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1.
本文设计了一套基于FPGA的鲸豚声信号实时数据采集与分析系统,在采集存储水族馆内声信号的同时,应用改进的HHT算法处理鲸豚叫声中的click信号,实现实时的甄别瓶鼻海豚和白鲸功能,可用于针对大型哺乳动物的远洋实时跟踪科考。  相似文献   

2.
The whales are an interesting group in several aspects of science, including evolutionary biology, marine ecology and toxicology. Some of the whale species, including the minke whale, graze at the top of the food chains, where they become susceptible to the accumulation of marine pollutants ingested by organisms at lower levels. The northern stock of the minke whale grazes in Arctic waters in the summer, an area of increasing interest in the development of new oil fields. Studies on the metabolism, disposition and effects of xenobiotics in marine mammals are few. The only reports in the open literature so far have dealt with these questions in seals.1–3 Although the marine mammals comprise a particularly interesting group in marine ecology and toxicology, no data have to our knowledge been presented on the xenobiotic metabolising enzyme systems of the whales. In this study, components of the microsomal cytochrome P-450 system were measured in liver samples from several females, one male, and two foetal minke whales, caught in the Norwegian whaling season of 1983. Because of the limited number of samples studied we have treated the samples individually and not performed any statistical analysis of the data. The trends discussed below must therefore be considered with this background.  相似文献   

3.
Concern about the impact of sound on marine mammals has increased over the last decade, causing governments to take a more rigorous look at the potential impact of activities that introduce sound into the ocean. Environmental Impact Statements (EIS's) can be prepared using differing analysis methods to estimate the impact on marine mammals. To assess consistency in assessment methods, differences in the base assumptions were investigated; in particular, differences that arise between assumptions of dynamic marine mammals (animat method) and static distributions of marine mammals (static distribution method). Using several ocean environment scenarios and species, it is demonstrated that differences consistently arise between the two methods. The static distribution method underestimates the number of behavioral harassments compared with the animat method. Repeating many simulations with the animat method provides a robust risk assessment, provides a measure of variability, and allows the probability of "spurious events" to be estimated.  相似文献   

4.
In support of its acoustic risk mitigation policy, NATO SACLANT Undersea Research Centre (SACLANTCEN) is sponsoring a series of sea trials, entitled "Sirena" to collect a multiyear integrated oceanographic, biological, and hydrographic data set, the goal being to explain, based on these parameters, the distribution of marine mammals found in specific locations. By understanding how ocean dynamics affects the distribution and behavior of whales and the organisms forming the food web upon which the whales feed, it may be possible to conduct acoustic exercises in areas of low cetacean density. The first two Sirena multidisciplinary cruises were conducted in the Ligurian Sea in late summer time frame during 1999 and 2000. The focus of this analysis is to determine whether remotely sensed satellite data can indicate nutrient-rich regions in areas where the oceanography is known and to determine if these regions of higher productivity, coupled with knowledge of cetacean presence from all available sources, could be used as an indicator of marine mammal presence for acoustic risk mitigation purposes. For the two years of data examined, cooler sea-surface temperature data correlated with high levels of chlorophyll production as seen by remotely sensed images. This remotely sensed data correlated well with measured subsurface values of the same parameters. Coincident sightings of three species of marine mammals indicated that fin and sperm whales generally preferred the deep, nutrient-rich portion of the basin while Cuvier's beaked whales preferred a submarine canyon where there is a frontal influence, as indicated from satellite data and historical oceanography. This paper is intended as a contribution to the longer term objective of developing the means to accurately predict cetacean presence from physical oceanographic characteristics.  相似文献   

5.
Evidence of the presence of a group of sei whales (Balaenoptera borealis) detected around drifting fish aggregating devices (FADs) was provided by omnidirectional multi‐beam sonar during a survey off the Seychelles (Indian Ocean). The short visit by the sei whales produced a significant change in the behaviour of the fish assemblage associated with the FAD. There was first a significant increase in fish density when the whales approached the FAD, then a marked decrease after the whales had moved away from the FAD. Furthermore, the fish density was still low, 3 h after the whales had left the FAD. We assume that the presence and behaviour of the sei whales led some of the fish initially associated with the FAD to move away from it. There has been a considerable increase in the use of drifting artificial FADs in the Indian Ocean in recent decades. The frequency of cetacean visits to drifting FADs in the Indian Ocean is unknown, but they may have a major impact on assemblages of pelagic fish species around FADs. The effect of marine mammals on FAD‐associated fish could be relevant to the ecological trap theory (FAD acting as a trap for their associated fish) because of their impact on the dynamics of fish aggregation processes, through commensalism and/or predator–prey interactions.  相似文献   

