Marine tucuxi dolphin (Sotalia guianensis) injuries as a possible indicator of fisheries interaction in southeastern Brazil

Nery, Mariana F.; Espécie, Mariana de Assis; Simão, Sheila M.

doi:10.1590/s1679-87592008000400007

Cited by 18 publications

(11 citation statements)

References 8 publications

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“…However, the proportion of injuries in Aruba was lower than that reported for Guiana dolphin ( Sotalia guianensis ) in Brazil (5.0% [28]; 9.0% [29]), offshore common bottlenose dolphins in Peru (7.7% [27]) and Indo-Pacific bottlenose dolphins ( Tursiops aduncus ) around Mayotte (19.1% [14]). …”

Section: Discussionmentioning

confidence: 55%

Prevalence of External Injuries in Small Cetaceans in Aruban Waters, Southern Caribbean

Luksenburg

2014

PLoS ONE

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Aruba, located close to the coasts of Colombia and Venezuela, is one of the most densely populated islands in the Caribbean and supports a wide range of marine-related socio-economic activities. However, little is known about the impacts of human activities on the marine environment. Injuries in marine mammals can be used to examine interactions with human activities and identify potential threats to the survival of populations. The prevalence of external injuries and tooth rake marks were examined in Atlantic spotted dolphin (Stenella frontalis) (n = 179), bottlenose dolphin (Tursiops truncatus) (n = 76) and false killer whale (Pseudorca crassidens) (n = 71) in Aruban waters using photo identification techniques. Eleven injury categories were defined and linked to either human-related activities or natural causes. All injury categories were observed. In total, 18.7% of all individuals had at least one injury. Almost half (41.7%) of the injuries could be attributed to human interactions, of which fishing gear was the most common cause (53.3%) followed by propeller hits (13.3%). Major disfigurements were observed in all three species and could be attributed to interactions with fishing gear. The results of this study indicate that fishing gear and propeller hits may pose threats to small and medium-sized cetaceans in Aruban waters. Thus, long-term monitoring of population trends is warranted. Shark-inflicted bite wounds were observed in Atlantic spotted dolphin and bottlenose dolphin. Bite wounds of cookie cutter sharks (Isistius sp.) were recorded in all three species, and include the first documented record of a cookie cutter shark bite in Atlantic spotted dolphin. This is one of the few studies which investigates the prevalence of injuries in cetaceans in the Caribbean. Further study is necessary to determine to which extent the injuries observed in Aruba affect the health and survival of local populations.

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Section: Discussionmentioning

confidence: 55%

Prevalence of External Injuries in Small Cetaceans in Aruban Waters, Southern Caribbean

Luksenburg

2014

PLoS ONE

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“…According to the descriptions in previous scientific papers, skin marks were also divided into: (1) Skin lesions, including marks due to infectious diseases such as bacterial, viral or parasitic infections [7, 10, 14, 16, 17, 19, 28, 57, 58]; (2) Traumata, including natural marks and scars due to intra- and/or interspecific interactions [7, 22, 35, 36, 41–44, 59–62], abrasions with rocks and other natural sharp objects while swimming [7, 44] and marks due to impact with vessels, propellers, interaction with fishing gears or direct damage by fishermen [13, 29, 30, 32, 62–67] (Table 1). Skin marks were also divided according to time of permanence: (1) Temporary, are skin marks with permanence time on the individual ≤ 4 years; (2) Permanent are skin marks with permanence time on the individual > 4 years or visible for the whole study period (Table 1).…”

Section: Methodsmentioning

confidence: 99%

Skin marks in bottlenose dolphins (Tursiops truncatus) interacting with artisanal fishery in the central Mediterranean Sea

