus) accounted for 90% of the reported incidental mortality in the Gulf of Alaska and eastern Bering Sea. Nearly half of these sea lions were taken in trawl nets in the Shelikof Strait, Alaska, joint venture fishery during 1982-84. However, high incidental mortality rates (>25 sea lions per 10,000 metric tons of groundfish catch) also occurred in the foreign fisheries near Kodiak Island and in the Aleutian Islands area in earlier years. Estimated annual mortality of incidentally caught northern sea lions in Alaska declined from 1,000 to 2,000 animals per year during the early 1970s and 1982 to fewer than 100 animals in 1988. In the Bering Sea most sea lions incidentally caught were males, while in the Gulf of Alaska females were more frequently caught. Females may also have been dominant in the incidental catch of sea lions in the Aleutian Islands area, but age and sex composition data are limited. Incidental mortality of adult female sea lions by foreign trawl fisheries in these areas could have partially contributed to the reported declines in northern sea lion populations in Alaska during the 1970s, but it cannot alone account for the present decline in population size. (PDF file contains 64 pages.)

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Some 25 to 30 yr ago, when we as students were beginning our respective careers and were developing for the first time our awareness of marine mammals in the waters separating western North America from eastern Asia, we had visions of eventually bridging the communication gap which existed between our two countries at that time. Each of us was anxious to obtain information on the distribution, biology, and ecological relations of "our" seals and walruses on "the other side," beyond our respective political boundari~s where we were not permitted to go to study them. We were concerned that the resource management practices on the other side of the Bering and Chukchi Seas, implemented in isolation, on a purely unilateral basis, might endanger the species which we had come to know and were striving to conserve. At once apparent to both of us was the need for free exchange of biological information between our two countries and, ultimately, joint management of our shared resources. In a small way, we and others made some initial efforts to generate that exchange by personal correspondence and through vocal interchange at the annual meetings of the North Pacific Fur Seal Commission. By the enabling Agreement on Cooperation in the Field of Environmental Protection, reached between our two countries in 1972, our earlier visions at last came true. Since that time, within the framework of the Marine Mammal Project under Area V of that Agreement, we and our colleagues have forged a strong bond of professional accord and respect, in an atmosphere of free intercommunication and mutual understanding. The strength and utility of this arrangement from the beginning of our joint research are reflected in the reports contained in this, the first compendium of our work. The need for a series of such a compendia became apparent to us in 1976, and its implementation was agreed on by the regular meeting of the Project in La Jolla, Calif., in January 1977. Obviously, the preparation and publication of this first volume has been excessively delayed, in part by continuing political distrust between our governments but mainly by increasing demands placed on the time of the contributors. In this period of growing environmental concern in both countries, we and our colleagues have been totally immersed in other tasks and have experienced great difficulty in drawing together the works presented here. Much of the support for doing so was provided by the State of Alaska, through funding for Organized Research at the University of Alaska-Fairbanks. For its ultimate completion in publishable form we wish to thank Helen Stockholm, Director of Publications, Institute of Marine Science, University of Alaska, and her staff, especially Ruth Hand, and the numerous referees narned herein who gave willingly oftheir time to review each ofthe manuscripts critically and to provide a high measure of professionalism to the final product. (PDF file contains 110 pages.)

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The U.S. East Coast pelagic longline fishery has a history of interactions with marine mammals, where animals are hooked and entangled in longline gear. Pilot whales (Globicephala spp.) and Risso’s dolphin (Grampus griseus) are the primary species that interact with longline gear. Logistic regression was used to assess the environmental and gear characteristics that influence interaction rates. Pilot whale inter-actions were correlated with warm water temperatures, proximity to the shelf break, mainline lengths greater than 20 nautical miles, and damage to swordfish catch. Similarly, Risso’s dolphin interactions were correlated with geographic location, proximity the shelf break, the length of the mainline, and bait type. The incidental bycatch of marine mammals is likely associated with depredation of the commercial catch and is increased by the overlap between marine mammal and target species habitats. Altering gear characteristics and fishery practices may mitigate incidental bycatch and reduce economic losses due to depredation.

