Journal articles: 'Shark'

1

HART, Nathan S., and Shaun P. COLLIN. "Sharks senses and shark repellents." Integrative Zoology 10, no. 1 (January 2015): 38–64. http://dx.doi.org/10.1111/1749-4877.12095.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Corn, Katherine A., Stacy C. Farina, Jeffrey Brash, and Adam P. Summers. "Modelling tooth–prey interactions in sharks: the importance of dynamic testing." Royal Society Open Science 3, no. 8 (August 2016): 160141. http://dx.doi.org/10.1098/rsos.160141.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

3

Van Houtan, Kyle S., Tyler O. Gagné, Gabriel Reygondeau, Kisei R. Tanaka, Stephen R. Palumbi, and Salvador J. Jorgensen. "Coastal sharks supply the global shark fin trade." Biology Letters 16, no. 10 (October 2020): 20200609. http://dx.doi.org/10.1098/rsbl.2020.0609.

Full text

Abstract:

Progress in global shark conservation has been limited by constraints to understanding the species composition and geographic origins of the shark fin trade. Previous assessments that relied on earlier genetic techniques and official trade records focused on abundant pelagic species traded between Europe and Asia. Here, we combine recent advances in DNA barcoding and species distribution modelling to identify the species and source the geographic origin of fins sold at market. Derived models of species environmental niches indicated that shark fishing effort is concentrated within Exclusive Economic Zones, mostly in coastal Australia, Indonesia, the United States, Brazil, Mexico and Japan. By coupling two distinct tools, barcoding and niche modelling, our results provide new insights for monitoring and enforcement. They suggest stronger local controls of coastal fishing may help regulate the unsustainable global trade in shark fins.

APA, Harvard, Vancouver, ISO, and other styles

4

Brunnschweiler, Juerg. "Shark Attacks and Shark Diving." Wilderness & Environmental Medicine 26, no. 2 (June 2015): 276–77. http://dx.doi.org/10.1016/j.wem.2014.11.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Howland-Myers, Julia. "Shark." Red Cedar Review 47, no. 1 (2012): 61–66. http://dx.doi.org/10.1353/rcr.2012.0005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Morton, Brian. "Shark!" Marine Pollution Bulletin 28, no. 6 (June 1994): 340–41. http://dx.doi.org/10.1016/0025-326x(94)90257-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Yusrina, Firda. "DAMPAK PENGOLAHAN DAN KONSUMSI SUP SIRIP IKAN HIU." Journal of Food Technology and Agroindustry 1, no. 2 (October 22, 2019): 31–36. http://dx.doi.org/10.24929/jfta.v1i2.748.

Full text

Abstract:

Indonesia is an archipelagic country that consist of 2/3 ocean and 1/3 land. The extensive territorial ocean is certainly have a lot of diversity of marine existence. One of them is shark. There are 25 kinds of sharks in indonesian’s oncean. Lately sharks have become one of the topics discussed in fisheries institutions and fauna activists, due to the increasing activity of hunting shark. Shark finning is cutting off a shark’s fin and throwing the rest of the still-living body, often by dumping it back into the ocean.The body’s sharks without fins are often thrown back into the ocean alive, where they are die because unable to swim properly and bleeding profusely or die of blood loss. Shark fins are tempting targets for fishermen because they have high monetary and cultural value. Fins are used in a popular dish called shark fin soup, which is a symbol of status. This review will provide a description of definition of shark finning, shark fin soup, dengerous delicacy for humans and sharks alike and aim to protect Indonesia is an archipelagic country that consist of 2/3 ocean and 1/3 land. The extensive territorial ocean is certainly have a lot of diversity of marine existence. One of them is shark. There are 25 kinds of sharks in indonesian’s oncean. Lately sharks have become one of the topics discussed in fisheries institutions and fauna activists, due to the increasing activity of hunting shark. Shark finning is cutting off a shark’s fin and throwing the rest of the still-living body, often by dumping it back into the ocean.The body’s sharks without fins are often thrown back into the ocean alive, where they are die because unable to swim properly and bleeding profusely or die of blood loss. Shark fins are tempting targets for fishermen because they have high monetary and cultural value. Fins are used in a popular dish called shark fin soup, which is a symbol of status. This review will provide a description of definition of shark finning, shark fin soup, dengerous delicacy for humans and sharks alike and aim to protect shark population. Keyword : Indonesian’s ocean ; Save our shark ; Shark Finning ; Shark fin soup. shark population.

APA, Harvard, Vancouver, ISO, and other styles

8

Whitenack, Lisa B., Brady L. Mickley, Julia Saltzman, Stephen M. Kajiura, Catherine C. Macdonald, and David S. Shiffman. "A content analysis of 32 years of Shark Week documentaries." PLOS ONE 17, no. 11 (November 3, 2022): e0256842. http://dx.doi.org/10.1371/journal.pone.0256842.

Full text

Abstract:

Despite evidence of their importance to marine ecosystems, at least 32% of all chondrichthyan species are estimated or assessed as threatened with extinction. In addition to the logistical difficulties of effectively conserving wide-ranging marine species, shark conservation is believed to have been hindered in the past by public perceptions of sharks as dangerous to humans. Shark Week is a high-profile, international programming event that has potentially enormous influence on public perceptions of sharks, shark research, shark researchers, and shark conservation. However, Shark Week has received regular criticism for poor factual accuracy, fearmongering, bias, and inaccurate representations of science and scientists. This research analyzes the content and titles of Shark Week episodes across its entire 32 years of programming to determine if there are trends in species covered, research techniques featured, expert identity, conservation messaging, type of programming, and portrayal of sharks. We analyzed titles from 272 episodes (100%) of Shark Week programming and the content of all available (201; 73.9%) episodes. Our data demonstrate that the majority of episodes are not focused on shark bites, although such shows are common and many Shark Week programs frame sharks around fear, risk, and adrenaline. While criticisms of disproportionate attention to particular charismatic species (e.g. great whites, bull sharks, and tiger sharks) are accurate and supported by data, 79 shark species have been featured briefly at least once. Shark Week’s depictions of research and of experts are biased towards a small set of (typically visual and expensive) research methodologies and (mostly white, mostly male) experts, including presentation of many white male non-scientists as scientific experts. While sharks are more often portrayed negatively than positively, limited conservation messaging does appear in 53% of episodes analyzed. Results suggest that as a whole, while Shark Week is likely contributing to the collective public perception of sharks as bad, even relatively small alterations to programming decisions could substantially improve the presentation of sharks and shark science and conservation issues.

APA, Harvard, Vancouver, ISO, and other styles

9

Hardiman, Nigel, Shelley Burgin, and Jia Shao. "How Sharks and Shark–Human Interactions are Reported in Major Australian Newspapers." Sustainability 12, no. 7 (March 29, 2020): 2683. http://dx.doi.org/10.3390/su12072683.

