Seabird interactions and by-catch in the anchovy pelagic trawl fishery operating in northern Argentina

PAZ, JESICA ANDREA; PON, JUAN PABLO SECO; FAVERO, MARCO; BLANCO, GABRIEL; COPELLO, SOFÍA

AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS

JOHN WILEY & SONS LTD

Año: 2018 p. 1 - 11

1052-7613

1. Commercial fishing has been identified as one of the main threats affecting the survivalof most seabird species. Although seabird mortality in Argentine longline anddemersal trawl fisheries has already been characterized and quantified, the interactionswith pelagic trawl fisheries targeting anchovy (Engraulis anchoita Hubbs &Marini, 1935) remains unknown.2. The goal of this study was to characterize seabird assemblages attending pelagictrawl vessels and to analyse their interactions (i.e. contact of the birds with the vesseland/or fishing gear and by‐catch). Data were obtained by on‐board observersduring three consecutive fishery runs, 2011?2013.3. From a total of 333 observations, seabird abundance averaged 157.3 ± 229.7 birdsper haul (totalling 23 species). Procellariiform followed by Charadriiform birds werethe more frequent and abundant groups. The black‐browed albatross (Thalassarchemelanophris (Temminck, 1828)), shearwaters (Ardenna spp. and Puffinus spp.), whitechinnedpetrel (Procellaria aequinoctialis Linnaeus, 1758), and the kelp gull(Larus dominicanus Lichtenstein, 1823) were the most frequent and abundantattending species.4. The seabird abundance increased when the swell and the number of neighbouringvessels decreased.5. Seabird interactions with the vessel and/or fishing gear occurred in approximately70% of the observations, with most of these representing interactions with the net(92%). The estimated contact rate was 16.7 birds h−1 per haul. A total of 121 birdswere by‐caught and the average mortality rate was 0.55 birds h−1 per haul. Shearwatersand Magellanic penguins (Spheniscus magellanicus (Forster, 1781)) were themain by‐caught species (101 and 12 individuals, respectively). Lower levels of mortalitywere recorded in black‐browed albatrosses and white‐chinned petrels.6. The interactions increased in the presence of fishing discards and during haulbackoperations.7. This study is relevant to the implementation of the Argentine National Plan of Action? Seabirds, as well as for the continuing certification process in the anchovy fishery.