Deep-water feeding and behavioral plasticity in Manta birostris revealed by archival tags and submersible observations
Joshua D. Stewart, Edgar Mauricio Hoyos-Padilla, Katherine R. Kumlie, Robert D. Rubin
Contrasts in the movements and habitat use of juvenile and adult white sharks (Carcharodon carcharias) at Guadalupe Island, Mexico
E. Mauricio Hoyos‑Padilla, A. Peter Klimley, Felipe Galván‑Magaña and Alex Antoniou
Occurrence of Cuvier’s beaked whales (Ziphius cavirostris) at Guadalupe Island, Mexico, from 2006 through 2009
Gustavo Cárdenas-Hinojosa, Mauricio Hoyos-Padilla and Lorenzo Rojas-Bracho
Cuvier’s beaked whale (Ziphius cavirostris) is the most widely distributed species of beaked whale, with a cosmopolitan distribution throughout almost all temperate, subtropical and tropical waters of the world as well as sub-polar and even polar waters in some areas (Heyning, 1989; MacLeod and D’Amico, 2006). Globally, it may also be the most abundant species of beaked whale within the family Ziphiidae (Heyning, 1989). However, there is little information on local distribution in many areas around the world…
Shark Trails of the Eastern Pacific
Klimley, A.P., D. Acuña, R. Arauz, S. Bessudo, E. Espinosa, J.R. Green, H. Guzman, A. Hearn, M. Hoyos, J. Ketchum, C. Peñeherrera, G. Shillinger, and G. Soler. 2015.
Tracking their subjects by satellite, biologists learn when sharks migrate, where they go, and how they use magnetic clues on the ocean floor for navigation.
Ontogenetic migration of a female scalloped hammerhead shark Sphyrna lewini in the Gulf of California
E Mauricio Hoyos-Padilla, James T Ketchum, A Peter Klimley and Felipe Galván-Magaña - Animal Biotelemetry 2014, 2:17
Our study documents a female scalloped hammerhead shark changing life history phases from a nursery-inhabiting juvenile inshore to a migratory sub-adult offshore. We also infer that this shark swam within a school of conspecifics at an offshore island or seamount during the day, and migrated away at night, diving to greater depths to feed on mesopelagic prey. We show that this female shark carried out her complete biological cycle in both coastal and offshore areas of the central and southwestern Gulf of California, suggesting maximization of foraging opportunities and continued growth. In this study, we provide evidence for the first time of an ontogenetic migration of a juvenile scalloped hammerhead shark in the Gulf of California, which could be of great significance for the regional management and conservation of sharks in the Gulf of California.
Whale shark Rhincodon typus populations along the west coast of the Gulf of California and implications for management
Dení Ramírez-Macías, Abraham Vázquez-Haikin, Ricardo Vázquez-Juárez - Endangered Species Research, 2012 Vol. 18: 115–128
Satellite tracking of whale sharks using tethered tags
Andrew Gifford, Leonard J.V. Compagno, Marie Levine, Alex Antoniou - Fisheries Research 84 (2007) 17–24
Research on sharks has been slow and inconsistent. There are two main reasons; one is the dangers and difficulties of studying them in their natural habitat, and two, the lack of funding. However, we are beginning to understand sharks and their behavior, where sharks go and why they go there. For example, satellite tagging of whale sharks has demonstrated that this species can be highly migratory traveling across ocean basins. Knowing that a species is highly migratory means it more susceptible to fisheries in areas where it is not protected. Acoustic tags have also been used to study sharks in a particular area to determine their residency status. Acoustic tags are attached to the sharks and receivers are placed on the sea floor so that when a shark with an acoustic tag gets close the receiver stores the data transmitted by the tag.
Both satellite and acoustic tags can be equipped to record depth, temperature and location information. This kind of science requires a tremendous amount of money, and this money is usually not available unless the end results could lead to useful applications and profits. Research into sharks for their own sake is more difficult to fund. However, this is essential for their survival. The scientific data is needed to back-up any conservation argument.