Full text

Abstract:

Few phrases evoke more negative emotion, or generate more media coverage, than ‘shark attack’ despite the few deaths that have been attributed to shark bite. Typically, tabloids are considered to provide more sensational coverage than broadsheets. We investigated how sharks and shark–human interactions were portrayed in four major Australian newspapers during a period of a record number of shark attacks in Australian waters. There was strong focus on human risk from sharks, and over-reportage of negative aspects. Thirty incidents were recorded: two fatal, 20 injury, and eight ‘near-miss’. Of 309 ‘shark’ articles surveyed, 24% mentioned fatalities (65% occurred prior to the study, some decades earlier). Injury was reported in 40% of articles, and ‘near-miss’ in 33% (89% related to an incident in South Africa involving an Australian surfing celebrity). The tabloid, Telegraph, published substantially more shark-related articles and photographs than other newspapers. There was otherwise no consistent pattern of difference between genre or newspapers.

APA, Harvard, Vancouver, ISO, and other styles

10

Dharmadi, Dharmadi, Mahiswara Mahiswara, and Kamaluddin Kasim. "CATCH COMPOSITION AND SOME BIOLOGICAL ASPECTS OF SHARKS IN WESTERN SUMATERA WATERS OF INDONESIA." Indonesian Fisheries Research Journal 22, no. 2 (January 24, 2017): 99. http://dx.doi.org/10.15578/ifrj.22.2.2016.99-108.

Full text

Abstract:

This study was conducted in western Sumatera and since October 2013 to June 2014. The sampling locations in Banda Aceh and Sibolga-North Sumatera which were the largest base of fisheries in western Sumatera region. Shark landing recorded by enumerators was used as sampling data daily . This research aim to describ sex ratio, size composition, catch composition of sharks, and length at first maturity. In Banda Aceh, the sharks as target fish collected by sorting the bycatch from tuna longlines and tuna handlines. In Sibolga, sharks is bycatch from fish net, bottom gillnet and purse seine. Overall, there were 20 species of shark caught in west Indian Ocean and landed at those fish landing sites, dominated by Spot tail shark (23%) and Silky shark (13%), whereas Hammerhead shark contributed about 10% and Oceanic whitetip shark was only less than 1%. Almost of Spot tail shark, Silky shark, and Scalloped hammerhead that caught in that area were immature, while for the almost part of Tiger shark and Pelagic thresher were matured. The sex ratios for Spot tail shark, Silky shark, Tiger shark, Pelagic thresher, and Scalloped hammerhead caught and landed at Lampulo and Sibolga fish landing sites were not balance. The length at first maturity for Spot tail shark was Lm=87,1 cm and Lm = 213,2 cm total length for Tiger shark.

APA, Harvard, Vancouver, ISO, and other styles

11

Liu, John Chung-En, Brandon Gertz, and Naomi Newman. "Shark Fin Regulations in the United States: Animal Welfare, Cultural, and Policy Considerations." Case Studies in the Environment 3, no. 1 (December 31, 2019): 1–6. http://dx.doi.org/10.1525/cse.2018.001438.

Full text

Abstract:

Sharks play critical roles in the marine ecosystem, and they face serious threats due to overfishing. Conservation efforts have focused on the consumption of shark fins, especially the “finning” practice that removes the fins of a shark and discards the carcass at sea. This article reviews the shark fin legislation in the United States, including the “finning ban” which outlaws finning practices and the “fin ban” that prohibits the use of shark fins entirely. Our case study specifically focuses on the animal welfare, cultural, and policy debates surrounding these bans. We discuss how and why shark finning is regarded as a cruel practice and whether shark fin bans discriminate against Chinese Americans. At the policy level, there is an ongoing policy debate whether a ban on shark fins in the United States would lead to increased protection of sharks or it would have little effect on the global trade. Due to the lack of detailed information on shark fisheries, the policy discussion is likely to persist. Although this case study focuses only on regulations on shark fins, we would like to emphasize that shark fin industry is not the only threat to sharks. Conservationists also need to consider other issues such as bycatch, habitat destruction, and a wider array of policy tools to protect sharks.

APA, Harvard, Vancouver, ISO, and other styles

12

Cajiga, Rosa María. "Shark Finning Legislation and Shark Welfare. An Analysis of the Kristin Jacobs Ocean Conservation Act." Derecho Animal. Forum of Animal Law Studies 12, no. 3 (December 9, 2021): 78–110. http://dx.doi.org/10.5565/rev/da.566.

Full text

Abstract:

Thousands of sharks are cruelly killed worldwide every day due to the lucrative shark finning trade. This practice is negatively impacting marine life, as sharks are the greatest ocean predators and maintain the delicate balance of the marine ecosystem. Shark finning consists of removing the fins and discarding the rest. The sharks are alive during the process, and when tossed back into the water without fins they cannot swim, thus sinking to the depths where they asphyxiate and / or are devoured by other fish. The fins are primarily consumed in China, Hong Kong, Taiwan, and Asian communities elsewhere in the world for making shark-fin soup. Efforts to stop the practice of shark finning vary, ranging from demanding fisheries to bring sharks to land before removing the fins, to prohibiting the trade of shark products, to the total ban of shark fishing. Legislation varies significantly between countries and states, ranging from zero to absolute protection, whereby absolute means prohibiting the possession, sale, importation and exportation of shark fins. The economic implications of the shark-fin trade are considerable, which renders the application of laws and regulations very difficult. However, the increasing business of diving with sharks offers an alternative that shows us that the value of a living shark is far greater than when it is sold for parts. Analyzing legislation from the United States, as well as international legislation, aims to show its weakness when it comes to efforts to protect sharks, and in particular the application of the concept of shark welfare when legislating in their favor. The case study will focus on the Kristin Jacobs Ocean Conservation Act, investigating and analyzing the legal efforts made in the state of Florida (USA) to stop shark finning, and analyzing the legal implications for shark welfare.

APA, Harvard, Vancouver, ISO, and other styles

13

Lentz, Ashley K., George H. Burgess, Karen Perrin, Jennifer A. Brown, David W. Mozingo, and Lawrence Lottenberg. "Mortality and Management of 96 Shark Attacks and Development of a Shark Bite Severity Scoring System." American Surgeon 76, no. 1 (January 2010): 101–6. http://dx.doi.org/10.1177/000313481007600120.

Full text

Abstract:

Humans share a fascination and fear of sharks. We predict that most shark attacks are nonfatal but require skilled, timely medical intervention. The development of a shark bite severity scoring scale will assist communication and understanding of such an injury. We retrospectively reviewed records of the prospectively maintained International Shark Attack File (ISAF) at the University of Florida. The ISAF contains 4409 investigations, including 2979 documented attacks, 96 of which have complete medical records. We developed a Shark-Induced Trauma (SIT) Scale and calculated the level of injury for each attack. Medical records were reviewed for the 96 documented shark attack victims since 1921. Calculated levels of injury in the SIT Scale reveal 40 Level 1 injuries (41.7%), 16 Level 2 injuries (16.7%), 18 Level 3 injuries (18.8%), 14 Level 4 injuries (14.6%), and eight Level 5 injuries (8.3%). The overall mortality of shark attacks was 8.3 per cent. However, SIT Scale Level 1 injuries comprised the greatest percentage of cases at 41.7 per cent. Injury to major vascular structures increases mortality and necessitates immediate medical attention and definitive care by a surgeon. Shark bites deserve recognition with prompt resuscitation, washout, debridement, and follow up for prevention of infection and closure of more complex wounds.

