Japanese longline observer data-USEEZ 1978-1988

This data set contains data that were collected by trained observers aboard Japanese pelagic longline vessels operating in the US EEZ. Observers collected information on the catch, bycatch, and fishing effort details of these fishing operations. Of particular concern were catches of bluefin tuna, and bycatch of marlins.

Data steward's PC

Only available to those with a valid non-disclosure agreement in place with the SEFSC, as specified in NOAA Administrative Order 216-100

Any paper copies of data set must be keep in a locked storage cabinet accessible only to NDA holder, within a locked office or lab that is accessible only to a limited number of the NDA holder's associates. Electronic copies of the data must be stored on a PC that is password protected/restricted to the NDA holder and located in a locked office or lab that is accessible only to a limited number of the NDA holder's associates. Alternatively the data can be stored on an oracle type data storage with access to the system restricted and access to the specific data table/tables restricted to the NDA holder.

Need SEFSC NDA. NDAs can only be granted to NOAA employees, contractors, or grantee's with a need for the data (see NOAA Administrative Order 216-100) .

Contact data steward Beerkircher or SEFSC Miami Laboratory Fisheries Statistics Division Chief.

None for NDA holders with a specific need for the data. No access permitted for non NDA holders. Aggregated data may be available, contact data steward.

Usually defined in the NDA. Publicly available research results must conform to current aggregation procedures (rule of three).

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Representativeness: It is unknown if JPLL data are likely representative of the fleet’s catch and effort characteristics, at the very least some “observer effect” (vessels altering fishing practices when an observer is on board) is possible. No documentation exists on how these vessels were selected for coverage. Some documentation indicates a 20% coverage rate was targeted. There are no known quantitative analyses of the representativeness of this data set.

Accuracy: Nothing is known about the degree of agreement between individual measurements in the JPLL data set and the true measurements, as the observer colleting the data is the sole source of the information and it cannot be cross checked with alternate sources.

Analytical Accuracy: See above. The accuracy of analytical results to the “true” values cannot be determined as the true values cannot be calculated without 100 % observer coverage and multiple observers on each vessel. Neither situation ever occurred during collection of JPLL data.

Quantitative Limits: The JPLL data system was devised to collect a large amount of variables for use in many different types of analyses rather than a single purpose system designed to estimate or produce one set of values. Further, the quantitative limits for many values would be dependent on the frequency of the observations, which is highly species dependent.

Bias: There have been no quantitative studies to detect potential bias in JPLL.

Comparability: There are no known comparable data sets to JPLL; even the Japanese do not seem to have the vessel catch logs for this fleet from this era

Completeness Measure: All vessel hauls were planned to be observed during an observer deployment; however it is likely that at least some hauls were unobserved due to observer sickness, and even during an observed haul some animals might not have been seen. There is nothing in the data that allows quantification of this.

Precision: There have been no quantitative studies to determine the precision of observations in JPLL. Since the “instrument” used to quantify the variable is generally the human observer themselves, measures of precision would require the same observer to record a variable, of known property, multiple times under the exact same conditions. Such studies are not practical.

Analytical Precision: See above, no information available.

Field Precision: See above, no information available.

Sensitivity: Since the “instrument” used to quantify the variables is generally the human observer themselves, sensitivity largely relies on the ability of the individual observer to see small variations in conditions, morphology, lengths, etc. No analyses of this characteristic have been conducted for this data collection system specifically or for fisheries observation systems in general.

Detection Limits: Not applicable. Variables collected in the JPLL system where specifically chosen such that they could be consistently and reliably determined by the human observer themselves.

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