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Data Collection |
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Fishery Dependent Sampling (sampling from the fleet) Daily vessel unloads are reported monthly to the National Marine Fisheries Service. Detailed daily activity of each menhaden vessel in the Gulf fleet is reported via the Captain's Daily Fishing Report or CDFR. The captain from every vessel records details on every set their crew makes in a day. Information is recorded on the time and duration of every set, the location, the water and weather conditions, and finally, the estimated number of fish in each set. These reports are sent by the company every week to the NMFS to be entered into the gulf menhaden database which currently has CDFR data from 1982 to 2006. Additionally, the 1979-1981 data sheets have been scanned for future use.
Biostatistical protocols for sampling the reduction fishery consist of a sampler randomly selecting a vessel at dockside, and then randomly selecting 10 fish (20 in 1964–1971) from a bucket of fish obtained from the top of the fish hold. Each of these fish is measured for fork length (mm) and weight (g), and a scale patch is removed for ageing. The sample is not assumed to represent the entire fish hold, but rather the last purse-seine set of the fishing day. In recent years, about 4,000-5,000 fish have been processed annually. At the end of the fishing season, biostatistical data are merged with landings on a port-week basis to produce estimated landings of fish at age (in numbers). Estimates are summed over all port-weeks for the entire fishing season to produce annual estimates of total landings at age. Fishery Independent Sampling (agency
sampling) Each state agency has its own
sampling protocols which identify juvenile gulf menhaden abundance
based on catch per-unit-effort. Data are acquired from |