APA, Harvard, Vancouver, ISO, and other styles

14

Lucrezi, Serena, Filippo Bargnesi, and Francois Burman. ""I Would Die to See One": A Study to Evaluate Safety Knowledge, Attitude, and Behavior Among Shark Scuba Divers." Tourism in Marine Environments 15, no. 3 (October 14, 2020): 127–58. http://dx.doi.org/10.3727/154427320x15779149069752.

Full text

Abstract:

Shark diving tourism is an activity that can contribute significantly to coastal economies, while also offering tremendous help to shark conservation efforts. Nevertheless, like any form of wildlife-based tourism, shark diving poses management challenges revolving around ethical and safety considerations. Safety in shark diving normally focuses on operational self-efficacy and adherence to shark diving codes of conduct to prevent incidents such as shark bites and to minimize ecological harm. However, safety issues in shark diving can arise from personal choices to exceed standard certification limits. Any detrimental results are capable of casting doubts on the sustainability of shark diving, thus jeopardizing its future as well as shark conservation. This study addressed compliance with shark diving codes of conduct and standard diving safety by examining the knowledge, attitude, and behavior of people who engage in free scuba diving with predatory sharks. The research made use of mixed methods of data collection, including interviews with shark divers at two popular shark diving destinations in Southeast Africa (n = 86) and an online questionnaire survey among shark divers (n = 89). The results showed that divers had positive attitudes towards sharks and shark diving. However, a notable proportion declared that they had exceeded certification limits and broken codes of conduct during shark diving. In particular, diving experience and being a professional diver were correlated significantly with poor safety attitudes and behavior. The results highlight the need to create an understanding among scuba divers of the connection between shark diving safety and conservation, including the negative implications of safety breaches, whether big or small, for the future of shark diving tourism and of sharks.

APA, Harvard, Vancouver, ISO, and other styles

15

Friedrich, Laura A., Rebecca Jefferson, and Gillian Glegg. "Public perceptions of sharks: Gathering support for shark conservation." Marine Policy 47 (July 2014): 1–7. http://dx.doi.org/10.1016/j.marpol.2014.02.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Varghese, Sijo P., N. Unnikrishnan, Deepak K. Gulati, and A. E. Ayoob. "Size, sex and reproductive biology of seven pelagic sharks in the eastern Arabian Sea." Journal of the Marine Biological Association of the United Kingdom 97, no. 1 (March 9, 2016): 181–96. http://dx.doi.org/10.1017/s0025315416000217.

Full text

Abstract:

Studies on reproduction in sharks are important for their management, since the attainment of sexual maturity has a substantial impact on their distribution, behaviour and biology. However, reproductive biology of large oceanic sharks is poorly studied in the Indian seas. In this study, the size structure, sex and maturity of pelagic thresher (Alopias pelagicus), bigeye thresher (A. superciliosus), oceanic whitetip shark (Carcharhinus longimanus), tiger shark (Galeocerdo cuvier), shortfin mako (Isurus oxyrinchus), longfin mako (I. paucus) and blue shark (Prionace glauca) in the eastern Arabian Sea are described based on 1449 specimens collected from gillnet-cum-longline landings at the Cochin fisheries harbour during 2013–2014. Sex ratios of sampled specimens were biased to males in pelagic thresher, bigeye thresher, tiger shark and blue shark, while females dominated in the specimens of oceanic whitetip shark. Females matured at greater lengths than males in all species except oceanic whitetip shark. Lengths at maturity for males were in the range of 189.05–286.56 cm, whereas those of females were in the range of 187.74–310.69 cm. Litter sizes of both the thresher shark species were always two, while in oceanic whitetip shark, litter size was 3–9 and 22–51 in tiger shark. Seasonal reproduction was noticed in oceanic whitetip shark and tiger shark. Pregnant females were not found in the blue shark, shortfin and longfin makos sampled during the study period. Reproductive aspects of pelagic thresher, bigeye thresher, oceanic whitetip shark, tiger shark, shortfin mako, longfin mako and blue sharks in the eastern Arabian Sea are generally consistent with earlier reports from other regions of the world's oceans. These preliminary findings should be useful to identify suitable management measures for the above shark species.

APA, Harvard, Vancouver, ISO, and other styles

17

Filkins, Peter. "Owen's Shark." Iowa Review 39, no. 1 (April 2009): 184–85. http://dx.doi.org/10.17077/0021-065x.6690.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Kwan, P. W. L. "Shark Fate." Science News 162, no. 23 (December 7, 2002): 367. http://dx.doi.org/10.2307/4013892.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Venugopal, A., A. Marya, and M. I. Karobari. "Shark teeth." British Dental Journal 231, no. 1 (July 2021): 3. http://dx.doi.org/10.1038/s41415-021-3238-y.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Milius, Susan. "Shark Serengeti." Science News 164, no. 6 (August 9, 2003): 85. http://dx.doi.org/10.2307/3982119.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Wunderlich, Mark. "Sand Shark." Missouri Review 35, no. 1 (2012): 171–72. http://dx.doi.org/10.1353/mis.2012.0022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Gorman, Jessica. "Shark Sense." Science News 163, no. 5 (February 1, 2003): 68. http://dx.doi.org/10.2307/4014329.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Browner, Jesse. "Shark Bait." Gastronomica 3, no. 1 (2003): 78–81. http://dx.doi.org/10.1525/gfc.2003.3.1.78.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Guidera, Kenneth J., John A. Ogden, Kenneth Highhouse, Linda Pugh, and Ellen Beatty. "Shark Attack." Journal of Orthopaedic Trauma 5, no. 2 (1991): 204–8. http://dx.doi.org/10.1097/00005131-199105020-00015.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Hyde, Allegra. "Shark Fishing." New England Review 35, no. 4 (2015): 83–100. http://dx.doi.org/10.1353/ner.2015.0003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Estrada, James A., Aaron N. Rice, Molly E. Lutcavage, and Gregory B. Skomal. "Predicting trophic position in sharks of the north-west Atlantic Ocean using stable isotope analysis." Journal of the Marine Biological Association of the United Kingdom 83, no. 6 (December 2003): 1347–50. http://dx.doi.org/10.1017/s0025315403008798.