6.
The U.S. Navy, whose sonars kill marine mammals, provides approximately 50% of the funds for marine mammal research worldwide. We examined six reviews of research on the effects of anthropogenic sound on marine mammals, as well as the primary papers cited in the reviews. These reviews cite references showing noise has no effect on marine mammals at an increasing frequency as their funding moves from a conservation organization to independent to partial U.S. military sources. Primary papers are 2.3 times more likely to be cited in the reviews as concluding no effect of noise if the research was militarily-funded than if not. Thus, conflict of interest may have led to a misrepresentation of the effects of noise on marine mammals in both the primary and secondary literature, and thus misinform public policy decisions.  相似文献   

7.
Commercial fishermen in many parts of the world perceive marine mammals as competitors for a scarce resource: fish. The importance of predation by marine mammals can be evaluated crudely by considering the marine mammal as a rival fishery whose operation is constrained by physiology and energetic requirements, rather than by catch limits and gear restrictions. Evidence collected from grey seals Halichoerus grypus in the United Kingdom, southern elephant seals Mirounga leonina and beluga whales Delphinapterus leucas shows that published information on distribution, based on the location of breeding sites and sightings in shallow water, may give an unrealistic picture of foraging distribution. Studies of diet and distribution can give an impression of the static nature of the inter-action between a marine mammal and the fishery. However, it is the dynamics of the interaction which are important. A critical question to be posed is how will the consumption of a particular prey species vary with its availability to the predator?  相似文献   

8.
The U.S. Navy has initiated a multidisciplinary research and development program to study the Effects of Sound on the Marine Environment (ESME). As part of this effort, the Naval Research Laboratory (NRL) is developing a software workbench for estimating the effects of cumulative sound exposure on marine mammals. This paper describes the workbench, and presents some preliminary simulation results. The workbench integrates data sets and computer models contributed by researchers in the areas of oceanography, underwater acoustic propagation, and marine mammal physiology and behavior. Models are incorporated for simulating animal movement, for estimating the received acoustic time series along an animal's track, and for predicting temporary threshold shifts (TTSs) induced by acoustic exposure. TTS predictions are shown to be highly dependent upon both the environmental variables and the movement of the marine mammals.  相似文献   

9.
The objective of this paper was to investigate and illustrate how insights gained from experience managing human activities in order to protect North Atlantic right whales (Eubalaena glacialis) along the heavily industrialized east coast of North America might be applied in the Arctic, where bowhead whales (Balaena mysticetus) face some of the same risks as right whales. The reduced extent and thickness of sea ice and the resultant longer open-water season have major, complex implications for the Arctic marine ecosystem. Increased maritime ship traffic and commercial fishing in the Arctic are bound to affect bowheads and Native (indigenous) hunting communities who depend on whales for subsistence and cultural identity. Bowheads and right whales were greatly depleted by commercial whaling in the 19th and early 20th centuries. While the Western Arctic bowhead population has been recovering steadily in recent decades, North Atlantic right whales remain highly endangered because of persistent lethal and sublethal vessel strikes and frequent entanglement in commercial fishing gear. Entanglement can be transitory or persistent, with debilitation lasting for months before the animal finally succumbs. Vessel strike and fishing gear trauma has been documented in bowheads, but at a much lower rate than in right whales. Initiatives intended to mitigate the impacts of ship traffic on North Atlantic right whales have included speed limits and routing changes. Those meant to reduce the incidence and severity of entanglements include the modification of gear design and gear deployment practices. Management measures need to be considered in advance in the Arctic in order to minimize the risks to bowhead whales as shipping and industrial fishing expand in the Arctic with ice retreat.  相似文献   

