Bycatch of franciscana dolphins Pontoporia blainvillei and the dynamic of artisanal fisheries in the species' southernmost area of distribution

In Argentina, the franciscana dolphin is one of the most vulnerable cetaceans regularly entangled in coastal artisanal fishery nets. The aim of this paper is to estimate the species' incidental mortality on the Southern coast of Buenos Aires province through interviews with the captains of artisanal fishing vessels, in the period 2006-2009. Franciscana bycatch was reported for gillnets and shrimper gear all year round but it occurred more frequently between October and February, at 5 km offshore and 10-20 m depth. The estimated mean annual incidental mortality was 107 dolphins (CI 95% = 87-129), 92 caught in gillnets (CI 95% = 73-112) and 15 in shrimpers' gear (CI 95% = 8-25) with a capture per unit effort of 0.029 dolphins per km of gillnet (CI 95% = 0.023-0.036) and 0.022 per shrimpe r's net (CI 95% = 0.012-0.035). Annual fluctuations were due to differences in the number of gillnetting fishing days. If mortality estimates for the Northern coast are also taken into account, values attain a maximum of 360-539 dolphins bycaught in the entire Buenos Aires province, representing 2.5-3.7% of the species' abundance in Argentina. This will inevitably lead to the decline of franciscana dolphin populations in the near future unless alternative fishing grounds are identified and alternative gearadopted.

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Biological parameters of franciscana dolphins, Pontoporia blainvillei, by-caught in artisanal fisheries off southern Buenos Aires, Argentina

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315414000393 ◽

2014 ◽

Vol 96 (4) ◽

pp. 821-829 ◽

Cited By ~ 7

Author(s):

María Fernanda Negri ◽

María Victoria Panebianco ◽

Pablo Denuncio ◽

María Natalia Paso Viola ◽

Diego Rodríguez ◽

...

Keyword(s):

Body Condition ◽

Buenos Aires ◽

The Body ◽

Artisanal Fisheries ◽

Buenos Aires Province ◽

Biological Parameters ◽

Western Atlantic ◽

Pontoporia Blainvillei ◽

The Impact ◽

Franciscana Dolphin

The franciscana dolphin (Pontoporia blainvillei) is a small coastal dolphin endemic to the south-western Atlantic Ocean. Incidental captures in fishing gillnets is possibly the greatest conservation concern for this species, and occurs within most of its geographical distribution. The aim of this paper is to determine the biological parameters of franciscana dolphin by-caught from artisanal coastal fisheries of the southern Buenos Aires province, Argentina. Between 2003 and 2009, carcasses of 54 incidentally captured franciscanas were collected. The age, sexual and physical maturity and body condition of each specimen was determined. The sex-ratio of the by-caught dolphins did not differ from parity and, consistent with other areas, juveniles younger than 4 yr old were captured in higher proportion (69%). In addition, 74% of the entangled animals were sexually immature and 85% physically immature. Sexually immature dolphins were predominant in the spring, a period which coincides with the breeding season. An assessment of the body condition of captured franciscanas suggests that entanglements were not associated with a disease or physiological disorder. The results presented here are important to assess the impact of artisanal fisheries on the population of franciscana dolphins in the southernmost area of its distribution.

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Incidental mortality of franciscana dolphin (Pontoporia blainvillei) in Argentina

Latin American Journal of Aquatic Mammals ◽

10.5597/lajam00118 ◽

2007 ◽

Vol 6 (2) ◽

Cited By ~ 21

Author(s):

H. L. Cappozzo ◽

M. F. Negri ◽

F. H. Pérez ◽

D. Albareda ◽

F. Monzón ◽

...