Full text

Abstract:

Trophic positions (TP) were estimated for the blue shark (Prionace glauca), shortfin mako (Isurus oxyrinchus), thresher shark (Alopias vulpinus), and basking shark (Cetorhinus maximus) using stable isotope ratios of carbon (δ13C) and nitrogen (δ15N). The basking shark had the lowest TP (3·1) and δ15N value (10·4‰), whereas the thresher shark had the highest values (4·5, 15·2‰). Mako sharks showed considerable variation in TP and isotopic values, possibly due to foraging from both inshore and offshore waters. Thresher sharks were significantly more enriched in δ15N than blue sharks and mako sharks, suggesting a different prey base. The δ13C values of thresher sharks and mako sharks varied significantly, but neither was significantly different from that of blue sharks. No statistical differences were found between our TP estimations and those derived from published stomach contents analyses, indicating that stable isotope data may be used to estimate the trophic status of sharks.

APA, Harvard, Vancouver, ISO, and other styles

27

Heithaus, Michael R., Derek Burkholder, Robert E. Hueter, Linda I. Heithaus, Harold L. Pratt, Jr., and Jeffrey C. Carrier. "Spatial and temporal variation in shark communities of the lower Florida Keys and evidence for historical population declines." Canadian Journal of Fisheries and Aquatic Sciences 64, no. 10 (October 1, 2007): 1302–13. http://dx.doi.org/10.1139/f07-098.

Full text

Abstract:

Sharks are top predators in many marine ecosystems. Despite recent concerns over declines in shark populations, studies of shark communities in coastal habitats are limited. We used drumlines and longlines to determine shark community composition and habitat affinities in the Florida Keys, USA. Community composition varied among habitats. Catch rates of smaller sharks were highest in protected shallow waters, while large sharks were more abundant in deep channels. Overall probabilities of catching large sharks on drumlines did not vary with water temperature, while catches of small sharks on longlines increased with increasing water temperature. Individual species differed in their responsiveness to variation in water temperatures and habitat. Bait type affected catch rates of some species, suggesting that fishing methods should be considered explicitly in studies describing shark communities or temporal trends in abundance. Catch rates of large-bodied sharks were higher in a remote and protected location compared with similar habitats near inhabited Keys. Also, historical accounts of a shark fishery in the study area during the 1920s suggest substantial declines in large shark abundance and shifts in community composition. By implication, ecosystem impacts of changes in the large shark community may be dramatic and likely occurred before adequate baselines were established.

APA, Harvard, Vancouver, ISO, and other styles

28

Braccini, Matias, and Hilario Murua. "Quantifying shark and ray discards in Western Australia’s shark fisheries." Marine and Freshwater Research 73, no. 3 (November 9, 2021): 283–91. http://dx.doi.org/10.1071/mf21159.

Full text

Abstract:

Commercial fisheries can discard a considerable volume of sharks and rays, which, as a group, are of high conservation concern. In Western Australia (WA), commercial shark fishing commenced in the 1940s; however, catch time series are not available for discarded species. The present study quantified catch (i.e. dead individuals) time series of discarded sharks and rays in WA’s shark fisheries using on-board observer information collected since 1993 and testing assumptions through sensitivity analysis. Overall, 18 shark and ray taxonomic groups were discarded, comprising ~20% of the observed catch by number. Port Jackson shark, southern eagle ray and spurdogs were the most commonly discarded elasmobranchs, followed by western wobbegong, angel sharks, stingrays, and guitarfish and shovelnose rays. For the base case scenario, the catch of these species was small, peaking at 12.6, 5.6, 1.3, 1.8, 4, 1.3 and 2.7 tonnes (Mg) respectively, given their low post-release mortality (PRM). Current catch levels were even lower (e.g. <5 Mg for Port Jackson shark). Other discarded elasmobranchs were rarely caught. Assuming 100% PRM resulted in higher annual catches, highlighting the need for further research on the PRM of sharks and rays. The reconstructed catch series will be used in risk assessments to determine the sustainability of discarded species.

APA, Harvard, Vancouver, ISO, and other styles

29

Pedro Barreiros, João, Otto B. F. Gadig, and Vidal Haddad. "In Reply to Shark Attacks and Shark Diving." Wilderness & Environmental Medicine 26, no. 2 (June 2015): 277–78. http://dx.doi.org/10.1016/j.wem.2014.11.018.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Alaudin, Alaudin, Jaliadi Jaliadi, and Burhanis Burhanis. "SEBARAN UKURAN DAN PERTUMBUHAN HIU MARTIL (BY CATCH) YANG DIDARATKAN DI PANGKALAN PENDARATAN IKAN (PPI) UJONG BAROH MEULABOH." JURNAL PERIKANAN TROPIS 8, no. 1 (June 3, 2021): 65. http://dx.doi.org/10.35308/jpt.v8i1.2595.

Full text

Abstract:

Hammerhead shark is a type of predator shark belongs to the family of Sphyrnidae. This shark is so aggressive in hunting prey such as fish, squid, and shrimp. The hammerhead shark in Indonesia is included in Appendix II of CITES and has been a special concern in the field of capture fisheries. The aim of the study was to see the size spread, the number of catches, the first size caught, the age growth and the genital ratio of the hammerhead sharks caught with the base fish net. The study was conducted from October to December 2019. The shark measurement was performed once in 2 weeks. Sharks caught by the gills of the base (buttom gilt net) were measured using a roll meter. The collection of hammerhead sharks included total length (TL), number of catches and genital ratio. The analysis was done descriptively using the ELEFAN I existing on Sofwere FiSAT II. The results showed that the hammerhead sharks caught with an gill net of 65 tails from October to December 2019 were taken on the male genital. The total size spread of female malletic sharks were between 61.5-131.5 cm and male hammering sharks between 61.5-111.5 cm. The morphologically spread of the female hammerhead was relatively longer than the male shark. The male hammerhead shark was first captured at a length of 117.9 cm and a female hammerhead shark at a size of 106.2 cm. Hammerhead shark growth by following the curve of von Bertalanffy mallet were male Lt = 138,08 (1-exp (-0.480 (t + 0.0487)) and female mallet shark Lt = 138,08 (1-exp (-0.430 (t + 0.0434)). Such equations can be known by using the relationship curve model between the age and length of fish.

APA, Harvard, Vancouver, ISO, and other styles

31

Francis, Malcolm P. "New Zealand shark fisheries: development, size and management." Marine and Freshwater Research 49, no. 7 (1998): 579. http://dx.doi.org/10.1071/mf97076.

Full text

Abstract:

New Zealand’s shark fisheries have increased steadily since 1975 to reach 17 000–19 000 t per year. Commercial fisheries catch mainly spiny dogfish (Squalus acanthias), school shark (Galeorhinus galeus), skates (Raja nasuta and R. innominata), ghost sharks (Hydrolagus novaezealandiae and Hydrolagus sp.), rig (Mustelus lenticulatus) and elephantfish (Callorhinchus milii). School shark, rig and elephantfish fisheries have long histories, and catches are limited by Individual Transferable Quotas. Fisheries for spiny dogfish, skates and ghost sharks have only developed since 1979. Spiny dogfish and skate landings are partially regulated by total quotas. Other sharks are prohibited target species. Blue (Prionace glauca), porbeagle (Lamna nasus) and mako (Isurus oxyrinchus) sharks are taken as by-catch of the tuna longline fishery. There is a small recreational catch of spiny dogfish, school shark, rig, mako shark and blue shark. Historically important Maori fisheries for spiny dogfish, school shark and rig are now minor. A beach netting programme has operated off Dunedin beaches since 1969 to protect swimmers from shark attacks. Fisheries management measures include commercial quotas, prohibitions on target fishing many species, recreational bag limits, limits on set-net length, mesh size and soak time, and closure of many inshore waters to set-netting, trawling and Danish seining.

