Seabird observations in Subareas 48.1, 48.2 and 88.3 and proposal for a new streamer line design

A 43-day cruise on FV Tierra del Fuego took place in February and March 1997, as part of the New Fisheries Project developed by Chile in Statistical Subareas 88.3, 48.1 and 48.2. During this research study every measure currently in force was used to prevent incidental seabird mortality, carrying out bird observations in each one of the 52 castings with the Spanish-designed longlines as well. The streamer line suggested by the CCAMLR was not appropriate during wind conditions, so an alternate design was tried out using loophole sacks as secondary elements, which proved more efficient due to their simpler construction and increased visibility. Neither bird capture nor mortality was reported during the fishing activities. During the entire cruise a total of 436 birds were observed. The most abundant was Diomedea melanophrys, with 204 sightings, followed by Oceanities oceanicus, with 77; Catharacta lonnbergi, with 40; and Diomedea chrysostoma, with 37. The highest relative abundance was found in Subarea 48.1 with I1 .I birds/haul, followed by Subareas 48.2 and 88.3 with 7.6 and 5.0 birds/haul, respectively. The highest number of species was found in Subarea 48.1 with 19 species observed and the least in Subarea 48.2 with the presence of only 4 species.