10.
Acoustic monitoring and aerial visual surveys of marine mammal activity were conducted simultaneously at the Navy's Pacific Missile Range Facility near Kauai, HI, during times of both high- and low-whale density from February 2002 to March 2003. Specifically, recordings from the range's 24 broadband hydrophones were made during 11 of 16 "in-season" and during six of ten "off-season" aerial surveys. Basic acoustic detections consisted primarily of humpback whale calls and sperm-whale clicks, and those two species were also reported in the visual surveys. The relative number of acoustic detections roughly corresponded with the visual survey results throughout the year. The same acoustic data were also provided to a passive-acoustic-localization algorithm based on acoustic propagation models which generated estimates of sperm-whale movement through the range. The acoustic localizations are in close proximity in space and time to the visual observations of sperm whales. Verification of the model-based localization algorithm's accuracy was demonstrated in a controlled-source experiment at the Navy's Atlantic Undersea Test and Evaluation Center (AUTEC) range in the Bahamas where the recordings of sperm-whale clicks were broadcast and successfully tracked. The localization accuracy of the model-based technique and traditional hyperbolic techniques is compared. These results raise the possibility of using existing Navy assets to detect and track marine mammals, particularly during times when visual sighting conditions are not favorable, in efforts to minimize their exposure to underwater sound.  相似文献   

11.
Our understanding of the significance of sound production to the ecology of deep-sea fish communities has improved little since anatomical surveys in the 1950s first suggested that sound production is widespread among slope-water fishes. The recent implementation of cabled ocean observatory networks around the world that include passive acoustic recording instruments provides scientists an opportunity to search for evidence of deep-sea fish sounds. We examined deep-sea acoustic recordings made at the NEPTUNE Canada Barkley Canyon Axis Pod (985 m) located off the west coast of Vancouver Island in the Northeast Pacific between June 2010 and May 2011 to determine the presence of fish sounds. A subset of over 300 5-min files was examined by selecting one day each month and analyzing one file for each hour over the 24 h day. Despite the frequent occurrence of marine mammal sounds, no examples of fish sounds were identified. However, we report examples of isolated unknown sounds that might be produced by fish, invertebrates, or more likely marine mammals. This finding is in direct contrast to recent smaller studies in the Atlantic where potential fish sounds appear to be more common. A review of the literature indicates 32 species found off British Columbia that potentially produce sound could occur in depths greater than 700 m but of these only Anoplopoma fimbria and Coryphaenoides spp. have been previously reported at the site. The lack of fish sounds observed here may be directly related to the low diversity and abundance of fishes present at the Barkley Canyon site. Other contributing factors include possible masking of low amplitude biological signals by self-generated noise from the platform instrumentation and ship noise. We suggest that examination of data both from noise-reduced ocean observatories around the world and from dedicated instrument surveys designed to search for deep-sea fish sounds to provide a larger-scale, more conclusive investigation into the role, or potential lack thereof, of sound production.  相似文献   

12.
Acoustic data collected on the R/V Cory Chouest in February and March 1996 during an active operation of the U.S. Navy's surveillance-towed-array-sensor-system low-frequency-active (LFA) sonar were analyzed for blue whale (Balaenoptera musculus) and fin whale (B. physalus) sounds. Operational monitoring and mitigation protocols were implemented throughout the exercise to reduce the chances of an acoustic impact on marine mammals and sea turtles. The operational schedule did not include intentional "control" periods without transmissions but did include periods when the LFA sonar was not operating for other reasons (e.g., repairs). There were insufficient detections of blue whales for further analysis. Fin whale acoustic detection probabilities were calculated from the postprocessed data. A local-linear-regression analysis was used to compare fin whale detection probabilities from 2065 11-min intervals under conditions when the LFA sonar was and was not transmitting. There was an indication of a slightly higher probability of detecting fin whale sounds during periods when there were no LFA transmissions than during periods with transmissions. This may be the result of the following: 1) Reduced vocal activity by whales in response to LFA transmissions; 2) the effect of the mitigation protocols; or 3) some combination of 1) and 2). The data presently available do not allow one to distinguish definitively between these explanations, mainly because there were not enough data recorded for periods without LFA transmissions.  相似文献   

13.
Whale watching is now reputed to be a $2 billion a year industry. This industry has the potential to impact the politics of whaling, specifically the moratorium on all commercial whaling in three ways: by creating political and economic counterweights to whalers, by countering claims about who may legitimately manage whales and to what end and by transforming views about whales and whaling both within whaling states and beyond. This article examines whale watching in Latin America and the Caribbean and the alliance of Latin American and Caribbean members of the International Whaling Commission (IWC) known as the Buenos Aires Group (BAG). The BAG group has emerged as coherent group opposing the ending of the moratorium and championing the views of whale watchers. The article finds that whale watching creates a politically important interest group in an area lacking whaling operations; it argues that these regional opponents of whaling provide a counter weight to charges that opposition to whaling is exclusively the providence of rich, urban citizens of developed countries and draw upon politically powerful frames in justifying their opposition to the lifting of the moratorium. Finally, it finds limited evidence that whale-watching is associated with a rise in general concern for marine mammals in the region. There remains the question, however, of what the future of whale watching in the region will be over the longer term.  相似文献   