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A competitive enzyme-linked immunosorbent assay (cELISA) was developed by using a whole-cell antigen from a marine Brucella sp. isolated from a harbor seal (Phoca vitulina). The assay was designed to screen sera from multiple marine mammal species for the presence of antibodies against marine-origin Brucella. Based on comparisons with culture-confirmed cases, specificity and sensitivity for cetacean samples tested were 73% and 100%, respectively. For pinniped samples, specificity and sensitivity values were 77% and 67%, respectively. Hawaiian monk seal (Monachus schauinslandi; n = 28) and bottlenose dolphin (Tursiops truncatus; n = 48) serum samples were tested, and the results were compared with several other assays designed to detect Brucella abortus antibodies. The comparison testing revealed the marine-origin cELISA to be more sensitive than the B. abortus tests by the detection of additional positive serum samples. The newly developed cELISA is an effective serologic method for detection of the presence of antibodies against marine-origin Brucella sp. in marine mammals.

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We examined the summer distribution of marine mammals off the northern Washington coast based on six ship transect surveys conducted between 1995 and 2002, primarily from the NOAA ship McArthur. Additionally, small boat surveys were conducted in the same region between 1989 and 2002 to gather photographic identification data on humpback whales (Megaptera novaeangliae) and killer whales (Orcinus orca) to examine movements and population structure. In the six years of ship survey effort, 706 sightings of 15 marine mammal species were made. Humpback whales were the most common large cetacean species and were seen every year and a total of 232 sightings of 402 animals were recorded during ship surveys. Highest numbers were observed in 2002, when there were 79 sightings of 139 whales. Line-transect estimates for humpback whales indicated that about 100 humpback whales inhabited these waters each year between 1995 and 2000; in 2002, however, the estimate was 562 (CV= 0.21) whales. A total of 191 unique individuals were identified photographically and mark recapture estimates also indicated that the number of animals increased from under 100 to over 200 from 1995 to 2002. There was only limited interchange of humpback whales between this area and feeding areas off Oregon and California. Killer whales were also seen on every ship survey and represented all known ecotypes of the Pacific Northwest, including southern and northern residents, transients, and offshore-type killer whales. Dall’s porpoise (Phocoenoides dalli) were the most frequently sighted small cetacean; abundance was estimated at 181−291 individuals, except for 2002 when we observed dramatically higher numbers (876, CV= 0.30). Northern fur seals (Callorhinus ursinus) and elephant seals (Mirounga angustirostris) were the most common pinnipeds observed. There were clear habitat differences related to distance offshore and water depth for different species.

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Study on the interactions between marine mammals or marine birds and fisheries in the PICES region of interest. (PDF contains 168 pages)

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Key Messages [pdf, 2.5 Mb] Climate Information Gaps Ocean Productivity Information gaps Living Marine Resources Information gaps Climate [pdf, 1.8 Mb] Productivity [pdf, 5.2 Mb] Nutrients Phytoplankton Zooplankton Living Resources [pdf, 10 Mb] Subarctic coastal systems Central oceanic gyres Temperate coastal and oceanic systems Marine mammals The Human Population [pdf, 5 Mb] Contaminants and Habitat Modifications Aquaculture Knowledge Gaps Glossary Ocean and Climate Changes [pdf, 4.1Mb] Highlights Introduction Atmospheric Indices Change in 1998/99 Comparison of Atmospheric Indices Authorship Yellow Sea / East China Sea [pdf, 2.3 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Benthos Fish and invertebrates Marine birds and mammals Issues Critical factors causing change Authorship Japan/East Sea [pdf, 3.3 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical factors causing change Issues Authorship Okhotsk Sea [pdf, 1.7 Mb] Background Status and Trends Climate Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Critical factors causing change Authorship Oyashio / Kuroshio [pdf, 4.5 Mb] Highlights Background Status and Trends Hydrography Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Western Subarctic Gyre [pdf, 4.5 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Bering Sea [pdf, 2.2 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Gulf of Alaska [pdf, 2.6 Mb] Highlights Background Status and trends Hydrography Chemistry Plankton Fish and Invertebrates Marine birds and mammals Critical factors causing change Issues Authorship California Current [pdf, 2.7 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Gulf of California [pdf, 1.7 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fisheries Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Transition Zone [pdf, 2.5 Mb] Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Tuna [pdf, 1.5 Mb] Highlights Background Pacific bluefin tuna Albacore tuna Status and trends Ecosystem model and climate forcing Authorship Pacific halibut [pdf, 1.1 Mb] Background The Fishery Climate Influences Authorship Pacific salmon [Updated, pdf, 0.4 Mb] Background Status and Trends Washington, Oregon, and California British Columbia Southeast Alaska Central Alaska Western Alaska Russia Japan Authorship References [pdf, 0.5 Mb]