Leone¹,

Ferraro²,

Boitani

et al. 2019

PLoS ONE

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Skin marks occur frequently in many cetacean species across the globe revealing a broad spectrum of causes, including social interactions, infectious diseases and injuries produced by anthropogenic factors. The current study used photo-id data from 2005–2014 to estimate the skin mark pattern on resident bottlenose dolphins (Tursiops truncatus) from the Aeolian Archipelago (Italy). Thirteen skin mark types were identified and their origin, prevalence and permanence time were examined. The pattern of skin marks was assessed for the abundance, richness, distribution and severity in six body regions and compared among age classes, sex and degree of dolphins’ interaction with trammel nets (DIN). Our results showed higher prevalence, abundance, richness and distribution of skin marks in adults than in the younger age classes, with the exception of black marks and white ring lesions. The prevalence and abundance of skin marks were higher in males than females, with the exception of scratches and white patches. Moreover, gunshot wounds, mutilations and irregular dorsal fin edges were found only on adult males. Since males showed higher DIN than females and, in dolphins with higher DIN, skin marks were more abundant and frequently distributed in different body regions, the skin mark pattern in regard to DIN seems to be sex-related. The more severe marks were observed on adults, males and dolphins with higher DIN, namely skin disorder, tooth rake marks, small shallow indentations, deep indentations and mutilations. On the contrary, the severity of scratches, white patches and dark ring lesions was higher in females than males, but not significantly related to DIN and age of the individuals. Our results showed that photo-id data provide an efficient and cost-effective approach to document the occurrence of skin marks in free-ranging bottlenose dolphin populations, a critical step toward understanding the cause and supporting the conservation strategies.

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“…This ecologically important area is surrounded by more than de delfines Guiana que son consistentemente encontrados durante todo el año; los individuos se han registrados por más de 12 años y probablemente usan la bahía para alimentarse y reproducirse (Nery et al 2008a). Datos sobre la abundancia y fidelidad de hábitat de estos delfines son esenciales para la conservación efectiva y también para fines de manejo, particularmente en áreas costeras y de estuario como es la bahía de Sepetiba, donde las poblaciones humanas se están expandiendo rápidamente, aumentando las amenazas directas e indirectas a los animales (Nery et al 2008b).…”

Section: Methodsunclassified

“…Data on Guiana dolphin abundance and site fidelity are essential for effective conservation and management purposes, particularly in coastal and estuarine areas like Sepetiba Bay, where human populations are rapidly expanding, increasing the direct and indirect threats to dolphins (Nery et al 2008b).…”

Section: Capture-recapture Abundance Estimate Of Guiana Dolphins In Smentioning

confidence: 99%

Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil

Nery

Simão

2012

Cienc. Mar.

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ABSTRACT. The objective of this study was to estimate the abundance of Sotalia guianensis in Sepetiba Bay, southeastern Brazil, based on photographic identification of animals. Estimates of population size were obtained using capture-recapture models for a closed population. Photo-identification data were analyzed using a model-fitting approach in the computer programs CAPTURE and MARK, and the Schnabel and Schumacher-Eschmeyer estimators were used to calculate the abundance of individuals with natural marks. These estimates were corrected to include unmarked individuals using data of the proportion of identifiable individuals in this population. During the surveys conducted between April 2006 and April 2007, a total of 9990 photographs of dolphins were taken and, of these, 2567 images were of sufficient quality for analysis; 382 dolphins were identified and catalogued from distinctive nicks and notches on their dorsal fins and, among them, 153 dolphins were photographed on more than one occasion. The resulting abundance estimates, corrected to account for the proportion (0.47) of unmarked dolphins in the population, showed an overlap among estimators ranging from 1004 to 1099 individuals. This is the largest estimated abundance for a population of S. guianensis reported to date using the capture-recapture technique.

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Marine tucuxi dolphin (Sotalia guianensis) injuries as a possible indicator of fisheries interaction in southeastern Brazil

Cited by 18 publications

References 8 publications

Prevalence of External Injuries in Small Cetaceans in Aruban Waters, Southern Caribbean

Prevalence of External Injuries in Small Cetaceans in Aruban Waters, Southern Caribbean

Skin marks in bottlenose dolphins (Tursiops truncatus) interacting with artisanal fishery in the central Mediterranean Sea

Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil

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