EK60 Water Column Sonar Data Collected During GU1101

SEAMAP 2011 Spring Plankton Survey (CU1101, EK60). The primary survey objective was to assess the occurrence, abundance and geographical distribution of the early life stages of spring spawning fishes, especially bluefin tuna (Thunnus thynnus), from the continental shelf edge to deep Gulf waters using a bongo frame fitted with 0.335 mm nets and a neuston frame fitted with a 0.950 mm net at selected SEAMAP stations in support of annual stock assessments. An additional neuston frame fitted with a 0.505 mm net and a flowmeter was fished subsurface at all stations.Sampling was also conducted to describe the pelagic habitat of fish larvae through measurements of various physical and biological parameters including salinity, fluorescence, dissolved oxygen, turbidity, and chlorophyll. The distribution of fish eggs along the cruise track was sampled using a Continuous Underway Fish Egg Sampler (CUFES) and vertical distribution of fish larvae were estimated by sampling discrete depths using a 1 m Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS) with 0.505 mm nets.