Site fidelity and movements of sharks associated with ocean-farming cages in Hawaii

2010 ◽  
Vol 61 (12) ◽  
pp. 1366 ◽  
Author(s):  
Yannis P. Papastamatiou ◽  
David G. Itano ◽  
Jonathan J. Dale ◽  
Carl G. Meyer ◽  
Kim N. Holland
Keyword(s):  
Site Fidelity ◽  
Hawaiian Island ◽  
Fish Farms ◽  
Carcharhinus Plumbeus ◽  
Galeocerdo Cuvier ◽  
Water Users ◽  
Top Predators ◽  
Coastal Species ◽  
Main Hawaiian Island ◽  
Passive Acoustic

Sharks are found in association with main Hawaiian Island ocean fish farms more frequently and at higher densities than is typical for coastal Hawaiian waters. Sharks attracted to fish farms could potentially threaten human water users, interact negatively with other fisheries, and seasonal migrations could be disrupted if individuals become entrained around farms throughout the year. We hypothesised that smaller coastal species would reside near farms, whereas more wide-ranging species would associate with farms only for short periods. We utilised passive acoustic telemetry to monitor the movements and behaviour of sandbar (Carcharhinus plumbeus) and tiger (Galeocerdo cuvier) sharks adjacent to two open ocean fish farms in Hawaii. Approximately half the tagged sandbar sharks showed site fidelity to the farms, with some individuals being detected repeatedly for 2.5 years. Sandbar sharks moved seasonally to the west coast of Oahu, suggesting that fish farms are not disrupting natural seasonal cycles in this species. Tiger sharks tagged near the cages were more transient, and showed much shorter residence times although some individuals returned sporadically to the cages over the 3-year period. Ocean fish cages appear to aggregate sandbar sharks, but are only ‘visited’ by tiger sharks. Although threats to public safety are probably minimal, the ecological effects of aggregating top-predators are still unknown.

scholarly journals Modelling tooth–prey interactions in sharks: the importance of dynamic testing

2016 ◽  
Vol 3 (8) ◽  
pp. 160141 ◽  
Author(s):  
Katherine A. Corn ◽  
Stacy C. Farina ◽  
Jeffrey Brash ◽  
Adam P. Summers
Keyword(s):  
Dynamic Testing ◽  
Testing Device ◽  
Carcharhinus Plumbeus ◽  
Biologically Relevant ◽  
Galeocerdo Cuvier ◽  
Shark Teeth ◽  
Repeated Use ◽  
And Performance ◽  
Predictive Relationship ◽  
Testing Protocols

The shape of shark teeth varies among species, but traditional testing protocols have revealed no predictive relationship between shark tooth morphology and performance. We developed a dynamic testing device to quantify cutting performance of teeth. We mimicked head-shaking behaviour in feeding large sharks by attaching teeth to the blade of a reciprocating power saw fixed in a custom-built frame. We tested three tooth types at biologically relevant speeds and found differences in tooth cutting ability and wear. Teeth from the bluntnose sixgill ( Hexanchus griseus ) showed poor cutting ability compared with tiger ( Galeocerdo cuvier ), sandbar ( Carcharhinus plumbeus ) and silky ( C. falciformis ) sharks, but they also showed no wear with repeated use. Some shark teeth are very sharp at the expense of quickly dulling, while others are less sharp but dull more slowly. This demonstrates that dynamic testing is vital to understanding the performance of shark teeth.

scholarly journals HELMINTOS PARÁSITOS INTESTINALES DE ALGUNOS TIBURONES (PISCES: ELASMOBRANCHII) DEL GOLFO DE MÉXICO

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Oscar Méndez ◽  
Elizabeth Valero Pacheco ◽  
Miguel Angel Dorantes González
Keyword(s):  
Carcharhinus Plumbeus ◽  
Galeocerdo Cuvier ◽  
Distribución Geográfica

