Estimates of seabird by-catch along the Patagonian Shelf by Argentine longline fishing vessels, 1999–2001

Favero, Marco; Khatchikian, Camilo E.; Arias, Alejandro Valencia; Rodríguez, Maximiliano; Cañete, Guillermo; Mariano-Jelicich, Rocío

doi:10.1017/s0959270903003204

Cited by 64 publications

(55 citation statements)

References 4 publications

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“…Black-browed albatross populations have shown a significant reduction in numbers, particularly at the South Georgia, Kerguelen and Malvinas Islands (Robertson & Gales 1998, Huin 2001, and it has been argued that this is in part a result of the incidental mortality recorded in longline fisheries (Robertson & Gales 1998). Recent information indicates that the blackbrowed albatross is one of the species most affected by the longline fisheries operating on the Argentine continental shelf (Favero et al 2003) and by the trawlers operating in the water of the Malvinas Islands (Sullivan 2004). This study shows that >100 birds of this species were drowned in each of the studied periods when they were trapped by cables.…”

Section: Discussionmentioning

confidence: 99%

Seabird use of discards and incidental captures at the Argentine hake trawl fishery in the Golfo San Jorge, Argentina

González-Zevallos¹,

Yorio²

2006

Mar. Ecol. Prog. Ser.

107

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We studied discard use and incidental mortality of seabirds attracted to high-sea trawl vessels operating in the Golfo San Jorge, Argentina, during the height of the fishing season in 2003 and 2004. Fourteen seabird species ate food made available by fishing operations. The most frequent and abundant seabirds (percent occurrence, mean number per haul) were the kelp gull Larus dominicanus (98.9%, 207.0), the black-browed albatross Thalassarche melanophrys (98.9%, 94.2) and the white-chinned petrel Procellaria aequinoctialis (91%, 8.4). Flock sizes for the 3 species varied from a few to a maximum of 1600 birds. Total seabird abundance varied significantly between stages of the fishing operation, being higher during discarding and haulback than during towing. Incidental capture of seabirds in nets was recorded in 37% of 89 hauls, with a mean capture rate of 1.2 birds per haul. Species incidentally caught were the great shearwater Puffinus gravis, the imperial cormorant Phalacrocorax atriceps and the Magellanic penguin Spheniscus magellanicus, with rates that varied between months and years. Considering the fishery's fishing effort, the estimated total numbers of birds killed during the study were 2254 great shearwaters (CV = 1.1), 1233 imperial cormorants (CV = 1.1) and 35 Magellanic penguins (CV = 2.4) in 2003, and 311 imperial cormorants (CV = 1.7) and 1516 Magellanic penguins (CV = 1.1) in 2004. Black-browed albatrosses and kelp gulls were also struck by the warp cable while feeding on discards from the surface, and drowned when they were dragged underwater. The results obtained in this study show that the hake trawl fishery operating in the Golfo San Jorge may have a significant effect on some seabird populations through the provision of fishing discards and incidental mortality.

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Section: Discussionmentioning

confidence: 99%

Seabird use of discards and incidental captures at the Argentine hake trawl fishery in the Golfo San Jorge, Argentina

González-Zevallos¹,

Yorio²

2006

Mar. Ecol. Prog. Ser.

107

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“…The combined estimates for (adult-plumaged) albatross mortality along the Patagonian shelf and shelf break maybe of the order of ca. 5,000 individuals per year (from Neves and Olmos 1997;Yorio and Caille 1999;Olmos et al 2000;Favero et al 2003;Reid et al 2004;Reid and Edwards 2005;Crofts 2006;Gandini and Frere 2006;González-Zevallos and Yorio 2006;Laich et al 2006;Moreno et al 2006;Sullivan et al 2006b;González-Zevallos et al 2007;Otley et al 2007;Bugoni et al 2008;Moreno et al 2008;Sancho 2009;Jiménez et al 2009Jiménez et al , 2010Favero et al 2010). Even if we assume that the true mortality is twice as high as the above estimate (which is not unreasonable) and is entirely of birds from the local population, fisheries-related mortality would affect less than 1% of the birds from the Falklands.…”

