Article
Biodiversity Conservation
Alyssa M. Budd, Madalyn K. Cooper, Agnes Le Port, Tom Schils, Matthew S. Mills, Mari E. Deinhart, Roger Huerlimann, Jan M. Strugnell
Summary: Scalloped hammerhead sharks have experienced significant population declines and are now classified as 'critically endangered'. The use of eDNA methods is proposed as a cost-effective and non-invasive way to monitor and protect these species in areas where traditional survey methods are impractical.
ECOLOGICAL INDICATORS
(2021)
Article
Fisheries
M. E. Green, S. A. Appleyard, W. T. White, S. R. Tracey, M. R. Heupel, J. R. Ovenden
Summary: This study used a genetic multi-marker approach to investigate the population structure of scalloped hammerheads in the Indo-Pacific. The findings suggest that management of these shark populations will require international and national cooperation.
FISHERIES RESEARCH
(2022)
Article
Parasitology
Kaitlyn M. Dalrymple, Isaure de Buron, Kristina M. Hill-Spanik, Ashley S. Galloway, Amanda Barker, David S. Portnoy, Bryan S. Frazier, Walter A. Boeger
Summary: This study investigated the parasites infecting neonates of hammerhead sharks, including S. lewini, S. gilberti, and their hybrids. Three species of monogenoids were identified and described, revealing new information about the parasite fauna in these shark species.
Article
Biodiversity Conservation
Melanie Hutchinson, Molly Scott, Robert Bauer, James Anderson, Daniel M. Coffey, Kim Holland, Carl Meyer, John O'Sullivan, Mark Royer
Summary: This long-term telemetry study provides important insights into the movement behavior and habitat preferences of scalloped hammerhead sharks around the Hawaiian Islands. The study highlights the seasonal site fidelity of adult males to a specific area and their ability to dive to great depths during vertical movements.
ENDANGERED SPECIES RESEARCH
(2023)
Article
Environmental Sciences
Aura Maria Rodriguez-Burgos, Francisco Javier Briceno-Zuluaga, Julian Leonardo Avila Jimenez, Alex Hearn, Cesar Penaherrera-Palma, Eduardo Espinoza, James Ketchum, Peter Klimley, Todd Steiner, Randall Arauz, Elpis Joan
Summary: This study evaluated the impact of climate change on the distribution of the common hammerhead shark in the Eastern Tropical Pacific Marine Corridor and predicted that the species would migrate southward by 2050.
MARINE ENVIRONMENTAL RESEARCH
(2022)
Article
Ecology
Estefania Bravo-Ormaza, Randall Arauz, Sandra Bessudo, Alex Hearn, A. Peter Klimley, Felipe Ladino-Archila, Jean Lopez-Macias, Todd Steiner, Cesar Penaherrera-Palma
Summary: This study comparatively assessed the relationship between the abundance of scalloped hammerhead sharks (Sphyrna lewini) and environmental factors such as temperature in three marine protected areas in the Eastern Tropical Pacific. The results showed that the Galapagos Islands in Ecuador had the highest relative abundance of S. lewini, followed by Cocos Island in Costa Rica and Malpelo in Colombia. The abundance of the sharks fluctuated with different seasons and environmental factors. This research contributes to the decision-making tools for the climate-smart management of the species in the region.
ENVIRONMENTAL BIOLOGY OF FISHES
(2023)
Article
Fisheries
N. A. Lopez, R. B. Mcauley, S. van Elden, J. J. Meeuwig
Summary: This study used drones to characterize the spatial and temporal distribution of a scalloped hammerhead shark aggregation in the Shoalwater Islands Marine Park in southwest Western Australia. The presence of the sharks was influenced by lunar illumination phases, indicating that the aggregation site may serve as a refuge. The study also highlights the need for management measures to limit potential impacts.
