Pelagic Pre-Recruit Mesopelagic Biomass Survey on the Africana Voyage 090, March 1991

The Pelagic Pre-Recruit Mesopelagic Biomass Survey was conducted on the Africana Voyage 090 from 05-19 March 1991. The objectives of the cruise were to get an estimation of the biomass and population structure of epi-pelagic pre-recruit fish off the West Coast by means of echo-integration and midwater trawling; get an estimation of an epi-pelagic pre-recruit biomass index using quantitative Methot trawls; get an estimation of the biomass and population structure of mesopelagic fish using echo-integration and midwater trawling; to investigate the behaviour of pelagic pre-recruit fish in relation to oceanographic variables; get a collection of biological material for age, oil content, diet and condition studies on pelagic pre-recruits; to determine oxygen concentrations in rock lobster distribution areas; the profiling of currents by means of the acoustic doppler current profiler; and testing the feasibility of the acoustic assessment of juvenile hake.

1991年3月5日至19日，在“Africana Voyage 090”航次中，进行了针对浮游初级鱼类的中层中层生物量调查。航次的目的是通过声学积分和中层拖网技术，对西海岸浮游初级鱼类的生物量和种群结构进行估算；利用定量Methot拖网技术，估算浮游初级鱼类的生物量指数；通过声学积分和中层拖网技术，对中层鱼类的生物量和种群结构进行估算；研究浮游初级鱼类与海洋学变量之间的关系；收集浮游初级鱼类的生物材料，用于年龄、油脂含量、饮食和状况研究；确定岩龙虾分布区的氧气浓度；利用声学多普勒流速剖面仪对水流进行 profiling；以及测试对幼年鲈鱼进行声学评估的可行性。