INVESTIGADORES
SECO PON Juan Pablo
artículos
Título:
Seabird mortality associated with ice trawlers in the Patagonian Shelf: effect of discards on the ocurrence of interactions with fishing gear
Autor/es:
MARCO FAVERO; GABRIEL BLANCO; GERMÁN GARCÍA; SOFÍA COPELLO; JUAN PABLO SECO PON; ESTEBAN FRERE; FLAVIO QUINTANA; PABLO YORIO; FABIÁN RABUFFETTI; GUILLERMO CAÑETE; PATRICIA GANDINI
Revista:
ANIMAL CONSERVATION
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2010 vol. 14 p. 131 - 139
ISSN:
1367-9430
Resumen:
This study investigated the level of seabird mortality caused by the domestic trawl
fleet (freshies) for hake (among other less important targets) operating in waters
off central Patagonia (37481S), analyzing the effect of environmental and
operational variability on the level of seabird interactions. With a total of 135
vessels, the fleet is one of the largest in Argentina. Specifically tasked seabird
observers were placed onboard trawlers during the summer and winter seasons of
the years 2006 and 2007. The type and number of seabird interactions (i.e. contacts
with fishing gear) were recorded during shooting and hauling operations, covering
72 days of observation and 328 trawls. Black-browed albatrosses, white-chinned
petrels Procellaria aequinoctialis, southern giant petrels Marconectes giganteus and
southern royal albatrosses Diomedea epomophora were the most abundant species
interacting with trawlers. Confirmed mortalities of black-browed and southern
royal albatrosses were the result of collisions and entanglement with the warp
cable while birds were scavenging. The estimated total mortality rate was 0.017
birds h_1 and 0.105 birds per vessel per day. The intensity of interactions (in terms
of the number of contacts per unit time) was largely explained by the distribution
of the fishing effort. Seasonality and the incidence of discards were the strongest
factors explaining the occurrence of seabird interactions. The total annual
mortality in the trawl fleet under investigation was roughly estimated to be from
several hundred to over a thousand albatrosses. However, these figures should be
considered preliminary due to the limited spatial and temporal coverage of data
and the fact that estimations were based on a low number of observed mortalities.
The implementation of a strategic discard management may significantly reduce
the number of seabird mortalities from collisions with warp cables or improve the
effectiveness of other complementary mitigation methods. Urgent implementation
of mitigation measures is needed in this fleet to reduce the mortality of albatrosses
and petrels along the Patagonian Shelf.