ICES JOURNAL OF MARINE SCIENCE
(2023)
Article
Marine & Freshwater Biology
Jose Miguel Rangel-Morales, Loray Paulina Rosales-Lopez, Pindaro Diaz-Jaimes, Felipe Amezcua-Martinez, James T. Ketchum, Mauricio Hoyos-Padilla, Antonio Corgos
Summary: This study investigated the population genetic structure and female philopatry of the scalloped hammerhead shark along different mangrove estuaries in the Mexican Pacific coast. The results showed significant differences in genetic variation between different regions based on mitochondrial DNA analysis, while no differences were found in nuclear markers. The study also revealed moderate levels of relatedness among individuals within nurseries, suggesting the presence of female philopatry. The findings suggest that the pattern of nursery grounds of the scalloped hammerhead shark in the Mexican Pacific is regional.
Article
Environmental Sciences
Vital Heim, Felicie Dhellemmes, Matthew J. Smukall, Samuel H. Gruber, Tristan L. Guttridge
Summary: The study showed that great hammerhead sharks were able to meet their daily energy requirements from provisioned food during dives. Sharks displayed different behaviors during provisioning activities based on their previous experience at the dive site.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Fisheries
Hua Hsun Hsu, Zahid Nazeer, Premlal Panickan, Yu-Jia Lin, Ali Qasem, Lotfi Jilani Rabaoui, Mohammad Ali Qurban
Summary: This study analyzed the stomach contents of juvenile great hammerhead sharks caught in Saudi Arabian waters. The study found that teleosts, especially Platycephalus indicus, were the main prey for these sharks. Moreover, significant dietary differences were observed with age, indicating a shift in prey preference. The study also determined the trophic level of the great hammerhead sharks to be tertiary consumers.
Article
Biodiversity Conservation
Alyssa M. Budd, Tom Schils, Madalyn K. Cooper, Mitchell B. Lyons, Matthew S. Mills, Mari E. Deinhart, Agnes Le Port, Roger Huerlimann, Jan M. Strugnell
Summary: Evidence-based environmental management is crucial for achieving global conservation commitments. Innovative ecological monitoring techniques, such as environmental DNA surveys, can help fill biodiversity knowledge gaps. These methods offer opportunities to overcome logistical and financial challenges previously associated with traditional monitoring.
BIOLOGICAL CONSERVATION
(2023)
Article
Environmental Sciences
Camila Arnes-Urgelles, Pelayo Salinas-de-Leon, Etienne Rastoin-Laplane, Leandro Vaca-Pita, Jenifer Suarez-Moncada, Diego Paez-Rosas
Summary: This study found that climatic variability impacts the feeding ecology of scalloped hammerhead sharks in the Galapagos Marine Reserve, with La Nina event potentially benefiting their trophic needs.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Biochemistry & Molecular Biology
Helene J. Coetzee, Kristina Naidoo, Ina Wagenaar
Summary: The study focused on describing the germ cell development in the testes of sexually mature male scalloped hammerhead sharks. Through necropsy and histological assessment of three individual sharks, it was found that the testes of S. lewini consist of seminiferous tubules with germ cells in different stages of development, conforming to the testes structure of elasmobranch males.
FISH PHYSIOLOGY AND BIOCHEMISTRY
(2021)
Article
Marine & Freshwater Biology
Colombo Estupinan-Montano, Maribel Carrera-Fernandez, Felipe Galvan-Magana
Summary: Limited data on the reproductive biology of the scalloped hammerhead in Ecuadorian waters hinders appropriate management measures of its populations. Females were more frequently caught, carrying 16-22 embryos that mature over a gestation period of 10-11 months, with newborns measuring 47-55 cm TL.
JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM
(2021)
Article
Ecology
Sydney P. Harned, Andrea M. Bernard, Pelayo Salinas-de-Leon, Marissa R. Mehlrose, Jenifer Suarez, Yolani Robles, Sandra Bessudo, Felipe Ladino, Andres Lopez Garo, Ilena Zanella, Kevin A. Feldheim, Mahmood S. Shivji
Summary: The scalloped hammerhead shark has a single genetic stock in the Eastern Tropical Pacific region, with no evidence of population structure. The adult scalloped hammerheads form annual aggregations in the Galapagos Islands that are not kin-based. Despite high levels of exploitation, the genetic diversity of adult scalloped hammerheads in this region is higher compared to other parts of the species' global distribution. The species comprises three distinct matrilines corresponding to the three major world ocean basins, highlighting the importance of conservation for these unique lineages.
