Artisanal shark fisheries of Bahía San Blás MPA (Argentina): the last oral records.

GARCÍA, M.L.; CUEVAS, JUAN MARTIN; CHIARAMONTE, GUSTAVO ENRIQUE; GOMEZ, S.

Joao Pessoa

Conferencia; III Sharks International Conference; 2018

Bahía San Blás (BSB), Northern Patagonia (Argentina), is an important shark breeding and nursery ground in the Southwest Atlantic, including endemic species such as the narrownose smouthhound Mustelus schmitti. It was declared in 2001 as a MPA with multiple uses including small scale fisheries. Although artisanal fishing was allowed to continue in the area after its protection and included in its Management Plan in 2007 the last license was approved in 2010. The aim of the study was to interview the last artisanal shark fishers of BSB MPA to describe their fishing activity and increase management knowledge of targeted species. During November 2017 three fishermen of BSB were interviewed in person and individually to register: target species, fishing, capture and trade information, including temporal and spatial data. At the same time we used maps in each interview to identify fishing areas, number of gillnets deployed per species and parturition sites. The artisanal fleet was of 5 boats with crew members varying between 3 and 8 people per boat. Three species were targeted by gillnets, M. schmitti, the tope shark Galeorhinus galeus and the copper shark Carcharhinus brachyurus while the hidden angelshark Squatina guggenheim was captured as bycatch. Fishing season period used to be between 30 and 45 days per species as following: M. schmitti (Oct-Nov), G. galeus (Nov-Dec) and C. brachyurus (Dec-Jan-Feb). All fishers used bottom gillnets (Height: 1.3m, Length: 50m) made by hand and with nylon or polyester materials with different mesh sizes: M. schmitti (10.5-12 cm), G. galeus (18-20 cm) and C. brachyurus (34-35 cm) and operated by hand. The number of nets deployed per day varied between 3 (G. galeus and C. brachyurus) and 20 (M. schmitti). Bottom gillnets were deployed against current at different depths: 3-4 m for M. schmitti and G. galeus and > 5m for C. brachyurus. Catch was sold to fish traders with cold chambers settled in Mar del Plata and Bahía Blanca. Mustelus schmitti were sold fresh while G. galeus and C. brachyurus dried and salty. The maximum harvest per season of M. schmitti was 2600 fish-boxes while for G. galeus was 3.8 tonnes (N=2111 individuals) of dried products while a ?good fishing day? were around 70 fish-boxes for M. schmitti and 250 and 12 individuals for G. galeus and C. brachyurus respectively. One interviewed used to target only M. schmitti in one particular site and reported that 85% of his captures used to be males. No capture trend was recorded for any of the targeted species. Spatial analysis showed overlapping between species fishing areas as well as artisanal activity areas, assuming no exclusive zones. A sustainability assessment, including ecological, community and socioeconomic components, is recommended before reopen in the future this activity targeting threatened species.