APA, Harvard, Vancouver, ISO, and other styles

32

Yates, Peter M., Michelle R. Heupel, Andrew J. Tobin, Stephen K. Moore, and Colin A. Simpfendorfer. "Diversity in immature-shark communities along a tropical coastline." Marine and Freshwater Research 66, no. 5 (2015): 399. http://dx.doi.org/10.1071/mf14033.

Full text

Abstract:

Effective conservation and management of shark populations is complicated by our limited understanding of their spatial ecology. For example, there are scarce data on diversity in community structure and nursery function across broader geographic scales (e.g. across multiple inshore systems) and the implications of this diversity for shark populations. Accordingly, fishery-independent surveys were undertaken to investigate shark communities along ~400km of the tropical eastern coast of Australia (18.1–20.6°S, 146.0–148.8°E). A variety of shark species were encountered, with 19 species of Carcharhiniformes contributing 99.2% of the total shark catch. Of the 1806 sharks captured, 567 were immature, including 336 young-of-the-year individuals. Immature sharks from 18 species were present; however, interspecific variation in the proportions of life-history stages was apparent. Multivariate analyses identified significant spatial heterogeneity in immature-shark communities. Results also highlighted the importance of tropical coastal habitats for numerous shark species, and indicated community-wide spatial structuring of sharks on the basis of body size rather than life-history stage. In addition to building on traditional shark-nursery paradigms, these results demonstrated that data on nursery function from restricted areas may not accurately portray patterns occurring over broader geographic scales, and this diversity may provide population-level benefits for sharks.

APA, Harvard, Vancouver, ISO, and other styles

33

Mitchell, Jonathan D., Tracey B. Scott-Holland, and Paul A. Butcher. "Factors Affecting Shark Detection from Drone Patrols in Southeast Queensland, Eastern Australia." Biology 11, no. 11 (October 23, 2022): 1552. http://dx.doi.org/10.3390/biology11111552.

Full text

Abstract:

Drones enable the monitoring for sharks in real-time, enhancing the safety of ocean users with minimal impact on marine life. Yet, the effectiveness of drones for detecting sharks (especially potentially dangerous sharks; i.e., white shark, tiger shark, bull shark) has not yet been tested at Queensland beaches. To determine effectiveness, it is necessary to understand how environmental and operational factors affect the ability of drones to detect sharks. To assess this, we utilised data from the Queensland SharkSmart drone trial, which operated at five southeast Queensland beaches for 12 months in 2020–2021. The trial conducted 3369 flights, covering 1348 km and sighting 174 sharks (48 of which were >2 m in length). Of these, eight bull sharks and one white shark were detected, leading to four beach evacuations. The shark sighting rate was 3% when averaged across all beaches, with North Stradbroke Island (NSI) having the highest sighting rate (17.9%) and Coolum North the lowest (0%). Drone pilots were able to differentiate between key shark species, including white, bull and whaler sharks, and estimate total length of the sharks. Statistical analysis indicated that location, the sighting of other fauna, season and flight number (proxy for time of day) influenced the probability of sighting sharks.

APA, Harvard, Vancouver, ISO, and other styles

34

Afonso, André S., Yuri V. Niella, and Fábio H. V. Hazin. "Inferring trends and linkages between shark abundance and shark bites on humans for shark-hazard mitigation." Marine and Freshwater Research 68, no. 7 (2017): 1354. http://dx.doi.org/10.1071/mf16274.

Full text

Abstract:

The present study aims at inferring linkages between the abundance of potentially dangerous sharks (PDSs) and shark hazard, so as to derive information about the underlying processes of shark peril off Recife, Brazil. Fishery-independent longline and drumline data collected from May 2004 through December 2014 for Carcharhinus leucas and Galeocerdo cuvier measuring ≥109cm were considered for analysis. Generalised additive models showed that the frequency of shark bites was directly proportional to and followed the same seasonal trends as PDS abundance, meeting the hypothesis that higher shark abundance may result in an increased chance of a shark bite. However, the species-specific seasonality of bull and tiger sharks seemed to follow distinct patterns. This method was helpful in comparing the abundance dynamics of the PDSs caught by the local shark hazard-mitigation program with the distribution of shark bites, so as to infer whether the species involved in the incidents were being effectively captured. Also, it provided some information about each species’ contribution to the overall dynamics in local shark hazard. However, despite being a potentially useful risk-management tool, its predictive efficacy for shark-peril mitigation may depend on the availability of abundant data spanning across wide temporal ranges.

APA, Harvard, Vancouver, ISO, and other styles

35

Dillon, Erin M., Douglas J. McCauley, Jorge Manuel Morales-Saldaña, Nicole D. Leonard, Jian-xin Zhao, and Aaron O’Dea. "Fossil dermal denticles reveal the preexploitation baseline of a Caribbean coral reef shark community." Proceedings of the National Academy of Sciences 118, no. 29 (July 6, 2021): e2017735118. http://dx.doi.org/10.1073/pnas.2017735118.

Full text

Abstract:

Preexploitation shark baselines and the history of human impact on coral reef–associated shark communities in the Caribbean are poorly understood. We recovered shark dermal denticles from mid-Holocene (∼7 ky ago) and modern reef sediments in Bocas del Toro, Caribbean Panama, to reconstruct an empirical shark baseline before major human impact and to quantify how much the modern shark community in the region had shifted from this historical reference point. We found that denticle accumulation rates, a proxy for shark abundance, declined by 71% since the mid-Holocene. All denticle morphotypes, which reflect shark community composition, experienced significant losses, but those morphotypes found on fast-swimming, pelagic sharks (e.g., families Carcharhinidae and Sphyrnidae) declined the most. An analysis of historical records suggested that the steepest decline in shark abundance occurred in the late 20th century, coinciding with the advent of a targeted shark fishery in Panama. Although the disproportionate loss of denticles characterizing pelagic sharks was consistent with overfishing, the large reduction in denticles characterizing demersal species with low commercial value (i.e., the nurse shark Ginglymostoma cirratum) indicated that other stressors could have exacerbated these declines. We demonstrate that the denticle record can reveal changes in shark communities over long ecological timescales, helping to contextualize contemporary abundances and inform shark management and ecology.