Se registran los helmintos intestinales de ocho tiburones pertenecientes a cuatro especies: Carcharhinus plumbeus (Nardo, 1827) (n=1), Galeocerdo cuvier (Péron y LeSueur, 1822) (n=1), Isurus oxyrhinchus Rafinesque, 1810 (n=3) y Squatina dumeril (Lesueur, 1818) (n=3), capturados por la pesca artesanal en Chachalacas, Veracruz, en octubre-noviembre de 2014 y octubre de 2015. Cada intestino se colocó en una bolsa de plástico con formaldehído al 10% y se transportaron al laboratorio. Se determinaron 20 especies pertenecientes a seis órdenes. Se colectaron 619 individuos helmintos, de estos, 615 son cestodos de 18 especies y cuatro nematodos de una especie. Los órdenes Trypanorhyncha y Phyllobothriidea registraron el mayor número de especies con siete y cinco, respectivamente. El número de especies de helmintos por especie de tiburón varió de cuatro en S. dumeril a seis en I. oxyrhinchus. Todos los tiburones estuvieron parasitados con al menos una especie de parásito. El mínimo de helmintos parásitos registrados en un tiburón fue de uno (I. oxyrhinchus y S. dumeril), mientras que G. cuvier registró el mayor número con 253 individuos. Los cestodos Aberrapex sp. Jensen, 2001; Calyptrobothrium sp. Monticelli, 1893 y Paraorygmatobothrium sp., se registraron una sola vez en S. dumeril, I. oxyrhinchus y G. cuvier con un solo individuo, mientras que Thysanocephalum thysanocephalum (Linton, 1889) Braun, 1900 registró el mayor número con 233 individuos en G. cuvier. El cestodo Disculiceps pileatus (Linton, 1891) Joyeux y Baer, 1936 se registra por primera vez en C. plumbeus. Los hábitos alimenticios y la especificidad hospedatoria son factores importantes que influyen en la composición de especies de helmintos parásitos en estos tiburones. Con estos datos ampliamos la distribución geográfica y el registro de nuevos hospederos en México.

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.

АНАЛИЗ ВОДООБЕСПЕЧЕННОСТИ АПК КРАСНОДАРСКОГО КРАЯ

2020 ◽  
pp. 7
Author(s):  
I.G. Bondarik
Keyword(s):  
Water Management ◽  
Water Intake ◽  
Water Consumption ◽  
Water Availability ◽  
Management System ◽  
Animal Husbandry ◽  
Fish Farms ◽  
Water Management System ◽  
Water Users ◽  
The Future

В статье проведен анализ водообеспеченности агропромышленного комплекса Краснодарского края за 10 лет и на перспективу. Рассмотрены основные водопользователи и отрасли с наибольшим потреблением воды, такие как рисосеяние, животноводство и прудовые рыбоводческие хозяйства. Выявлено сокращение поливаемых земель в Краснодарском крае, снижение суммарного водозабора и оросительных норм. Выполнен прогноз водообеспеченности на перспективу до 2030 г. и предложены меры по оптимизации системы управления водным хозяйством.The article analyzes the water availability of the agricultural complex of the Krasnodar Territory over 10 years and for the future. The main water users and sectors with the highest water consumption, such as rice cultivation, animal husbandry and pond fish farms, are considered. The reduction an irrigated land in the Krasnodar Territory, the decrease in the total water intake and irrigation norms were identified. The forecast of water availability for the future until 2030 has been completed and measures have been proposed to optimize the water management system.

scholarly journals A Methodological Framework to Estimate the Site Fidelity of Tagged Animals Using Passive Acoustic Telemetry

PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0134002 ◽  
Author(s):  
Manuela Capello ◽  
Marianne Robert ◽  
Marc Soria ◽  
Gael Potin ◽  
David Itano ◽  
...  
Keyword(s):  
Acoustic Telemetry ◽  
Site Fidelity ◽  
Methodological Framework ◽  
Passive Acoustic

scholarly journals Effects of intense storm events on dolphin occurrence and foraging behavior

