Residency, space use and movement patterns of juvenile sandbar sharks (Carcharhinus plumbeus) within a Virginia summer nursery area

2010 ◽  
Vol 61 (2) ◽  
pp. 223 ◽  
Author(s):  
C. L. Conrath ◽  
J. A. Musick
Keyword(s):  
Movement Patterns ◽  
Nursery Area ◽  
Small Scale ◽  
Shark Species ◽  
Eastern Shore ◽  
Carcharhinus Plumbeus ◽  
Near Shore ◽  
Passive Acoustic ◽  
Conservation And Management ◽  
Juvenile Sharks

Neonates and juveniles of many large coastal shark species occupy shallow inshore nursery areas during portions of the year. The identification of how these areas are used by large coastal shark populations is an important consideration in conservation and management efforts. An array of passive acoustic receivers was utilised to track the movements of 64 neonate and juvenile sandbar sharks within the Eastern Shore of Virginia summer nursery during the summers of 2003–2005. Residency patterns were variable during each year of the study, with younger sandbar sharks spending more time within the array area than older sharks. The number of detections was positively related to the distance of the receiver inshore from the inlet, indicating that young sandbar sharks preferentially utilise protected, shallow near-shore waters. Neonate and juvenile sandbar sharks tended to be detected more frequently within all areas of the inlet at slack tides, during the night and during early dawn hours. Periodogram analyses indicated that juvenile sharks tend to move in the direction of tidal currents. The present study documents large- and small-scale movement patterns of juvenile sandbar sharks and emphasises the importance of nursery-area habitats for this species.

Nursery grounds, movement patterns and growth rates of dusky sharks, Carcharhinus obscurus: a long-term tag and release study in South African waters

2009 ◽  
Vol 60 (6) ◽  
pp. 571 ◽  
Author(s):  
Nigel E. Hussey ◽  
Ian D. McCarthy ◽  
Sheldon F. J. Dudley ◽  
Bruce Q. Mann
Keyword(s):  
South African ◽  
Growth Rates ◽  
Movement Patterns ◽  
Small Scale ◽  
Shark Species ◽  
Early Life Stages ◽  
Kwazulu Natal ◽  
Management Plans ◽  
Carcharhinus Obscurus

Knowledge of movement patterns of sharks in coastal waters is critical for the structuring of regional management plans. Through a long-term tag–recapture program, 9716 dusky sharks (Carcharhinus obscurus) were tagged and released along the east coast of South Africa. A total of 648 C. obscurus, principally small sharks (<100 cm PCL), were recaptured. Most recaptures were within 100 km of the tagging location in the nursery habitat in KwaZulu-Natal (KZN) with small scale movements occurring throughout the year. Forty-eight C. obscurus undertook movements >200 km that indicated a southerly migration between KZN and Eastern/Southern Cape (E/SC) between June and November. Seasonal northerly migrations were less well defined. The largest southerly and northerly movements were 1323 km and 1374 km, respectively. For sharks moving 1–100 km south from their tagging locality in KZN, an increase in displacement occurred between June and September identifying animals beginning their migration to the E/SC. With increasing displacement, there was also an increase in minimum swimming speed. Calculated growth rates of small sharks of 10.3–11.5 cm year–1 were in agreement with current literature values. Established tag–recapture programs provide an important tool in understanding the ecology of early life-stages of coastal shark species.

Hawaii Experimental Acoustics Range for Shallow Water Applications

2011 ◽  
Vol 45 (3) ◽  
pp. 69-76 ◽  
Author(s):  
Tom Fedenczuk ◽  
Eva-Marie Nosal
Keyword(s):  
Shallow Water ◽  
Water Environment ◽  
Shallow Water Acoustics ◽  
Central Node ◽  
Long Baseline ◽  
Wide Range ◽  
Shallow Water Environment ◽  
Near Shore ◽  
Monitoring And Surveillance ◽  
Passive Acoustic

AbstractShallow water acoustics provide a means for monitoring and surveillance of near-shore environments. This paper describes the current and future capabilities of the low- to high-frequency Hawaii Experimental Acoustics Range (HEAR) that was designed to facilitate a wide range of different shallow water acoustics experiments and allow researchers from various institutions to test various array components and configurations. HEAR is a portable facility that consists of multiple hydrophones (12‐16) cabled independently to a common central node. The design allows for variable array configurations and deployments in three modes: experimental (off boats and piers), autonomous, and cabled. An application of HEAR is illustrated by the results from a deployment at Makai Research Pier, Oahu, Hawaii. In this deployment, HEAR was configured as a long-baseline range of two volumetric subarrays to study passive acoustic tracking capabilities in a shallow water environment.

