Ocean Career: Ocean Associates Ichthyoplankton Ecology Program

Ichthyology Laboratory Technician

SWFSC staff sort, identify, measure, and count the ichthyoplankton and para larval cephalopods collected during SWFSC's research surveys, and routinely identify fish eggs and larvae and cephalopod paralarvae from the eastern, central, and tropical Pacific. Data produced in the Ichthyoplankton Laboratory are critical to the Fisheries Resources Division's mission to conduct stock assessments and monitor the species and health of the California Current ecosystem.

Ichthyoplankton data are key contributions to the stock assessments of Pacific sardine and Pacific mackerel, have been used in recent assessments of Bocaccio and Cowcod rockfishes, and can provide fishery-independent time series information for many other fish species as well as market squid and California spiny lobster. In addition, the data is used to study distribution and abundance changes of many fish species in relation to ecosystem change in the California Current region and the eastern tropical Pacific.

The Ichthyoplankton Ecology Program analyzes plankton samples collected during California Cooperative Fisheries Investigations (Cal COFI) and FRD research cruises to provide data on fish eggs and larvae and cephalopod paralarvae that are used to support biomass assessments, Integrated Ecosystem Assessment, and ecological and taxonomic studies. Lobster larvae also are sorted from the plankton samples and provided to California Department of Fish and Wildlife and Scripps Institution of Oceanography scientists in support of state management of that species.

The Ichthyoplankton Ecology Program supports FRD plankton and trawling research cruises as needed by providing personnel to serve as members of scientific crews aboard ship.

Key tasks include, but are not necessarily limited to, the following:

• Laboratory work, including sorting all ichthyoplankton, para larval cephalopods, and spiny lobster larvae from plankton samples, identifying target taxa and counting all sorted specimens of all taxa, measuring lengths of key taxa, recording all counts and measurements on standard data forms, and delivering completed data forms for data entry.
• Using a binocular dissecting microscope, remove target taxa (all fish eggs, fish larvae, cephalopod paralarvae, and lobster phyllosoma larvae) from Cal COFI, Coastal Pelagic Species Biomass Estimation, and other SWFSC Bongo, Manta and Pairovet net tow plankton samples stored at Southwest Fisheries Science Center, following standard Cal COFI protocols. The remaining fraction of each sample will be returned to its collection for subsequent archiving at the Scripps Institution of Oceanography Pelagic Invertebrates Collection.
  
  Unsorted Bongo net samples collected during Cal COFI and FRD resource cruises will be sorted following the priority schedule posted in the Ichthyoplankton Ecology Laboratory.
• Count all sorted ichthyoplankton, cephalopod, and lobster specimens, measure standard or notochord lengths of up to 100 specimens each of selected key taxa (currently Pacific sardine, northern anchovy, and Pacific hake larvae), and bottle each category separately. Categories are:
  1) sardine eggs;
  2) anchovy eggs;
  3) all other fish eggs;
  4) sardine larvae;
  5) anchovy larvae;
  6) hake larvae;
  7) all other fish larvae;
  8) juvenile fish;
  9) lobster larvae; and 10) cephalopod paralarvae. Samples collected during the spring Cal COFI and Coastal Pelagic Species cruises, and as many other unprocessed samples as can be sorted in the available time following the priority schedule, will be completed by the end of each period of performance.
• Record all specimen counts and measurements on standard data sheets and deliver the sheets to the appropriate FRD data entry personnel for subsequent entry into the Cal COFI/FRD database.
• Aid, as needed, in entering the resulting data into the Cal COFI databases, and contribute as needed to analyses of the ichthyoplankton data and to preparation of scientific manuscripts resulting from these analyses.
• If sufficient specimens are available in the plankton samples, assemble developmental sequences of selected rockfish species, and collect meristic, morphometric, and pigmentation data from those specimens for use in preparation of manuscripts describing larval development of those species.

• Field work, consisting primarily of service on scientific crew aboard a research vessel during fishery resource assessment or ecosystem surveys
• Serve as a member of the scientific crew aboard a research vessel for up to 63 days at sea (typically three 21-day cruise legs) during a Coastal Pelagic Species (CPS) Biomass Estimation Survey or a Cal COFI survey during each period of performance. Duties will consist mainly of working as a member of the trawling team to conduct shipboard demographic analysis of trawl catches with primary emphasis on coastal pelagic species (northern anchovy, Pacific sardine, jack and Pacific mackerel, market squid) during a CPS survey or as a member of the FRD…