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On 15-16 January 2005, three offshore species of cetaceans (33 short-finned pilot whales, Globicephala macrorhynchus, one minke whale, Balaenoptera acutorostrata, and two dwarf sperm whales, Kogia sima) stranded alive on the beaches of North Carolina. The pilot whales stranded near Oregon Inlet, the minke whale in northern North Carolina, and the dwarf sperm whales near Cape Hatteras. Live strandings of three species in one weekend was unique in North Carolina and qualified as an Unusual Mortality Event. Gross necropsies were conducted on 16-17 January 2005 on 27 pilot whales, two dwarf sperm whales, and the minke whale. Samples were collected for clinical pathology, parasitology, gross pathology, histopathology, microbiology and serology. There was variation in the number of animals sampled for each collection type, however, due to carcasses washing off the beach or degradation in carcass condition during the course of the response. Comprehensive histologic examination was conducted on 16 pilot whales, both dwarf sperm whales, and the minke whale. Limited organ or only head tissue suites were obtained from nine pilot whales. Histologic examination of tissues began in February 2005 and concluded in December 2005 when final sampling was concluded. Neither the pilot whales nor dwarf sperm whales were emaciated although none had recently ingested prey in their stomachs. The minke whale was emaciated; it was likely a dependent calf that became separated from the female. Most serum biochemistry abnormalities appear to have resulted from the stranding and indicated deteriorating condition from being on land for an extended period. Three pilot whales had clinical evidence of pre-existing systemic inflammation, which was supported by histopathologic findings. Although gross and histologic lesions involving all organ systems were noted, consistent lesions were not observed across species. Verminous pterygoid sinusitis and healed fishery interactions were seen in pilot whales but neither of these changes were causes of debilitation or death. In three pilot whales and one dwarf sperm whale there was evidence of clinically significant disease in postcranial tissues which led to chronic debilitation. Cardiovascular disease was present in one pilot whale and one dwarf sperm whale; musculoskeletal disease and intra-abdominal granulomas were present in two pilot whales. These lesions were possible, but not definitive, causal factors in the stranding. Remaining lesions were incidental or post-stranding. The minke whale and three of five tested pilot whales had positive morbillivirus titers (≥1:8 with one at >1:256), but there was no histologic evidence of active viral infection. Parasites (nematodes, cestodes, and trematodes) were collected from 26 pilot whales and two dwarf sperm whales. Sites of collection included stomach, nasal/pterygoid, peribullar sinuses, blubber, and abdominal cavity. Parasite species, locations and loads were within normal limits for free-ranging cetaceans and were not considered causative for the stranding event. Gas emboli lesions which were considered consistent with or diagnostic of sonarassociated strandings of beaked whales or small cetaceans were not found in the whales stranded as part of UMESE0501Sp. Twenty-five heads were examined with nine specific anatomic locations of interest: extramandibular fat, intramandibular fat, auditory meatus, peribullar acoustic fat, peribullar soft tissue, peribullar sinus, pterygoid sinus, melon, and brain. The common finding in all examined heads was verminous pterygoid sinusitis. Intramandibular adipose tissue reddening, typically adjacent to the vascular plexus, was observed in some individuals and could represent localized hemorrhage resulting from vascular rete rupture, hypostatic congestion, or erythrocyte rupture during the freeze/thaw cycle. One cetacean had peracute to acute subdural hemorrhage that likely occurred from thrashing on the beach post-stranding, although its occurrence prior to stranding cannot be excluded. Information provided to NMFS by the U.S. Navy indicated routine tactical mid-frequency sonar operations from individual surface vessels over relatively short durations and small spatial scales within the area and time period investigated. No marine mammals were detected by marine mammal observers on operational vessels; standard operating procedure for surface naval vessels operating mid-frequency sonar is the use of trained visual lookouts using high-powered binoculars. Sound propagation modeling using information provided to NMFS indicated that acoustic conditions in the vicinity likely depended heavily on position of the receivers (e.g., range, bearing, depth) relative to that of the sources. Absent explicit information on the location of animals meant that it was not possible to estimate received acoustic exposures from active sonar transmissions. Nonetheless, the event was associated in time and space with naval activity using mid-frequency active sonar. It also had a number of features in common (e.g., the “atypical” distribution of strandings involving multiple offshore species, all stranding alive, and without evidence of common infectious or other disease process) with other sonar-related cetacean mass stranding events. Given that this event was the only stranding of offshore species to occur within a 2-3 day period in the region on record (i.e., a very rare event), and given the occurrence of the event simultaneously in time and space with a naval exercise using active sonar, the association between the naval sonar activity and the location and timing of the event could be a causal rather than a coincidental relationship. However, evidence supporting a definitive association is lacking, and, in particular, there are differences in operational/environmental characteristics between this event and previous events where sonar has apparently played a role in marine mammal strandings. This does not preclude behavorial avoidance of noise exposure. No harmful algal blooms were present along the Atlantic coast south of the Chesapeake Bay during the months prior to the event. Environmental conditions, including strong winds, changes in upwelling- to downwelling-favorable conditions, and gently sloping bathymetry, were consistent with conditions which have been correlated with other mass strandings. In summary, we did not find commonality in gross and histologic lesions that would indicate a single cause for this stranding event. Three pilot whales and one dwarf sperm whale had debilitating conditions identified that could have contributed to stranding, one pilot whale had a debilitating condition (subdural hemorrhage) that could have been present prior to or resulting from stranding. While the pilot and dwarf sperm whale strandings may have had a common cause, the minke whale stranding was probably just coincidental. On the basis of examination of physical evidence in the affected whales, however, we cannot definitively conclude that there was or was not a causal link between anthropogenic sonar activity or environmental conditions (or a combination of these factors) and the strandings. Overall, the cause of UMESE0501Sp in North Carolina is not and likely will not be definitively known. (PDF contains 240 pages)

