%0 Journal Article %T Copepod distribution in surface waters of the Drake Passage using Continuous Plankton Recorder and a Pump-Net onboard system %A Gustavo Thompson %A Estela O. Dinofrio %A Viviana A. Alder %A Kunio T. Takahashi %J Brazilian Journal of Oceanography %D 2012 %I Universidade de S?o Paulo %R 10.1590/s1679-87592012000300009 %X There is no single instrument that can sample quantitatively the complete spectrum of pelagic organisms, or even all the components of zooplankton. Mesh size is the main factor affecting species selectivity in the Continuous Plankton Recorder (CPR), implying a need to use multiple net systems to fully characterize a community. The spatial distribution of copepod communities in the water masses of the western and eastern sectors of Drake Passage were studied using, respectively, a CPR and a Pump Net onboard system. For this purpose, and assuming that copepod community size structures of each of the three water masses were similar in both the sectors studied, the possibility of complementing CPR results using a Pump-Net onboard system was evaluated. The latter system allows the estimation of absolute abundances and has the advantage of solving two problems associated with CPR, namely mesh clogging and low catching efficiency. The contribution of the nauplius forms and species accurately identified with both samplers was analyzed. Although Oithona similis dominated both communities, in the western sector small species made a greater contribution than Calanus simillimus, the opposite being true for the eastern sector. Nauplii and early copepodite stages of O. similis were missing from the CPR samples and represented between 69 and 79% of total copepod communities, whereas small calanoid copepods, C. simillimus copepodites and later stages of O. similis were inaccurately sampled by the CPR and represented between 14 and 18% of the copepod community. Hence, the Pump Net sampler is useful for complementing the semi-quantitative information of the CPR and for its calibration. N o h¨¢ um ¨²nico instrumento que possa efetuar uma amostragem quantitativa completa para o espectro de organismos pel¨¢gicos, ou mesmo, para todos os componentes do zooplancton. O tamanho da malha ¨¦ o principal fator que afeta a seletividade de esp¨¦cies no Registro Cont¨ªnuo de Plancton (CPR). Neste trabalho, estudamos a distribui o espacial das comunidades da cop¨¦pode nas massas de ¨¢gua registradas nos setores ocidentais e orientais da Passagem de Drake, usando um CPR e um equipamento de amostragem que consiste em uma bomba de suc o instalada a uma rede de malha de 20 ¦Ìm, respectivamente. Para este fim, e supondo que o tamanho das estruturas da comunidade de Cop¨¦podes de cada uma das tr¨ºs massas de ¨¢gua s o similares em ambos setores estudados, foi avaliada a possibilidade de complementar resultados obtidos com o uso de CPR usando ¨¤ bordo o sistema de bomba de suc o-rede. Este sistema perm %K Cop¨¦podos %K densidade %K Registro Cont¨ªnuo de Plancton %K sistema bomba de suc o %K Passagem de Drake %K Oceano Ant¨¢rtico %K Copepod %K Continuous Plankton Recorder %K Pump Net sampler %K Drake Passage %K Southern Ocean %U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592012000300009