Keyword(s):

Pontoporia Blainvillei ◽

Incidental Mortality ◽

Franciscana Dolphin

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Feeding habits of the franciscana dolphin (Pontoporia blainvillei) in south-eastern Brazil

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315420000120 ◽

2020 ◽

Vol 100 (2) ◽

pp. 301-313

Author(s):

Laura Busin Campos ◽

Xênia Moreira Lopes ◽

Ednilson da Silva ◽

Marcos César de Oliveira Santos

Keyword(s):

Feeding Habits ◽

Stomach Contents ◽

Small Fish ◽

South Eastern ◽

Important Prey ◽

Fishing Vessels ◽

Eastern Brazil ◽

Significant Difference ◽

Pontoporia Blainvillei ◽

Franciscana Dolphin

AbstractThis study evaluated the feeding habits of the franciscana dolphin (Pontoporia blainvillei) in south-eastern Brazil. Stomach contents were collected from a total of 145 dead specimens found incidentally caught by fishing vessels or stranded between 2005 and 2015. Fish otoliths, cephalopod beaks and whole non-digested prey were used for prey species identification. A total of 9337 prey items were identified, including 26 species of teleost fishes and three species of cephalopods. The most important prey families were Sciaenidae among fish and Loliginidae among cephalopods. Franciscana dolphins tended to feed on small fish (mean = 5.25 cm) and cephalopods (mean = 8.57 cm). The index of relative importance (IRI) showed that Pellona harroweri and Doryteuthis plei were the most important prey for both males and females. The PERMANOVA test confirmed that there is no significant difference between the feeding habits of different sexes, but detected a significant difference among seasons. Overall, our results show that franciscana dolphins are predominantly ichthyophagous and non-selective in relation to the type of prey, feeding on pelagic, demersal and pelagic-demersal prey.

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Heavy Metals in Liver of the Franciscana Dolphin, Pontoporia blainvillei, from the Southern Coast of Buenos Aires, Argentina

Journal of the Brazilian Society of Ecotoxicology ◽

10.5132/jbse.2012.01.006 ◽

2012 ◽

Vol 7 (1) ◽

pp. 33-41 ◽

Cited By ~ 10

Author(s):

M.V. Panebianco ◽

S.E. Botte ◽

M.F. Negri ◽

J.E. Marcovecchio ◽

H.L. Cappppozzo

Keyword(s):

Heavy Metals ◽

Buenos Aires ◽

Southern Coast ◽

Pontoporia Blainvillei ◽

Franciscana Dolphin

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Diet composition of franciscana dolphin Pontoporia blainvillei from southern Buenos Aires, Argentina and its interaction with fisheries

Revista de biología marina y oceanografía ◽

10.4067/s0718-19572014000200019 ◽

2014 ◽

Vol 49 (2) ◽

pp. 393-400 ◽

Cited By ~ 12

Author(s):

María Natalia Paso-Viola ◽

Pablo Denuncio ◽

María Fernanda Negri ◽

Diego Rodríguez ◽

Ricardo Bastida ◽

...

Keyword(s):

Diet Composition ◽

Buenos Aires ◽

Pontoporia Blainvillei ◽

Franciscana Dolphin

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REDUCING INCIDENTAL MORTALITY OF FRANCISCANA DOLPHIN PONTOPORIA BLAINVILLEI WITH ACOUSTIC WARNING DEVICES ATTACHED TO FISHING NETS

Marine Mammal Science ◽

10.1111/j.1748-7692.2002.tb01076.x ◽

2002 ◽

Vol 18 (4) ◽

pp. 833-842 ◽

Cited By ~ 52

Author(s):

P. Bordino ◽

S. Kraus ◽

D. Albareda ◽

A. Fazio ◽

A. Palmerio ◽

...