Long-term migration patterns and bisexual philopatry in a benthic shark species

2017 ◽  
Vol 68 (8) ◽  
pp. 1414 ◽  
Author(s):  
Nathan Charles Bass ◽  
Johann Mourier ◽  
Nathan A. Knott ◽  
Joanna Day ◽  
Tristan Guttridge ◽  
...  
Keyword(s):  
Management Strategies ◽  
Movement Patterns ◽  
Conclusive Evidence ◽  
Migration Route ◽  
Shark Species ◽  
Apex Predators ◽  
Arrival Times ◽  
And Bisexual ◽  
Australian Coastline ◽  
Port Jackson

Knowledge of the broad-scale movement patterns of sharks is essential to developing effective management strategies. Currently there is a large bias in studies focusing on species that are either large apex predators or found in tropical to subtropical regions. There is limited knowledge of the movements and migrations of benthic and temperate shark species. The present study used passive acoustic telemetry to investigate the movement patterns of a benthic shark species, the Port Jackson shark (Heterodontus portusjacksoni). Individuals were tagged with acoustic transmitters between 2012 and 2014 and their movements were monitored within Jervis Bay and along the east Australian coastline for up to 4 years. Male and female Port Jackson sharks demonstrated high levels of philopatry to both Jervis Bay and their tagging location across multiple years. Although males and females did not differ in their arrival times, females departed from Jervis Bay later than males. Approximately half the tagged individuals migrated in a southward direction, with individuals being detected at Narooma, Bass Strait and Cape Barron Island. This study provides conclusive evidence of bisexual philopatry in a benthic temperate shark species, confirming previous hypotheses, and presents the most detailed migration route for Port Jackson sharks to date.

Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States

2007 ◽  
Keyword(s):  
United States ◽  
Gulf Of Mexico ◽  
East Coast ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
The United States ◽  
Shark Species ◽  
Carcharhinus Plumbeus ◽  
Nursery Areas ◽  
Pesticide Metabolites

<em>Abstract.</em>—Because of their tendency to accumulate in estuaries and coastal regions, organochlorine (OC) contaminants such as pesticides and polychlorinated biphenyls (PCBs) represent potential threats to the quality of essential fish habitat for many shark species. These compounds pose special risks to immature sharks in particular because of their ability to impair growth and sexual maturation in juvenile fish at environmentally relevant levels of exposure. In order to assess the extent of these risks in shark populations on the East Coast of the United States, the present study examined concentrations of 30 OC pesticides/pesticide metabolites and total PCBs in juvenile sandbar <em>Carcharhinus plumbeus </em>and blacktip <em>C. limbatus </em>sharks from seven major nursery areas in the western Atlantic Ocean and eastern Gulf of Mexico. Quantifiable levels of PCBs and 13 OC pesticides/ pesticide metabolites were detected via gas chromatography and mass spectrometry in liver of 25 young-of-the-year blacktip sharks from the southeastern U.S. Atlantic coast and three regions on Florida’s gulf coast: Cedar Key, Tampa Bay, and Charlotte Harbor. Similarly, quantifiable levels of PCBs and 14 OC pesticides/metabolites were detected in 23 juvenile <em>C. plumbeus </em>from three sites on the northeastern U.S. coast: middle Delaware Bay, lower Chesapeake Bay, and Virginia’s eastern shore. Liver OC concentrations in Atlantic sandbar and blacktip sharks were higher than expected and, in some cases, comparable with elevated levels observed in deep-sea and pelagic sharks. Although significantly lower than those observed in Atlantic sharks, pesticide and PCB levels in Florida blacktip sharks were similar to, if not greater than, OC concentrations reported in adults of other coastal shark species. Based on these data, OC contamination appears to pose significant threats to habitat quality in sandbar and blacktip shark nursery areas on the U.S. Atlantic coast.

