Discovery of a putative scalloped hammerhead shark Sphyrna lewini (Carcharhiniformes: Sphyrnidae) nursery site at the Galapagos Islands, Eastern Tropical Pacific

2022 ◽  
Author(s):  
Yasuní Chiriboga-Paredes ◽  
Ángela Palomino ◽  
Lauren Goodman ◽  
Florencia Córdova ◽  
Viviana Páez ◽  
...  
Keyword(s):  
Galapagos Islands ◽  
Tropical Pacific ◽  
Galápagos Islands ◽  
Eastern Tropical Pacific ◽  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Scalloped Hammerhead

Residency of the scalloped hammerhead shark (Sphyrna lewini) at Malpelo Island and evidence of migration to other islands in the Eastern Tropical Pacific

2011 ◽  
Vol 91 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Sandra Bessudo ◽  
German Andres Soler ◽  
A. Peter Klimley ◽  
James T. Ketchum ◽  
Alex Hearn ◽  
...  
Keyword(s):  
Tropical Pacific ◽  
Eastern Tropical Pacific ◽  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Scalloped Hammerhead ◽  
Malpelo Island

Ontogenetic feeding ecology of the scalloped hammerhead shark Sphyrna lewini in the Colombian Eastern Tropical Pacific

2021 ◽  
Author(s):  
C Estupiñán-Montaño ◽  
F Galván-Magaña ◽  
F Elorriaga-Verplancken ◽  
MJ Zetina-Rejón ◽  
A Sánchez-González ◽  
...  
Keyword(s):  
Feeding Ecology ◽  
Tropical Pacific ◽  
Eastern Tropical Pacific ◽  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Scalloped Hammerhead

Inter-island movements of scalloped hammerhead sharks (Sphyrna lewini) and seasonal connectivity in a marine protected area of the eastern tropical Pacific

2014 ◽  
Vol 161 (4) ◽  
pp. 939-951 ◽  
Author(s):  
James T. Ketchum ◽  
Alex Hearn ◽  
A. Peter Klimley ◽  
César Peñaherrera ◽  
Eduardo Espinoza ◽  
...  
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Tropical Pacific ◽  
Eastern Tropical Pacific ◽  
Sphyrna Lewini ◽  
Scalloped Hammerhead ◽  
Hammerhead Sharks

scholarly journals A first assessment of the distribution and abundance of large pelagic species at Cocos Ridge seamounts (Eastern Tropical Pacific) using drifting pelagic baited remote cameras

2020 ◽  
Author(s):  
Marta Cambra ◽  
Frida Lara-Lizardi ◽  
Cesar Peñaherrera ◽  
Alex Hearn ◽  
James T. Ketchum ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Critical Role ◽  
Positive Association ◽  
Open Water ◽  
Sea Turtle ◽  
Galapagos Islands ◽  
Tropical Pacific ◽  
Galápagos Islands ◽  
Eastern Tropical Pacific ◽  
Pelagic Species

AbstractUnderstanding the link between seamounts and large pelagic species (LPS) is critical for guiding management and conservation efforts in open water ecosystems. The seamounts along the Cocos Ridge in the Eastern Tropical Pacific (ETP) are thought to play a critical role for LPS moving between Cocos Island (Costa Rica) and Galapagos Islands (Ecuador). However, to date, research efforts to understand pelagic community structure beyond the borders of these oceanic Marine Protected Areas (MPAs) have been limited. This study used drifting-pelagic baited remote underwater video stations (BRUVS) to characterize the distribution and relative abundance of LPS at Cocos Ridge seamounts. Our drifting-pelagic BRUVS detected a total of 21 species including sharks, large teleosts, small teleosts, dolphins and one sea turtle, of which 4 are threatened species. Relative abundance and richness of LPS was significantly higher at shallow seamounts (<400m) compared to deeper ones (>400m) suggesting that seamount depth could be an important driver structuring LPS assemblages along the Cocos Ridge. Our cameras provided the first visual evidence of the schooling behaviour of S. lewini at two shallow seamounts outside the protection limits of Cocos and Galapagos Islands. However, further research is still needed to demonstrate a positive association between LPS and Cocos Ridge seamounts. Our findings showed that drifting pelagic BRUVS are an effective tool to survey LPS in fully pelagic ecosystems of the ETP. This study represents the first step towards the standardization of this technique throughout the region.

scholarly journals Movements of scalloped hammerhead sharks (Sphyrna lewini) at Cocos Island, Costa Rica and between oceanic islands in the Eastern Tropical Pacific

PLoS ONE ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. e0213741 ◽  
Author(s):  
Elena Nalesso ◽  
Alex Hearn ◽  
Oscar Sosa-Nishizaki ◽  
Todd Steiner ◽  
Alex Antoniou ◽  
...  
Keyword(s):  
Costa Rica ◽  
Oceanic Islands ◽  
Tropical Pacific ◽  
Eastern Tropical Pacific ◽  
Sphyrna Lewini ◽  
Scalloped Hammerhead ◽  
Cocos Island ◽  
Hammerhead Sharks

scholarly journals Transition to El Niño conditions in the eastern tropical Pacific in October 2015

2016 ◽  
Author(s):  
Lothar Stramma ◽  
Tim Fischer ◽  
Damian S. Grundle ◽  
Gerd Krahmann ◽  
Hermann W. Bange ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Galapagos Islands ◽  
Tropical Pacific ◽  
Nutrient Concentrations ◽  
Galápagos Islands ◽  
Eastern Tropical Pacific ◽  
Weak Current ◽  
Equatorial Undercurrent ◽  
Oxygen Concentrations

Abstract. A strong El Niño developed in early 2015. Measurements from a research cruise on the RV Sonne in October 2015 near the equator east of the Galapagos Islands and off the shelf of Peru, are used to investigate changes related to El Niño in the upper ocean in comparison with earlier cruises in this region. At the equator at 85°30’ W, a clear temperature increase leading to lower densities in the upper 350 m, despite a concurrent salinity increase from 40 to 350 m, developed in October 2015. Lower nutrient concentrations were also present in the upper 200 m, and higher oxygen concentrations were observed between 40 and 130 m. Except for the upper 60 m at 2°30’ S, however, there was no obvious increase in oxygen concentrations at sampling stations just north (1° N) and south (2°30’ S) of the equator at 85°30’ W. In the equatorial current field, the Equatorial Undercurrent (EUC) east of the Galapagos Islands almost disappeared in October 2015, with a transport of only 0.02 Sv in the equatorial channel between 1° S and 1° N, and a weak current band of 0.78 Sv located between 1° S and 2°30’ S. Such near-disappearances of the EUC in the eastern Pacific seem to occur only during strong El Niño events. Off the Peruvian shelf at ~9° S, where the sea surface temperature (SST) was elevated, upwelling was modified, and warm, saline and oxygen rich water was upwelled. Despite some weak El Niño related SST increase at ~12 to 16° S, the upwelling of cold, low salinity and oxygen-poor water was still active at the easternmost stations at three sections at ~12° S, ~14° S and ~16° S, while further west on these sections a transition to El Niño conditions appeared. Although in early 2015 the El Niño was strong and in October 2015 showed a clear El Niño influence on the EUC, in the eastern tropical Pacific the measurements only showed developing El Niño water mass distributions. In particular the oxygen distribution indicated the ongoing transition from ‘typical’ to El Niño conditions progressing southward along the Peruvian shelf.

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