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To be in compliance with the Endangered Species Act and the Marine Mammal Protection Act, the United States Department of the Navy is required to assess the potential environmental impacts of conducting at-sea training operations on sea turtles and marine mammals. Limited recent and area-specific density data of sea turtles and dolphins exist for many of the Navy’s operations areas (OPAREAs), including the Marine Corps Air Station (MCAS) Cherry Point OPAREA, which encompasses portions of Core and Pamlico Sounds, North Carolina. Aerial surveys were conducted to document the seasonal distribution and estimated density of sea turtles and dolphins within Core Sound and portions of Pamlico Sound, and coastal waters extending one mile offshore. Sea Surface Temperature (SST) data for each survey were extracted from 1.4 km/pixel resolution Advanced Very High Resolution Radiometer remote images. A total of 92 turtles and 1,625 dolphins were sighted during 41 aerial surveys, conducted from July 2004 to April 2006. In the spring (March – May; 7.9°C to 21.7°C mean SST), the majority of turtles sighted were along the coast, mainly from the northern Core Banks northward to Cape Hatteras. By the summer (June – Aug.; 25.2°C to 30.8°C mean SST), turtles were fairly evenly dispersed along the entire survey range of the coast and Pamlico Sound, with only a few sightings in Core Sound. In the autumn (Sept. – Nov.; 9.6°C to 29.6°C mean SST), the majority of turtles sighted were along the coast and in eastern Pamlico Sound; however, fewer turtles were observed along the coast than in the summer. No turtles were seen during the winter surveys (Dec. – Feb.; 7.6°C to 11.2°C mean SST). The estimated mean surface density of turtles was highest along the coast in the summer of 2005 (0.615 turtles/km², SE = 0.220). In Core and Pamlico Sounds the highest mean surface density occurred during the autumn of 2005 (0.016 turtles/km², SE = 0.009). The mean seasonal abundance estimates were always highest in the coastal region, except in the winter when turtles were not sighted in either region. For Pamlico Sound, surface densities were always greater in the eastern than western section. The range of mean temperatures at which turtles were sighted was 9.68°C to 30.82°C. The majority of turtles sighted were within water ≥ 11°C. Dolphins were observed within estuarine waters and along the coast year-round; however, there were some general seasonal movements. In particular, during the summer sightings decreased along the coast and dolphins were distributed throughout Core and Pamlico Sounds, while in the winter the majority of dolphins were located along the coast and in southeastern Pamlico Sound. Although relative numbers changed seasonally between these areas, the estimated mean surface density of dolphins was highest along the coast in the spring of 2006 (9.564 dolphins/km², SE = 5.571). In Core and Pamlico Sounds the highest mean surface density occurred during the autumn of 2004 (0.192 dolphins/km², SE = 0.066). The estimated mean surface density of dolphins was lowest along the coast in the summer of 2004 (0.461 dolphins/km², SE = 0.294). The estimated mean surface density of dolphins was lowest in Core and Pamlico Sounds in the summer of 2005 (0.024 dolphins/km², SE = 0.011). In Pamlico Sound, estimated surface densities were greater in the eastern section except in the autumn. Dolphins were sighted throughout the entire range of mean SST (7.60°C to 30.82°C), with a tendency towards fewer dolphins sighted as water temperatures increased. Based on the findings of this study, sea turtles are most likely to be encountered within the OPAREAs when SST is ≥ 11°C. Since sea turtle distributions are generally limited by water temperature, knowing the SST of a given area is a useful predictor of sea turtle presence. Since dolphins were observed within estuarine waters year-round and throughout the entire range of mean SST’s, they likely could be encountered in the OPAREAs any time of the year. Although our findings indicated the greatest number of dolphins to be present in the winter and the least in the summer, their movements also may be related to other factors such as the availability of prey. (PDF contains 28 pages)