Sex biased individual variation in movement patterns of a highly mobile, near‐shore marine planktivore, the reef manta ray Mobula alfredi

2019 ◽  
Vol 95 (6) ◽  
pp. 1399-1406
Author(s):  
Jeremy B. Axworthy ◽  
Joseph M. Smith ◽  
Martina S. Wing ◽  
Thomas P. Quinn
Keyword(s):  
Individual Variation ◽  
Movement Patterns ◽  
Near Shore ◽  
Manta Ray ◽  
Reef Manta Ray

On the locomotion of ascidian tadpole larvae

1992 ◽  
Vol 72 (1) ◽  
pp. 161-186 ◽  
Author(s):  
Q. Bone
Keyword(s):  
Gap Junctions ◽  
Electrical Activity ◽  
Movement Patterns ◽  
Muscle Cells ◽  
Small Scale ◽  
Number Range ◽  
Dorsal Muscle ◽  
Reynold’S Number ◽  
Ventral Muscle ◽  
40 Hz

This paper describes the locomotor movements of the tadpole larvae of the ascidians Ciona and Dcndrodoa and the associated electrical activity of the caudal muscle cells. Although very different in size and trunk shape, both larvae show essentially the same two movement patterns; symmetrical swimming and asymmetrical tail flicks. Swimming movements at tailbeat frequencies up to 40 Hz and forward speeds up to 10 L s (in the Reynold's number range 5·25) involve large lateral movements of the tail, and large yaw of the trunk. Tail oscillations are produced by muscle cells arranged in three segmented rows along the tail, coupled by gap junctions. Swimming is driven by axons innervating anterior ventral muscle cells. The second type of movement, single or multiple tail flicks, is driven by axons innervating dorsal muscle cells, all of which are innervated along the length of the tail. The middle row of muscle cells is not innervated. This small scale oscillatory swimming system is compared with those of chordates and larvacean tunicates, and it is concluded that both of these are very different from that of the ascidian tadpole.

scholarly journals Exploring movement patterns and changing distributions of baleen whales in the western North Atlantic using a decade of passive acoustic data

2020 ◽  
Vol 26 (9) ◽  
pp. 4812-4840 ◽  
Author(s):  
Genevieve E. Davis ◽  
Mark F. Baumgartner ◽  
Peter J. Corkeron ◽  
Joel Bell ◽  
Catherine Berchok ◽  
...  
Keyword(s):  
North Atlantic ◽  
Movement Patterns ◽  
Baleen Whales ◽  
Acoustic Data ◽  
Passive Acoustic

Demography of the central california population of the Leopard Shark (Triakis semifasciata)

1992 ◽  
Vol 43 (1) ◽  
pp. 183 ◽  
Author(s):  
GM Cailliet
Keyword(s):  
Population Growth ◽  
Reproductive Rate ◽  
Shark Species ◽  
Sandbar Shark ◽  
Lemon Shark ◽  
Carcharhinus Plumbeus ◽  
Net Reproductive Rate ◽  
Leopard Shark ◽  
Triakis Semifasciata ◽  
Leopard Sharks

Demographic analyses can be quite useful for effectively managing elasmobranch fisheries. However, they require valid estimates of age-specific mortality and natality rates, in addition to information on the distribution, abundance, habits and reproduction of the population, to produce reliable estimates of population growth. Because such detailed ecological information is usually unavailable, complete demographic analyses have been completed for only four shark species: the spiny dogfish, Squalus acanthias; the soupfin shark, Galeorhinus australis; the lemon shark, Negaprion brevirostris; and most recently the sandbar shark, Carcharhinus plumbeus. In California, reliable estimates of age, growth, mortality, age at maturity, and fecundity are available only for the leopard shark, Triakis semifasciata. A demographic analysis of this species yielded a net reproductive rate (Ro) of 4.467, a generation time (G) of 22.35 years, and an estimate of the instantaneous population growth coefficient (r) of 0.067. If the mean fishing pressure over 10 years (F= 0.084) is included in the survivorship function, Ro and r are reduced considerably, especially if leopard sharks first enter the fishery at early ages. A size limit of 120 cm TL (estimated age 13 years), especially for female sharks, is tentatively proposed for the leopard shark fishery.