ECOLOGY AND EVOLUTION
(2022)
Article
Fisheries
Graeme Parkes, Jill H. Swasey, Fiona M. Underwood, Timothy P. Fitzgerald, Kent Strauss, David J. Agnew
FISHERIES RESEARCH
(2016)
Article
Multidisciplinary Sciences
Stephen M. Kajiura, Shari L. Tellman
Article
Ecology
Marieke Desender, Stephen Kajiura, Bart Ampe, Lisa Dumolein, Hans Polet, Koen Chiers, Annemie Decostere
JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY
(2017)
Article
Zoology
David A. Ebert, Yannis P. Papastamatiou, Stephen M. Kajiura, Bradley M. Wetherbee
Article
Multidisciplinary Sciences
Eloise J. Cave, Stephen M. Kajiura
SCIENTIFIC REPORTS
(2018)
Review
Fisheries
Kyle C. Newton, Andrew B. Gill, Stephen M. Kajiura
JOURNAL OF FISH BIOLOGY
(2019)
Article
Marine & Freshwater Biology
Kyle C. Newton, Stephen M. Kajiura
Article
Fisheries
Melanie D. Doan, Stephen M. Kajiura
JOURNAL OF FISH BIOLOGY
(2020)
Article
Marine & Freshwater Biology
Kyle C. Newton, Stephen M. Kajiura
Article
Zoology
E. J. Cave, S. M. Kajiura
Article
Fisheries
Kathryn A. Ayres, James T. Ketchum, Rogelio Gonzalez-Armas, Felipe Galvan-Magana, Alex Hearn, Fernando R. Elorriaga-Verplancken, Edgar M. Hoyos-Padilla, Stephen M. Kajiura
Summary: Established in 1995, Cabo Pulmo National Park has seen a significant increase in fish biomass. A study using an unmanned aerial vehicle (UAV) found lemon sharks, bull sharks, and Pacific nurse sharks in shallow coastal habitats, with sharks being more common in the afternoon, potentially using warmer shallow areas for thermoregulation. This highlights the efficacy of UAV surveys for species identification compared to previous terrestrial surveys.
JOURNAL OF FISH BIOLOGY
(2021)
Article
Fisheries
Stephen M. Kajiura, John C. Loyer, Cassandra Ruddy, Marianne E. Porter
Summary: The Caribbean reef shark Carcharhinus perezi exhibits a unique behavior of resting on the substrate, which is not seen in other members of its genus. A study quantified the swimming kinematics of C. perezi in the wild, showing that its head yaw frequency is higher than its tailbeat frequency, but the amplitude of the tail exceeds that of the head. In comparison to its ram ventilating congener C. limbatus, C. perezi shows lower velocity, head yaw frequency, and tailbeat frequency.
JOURNAL OF FISH BIOLOGY
(2022)
Article
Ecology
Mary E. Bowers, Stephen M. Kajiura
Summary: Global climate change affects oceanic characteristics and animal distribution. Inconsistencies in the migratory movement of blacktip sharks off the U.S. East Coast challenge current knowledge. Published data can be interpreted in multiple ways and perpetuate uncertain observations, calling for further research on the movement ecology of blacktip sharks in this region.
ENVIRONMENTAL BIOLOGY OF FISHES
(2023)
Review
Remote Sensing
Paul A. Butcher, Andrew P. Colefax, Robert A. Gorkin, Stephen M. Kajiura, Naima A. Lopez, Johann Mourier, Cormac R. Purcell, Gregory B. Skomal, James P. Tucker, Andrew J. Walsh, Jane E. Williamson, Vincent Raoult
Summary: This paper discusses the application of drones in wildlife management and research over the past decade, particularly focusing on their value and importance in shark research. Drones have helped to fill knowledge gaps about shark behavior and their significance in ecosystems, while also contributing to reducing dangerous encounters between sharks and humans. Additionally, the paper explores the future trends in drone technology for shark monitoring and research.
Article
Behavioral Sciences
Kyle C. Newton, Stephen M. Kajiura