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Summary: This cruise report is a summary of a field survey conducted within the Stellwagen Bank National Marine Sanctuary (SBNMS), located between Cape Cod and Cape Ann at the mouth of Massachusetts Bay. The survey was conducted June 14 – June 21, 2008 on NOAA Ship NANCY FOSTER Cruise NF-08-09-CCEHBR. Multiple indicators of ecological condition and human dimensions were sampled synoptically at each of 30 stations throughout SBNMS using a random probabilistic sampling design. Samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants (metals, pesticides, PAHs, PCBs, PBDEs) in sediments and target demersal biota; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as depth, salinity, temperature, dissolved oxygen, turbidity, pH, sediment grain size, and organic carbon content. In addition to the fish samples that were collected for analysis of chemical contaminants relative to human-health consumption limits, other human-dimension indicators were sampled as well including presence or absence of fishing gear, vessels, surface trash, marine mammals, and noxious sediment odors. The overall purpose of the survey was to collect data to assess the status of ecosystem condition and potential stressor impacts throughout SBNMS, based on these various indicators and corresponding management thresholds, and to provide this information as a baseline for determining how such conditions may be changing with time. While sample analysis is still ongoing a few preliminary results and observations are reported here. A final report will be completed once all data have been processed. The results are anticipated to be of value in supporting goals of the SBNMS and National Marine Sanctuary Program aimed at the characterization, protection, and management of sanctuary resources (pursuant to the National Marine Sanctuary Reauthorization Act) as well as a new priority of NCCOS and NOAA to apply Ecosystem Based approaches to the Management of coastal resources (EBM) through Integrated Ecosystem Assessments (IEAs) conducted in various coastal regions of the U.S. including the Northeast Atlantic continental shelf. This was a multi-disciplinary partnership effort made possible by scientists from the following organizations:  NOAA, National Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS), Center for Coastal Environmental Health and Biomolecular Research (CCEHBR), Charleston, SC.  U.S. Environmental Protection Agency (EPA), National Health and Environmental Effects Research Laboratory (NHEERL), Atlantic Ecology Division (GED), Narragansett, RI.  U.S. Environmental Protection Agency (EPA), National Health and Environmental Effects Research Laboratory (NHEERL), Gulf Ecology Division (GED), Gulf Breeze, FL.  U.S. Geological Survey (USGS), National Wetlands Research Center, Gulf Breeze Project Office, Gulf Breeze, FL.  NOAA, Office of Marine and Aviation Operations (OMAO), NOAA ship Nancy Foster. (31pp) (PDF contains 58 pages)