West Coast Hake Biomass on the Africana Voyage 079, January 1990

The West Coast Hake Biomass Survey on the Africana Voyage 079 was conducted from 4 to 29 January 1990. The objectives of the cruise were to survey by means of trawling the abundance of adult and recruiting hake in South African waters, to investigate the diurnal cycle of hake and other demersal species, to investigate the environmental and ecological interrelationships of hake and other demersal species, to make some experimental trawls in deep water to determine hake distribution limits and collect deep-water specimens of fish and squid; to collect routine biological material on demersal species from Namibian waters (if time permitted); to investigate the occurence, distribution and abundance of squid and squid larvae; to study demersal community interrelationships; to study the biology of sharks and selected non-commercial fish species; to investigate zooplankton scattering layers and their influence on the feeding behaviour of small hake; to obtain coverage of chlorophyll-fluorescence distribution at the sea surface as part of an ongoing monitoring programme; to collect data concerning currents on the South African shelf region from as close to the surface to as close to the bottom as possible; and lastly to train oceanographic research assistants.

在1990年1月4日至29日进行的非洲之旅079航次中，实施了西海岸鲽鱼生物量调查。此次航次的宗旨在于，通过拖网调查手段，探究南非海域成年鲽鱼及幼鲽鱼的丰度，研究鲽鱼及其他底栖物种的昼夜节律，探究鲽鱼及其他底栖物种的环境与生态相互关系，进行深海拖网实验以确定鲽鱼的分布极限并采集深海鱼类及乌贼样本；在条件允许的情况下，从纳米比亚水域收集底栖物种的常规生物学材料；调查乌贼及其幼体的出现、分布及丰度；研究底栖群落间的相互关系；研究鲨鱼及特定非商业鱼类物种的生物学；探究浮游动物散射层及其对小型鲽鱼摄食行为的影响；作为持续监测计划的一部分，获取海表叶绿素荧光分布的覆盖范围；收集有关南非大陆架区域水流数据，从接近海面到接近海底尽可能全面地收集；最后，对海洋学研究助理进行培训。