14.
Toothed whales produce short, ultrasonic clicks of high directionality and source level to probe their environment acoustically. This process, termed echolocation, is to a large part governed by the properties of the emitted clicks. Therefore derivation of click source parameters from free-ranging animals is of increasing importance to understand both how toothed whales use echolocation in the wild and how they may be monitored acoustically. This paper addresses how source parameters can be derived from free-ranging toothed whales in the wild using calibrated multi-hydrophone arrays and digital recorders. We outline the properties required of hydrophones, amplifiers and analog to digital converters, and discuss the problems of recording echolocation clicks on the axis of a directional sound beam. For accurate localization the hydrophone array apertures must be adapted and scaled to the behavior of, and the range to, the clicking animal, and precise information on hydrophone locations is critical. We provide examples of localization routines and outline sources of error that lead to uncertainties in localizing clicking animals in time and space. Furthermore we explore approaches to time series analysis of discrete versions of toothed whale clicks that are meaningful in a biosonar context.  相似文献   

15.
Reports on the diving behavior of a sperm whale tagged and tracked on September 6, 2000 during the Sirena 2000 cruise in the Ligurian Sea. A total of about 4.5 h of acoustic and nonacoustic sensor data were recorded when a sperm whale was tagged with a Woods Hole Oceanographic Institution developed tag with a hydrophone, motion, and pressure sensors. The animal was simultaneously tracked with a passive sonar system deployed from the NATO research vessel NRV Alliance. By combining data from the tag and passive sonar, we were able to reconstruct a three-dimensional track of the whale, along with its orientation and vocal behavior. While it was tagged, the whale carried out three deep dives to a depth of about 900 m in an area with a bottom depth of about 2600 m. The inter-click intervals of the diving whale were not consistent with ranging on the bottom, but were consistent with the hypothesis that the whale was possibly echolocating on some target(s) near the depth at which it dove to feed. This study demonstrated an ability to track subtle changes in the behavior of diving whales. This ability is important for three areas: 1) basic research, 2) studies of the responses of these animals to controlled exposures of man-made noise, and 3) studies to infer the biological significance of behavioral disruption.  相似文献   

16.
Anticipating the impacts of a new policy before implementation on a complex social–ecological system is a challenging task for managers and policymakers. This paper reports on the development and use of an agent-based model (ABM) dedicated to support marine park managers in their effort to devise policies to sustainably manage whale-watching activities. The ABM, called the Marine Mammal and Maritime Traffic Simulator (3MTSim), represents the spatiotemporal dynamics of marine mammals and navigation activities in and around the Saguenay–St. Lawrence Marine Park in Canada. In the context of updating the current regulations on whale-watching in the Marine Park, 3MTSim was run to evaluate the merits of a proposed set of rules compared to the current regulations. To do so, a set of variables related to policies’ impacts on the three spheres of sustainable development, namely the impact on whales (Environment), on whale-watching companies (Economy), and tourist experience (Society) was analysed. 3MTSim's simulations highlighted that the proposed rules are expected to improve the situation regarding whale conservation and tourist experience with only marginal impact on the whale-watching industry. In the proposed regulations, one rule is expected to be very influential on whale-watching activities. This rule limits to 10 the number of whale-watching boats allowed to stand within 926 m of any boat in observation mode. Assuming efficient law enforcement, 3MTSim predicts a significant decrease in overall boat concentration around whales in the Marine Park, which is one of the management objectives benefiting both whales and tourists. Interestingly, 3MTSim reveals that this rule could indirectly force some boats to observe second-choice whales present in higher abundance rather than some more attractive species scarcer in the region. This highlights the following management tradeoffs: Reducing boat exposure for the humpback whale and endangered blue whale is likely to increase it for the more abundant fin whale listed as of special concern (Canada's Species at Risk Act) and minke whale. This work demonstrates the utility of ABMs to support policy analysis in the context of sustainable management in a Marine Park. ABMs developed in close relationship with end-users are unarguably a tool of choice to manage complex social–ecological systems since they provide insight into phenomena hard or impossible to measure in the real system. Despite the labour intensive nature of their implementation, this investment is worth the effort.  相似文献   

17.
Au et al.'s arguments against the hypothesis that humpback whale songs function as long-range sonar are based on questionable assumptions rather than on empirical data. Like other echolocating mammals (e.g., bats), singing humpback whales: 1) localize targets in the absence of visual information; 2) possess a highly innervated peripheral auditory system; and 3) modulate the temporal and spectral features of their sounds based on environmental conditions. The sonar equation is inadequate for determining whether humpback whale songs generate detectable echoes from other whales because it does not account for temporal variables that can strongly affect the detectability of echoes. In particular, the sonar equation ignores the fact that much of the noise encountered by singing humpback whales is spectrally and temporally predictable, and that audition in mammals is a dynamic and plastic process. Experiments are needed to test the hypothesis that singing humpback whales listen for and respond to echoes generated by their songs  相似文献   

18.
A sound reflection system for obtaining profiles of sedimentary structures in shelf and slope depths to 500 m has been developed, based on an Edgerton 1 kJ boomer as sound source. A logarithmic response receiver allows optimal recording of signals over a wide dynamic range. Penetrations of up to 500 m have been obtained from structures within both unconsolidated sediments and folded lower Tertiary structures. The equipment works reliably at speeds up to 9 knots.  相似文献   

19.
In mammals, the induction of cytochrome P4501A forms by chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, and halogenated biphenyls is under control of a soluble protein known as the Ah (aromatic hydrocarbon) receptor. Little is known about the presence and properties of the Ah receptor in other vertebrate and invertebrate species. In these studies, we sought evidence for an Ah receptor in the liver or liver-equivalent of 20 species of marine and freshwater animals, using the photoaffinity ligand 2-azido-3-[125I] iodo-7,8-dibromodibenzo-p-dioxin (N3[125I]Br2DD). Specific labeling of cytosolic proteins by N3[125I]Br2DD was observed in seven species of teleost and elasmobranch fish, in PLHC-I fish hepatoma cells, and in beluga whales. No specifically labeled proteins were found in cytosol from two species of agnathan fish nor in any of nine invertebrate species representing eight classes of four phyla. The presence or absence of specifically labeled polypeptides corresponds with the inducibility of cytochrome P4501A and sensitivity to the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related planar halogenated aromatic hydrocarbons in many of these groups. Thus, Ah receptor function may have arisen early invertebrate evolution and has been conserved from elasmobranch and teleost fish to mammals.  相似文献   

20.
To prevent grounding of ships and collisions between ships in shallow coastal waters, an underwater data collection and communication network is currently under development: Acoustic Communication network for Monitoring of underwater Environment in coastal areas (ACME). Marine mammals might be affected by ACME sounds since they use sounds of similar frequencies (around 12 kHz) for communication, orientation, and prey location. If marine mammals tend to avoid the vicinity of the transmitters, they may be kept away from ecologically important areas by ACME sounds. One marine mammal species that may be affected in the North Sea is the harbour porpoise. Therefore, as part of an environmental impact assessment program, two captive harbour porpoises were subjected to four sounds, three of which may be used in the underwater acoustic data communication network. The effect of each sound was judged by comparing the animals' positions and respiration rates during a test period with those during a baseline period. Each of the four sounds could be made a deterrent by increasing the amplitude of the sound. The porpoises reacted by swimming away from the sounds and by slightly, but significantly, increasing their respiration rate. From the sound pressure level distribution in the pen, and the distribution of the animals during test sessions, discomfort sound level thresholds were determined for each sound. In combination with information on sound propagation in the areas where the communication system may be deployed, the extent of the 'discomfort zone' can be estimated for several source levels (SLs). The discomfort zone is defined as the area around a sound source that harbour porpoises are expected to avoid. Based on these results, SLs can be selected that have an acceptable effect on harbour porpoises in particular areas. The discomfort zone of a communication sound depends on the selected sound, the selected SL, and the propagation characteristics of the area in which the sound system is operational. In shallow, winding coastal water courses, with sandbanks, etc., the type of habitat in which the ACME sounds will be produced, propagation loss cannot be accurately estimated by using a simple propagation model, but should be measured on site. The SL of the communication system should be adapted to each area (taking into account bounding conditions created by narrow channels, sound propagation variability due to environmental factors, and the importance of an area to the affected species). The discomfort zone should not prevent harbour porpoises from spending sufficient time in ecologically important areas (for instance feeding areas), or routes towards these areas.  相似文献   

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