APA, Harvard, Vancouver, ISO, and other styles

36

Clarke, C. R., J. S. E. Lea, and R. F. G. Ormond. "Changing relative abundance and behaviour of silky and grey reef sharks baited over 12 years on a Red Sea reef." Marine and Freshwater Research 64, no. 10 (2013): 909. http://dx.doi.org/10.1071/mf12144.

Full text

Abstract:

There is a lack of studies on how provisioning may influence shark numbers and behaviour. The effects of long-term provisioning were investigated at a Red Sea reef, where both grey reef shark (Carcharhinus amblyrhynchos) and silky shark (Carcharhinus falciformis) occurred. Initially, grey reef sharks outnumbered silky sharks, but over 6 years, silky shark numbers increased almost 20-fold, whereas grey-reef sightings decreased >90%. Following this, silky-shark sightings also declined considerably (>80%). It is suggested that these declines could relate to local overfishing. Many silky sharks were identified individually through distinctive markings or conventional tagging. Some individual silky sharks were recorded regularly over 2 years or more, but most appeared to be transient visitors. Sighting records indicated that provisioning extended the residency of transient individuals. If visiting silky sharks were drawn from a larger regional population, this would explain both their initial accumulation and why, to begin with, sightings were sustained despite local fishing pressure. Conversely, the site fidelity typical of grey reef sharks would have made them more susceptible to local depletion. Silky sharks were recorded as behaving more boldly when present in greater numbers, but the decline in grey reef sharks appears to be unrelated to the initial increase in the numbers of silky shark.

APA, Harvard, Vancouver, ISO, and other styles

37

Williams, H., and AH Schaap. "Preliminary results of a study into the incidental mortality of sharks in Gill-nets in two Tasmanian Shark Nursery Areas." Marine and Freshwater Research 43, no. 1 (1992): 237. http://dx.doi.org/10.1071/mf9920237.

Full text

Abstract:

Since the early 1960s, certain sheltered bays and estuaries around Tasmania have been designated shark nursery areas, where the taking of either the school shark (Galeorhinus galeus) or the gummy shark (Mustelus antarcticus) has been prohibited. Recent assessments of Australian stocks of school and gummy sharks indicate that they are close to collapse, and the management of the fishery has come under review. With respect to shark nursery areas, concern has focused on the potential rate of incidental mortality of sharks caused by recreational gill-net fishing and poaching. In 1990, a study was begun in Frederick Henry Bay and Norfolk Bay, the largest proclaimed shark nursery areas in Tasmania, to estimate recreational net-fishing effort and incidental captures of sharks. School sharks were caught in waters deeper than 5 m; gummy sharks and dogfish were caught at all depths. The diversity and relative abundance of shark species increased with depth, whereas the diversity of teleosts decreased with depth. Most captured school and gummy sharks were between 1+ and 3+ years of age. Preliminary estimates of potential incidental mortality demonstrate that gill-netting in depths greater than 5 m may be a significant source of mortality for both species.

APA, Harvard, Vancouver, ISO, and other styles

38

Duffin, Christopher J. "New shark remains from the British Rhaetian (latest Triassic) - 1. The earliest basking shark." Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1998, no. 3 (March 24, 1998): 157–81. http://dx.doi.org/10.1127/njgpm/1998/1998/157.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Choy, Christina Pei Pei, and Benjamin J. Wainwright. "What Is in Your Shark Fin Soup? Probably an Endangered Shark Species and a Bit of Mercury." Animals 12, no. 7 (March 22, 2022): 802. http://dx.doi.org/10.3390/ani12070802.

Full text

Abstract:

Shark fin soup, consumed by Asian communities throughout the world, is one of the principal drivers of the demand of shark fins. This near USD 1 billion global industry has contributed to a shark population declines of up to 70%. In an effort to arrest these declines, the trade in several species of sharks is regulated under the auspices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Despite this legal framework, the dried fins of trade-regulated sharks are frequently sold in markets and consumed in shark fin soup. Shark fins found in soups break down into a fibrous mass of ceratotrichia, meaning that identifying the species of sharks in the soup becomes impossible by visual methods. In this paper, we use DNA barcoding to identify the species of sharks found in bowls of shark fin soup collected in Singapore. The most common species identified in our samples was the blue shark (Prionace glauca), a species listed as Near Threatened on the International Union for Conservation of Nature (IUCN) Red List with a decreasing population, on which scientific data suggests catch limits should be imposed. We identified four other shark species that are listed on CITES Appendix II, and in total ten species that are assessed as Critically Endangered, Endangered or Vulnerable under the IUCN Red List of Threatened Species. Globally, the blue shark has been shown to contain levels of mercury that frequently exceed safe dose limits. Given the prevalence of this species in the examined soups and the global nature of the fin trade, it is extremely likely that consumers of shark fin soup will be exposed to unsafe levels of this neurotoxin.

APA, Harvard, Vancouver, ISO, and other styles

40

Dudley, S. F. J., R. C. Haestier, K. R. Cox, and M. Murray. "Shark control: experimental fishing with baited drumlines." Marine and Freshwater Research 49, no. 7 (1998): 653. http://dx.doi.org/10.1071/mf98026.

Full text

Abstract:

Protective gill-nets (shark nets) have been successful in reducing the frequency of shark attacks on the coast of KwaZulu-Natal (KZN), South Africa, since 1952. This is achieved primarily through a local reduction in numbers of large sharks. Yet the nets are non-selective in terms of shark species caught and take a by-catch of dolphins, sea turtles, batoids and teleosts. Baited lines, or drumlines, as used in the Queensland shark control programme, were tested as possible alternatives to gill-nets. They demonstrated greater species selectivity for sharks and also a reduced by-catch of non-shark animals. The shark catch included the three species responsible for most shark attacks on the KZN coast, Carcharhinus leucas, Galeocerdo cuvier and Carcharodon carcharias. The probability of the bait being scavenged, or a shark being caught, was modelled in relation to a number of physical environmental factors. Although there was insufficient variability in the effort data for a quantitative comparison of catch rates between nets and drumlines, the results suggested that an optimal solution may be to deploy a combination of nets and drumlines.

APA, Harvard, Vancouver, ISO, and other styles

41

Farthing, Geoffrey Daniel, and Hen-Guel Yeh. "Frequency Domain Transformations and CNNs to Predict Unlabeled Shark Behavior With GPS Data." International Journal of Interdisciplinary Telecommunications and Networking 14, no. 1 (January 1, 2022): 1–12. http://dx.doi.org/10.4018/ijitn.309698.

Full text

Abstract:

This paper provides a comprehensive analysis of frequency domain transformations applied to convolutional neural networks (CNN) to model and predict unlabeled shark behavior in the open ocean with GPS position data. The frequency domain-based CNN networks are compared against the time domain CNN to contrast the two CNN architectures. The shark behavior data were obtained through two datasets where tri-axis accelerometer data were collected from live sharks. The first dataset was from the CSULB Shark Lab and consisted of labeled shark behavior into four shark behavioral categories. The second dataset used in this study was unlabeled and recorded from sharks in the open ocean and had GPS positioning data and depth data points. Findings show that the CNN architecture based on the frequency domain slightly outperforms time-based CNNs for classifying California horn shark behavior. Through spectral density analysis, prominent features are extracted and allow for distinguishing the shark behaviors.

