Robinson, David P.,Jaidah, Mohammed Y.,Bach, Steffen S.,Rohner, Christoph A.,Jabado, Rima W.,Ormond, Rupert,Pierce, Simon J.
Some like it hot: Repeat migration and residency of whale sharks within an extreme natural environment Journal Article
In: PLOS ONE, vol. 12, no. 446, pp. e0185360, 2017.
Abstract | Links | BibTeX | Tags: Arabian Gulf, Gulf of Oman, habitat use, rhinccodon typus, Satellite telemetry, Sea of Oman, whale sharks
@article{,
title = {Some like it hot: Repeat migration and residency of whale sharks within an extreme natural environment},
author = {Robinson, David P.,Jaidah, Mohammed Y.,Bach, Steffen S.,Rohner, Christoph A.,Jabado, Rima W.,Ormond, Rupert,Pierce, Simon J.},
url = {https://doi.org/10.1371/journal.pone.0185360},
year = {2017},
date = {2017-01-01},
journal = {PLOS ONE},
volume = {12},
number = {446},
pages = {e0185360},
publisher = {Public Library of Science},
abstract = {The Arabian Gulf is the warmest sea in the world and is host to a globally significant population of the whale shark Rhincodon typus. To investigate regional whale shark behaviour and movements, 59 satellite-linked tags were deployed on whale sharks in the Al Shaheen area off Qatar from 2011–14. Four different models of tag were used throughout the study, each model able to collect differing data or quantities of data. Retention varied from one to 227 days. While all tagged sharks crossed international maritime boundaries, they typically stayed within the Arabian Gulf. Only nine sharks dispersed through the narrow Strait of Hormuz into the Gulf of Oman. Most sharks stayed close to known or suspected feeding aggregation sites over summer months, but dispersed throughout the Arabian Gulf in winter. Sharks rarely ventured into shallow areas (<40 m depth). A single, presumably pregnant female shark was the sole animal to disperse a long distance, crossing five international maritime boundaries in 37 days before the tag detached at a distance of approximately 2644 km from the tagging site, close to the Yemeni-Somali border. No clear space-use differentiation was evident between years, for sharks of different sizes, or between sexes. Whale sharks spent the most time (~66%) in temperatures of 24–30°C and in shallow waters <100 m depth (~60%). Sharks spent relatively more time in cooler (X2 = 121.692; p<0.05) and deeper (X2 = 46.402; p<0.05) water at night. Sharks rarely made dives deeper than 100 m, reflecting the bathymetric constraints of the Gulf environment. Kernel density analysis demonstrated that the tagging site at Al Shaheen was the regional hotspot for these sharks, and revealed a probable secondary aggregation site for whale sharks in nearby Saudi Arabian waters. Analysis of visual re-sightings data of tagged sharks revealed that 58% of tagged individuals were re-sighted back in Al Shaheen over the course of this study, with 40% recorded back at Al Shaheen in the year following their initial identification. Two sharks were confirmed to return to Al Shaheen in each of the five years of study.},
keywords = {Arabian Gulf, Gulf of Oman, habitat use, rhinccodon typus, Satellite telemetry, Sea of Oman, whale sharks},
pubstate = {published},
tppubtype = {article}
}
The Arabian Gulf is the warmest sea in the world and is host to a globally significant population of the whale shark Rhincodon typus. To investigate regional whale shark behaviour and movements, 59 satellite-linked tags were deployed on whale sharks in the Al Shaheen area off Qatar from 2011–14. Four different models of tag were used throughout the study, each model able to collect differing data or quantities of data. Retention varied from one to 227 days. While all tagged sharks crossed international maritime boundaries, they typically stayed within the Arabian Gulf. Only nine sharks dispersed through the narrow Strait of Hormuz into the Gulf of Oman. Most sharks stayed close to known or suspected feeding aggregation sites over summer months, but dispersed throughout the Arabian Gulf in winter. Sharks rarely ventured into shallow areas (<40 m depth). A single, presumably pregnant female shark was the sole animal to disperse a long distance, crossing five international maritime boundaries in 37 days before the tag detached at a distance of approximately 2644 km from the tagging site, close to the Yemeni-Somali border. No clear space-use differentiation was evident between years, for sharks of different sizes, or between sexes. Whale sharks spent the most time (~66%) in temperatures of 24–30°C and in shallow waters <100 m depth (~60%). Sharks spent relatively more time in cooler (X2 = 121.692; p<0.05) and deeper (X2 = 46.402; p<0.05) water at night. Sharks rarely made dives deeper than 100 m, reflecting the bathymetric constraints of the Gulf environment. Kernel density analysis demonstrated that the tagging site at Al Shaheen was the regional hotspot for these sharks, and revealed a probable secondary aggregation site for whale sharks in nearby Saudi Arabian waters. Analysis of visual re-sightings data of tagged sharks revealed that 58% of tagged individuals were re-sighted back in Al Shaheen over the course of this study, with 40% recorded back at Al Shaheen in the year following their initial identification. Two sharks were confirmed to return to Al Shaheen in each of the five years of study.
Pilcher, Nicolas J.,Antonopoulou, Marina,Perry, Lisa,Abdel-Moati, Mohamed A.,Al Abdessalaam, Thabit Zahran,Albeldawi, Mohammad,Al Ansi, Mehsin,Al-Mohannadi, Salman Fahad,Al Zahlawi, Nessrine,Baldwin, Robert,Chikhi, Ahmed,Das, Himansu Sekhar,Hamza, Shafeeq,Kerr, Oliver J.,Al Kiyumi, Ali,Mobaraki, Asghar,Al Suwaidi, Hana Saif,Al Suweidi, Ali Saqar,Sawaf, Moaz,Tourenq, Christophe,Williams, James,Willson, Andrew
Identification of Important Sea Turtle Areas (ITAs) for hawksbill turtles in the Arabian Region Journal Article
In: Journal of Experimental Marine Biology and Ecology, vol. 460, no. 428, pp. 89-99, 2014, ISBN: 0022-0981.
Abstract | Links | BibTeX | Tags: Arabian Gulf, Conservation and management, Eretmochelys imbricata, habitat use, Persian Gulf, Satellite tracking
@article{,
title = {Identification of Important Sea Turtle Areas (ITAs) for hawksbill turtles in the Arabian Region},
author = {Pilcher, Nicolas J.,Antonopoulou, Marina,Perry, Lisa,Abdel-Moati, Mohamed A.,Al Abdessalaam, Thabit Zahran,Albeldawi, Mohammad,Al Ansi, Mehsin,Al-Mohannadi, Salman Fahad,Al Zahlawi, Nessrine,Baldwin, Robert,Chikhi, Ahmed,Das, Himansu Sekhar,Hamza, Shafeeq,Kerr, Oliver J.,Al Kiyumi, Ali,Mobaraki, Asghar,Al Suwaidi, Hana Saif,Al Suweidi, Ali Saqar,Sawaf, Moaz,Tourenq, Christophe,Williams, James,Willson, Andrew},
url = {http://www.sciencedirect.com/science/article/pii/S0022098114001816},
issn = {0022-0981},
year = {2014},
date = {2014-01-01},
journal = {Journal of Experimental Marine Biology and Ecology},
volume = {460},
number = {428},
pages = {89-99},
abstract = {We present the first data on hawksbill turtle post-nesting migrations and behaviour in the Arabian region. Tracks from 90 post-nesting turtles (65 in the Gulf and 25 from Oman) revealed that hawksbills in the Arabian region may nest up to 6 times in a season with an average of 3 nests per turtle. Turtles from Qatar, Iran and the UAE generally migrated south and southwest to waters shared by the UAE and Qatar. A smaller number of turtles migrated northward towards Bahrain, Saudi Arabia and one reached Kuwait. Omani turtles migrated south towards Masirah island and to Quwayrah, staying close to the mainland and over the continental shelf. The widespread dispersal of hawksbill foraging grounds across the SW Gulf may limit habitat protection options available to managers, and we suggest these be linked to preservation of shallow water habitats and fishery management. In contrast, the two main foraging areas in Oman were small and could be candidates for protected area consideration. Critical migration bottlenecks were identified at the easternmost point of the Arabian Peninsula as turtles from Daymaniyat Islands migrate southward, and between Qatar and Bahrain. Overall, Gulf turtles spent 68% of the time in foraging ground with home ranges of 40–60 km2 and small core areas of 6 km2. Adult female turtles from Oman were significantly larger than Gulf turtles by ~ 11 cm x ¯ = 81.4 CCL and spent 83% of their time foraging in smaller home ranges with even smaller core areas (~ 3 km2), likely due to better habitat quality and food availability. Gulf turtles were among the smallest in the world x ¯ = 70.3 CCL and spent an average of 20% of time undertaking summer migration loops, a thermoregulatory response to avoid elevated sea surface temperatures, as the