Dolphin population specialized in foraging with artisanal fishers requires zero‐bycatch management to persist

2021 ◽  
Author(s):  
Carolina Bezamat ◽  
Philip S. Hammond ◽  
Pedro V. Castilho ◽  
Paulo C. Simões‐Lopes ◽  
Fábio G. Daura‐Jorge
Keyword(s):  
Artisanal Fishers ◽  
Dolphin Population

Variability of Hormonal Stress Markers Collected from a Managed Dolphin Population

2011 ◽  
Author(s):  
Dorian S. Houser ◽  
Samuel Wasser ◽  
John F. Cockrem ◽  
Nick Kellar ◽  
Tracy Romano
Keyword(s):  
Stress Markers ◽  
Dolphin Population

Variability of Hormonal Stress Markers Collected from a Managed Dolphin Population

2013 ◽  
Author(s):  
Dorian S. Houser ◽  
Samuel Wasser ◽  
John F. Cockrem ◽  
Nick Kellar ◽  
Tracy Romano
Keyword(s):  
Stress Markers ◽  
Dolphin Population

scholarly journals Ichthyological ethnoknowledge of the “piabeiros” from the Amazon region, Brazil

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Daniel da Silva Ladislau ◽  
Maiko Willas Soares Ribeiro ◽  
Philip Dalbert da Silva Castro ◽  
Jackson Pantoja-Lima ◽  
Paulo Henrique Rocha Aride ◽  
...  
Keyword(s):  
Fish Species ◽  
Local Ecological Knowledge ◽  
Middle Part ◽  
Ornamental Fish ◽  
Ecological Knowledge ◽  
Structured Interviews ◽  
Economic Activities ◽  
Negro River ◽  
Artisanal Fishers ◽  
Ecological Aspects

Abstract Background The capture of ornamental fish is one of the main economic activities of riverine families in the Amazon. However, studies regarding the local ecological knowledge of workers in this activity are still incipient. In view of this, we have studied and explored the local ecological knowledge of artisanal fishers who specialize in the capture of fish for the aquarium trade in the middle part of the Negro River basin and investigated issues related to the ecological aspects of the fish species that are targeted by this trade in the region. Methods Therefore, we conducted semi-structured interviews and applied questionnaires to artisanal fishers of ornamental fish (N = 89), from the municipality of Barcelos, from January to April 2016. Results In total, 41 popular names were cited, which correspond to four ethnocategories and 10 families. The main species were Paracheirodon axelrodi (12.5%), Hemigrammus bleheri (8.3%), Ancistrus dolichopterus (6.4%), Symphysodon discus (5.3%), and Potamotrygon motoro (3.8%). According to the fishers, the species of fish known in the region as “piabas” have a preference for living in clusters (28.9%) and carry out migratory movements (26.1%). The diet of local fish species reported by fisheries is diverse, though mainly based on periphyton (42.2%), and the reproductive cycle directly influenced by the period of flooding of rivers in the region (37.6%) Conclusion Our study revealed that the fishers possess information on the ecological aspects of local ornamental fish species, many of which are consistent with scientific literature. The information presented may assist in the decision-making process for the management of local fishery resources and contribute to the resumption of growth and sustainability in the capture of ornamental fish.

Artisanal fishers' perceptions of the ecosystem services derived from a dolphin-human cooperative fishing interaction in southern Brazil

2019 ◽  
Vol 173 ◽  
pp. 148-156
Author(s):  
Alexandre Marcel da Silva Machado ◽  
Fábio Gonçalves Daura-Jorge ◽  
Dannieli Firme Herbst ◽  
Paulo César Simões-Lopes ◽  
Simon Nicholas Ingram ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Southern Brazil ◽  
Artisanal Fishers

scholarly journals On the behaviour of an under-studied population of bottlenose dolphins in the Southern Adriatic Sea