APA, Harvard, Vancouver, ISO, and other styles

42

Johnston, Emmett M., Lewis G. Halsey, Nicholas L. Payne, Alison A. Kock, Gil Iosilevskii, Bren Whelan, and Jonathan D. R. Houghton. "Latent power of basking sharks revealed by exceptional breaching events." Biology Letters 14, no. 9 (September 2018): 20180537. http://dx.doi.org/10.1098/rsbl.2018.0537.

Full text

Abstract:

The fast swimming and associated breaching behaviour of endothermic mackerel sharks is well suited to the capture of agile prey. In contrast, the observed but rarely documented breaching capability of basking sharks is incongruous to their famously languid lifestyle as filter-feeding planktivores. Indeed, by analysing video footage and an animal-instrumented data logger, we found that basking sharks exhibit the same vertical velocity (approx. 5 m s −1 ) during breach events as the famously powerful predatory great white shark. We estimate that an 8-m, 2700-kg basking shark, recorded breaching at 5 m s −1 and accelerating at 0.4 m s −2 , expended mechanical energy at a rate of 5.5 W kg −1 ; a mass-specific energetic cost comparable to that of the great white shark. The energy cost of such a breach is equivalent to around 1/17th of the daily standard metabolic cost for a basking shark, while the ratio is about half this for a great white shark. While breaches by basking sharks must serve a different function to white shark breaches, their similar breaching speeds questions our perception of the physiology of large filter-feeding fish.

APA, Harvard, Vancouver, ISO, and other styles

43

Garzon, Francesco, Rachel T. Graham, Ivy Baremore, Dan Castellanos, Hilmar Salazar, Cynthia Xiu, Zeddy Seymour, Matthew J. Witt, and Lucy A. Hawkes. "Nation-wide assessment of the distribution and population size of the data-deficient nurse shark (Ginglymostoma cirratum)." PLOS ONE 16, no. 8 (August 24, 2021): e0256532. http://dx.doi.org/10.1371/journal.pone.0256532.

Full text

Abstract:

The study presents the first national assessment of a nurse shark (Ginglymostoma cirratum) population, conducted using a combination of transect surveys and baited remote underwater videos (BRUVs). Density of nurse sharks in Belize was found to be higher in reefs than in lagoons, and in the atolls furthest away from the mainland and human settlements. Only large and old protected areas were found to have a positive impact on nurse shark abundance. Absolute abundance of nurse sharks was estimated using distance sampling analysis, giving a total nurse shark population in the range of 3,858 to 14,375 sharks. Thanks to a vast area of suitable habitat for nurse sharks in the country and legislation already in place for the safeguard of the species, Belize could represent an important hotspot for nurse sharks in the Western Atlantic. The data presented here hence offers a baseline for the long-term monitoring of the Belizean nurse shark population and improves our understanding of nurse shark abundance and distribution in the wider Caribbean basin.

APA, Harvard, Vancouver, ISO, and other styles

44

Smith, Adam, Al Songcuan, Jonathan Mitchell, Max Haste, Zachary Schmidt, Glenn Sands, and Marcus Lincoln Smith. "Quantifying Catch Rates, Shark Abundance and Depredation Rate at a Spearfishing Competition on the Great Barrier Reef, Australia." Biology 11, no. 10 (October 18, 2022): 1524. http://dx.doi.org/10.3390/biology11101524.

Full text

Abstract:

We developed and applied a method to quantify spearfisher effort and catch, shark interactions and shark depredation in a boat-based recreational spearfishing competition in the Great Barrier Reef Marine Park in Queensland. Survey questions were designed to collect targeted quantitative data whilst minimising the survey burden of spearfishers. We provide the first known scientific study of shark depredation during a recreational spearfishing competition and the first scientific study of shark depredation in the Great Barrier Reef region. During the two-day spearfishing competition, nine vessels with a total of 33 spearfishers reported a catch of 144 fish for 115 h of effort (1.25 fish per hour). A subset of the catch comprised nine eligible species under competition rules, of which 47 pelagic fish were weighed. The largest fish captured was a 34.4 kg Sailfish (Istiophorus platypterus). The most common species captured and weighed was Spanish Mackerel (Scomberomorus commerson). The total weight of eligible fish was 332 kg and the average weight of each fish was 7.1 kg. During the two-day event, spearfishers functioned as citizen scientists and counted 358 sharks (115 h effort), averaging 3.11 sharks per hour. Grey Reef Sharks (Carcharhinus amblyrhynchos) comprised 64% of sightings. Nine speared fish were fully depredated by sharks as spearfishers attempted to retrieve their catch, which equates to a depredation rate of 5.9%. The depredated fish included four pelagic fish and five reef fish. The shark species responsible were Grey Reef Shark (C. amblyrhynchos) (66%), Bull Shark (Carcharhinus leucas) (11%), Whitetip Reef Shark (Triaenodon obesus) (11%) and Great Hammerhead (Sphyrna mokarran) (11%). There were spatial differences in fish catch, shark sightings and rates of depredation. We developed a report card that compared average catch of fish, sightings of sharks per hour and depredation rate by survey area, which assists recreational fishers and marine park managers to assess spatio-temporal changes. The participating spearfishers can be regarded as experienced (average 18 days a year for average 13.4 years). Sixty percent of interviewees perceived that shark numbers have increased in the past 10 years, 33% indicated no change and 7% indicated shark numbers had decreased. Total fuel use of all vessels was 2819 L and was equivalent to 6.48 tons of greenhouse gas emissions for the competition.

APA, Harvard, Vancouver, ISO, and other styles

45

Shimada, Kenshu. "Gigantic lamnoid shark vertebra from the Lower Cretaceous Kiowa Shale of Kansas." Journal of Paleontology 71, no. 3 (May 1997): 522–24. http://dx.doi.org/10.1017/s0022336000039536.

Full text

Abstract:

Fossil sharks are represented primarily by isolated teeth. Teeth are usually used for classification of extinct sharks, but their vertebrae may provide interesting paleoecological and taphonomical information even if not in association with teeth (e.g., Lucas et al., 1985; Gottfried, 1995). In this paper, I describe an isolated centrum of a shark vertebra from the Lower Cretaceous Kiowa Shale in Kansas, housed in the University of Kansas, Museum of Natural History (KUVP), Lawrence. A precise taxonomic assignment for this Kiowa shark is difficult because of its isolated occurrence, lack of large comparative collections of fossil shark vertebrae found in association with teeth, and poorly known morphological variation of fossil shark vertebrae. However, the specimen is noteworthy, because it is the largest Mesozoic shark vertebra known to date.