Distribution and movements of Black Guillemots (Cepphus grylle) in coastal waters of the southwestern Bay of Fundy, Canada

1987 ◽  
Vol 65 (11) ◽  
pp. 2682-2689 ◽  
Author(s):  
E. Nol ◽  
D. E. Gaskin
Keyword(s):  
Coastal Waters ◽  
Fast Moving ◽  
Movement Patterns ◽  
Food Resources ◽  
Small Scale ◽  
Bay Of Fundy ◽  
Island Region ◽  
Cepphus Grylle ◽  
Slow Moving ◽  
Tidal Waters

Distribution and movement patterns are described for summering (nonbreeding) Black Guillemots in the Deer Island region of the southwestern Bay of Fundy, Canada. Guillemots were distributed in areas with moderate current velocities (range, 30–68 cm/s) and shallow to intermediate depths (range, 17–31 m). The birds appeared to avoid shallow and deep areas with fast- or slow-moving water. Guillemots preferred islands with extensive underwater ledges, presumably because these harboured sufficient prey and provided protection from fast-moving tidal waters. Guillemots moved in and out of the approaches passively with the tide and, in contrast to larids in the region, made only small-scale flights to reposition themselves in relation to food resources.

scholarly journals A sedimentary and faunal study of the Blue Lias of Dorset and Glamorgan

1960 ◽  
Vol 242 (698) ◽  
pp. 1-44 ◽  
Author(s):  
A. Hallam ◽  
William Dickson Lang
Keyword(s):  
Small Scale ◽  
Population Fluctuations ◽  
Strontium Content ◽  
Rock Types ◽  
Sea Bottom ◽  
Bottom Waters ◽  
Near Shore ◽  
The Difference ◽  
Carboniferous Limestone ◽  
Aerobic And Anaerobic

The rocks of the Blue Lias in Dorset and Glamorgan can be divided into off-shore and near-shore facies. The off-shore facies has a characteristic pattern of regular, small-scale alternations of argillaceous calcilutites, marls and sometimes bituminous shales, the main variable being CaCO 3 content. Two distinct types of limestone are recognized and termed laminated and normal limestone, respectively. The marls are generally comparable with the limestones in all respects except their much lower CaCO 3 content. The bituminous shales are rich in bituminous matter which is arranged in fine laminae parallel to the bedding. Determinations of percentages of insoluble residues reveal a consistently large difference between the limestones and marls. Fuller chemical analyses of major constituents indicate, among other things, that nearly all the carbonate is present as CaCO 3 . The clay mineral content consists almost entirely of illite, with subsidiary kaolinite. The strontium content of the carbonate fraction of the marls appears to be markedly higher than that of the limestones. Vertical variation in Dorset, Glamorgan and Somerset is studied and compared by a graphical method based on the limestone-shale ratio. It has been established that the Blue Lias rhythm is primary in origin, but that there has also been a limited amount of early diagenetic segregation of CaCO 3 to produce nodular structures. The limestone textures are accounted for by recrystallization from an original lime mud and the respective importance of several processes including drusy and grain growth and granular and rim cementation assessed. Pyrite is considered to have been formed early in diagenesis under anaerobic conditions within the sediments. Its association in some drusy cavities with calcite is explained as due to the local fall in pH of interstitial fluids. The difference between the normal and laminated limestones and marls is considered to be the result of aerobic and anaerobic bottom conditions, respectively. The microlaminae in the bituminous shales are interpreted as varves due to the annual fall of plankton into anaerobic bottom waters. Evidence is put forward that the Blue Lias rhythm may be the result of repeated epeirogenic oscillations. Rocks of the near-shore facies are confined to Glamorgan. They include (besides calcilutites and subsidiary marls) skeletal limestones, oolites, conglomerates and cherty beds; locally the rocks lie unconformably on Carboniferous Limestone. Silica is found in the form of bands of nodules and silicified limestone pebbles and shells. The facies relationships of the different rock types can be satisfactorily related to the approach of an old shoreline. The silica was almost certainly derived from detrital chert weathered from the Carboniferous Limestone. Although there is a broad similarity in the fauna between Dorset and Glamorgan, a number of important differences are recognizable. Differences between the off-shore and near-shore facies are also described; whereas the former has pelecypods and ammonites as its most conspicuous elements the latter is notable for the abundance of corals and gastropods and, locally, of ribbed pectinids. A relationship between the fauna and the sediments is recognized in three cases: (1) shell enrichment in condensed beds (with glauconite and/or collophane); (2) dwarfing and general faunal impoverishment in the laminated rocks, related to poor aeration of the sea bottom ; and (3) variations in sedimentary rate and depth of sea probably account for the faunal differences between Dorset and Glamorgan in the off-shore facies. On the other hand, no relationship can be perceived in three other cases: (1) the increase in size up the succession in a number of forms, which is evolutionary; (2) the succession of different organisms due to ecological replacement and extinction; and (3) certain shell enrichments which may be due to population fluctuations. In a summary of the Blue Lias environment deductions are made about temperature, salinity, rate of sedimentation, depth of sea and current strengths.

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