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Amber D. Fandel ◽  
A. Garrod ◽  
A. L. Hoover ◽  
J. E. Wingfield ◽  
V. Lyubchich ◽  
...  
Keyword(s):  
Prey Species ◽  
Environmental Changes ◽  
Bottlenose Dolphins ◽  
Sea Surface ◽  
Storm Events ◽  
Environmental Disturbances ◽  
Top Predators ◽  
Intense Storm ◽  
Passive Acoustic ◽  
And Behavior

Abstract As storms become increasingly intense and frequent due to climate change, we must better understand how they alter environmental conditions and impact species. However, storms are ephemeral and provide logistical challenges that prevent visual surveys commonly used to understand marine mammal ecology. Thus, relatively little is known about top predators’ responses to such environmental disturbances. In this study, we utilized passive acoustic monitoring to characterize the response of bottlenose dolphins to intense storms offshore Maryland, USA between 2015 and 2017. During and following four autumnal storms, dolphins were detected less frequently and for shorter periods of time. However, dolphins spent a significantly higher percentage of their encounters feeding after the storm than they did before or during. This change in foraging may have resulted from altered distributions and behavior of their prey species, which are prone to responding to environmental changes, such as varied sea surface temperatures caused by storms. It is increasingly vital to determine how these intense storms alter oceanography, prey movements, and the behavior of top predators.

scholarly journals Is the tiger shark Galeocerdo cuvier a coastal species? Expanding its distribution range in the Atlantic Ocean using at-sea observer data

2016 ◽  
Vol 88 (3) ◽  
pp. 1223-1228 ◽  
Author(s):  
A. Domingo ◽  
R. Coelho ◽  
E. Cortes ◽  
B. Garcia-Cortes ◽  
F. Mas ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Distribution Range ◽  
Tiger Shark ◽  
Galeocerdo Cuvier ◽  
Coastal Species

scholarly journals Post-release survival of fallout Newell’s shearwater fledglings from a rescue and rehabilitation program on Kaua‘i, Hawai‘i

2020 ◽  
Vol 43 ◽  
pp. 39-50
Author(s):  
AF Raine ◽  
T Anderson ◽  
M Vynne ◽  
S Driskill ◽  
H Raine ◽  
...  
Keyword(s):  
Large Scale ◽  
Survival Rates ◽  
Hawaiian Island ◽  
Rehabilitation Program ◽  
Unresolved Issue ◽  
Root Cause ◽  
The North ◽  
Main Hawaiian Island ◽  
Satellite Transmitters ◽  
The North Pacific

Light attraction impacts nocturnally active fledgling seabirds worldwide and is a particularly acute problem on Kaua‘i (the northern-most island in the main Hawaiian Island archipelago) for the Critically Endangered Newell’s shearwater Puffinus newelli. The Save Our Shearwaters (SOS) program was created in 1979 to address this issue and to date has recovered and released to sea more than 30500 fledglings. Although the value of the program for animal welfare is clear, as birds cannot simply be left to die, no evaluation exists to inform post-release survival. We used satellite transmitters to track 38 fledglings released by SOS and compared their survival rates (assessed by tag transmission duration) to those of 12 chicks that fledged naturally from the mountains of Kaua‘i. Wild fledglings transmitted longer than SOS birds, and SOS birds with longer rehabilitation periods transmitted for a shorter duration than birds released immediately or rehabilitated for only 1 d. Although transmitter durations from grounded fledglings were shorter (indicating impacts to survivorship), some SOS birds did survive and dispersed out to sea. All surviving birds (wild and SOS) traveled more than 2000 km to the southwest of Kaua‘i, where they concentrated mostly in the North Pacific Equatorial Countercurrent Province, revealing a large-scale annual post-breeding aggregation zone for fledgling Newell’s shearwaters. While there was reduced survival among birds undergoing rehabilitation, SOS remains an important contribution toward the conservation of Newell’s shearwater because a proportion of released birds do indeed survive. However, light attraction, the root cause of fallout, remains a serious unresolved issue on Kaua’i.

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