APA, Harvard, Vancouver, ISO, and other styles

46

Stroud, Eric M., Craig P. O'Connell, Patrick H. Rice, Nicholas H. Snow, Brian B. Barnes, Mohammed R. Elshaer, and James E. Hanson. "Chemical shark repellent: Myth or fact? The effect of a shark necromone on shark feeding behavior." Ocean & Coastal Management 97 (August 2014): 50–57. http://dx.doi.org/10.1016/j.ocecoaman.2013.01.006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Dewi, S. P. S., O. S. Abdoellah, and Y. N. Ihsan. "An overview of shark fisheries in Kupang, East Nusa Tenggara Province, Indonesia." E3S Web of Conferences 249 (2021): 03008. http://dx.doi.org/10.1051/e3sconf/202124903008.

Full text

Abstract:

The biology of sharks makes them very vulnerable to fishing pressure. Globally, sharks are threatened because of uncontrolled fishing due to the increasing demand for their fins. In Indonesia, shark fishing occurs in almost all marine areas, and each area has different characteristics and conditions. Understanding the conditions and characteristics of each area will help to define strategies for the sustainable management of shark fisheries. This paper aimed to provide an overview of the condition of shark fisheries in Kupang, East Nusa Tenggara, Indonesia. This study used a qualitative method to get information about fishing techniques, catch composition, utilization, and trading. The data were collected through observation, interviews, and literature review. The result showed that fishermen in Kupang caught sharks as a fishing target using longline fishing gear. Almost all sharks were landed in pieces after being chopped up in the vessel. They were chopped off into some pieces, such as the fin, meat, skin, and cartilage. Sharks species could be identified by their fins, but their total length, weight, sex ratio, and adult size were difficult to identify. That makes it difficult to plan reasonable management strategies. Shark fins are more expensive than other parts, and the price depends on the fin size. Shark products are traded to Surabaya, Manado, Bogor, and Jakarta. Trade of shark products is regulated by the Minister of Marine Affairs and Fisheries Regulation number 61/PERMEN-KP/2018. Based on this study, management intervention must be undertaken to ensure sustainable shark fisheries in Kupang.

APA, Harvard, Vancouver, ISO, and other styles

48

Grant, Scott M., Rennie Sullivan, and Kevin J. Hedges. "Greenland shark (Somniosus microcephalus) feeding behavior on static fishing gear, effect of SMART (Selective Magnetic and Repellent-Treated) hook deterrent technology, and factors influencing entanglement in bottom longlines." PeerJ 6 (May 17, 2018): e4751. http://dx.doi.org/10.7717/peerj.4751.

Full text

Abstract:

The Greenland Shark (Somniosus microcephalus) is the most common bycatch in the Greenland halibut (Reinhardtius hippoglossoides) bottom longline fishery in Cumberland Sound, Canada. Historically, this inshore fishery has been prosecuted through the ice during winter but winter storms and unpredictable landfast ice conditions since the mid-1990s have led to interest in developing a summer fishery during the ice-free season. However, bycatch of Greenland shark was found to increase substantially with 570 sharks captured during an experimental Greenland halibut summer fishery (i.e., mean of 6.3 sharks per 1,000 hooks set) and mortality was reported to be about 50% due in part to fishers killing sharks that were severely entangled in longline gear. This study investigated whether the SMART (Selective Magnetic and Repellent-Treated) hook technology is a practical deterrent to Greenland shark predation and subsequent bycatch on bottom longlines. Greenland shark feeding behavior, feeding kinematics, and variables affecting entanglement/disentanglement and release are also described. The SMART hook failed to deter Greenland shark predation, i.e., all sharks were captured on SMART hooks, some with more than one SMART hook in their jaw. Moreover, recently captured Greenland sharks did not exhibit a behavioral response to SMART hooks. In situ observations of Greenland shark feeding show that this species uses a powerful inertial suction mode of feeding and was able to draw bait into the mouth from a distance of 25–35 cm. This method of feeding is suggested to negate the potential deterrent effects of electropositive metal and magnetic alloy substitutions to the SMART hook technology. The number of hooks entangled by a Greenland shark and time to disentangle and live-release a shark was found to increase with body length.

APA, Harvard, Vancouver, ISO, and other styles

49

Handayani, Ni Made Putri, Pande Gde Sasmita Julyantoro, and I. Ketut Wija Negara. "Alur Perdagangan Hiu sebagai Komoditas Ikan Hias dari Provinsi Bali." Journal of Marine and Aquatic Sciences 4, no. 1 (August 26, 2017): 58. http://dx.doi.org/10.24843/jmas.2018.v4.i01.58-66.

Full text

Abstract:

This study objectives were to investigate the track of shark trade from Bali Province, the exports volume of shark trade during 2015-2016, the length of sharks; species exported in the ETP category; and the effectiveness of shark trade license by BPSPL Denpasar based on EAFM analysis. This study used exploration method with questionnaires, interviews and secondary data from BPSPL Denpasar. The results showed that the track of shark trade started from when the shark is caught by the fishermen which purchased by exporter companies, then they had to get shipment recommendation letter from BPSPL Denpasar and fish health certificate from BKIPM Class I Denpasar, then sharks was brought to I Gusti Ngurah Rai International Airport for final check and ready to be exported to the destination country. During 2015-2016 there were 559 sharks from the species of Carcharhinus melanopterus, Triaenodon obesus, Orectolobus maculatus, Atelomycterus marmoratus, Chiloscyllium plagiosum and Halaelurus maculosus that have been exported to the 12 destination countries. The EAFM analysis of lengths indicated that the shark's size was at a very young until adult age. Meanwhile, the EAFM analysis of ETP species shows there were 4 shark types of Near Threatened, 1 type of Least Concern status and 1 type of Not Evaluated. Finally the result of EAFM analysis on the effectiveness of shark trade license by BPSPL Denpasar showed that the decision was well executed and run effectively, and so far the shark fishery management at Bali Province is applied successfully.

APA, Harvard, Vancouver, ISO, and other styles

50

Ritter, Erich K., and Alberto Munoz. "How to Kill Another Shark: A First Inside Look at a Potential Hunting Strategy of the Galapagos Shark." Open Fish Science Journal 11, no. 1 (November 30, 2018): 46–51. http://dx.doi.org/10.2174/1874401x01811010046.

Full text

Abstract:

Background: Close-up videos of sharks foraging on other live sharks are rare, especially when it comes to footage of the entire duration of an event. Objective: Our goal was to present an in-depth analysis involving a Galapagos shark, Carcharhinus galapagensis, foraging on a whitetip reef shark, Triaenodon obesus. Method: A frame by frame video examination was used to highlight the different aspects of this bout. Results: Several behavioral characteristics, including the somewhat cryptic approach, the extensive shaking once the Galapagos shark had the whitetip reef shark between its jaws, and devouring tail-first, stand out in this event. Conclusion: The entire act appeared very smooth, indicating that this bout, or at least parts thereof, may represent a common hunting strategy for Galapagos sharks.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Shark'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles