New publication: Abundance, residency and potential hazards for coastal bottlenose dolphins (Tursiops truncatus) off a productive lagoon in the Gulf of Mexico
Dear MARMAM readers, We are glad to annouce a new publication in Aquatic Mammals: Morteo E., Rocha-Olivares A., Abarca-Arenas L.G. 2017. Abundance, residency and potential hazards for coastal bottlenose dolphins (Tursiops truncatus) off a productive lagoon in the Gulf of Mexico. Aquatic Mammals, 43(3):308-319. ISSN: 1996-7292, doi: 10.1578/AM.43.3.2017.308 Abstract: Movements of many cetacean species are commonly related to temporal and spatial variations in food resources and human activities. Worldwide evidence shows that anthropogenic pressures faced by coastal dolphin populations are increasing; however, the lack of reliable baseline information generally prevents the assessment of such interactions. We studied the temporal dynamics in abundance, site fidelity, and residency of bottlenose dolphins (Tursiops truncatus) off the productive Alvarado lagoon in the Gulf of Mexico, and we assessed the potential hazards posed by human activities and natural predators. This 2-y study (2006 to 2008) was based on the photographic identification of 174 individuals from 871 high-quality dorsal fin photographs obtained during 41 surveys totaling 225.4 h of observation. Overall monthly abundance averaged 125 (SD = 52) dolphins, whereas naturally marked individuals averaged 106 (SD = 25); abundance values were somewhat consistent within and between years, but the community was composed of different dolphins at any given time. Seasonal site fidelity and residency were higher during the dry (March to June) and rainy (July to October) seasons. Previous studies from Alvarado and elsewhere suggest long-term residency (up to 7 y) but also widespread movements (100 to 300 km) for some individuals. Physical evidence of attacks by large predators was exclusively found in nonresident adult dolphins (3.5%), suggesting a seasonal incursion to the area by individuals from deeper waters. Also, dolphins bearing marks of interactions with fisheries were more common in adult residents (11.5%). Despite these threats, dolphins are recurrent in the area, possibly due to high prey abundance and availability, which may constitute the main factors driving their distribution and abundance. The PDF may be downloaded directly from the Aquatic Mammals web-page: http://www.aquaticmammalsjournal.org/ <http://www.aquaticmammalsjournal.org/> Or you may send an email to: eduardo.morteo@gmail.com <mailto:eduardo.morteo@gmail.com> to request a full PDF. All best, E. Eduardo Morteo, Dr. Head Researcher Marine Mammal Laboratory Institute of Biological Research Institute of Marine Sciences and Fisheries Universidad Veracruzana 617 Calle Hidalgo, Col. Río Jamapa, Boca del Río, Veracruz, Mexico. CP 94290 Ph: +52 (229) 956 72 27 Ext. 114 Fax: +52 (229) 956 70 70 E-mail: emorteo@uv.mx http://www.uv.mx/personal/emorteo/ http://uv-mx.academia.edu/EMorteo https://www.researchgate.net/profile/Eduardo_Morteo/?ev=hdr_xprf http://scholar.google.com.mx/citations?user=fDUl-IIAAAAJ
Dear MARMAM readers, On behalf of my coauthors, I’m pleased to announce our new publication: Morteo E., Rocha-Olivares A., Morteo R., Weller D.W. 2017. Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus) off Mexico. PeerJ5:e3415, ISSN 2167-8359, doi.org/10.7717/peerj.3415 <http://doi.org/10.7717/peerj.3415> Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus). In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n = 6, Gulf of California n = 6 and, Gulf of Mexico n = 7) were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p < 0.05) with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species. You may view and download the paper (and the supplementary materials) directly form the Open Access platform PeerJ: https://peerj.com/articles/3415/ <https://peerj.com/articles/3415/> Or you may send an email to: eduardo.morteo@gmail.com <mailto:eduardo.morteo@gmail.com> to request a full PDF, Kind regards, E. Eduardo Morteo, Dr. Head Researcher Marine Mammal Laboratory Institute of Biological Research Institute of Marine Sciences and Fisheries Universidad Veracruzana 617 Calle Hidalgo, Col. Río Jamapa, Boca del Río, Veracruz, Mexico. CP 94290 Ph: +52 (229) 956 72 27 Ext. 114 Fax: +52 (229) 956 70 70 E-mail: emorteo@uv.mx http://www.uv.mx/personal/emorteo/ http://uv-mx.academia.edu/EMorteo https://www.researchgate.net/profile/Eduardo_Morteo/?ev=hdr_xprf http://scholar.google.com.mx/citations?user=fDUl-IIAAAAJ
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Eduardo Morteo