The effects of elevated potassium, acidosis, reduced oxygen levels, and temperature on the functional properties of isolated myocardium from three elasmobranch fishes: clearnose skate (Rostroraja eglanteria), smooth dogfish (Mustelus canis), and sandbar shark (Carcharhinus plumbeus)

Abstract.—To identify and characterize shark nursery habitat in the coastal waters of Massachusetts, longline and shark angler surveys were conducted from 1989 to 2002 in the neritic waters of Nantucket Sound, Massachusetts. Additional samples and information were opportunistically collected from recreational and commercial fishermen, as well as published sources. A total of 123 longline sets of 5,591 hooks caught 372 sharks consisting of 344 (92.5%) smooth dogfish Mustelus canis, 23 (6.2%) sandbar sharks Carcharhinus plumbeus, and 5 (1.3%) dusky sharks C. obscurus. The sharks were taken during the period of 16 June–24 September in water temperature and depth ranges of 16.0–27.2°C and 1.2–27.1 m, respectively. Longline catch rates (number of sharks per longline set) were stratified by species, area, month, year, water temperature, and depth. Angler surveys reported the capture of 294 sharks, including sandbar sharks (72%) and smooth dogfish (28%). Data from 540 neonatal and adult smooth dogfish ranging 27.5–121.0 cm fork length (FL) support the conclusion that the neritic waters of southern Massachusetts serve as primary nursery habitat for this species. Size and sex data from 235 juvenile sandbar sharks ranging 61.0–157.0 cm FL indicate that this region provides secondary nursery habitat for this species. Opportunistic samples of juvenile sand tiger Carcharias taurus, white shark Carcharodon carcharias, basking shark Cetorhinus maximus, and tiger shark Galeocerdo cuvier provide evidence that these species utilize Massachusetts coastal waters for secondary nursery habitat.

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Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals

Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals ◽

10.47886/9781888569155.ch9 ◽

1999 ◽

Keyword(s):

Simulation Model ◽

Maximum Size ◽

Population Projections ◽

Population Declines ◽

Sandbar Shark ◽

Carcharhinus Plumbeus ◽

Marine Animals ◽

Important Species ◽

Age Structured ◽

Stage Class

Abstract. —The sandbar shark Carcharhinus plumbeus is the most important species caught in the commercial shark fishery operating off the U.S. Atlantic and Gulf of Mexico coasts. Previous demographic studies of this and other species of sharks have utilized age-structured, deterministic life tables that provided point estimates of maximum rates of increase. To reduce some of the uncertainty in estimates of age at maturity and longevity—especially acute in the case of the sandbar shark—I constructed a stage-based model based on an Usher matrix that utilizes the more reliable estimates of size at maturity and maximum size for this species in the northwest Atlantic. Because demographic variability also can affect estimated rates of increase, I introduced stochasticity into the model by randomly selecting fecundity rates from an empirically determined distribution, and natural mortality rates from estimates obtained through four life history methods. The simulation model was applied to females only. Population projections 20 years forward in time without exploitation predicted slowly growing populations at approximately 1.3%/year. Application of a constant instantaneous mortality rate (F ) of 0.1 to each stage-class separately indicated that removal of large juveniles would produce the greatest population declines, whereas removal of age-0 individuals would be sustainable. The simulation model was then used to predict potential outcomes under three hypothetical harvesting scenarios using the current U.S. commercial quota indicating that all strategies produced pronounced population declines.

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Gastric evacuation in the sandbar shark, Carcharhinus plumbeus

Journal of Fish Biology ◽

10.1111/j.1095-8649.1985.tb04263.x ◽

1985 ◽

Vol 26 (3) ◽

pp. 239-253 ◽

Cited By ~ 32

Author(s):

R. J. Medved

Keyword(s):

Sandbar Shark ◽

Carcharhinus Plumbeus ◽

Gastric Evacuation

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Microdetermination of dry mass content in the uterine fluid of four species of viviparous sharks (Squalus acanthias, Carcharhinus plumbeus, Mustelus canis and Rhizoprionodon terraenovae)

Comparative Biochemistry and Physiology Part A Physiology ◽

10.1016/0300-9629(94)90087-6 ◽

1994 ◽

Vol 108 (2-3) ◽

pp. 213-219

Author(s):

Brian D Strahl ◽

Julian Lombardi

Keyword(s):

Dry Mass ◽

Squalus Acanthias ◽

Mass Content ◽

Carcharhinus Plumbeus ◽

Rhizoprionodon Terraenovae ◽

Uterine Fluid ◽

Mustelus Canis

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

Marine and Freshwater Research ◽

10.1071/mf9920183 ◽

1992 ◽

Vol 43 (1) ◽

pp. 183 ◽

Cited By ~ 36

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.

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