Do the methane seep areas constitute aggregation spots for the Patagonian toothfish (Dissostichus eleginoides) off central Chile?

Javier Sellanes, Milton J. Pedraza-García, Germán Zapata-Hernández


DOI: https://doi.org/10.3856/vol40-issue4-fulltext-14

We report results of two seasons (winter and summer) fishing for Patagonian toothfish (Dissostichus eleginoides), performed on a methane seep area (AFM) and a nearby place used as a control. These campaigns were developed with the aim of determining whether the AFM are sites of aggregation of D. eleginoides. For each area, the average catch was recorded, fishing performance and, abundance and diversity of wildlife indexes were determined, including incidentally caught fauna. Patagonian toothfish caught at both sites were sexed, measured and weighed. Additionally, there are images taken in situ, within the AFM, documenting the presence of both D. eleginoides as well as lost fishing gear used in their capture off the coast of Concepcion. The largest catches and yields were observed in the AFM, with average values of 56.2 kg per fishing haul and average yields of 80.3 g/hook, being significantly higher compared to the control site. In the winter fishing season higher yields and catches were recorded in both areas. The faunal composition, evaluated through community indices, indicate significant differences between sites, with the greater number of bycatch species in the AFM, compared with the control site (18 and 14 species, respectively). We hypothesize that the greater abundance of toothfish in the AFM would be related to both the greater spatial heterogeneity, given by the presence of authigenic carbonate reefs, and with the availability of prey, constituting these zones into foraging sites. This paper provides information aimed at establishing the ecological role of the AFM and associated fauna bathyal environments off Chile.

Sellanes J, Pedraza-García M, Zapata-Hernández G. Do the methane seep areas constitute aggregation spots for the Patagonian toothfish (Dissostichus eleginoides) off central Chile?. Lat. Am. J. Aquat. Res.. 2017;40(4): 980-991. Available from: doi:10.3856/vol40-issue4-fulltext-14 [Accessed 12 Dec. 2019].
Sellanes, J., Pedraza-García, M., & Zapata-Hernández, G. (2017). Do the methane seep areas constitute aggregation spots for the Patagonian toothfish (Dissostichus eleginoides) off central Chile?. Latin American Journal of Aquatic Research, 40(4), 980-991. doi:http://dx.doi.org/10.3856/vol40-issue4-fulltext-14