Section: Discussionmentioning

confidence: 99%

Demographic parameters of black-browed albatrosses Thalassarche melanophris from the Falkland Islands

2011

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Black-browed albatrosses Thalassarche melanophris are currently classified as globally endangered. The most important populations of this species are believed to be declining due to, amongst other factors, unsustainable levels of incidental mortality in fishing gear. However, detailed demographic data are lacking for several critical populations, including the largest of all, nesting in the Falkland Islands. Here, we present data from the first Falkland Islands detailed demographic study (at New Island) and show that, from 2003 to 2009, the mean adult survival probability was 0.942 (95% CI: 0.930-0.952). Nesting frequency of adults is amongst the highest recorded for Thalassarche albatrosses and breeding success (0.564 chicks per egg) is within normal values. The nesting population in the intensively studied plots experienced an increase of 4% per year from 2004 to 2009. These results indicate that the Falklands population may not be as threatened as previously supposed, although studies from more sites and a longer time series are needed to confirm or refute this. The high survival rates may partly reflect recent efforts to mitigate bycatch made by the Falkland Islands and other fisheries in the region. The reinforcement of such initiatives may be critical to buffer the black-browed albatross population against ecosystem shifts and natural disasters (such as harmful algal blooms) that will likely become more frequent with ongoing global changes.

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“…Offshore fishing operations may provide food in the form of discards (Bugoni et al 2010), but also lead to incidental mortality of penguins, albatrosses, petrels, shearwaters and cormorants (e.g. Favero et al 2003;Phillips et al 2006;González-Zevallos & Yorio 2006;Bugoni et al 2008a;Jiménez et al 2009;Cardoso et al 2011) and to increased intake of heavy metals (Carvalho et al 2013). While some of these threats are locally restricted or could be remedied through political decisions, climatic phenomena have the potential to influence the whole region profoundly and add to the cumulative pressure affecting many seabird species.…”

Section: South American Large Marine Ecosystems and Climatementioning

confidence: 99%

Impacts of climate variation and potential effects of climate change on South American seabirds – a review

Quillfeldt

Masello

2013

Marine Biology Research

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The coastal and oceanic waters around the South American coasts provide rich foraging grounds for breeding and wintering seabirds, but there is growing concern that climate change will provide additional pressures to the seabirds around South America. As in many other coastal ecosystems, seabirds around South America are already faced with threats to their breeding habitats such as human disturbance and introduced predators, and threats at sea such as persistent pollutants and pesticides and direct mortality risks due to fisheries and oil spills. The sensitivity of South American marine ecosystems to ocean climate anomalies is well known from the dramatic population collapses caused by El Niñ o Southern Oscillation (ENSO) events. However, longer-term climate change effects have been explored less often and few long-term data sets exist for South American seabirds. Seven Large Marine Ecosystems (LME) border South America. While all LMEs experienced warming during the last 50 years, their climate dynamics have differed in recent decades. Climate models suggest that potential climate change effects may be important, especially due to changes in ENSO intensity and frequency and associated changes in the ocean climate of Atlantic and Pacific marine ecosystems. In this review, we found that the best studied seabird communities are those of the Patagonian Shelf and the Humboldt Current, but overall, our knowledge on climate effects on South American seabirds is scarce.

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Estimates of seabird by-catch along the Patagonian Shelf by Argentine longline fishing vessels, 1999–2001

Cited by 64 publications

References 4 publications

Seabird use of discards and incidental captures at the Argentine hake trawl fishery in the Golfo San Jorge, Argentina

Seabird use of discards and incidental captures at the Argentine hake trawl fishery in the Golfo San Jorge, Argentina

Demographic parameters of black-browed albatrosses Thalassarche melanophris from the Falkland Islands

Impacts of climate variation and potential effects of climate change on South American seabirds – a review

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