Gulf regularly experiences sustained sea surface temperatures > 30 °C. Fishery bycatch was determined for two of the 90 turtles. These spatio-temporal findings on habitat use will enable risk assessments for turtles in the face of multiple threats including oil and gas industries, urban and industrial development, fishery pressure, and shipping. They also improve our overall understanding of hawksbill habitat use and behaviour in the Arabian region, and will support sea turtle conservation-related policy decision-making at national and regional levels.},
keywords = {Arabian Gulf, Conservation and management, Eretmochelys imbricata, habitat use, Persian Gulf, Satellite tracking},
pubstate = {published},
tppubtype = {article}
}
We present the first data on hawksbill turtle post-nesting migrations and behaviour in the Arabian region. Tracks from 90 post-nesting turtles (65 in the Gulf and 25 from Oman) revealed that hawksbills in the Arabian region may nest up to 6 times in a season with an average of 3 nests per turtle. Turtles from Qatar, Iran and the UAE generally migrated south and southwest to waters shared by the UAE and Qatar. A smaller number of turtles migrated northward towards Bahrain, Saudi Arabia and one reached Kuwait. Omani turtles migrated south towards Masirah island and to Quwayrah, staying close to the mainland and over the continental shelf. The widespread dispersal of hawksbill foraging grounds across the SW Gulf may limit habitat protection options available to managers, and we suggest these be linked to preservation of shallow water habitats and fishery management. In contrast, the two main foraging areas in Oman were small and could be candidates for protected area consideration. Critical migration bottlenecks were identified at the easternmost point of the Arabian Peninsula as turtles from Daymaniyat Islands migrate southward, and between Qatar and Bahrain. Overall, Gulf turtles spent 68% of the time in foraging ground with home ranges of 40–60 km2 and small core areas of 6 km2. Adult female turtles from Oman were significantly larger than Gulf turtles by ~ 11 cm x ¯ = 81.4 CCL and spent 83% of their time foraging in smaller home ranges with even smaller core areas (~ 3 km2), likely due to better habitat quality and food availability. Gulf turtles were among the smallest in the world x ¯ = 70.3 CCL and spent an average of 20% of time undertaking summer migration loops, a thermoregulatory response to avoid elevated sea surface temperatures, as the Gulf regularly experiences sustained sea surface temperatures > 30 °C. Fishery bycatch was determined for two of the 90 turtles. These spatio-temporal findings on habitat use will enable risk assessments for turtles in the face of multiple threats including oil and gas industries, urban and industrial development, fishery pressure, and shipping. They also improve our overall understanding of hawksbill habitat use and behaviour in the Arabian region, and will support sea turtle conservation-related policy decision-making at national and regional levels.
Corkeron, Peter J,Collins, Gianna Minton Tim,Findlay, Ken,Willson, Andrew,Baldwin, Robert
Spatial models of sparse data to inform cetacean conservation planning: an example from Oman Journal Article
In: Endangered Species Research, vol. 15, no. 353, pp. 39-52, 2011, ISBN: 1863-5407.