Keyword(s):

Pontoporia Blainvillei ◽

Incidental Mortality ◽

Franciscana Dolphin

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Use of natural and anthropogenic resources by Olrog's Gull Larus atlanticus: implications for the conservation of the species in non-breeding habitats

Bird Conservation International ◽

10.1017/s0959270907000883 ◽

2007 ◽

Vol 17 (4) ◽

pp. 351-357 ◽

Cited By ~ 13

Author(s):

María Paula Berón ◽

Marco Favero ◽

Agustina Gómez Laich

Keyword(s):

Buenos Aires ◽

Radio Telemetry ◽

Conservation Status ◽

Buenos Aires Province ◽

Sport Fishing ◽

Breeding Habitats ◽

Radio Signals ◽

Olrog’S Gull ◽

Study Sites ◽

Near Future

AbstractWe studied the exploitation of crab-beds and fishing grounds by Olrog's Gulls Larus atlanticus in non-breeding areas along the coast of Buenos Aires province, Argentina. During 2004 and 2005, censuses were performed in different areas of Mar Chiquita coastal lagoon and Mar del Plata harbour. Additionally, from April to August 2005 the movements of five non-breeding individuals were studied by means of radio-telemetry. At both study sites the highest numbers of Olrog's Gulls were observed between June and August. A total of 278 radio-tracked locations (from 407 samples) were registered. All the tracked individuals showed strong site fidelity, with 96% of the radio signals registered in the vicinity of the lagoon's mouth, associated with both crab-beds and areas where sport-fishing activities took place. Conservation issues in non-breeding areas should be tackled in the near future, given the conservation status of this species (Vulnerable) and the fact that each year several Olrog's Gulls are being killed because of their interaction with sport-fishing activities.ResumoSe estudió la utilización de cangrejales y áreas de pesca por la Gaviota de Olrog durante el periodo no reproductivo. Durante los aãos 2004 y 2005 se realizaron censos en diferentes áreas de la Laguna Costera Mar Chiquita y el Puerto Mar del Plata, Provincia de Buenos Aires, Argentina. En ambos sitios de estudio el mayor número de individuos se observó entre los meses de junio y agosto. Adicionalmente entre los meses de abril y agosto de 2005 se estudiaron los movimientos de cinco individuos no reproductores mediante el uso de radio-transmisores. De un total de 407 muestras se obtuvieron 278 localizaciones. Todos los individuos instrumentados mostraron una alta fidelidad al sitio. El 96% de las localizaciones se registraron en cercanías de la desembocadura de la laguna, asociadas a cangrejales y areas de pesca deportiva. Considerando el estatus de conservación de la Gaviota de Olrog (‘Vulnerable’) y los efectos negativos de su interacción con la pesca deportiva, programas de conservación en áreas no reproductivas deben ser implementados.

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Análisis tafonómico de moluscos holocenos en el área costera del Estuario de Bahía Blanca, Argentina

Pesquisas em Geociências ◽

10.22456/1807-9806.20163 ◽

2001 ◽

Vol 28 (1) ◽

pp. 3 ◽

Cited By ~ 1

Author(s):

JORGE SPAGNUOLO ◽

ESTER FARINATI ◽

SALVADOR ALIOTTA

Keyword(s):

Buenos Aires ◽

Buenos Aires Province ◽

Northern Coast ◽

Medium Sand ◽

Bahía Blanca Estuary ◽

Storm Waves ◽

Holocene Transgression ◽

South West ◽

Paleoenvironmental Evolution ◽

Production Area

At the south west of the Buenos Aires province, Argentina, on the northern coast of the Bahía Blanca Estuary, sand-shell ridges sub-parallel to the coastline generated during the Holocene transgression-regression were deposited. These structures are composed mostly of coarse to medium sand and a high proportion of molluscs shells (19 species of bivalves and 16 species of gastropods). For this study three taxa from the fossil association located in the ridges (Brachidontes rodriguezi, Tegula patagonica and Crepidula aculeata) were selected and the mechanisms of taphonomic alteration that affected them were qualified. By means of ternary taphograms the variation of five taphonomic attributes (bioerosion, encrustation. fragmentation. wear and dissolution) was established. It has been determined that the bioestratinomic processes are subordinated to the fossildiagenetic mechanisms, where dissolution has left a series of taphonomic signatures. Based upon the taphonomic attributes of the fossil association a high stand sea level cycle with an important contribution of storm waves that affected the biogenic production area were established as a representation of the paleoenvironmental evolution.

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