2018 ◽  
Vol 99 (4) ◽  
pp. 1017-1023 ◽  
Author(s):  
Flavio Affinito ◽  
Cristobal Olaya Meza ◽  
Aylin Akkaya Bas ◽  
Deborah Brill ◽  
Guy Whittaker ◽  
...  
Keyword(s):  
Group Size ◽  
Bottlenose Dolphin ◽  
Adriatic Sea ◽  
Bottlenose Dolphins ◽  
Anthropogenic Pressure ◽  
Social Predictors ◽  
Dolphin Population ◽  
Autumn And Winter ◽  
Effective Conservation ◽  
Study Monitoring

AbstractPerhaps the world's best-known cetacean, the bottlenose dolphin shows considerable variation in behaviour between and within populations in relation to differences in natural and anthropogenic conditions. Drivers of behavioural variation need to be identified to understand the dynamics of wild dolphin populations. Little research has been published on the bottlenose dolphin population found in the Southern Adriatic Sea. Using a set of spatial, temporal and social predictors, we aimed to investigate what variables are related to the behaviour of an under-studied population of bottlenose dolphins along the coastline of Montenegro. We present the results of a year-long study monitoring the behaviour of bottlenose dolphins along coastal Montenegro. We considered the effect of topography, seasonality and group size. A large proportion of travelling (55%) small groups (mean 4, range 1–9) in shallow waters (<50 m) was observed. We showed that seasonality alone explained behaviour best, with surface-feeding and socializing-resting increasing in autumn and winter. Group size was found to be a result of behavioural choice. We suggest seasonal changes in environmental conditions and anthropogenic pressure may explain the recorded behavioural pattern. This research points to the necessity of increased collaboration in the region to help understand complex patterns in behaviour and habitat use of local dolphin populations if effective conservation measures are to be developed.

Distance does matter: close approaches by boats impede feeding and resting behaviour of Indo-Pacific bottlenose dolphins

2011 ◽  
Vol 38 (6) ◽  
pp. 455 ◽  
Author(s):  
Andre Steckenreuter ◽  
Robert Harcourt ◽  
Luciana Möller
Keyword(s):  
Bottlenose Dolphins ◽  
Tourism Industry ◽  
Empirical Measures ◽  
Resting Behaviour ◽  
South Wales ◽  
Animal Populations ◽  
Conflicting Objectives ◽  
Dolphin Population ◽  
Direction Of Movement ◽  
Dolphin Watching

Context Potential impacts of human disturbance on animal populations can be measured as behavioural responses and may affect the survival and fecundity of animals. In areas where human–wildlife interactions occur, conservation management needs to be in place to secure both a viable tourism industry and the sustainability of the targeted species. Aims We sought to evaluate whether different approach distances by boat have effects on the behaviour and group cohesion of dolphins that are targeted by Australia’s largest dolphin-watching industry. Methods The effects of different approach distances of boats on the behavioural states of dolphins, group dispersal and direction of movement were investigated in this area by controlled boat experiments conducted between August 2008 and December 2009. Key results Results showed that there was significantly less feeding when boats approached dolphin groups to a distance of 50 m than when they did to a distance of 150 m, or with controlled approaches. Resting was also observed significantly less when boats approached to a distance of 50 m than when they approached to a distance of 150 m. The dispersal of dolphin groups was significantly tighter (less dispersed) when boats approached to 50 m than that with 150-m-distance or controlled approaches. Furthermore, the dolphins’ direction of movement was less neutral when the experimental boat approaches were carried out at a distance of 50 m than when they were carried out at a distance of 150 m, or with controlled approaches. Similar results were also obtained for dolphin groups including calves. Conclusions On the basis of the results from this study, we recommend that the existing New South Wales regulations, which stipulate that dolphin-watching boats keep a distance of 50 m to groups with adults only and 150 m to groups with calves, are maintained within the Port Stephens–Great Lakes Marine Park (PSGLMP). Implications Management plans whose stated goals include both sustainability of a dolphin-watching industry and longer-term viability of a dolphin population may reconcile conflicting objectives and improve their decision making by using these empirical measures rather than best guesses.

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