Abstract | Links | BibTeX | Tags: Arabian Sea, cetaceans, Distribution, General linear model, habitat modelling, habitat use, Humpback Whale, megaptera novaeangliae, Oman, Spatial autocorrelation
@article{,
title = {Spatial models of sparse data to inform cetacean conservation planning: an example from Oman},
author = {Corkeron, Peter J,Collins, Gianna Minton Tim,Findlay, Ken,Willson, Andrew,Baldwin, Robert},
url = {https://www.int-res.com/articles/esr_oa/n015p039.pdf},
issn = {1863-5407},
year = {2011},
date = {2011-01-01},
journal = {Endangered Species Research},
volume = {15},
number = {353},
pages = {39-52},
abstract = {Habitat models are tools for understanding the relationship between cetaceans and their
environment, from which patterns of the animals’ space use can be inferred and management strategies
developed. Can working with space use alone be sufficient for management, when habitat cannot
be modeled? Here, we analyzed cetacean sightings data collected from small boat surveys off the
coast of Oman between 2000 and 2003. The waters off Oman are used by the Endangered Arabian
Sea population of humpback whales. Our data were collected primarily for photo-identification, using
a haphazard sampling regime, either in areas where humpback whales were thought to be relatively
abundant, or in areas that were logistically easy to survey. This leads to spatially autocorrelated data
that are not amenable to analysis using standard approaches. We used quasi-Poisson generalized linear
models and semi-parametric spatial filtering to assess the distribution of humpback and Bryde’s
whales in 3 areas off Oman relative to 3 simple physiographic variables in a survey grid. Our analysis
focused on the spatial eigenvector filtering of models, coupled with the spatial distribution of model
residuals, rather than just on model predictions. Spatial eigenvector filtering accounts for spatial
autocorrelation in models, allowing inference to be made regarding the relative importance of particular
areas. As an exemplar of this approach, we demonstrate that the Dhofar coast of southern Oman
is important habitat for the Arabian Sea population of humpback whales. We also suggest how conservation
planning for mitigating impacts on humpback whales off the Dhofar coast could start.},
keywords = {Arabian Sea, cetaceans, Distribution, General linear model, habitat modelling, habitat use, Humpback Whale, megaptera novaeangliae, Oman, Spatial autocorrelation},
pubstate = {published},
tppubtype = {article}
}
Habitat models are tools for understanding the relationship between cetaceans and their
environment, from which patterns of the animals’ space use can be inferred and management strategies
developed. Can working with space use alone be sufficient for management, when habitat cannot
be modeled? Here, we analyzed cetacean sightings data collected from small boat surveys off the
coast of Oman between 2000 and 2003. The waters off Oman are used by the Endangered Arabian
Sea population of humpback whales. Our data were collected primarily for photo-identification, using
a haphazard sampling regime, either in areas where humpback whales were thought to be relatively
abundant, or in areas that were logistically easy to survey. This leads to spatially autocorrelated data
that are not amenable to analysis using standard approaches. We used quasi-Poisson generalized linear
models and semi-parametric spatial filtering to assess the distribution of humpback and Bryde’s
whales in 3 areas off Oman relative to 3 simple physiographic variables in a survey grid. Our analysis
focused on the spatial eigenvector filtering of models, coupled with the spatial distribution of model
residuals, rather than just on model predictions. Spatial eigenvector filtering accounts for spatial
autocorrelation in models, allowing inference to be made regarding the relative importance of particular
areas. As an exemplar of this approach, we demonstrate that the Dhofar coast of southern Oman
is important habitat for the Arabian Sea population of humpback whales. We also suggest how conservation
planning for mitigating impacts on humpback whales off the Dhofar coast could start.
environment, from which patterns of the animals’ space use can be inferred and management strategies
developed. Can working with space use alone be sufficient for management, when habitat cannot
be modeled? Here, we analyzed cetacean sightings data collected from small boat surveys off the
coast of Oman between 2000 and 2003. The waters off Oman are used by the Endangered Arabian
Sea population of humpback whales. Our data were collected primarily for photo-identification, using
a haphazard sampling regime, either in areas where humpback whales were thought to be relatively
abundant, or in areas that were logistically easy to survey. This leads to spatially autocorrelated data
that are not amenable to analysis using standard approaches. We used quasi-Poisson generalized linear
models and semi-parametric spatial filtering to assess the distribution of humpback and Bryde’s
whales in 3 areas off Oman relative to 3 simple physiographic variables in a survey grid. Our analysis
focused on the spatial eigenvector filtering of models, coupled with the spatial distribution of model
residuals, rather than just on model predictions. Spatial eigenvector filtering accounts for spatial
autocorrelation in models, allowing inference to be made regarding the relative importance of particular
areas. As an exemplar of this approach, we demonstrate that the Dhofar coast of southern Oman
is important habitat for the Arabian Sea population of humpback whales. We also suggest how conservation
planning for mitigating impacts on humpback whales off the Dhofar coast could start.
Minton,G.,Collins,T.J.Q.,Findlay,K.P.,Baldwin,R.,Rosenbaum,H.C.,Kennedy,F.D.,Cockcroft,V.
Preliminary investigations of humpback whale Technical Report
no. 414, 2002, ISBN: SC/54/H3.
Abstract | BibTeX | Tags: abundance, Arabian Sea, Distribution, habitat use, Humpback Whale, humpback whales, megaptera novaeangliae, Northern Hemisphere, occurrence, Oman, population, relative abundance, sex-ratio, song, survey, whale, whales, whaling
@techreport{,
title = {Preliminary investigations of humpback whale },
author = {Minton,G.,Collins,T.J.Q.,Findlay,K.P.,Baldwin,R.,Rosenbaum,H.C.,Kennedy,F.D.,Cockcroft,V.},
issn = {SC/54/H3},
year = {2002},
date = {2002-01-01},
journal = {Document presented to the 54th meeting of the International Whaling Commission},
volume = {SC/54/H3},
number = {414},
pages = {1-19},
abstract = {Previously published data on the occurrence of humpback whales (Megaptera novaeangliae) in the Arabian Sea suggest that the region hosts a non-migratory population that adheres to a Northern Hemisphere breeding cycle. Six small boat surveys and one shore-based survey were conducted at three locations off the coast of Oman between February 2000 and February 2002. Encounter rates varied between surveys from 0.0 whales/hour to 0.545 whales per hour. Two of 36 photo-identified whales were re-sighted between surveys. Sex ratios in October were near parity while all whales sampled in February were male. Song was detected frequently in the Kuria Muria Bay in February, but records of mother-calf pairs are sparse and competitive groups were absent. Feeding was infrequently observed in both October and February. Implications for relative abundance and habitat use are discussed. Additional questions are raised and recommendations for further research are made.},
keywords = {abundance, Arabian Sea, Distribution, habitat use, Humpback Whale, humpback whales, megaptera novaeangliae, Northern Hemisphere, occurrence, Oman, population, relative abundance, sex-ratio, song, survey, whale, whales, whaling},
pubstate = {published},
tppubtype = {techreport}
}
Previously published data on the occurrence of humpback whales (Megaptera novaeangliae) in the Arabian Sea suggest that the region hosts a non-migratory population that adheres to a Northern Hemisphere breeding cycle. Six small boat surveys and one shore-based survey were conducted at three locations off the coast of Oman between February 2000 and February 2002. Encounter rates varied between surveys from 0.0 whales/hour to 0.545 whales per hour. Two of 36 photo-identified whales were re-sighted between surveys. Sex ratios in October were near parity while all whales sampled in February were male. Song was detected frequently in the Kuria Muria Bay in February, but records of mother-calf pairs are sparse and competitive groups were absent. Feeding was infrequently observed in both October and February. Implications for relative abundance and habitat use are discussed. Additional questions are raised and recommendations for further research are made.