22 Harbor Porpoise Bycatch
Description: Harbor Porpoise Bycatch Indicator
Found in: State of the Ecosystem - Gulf of Maine & Georges Bank (2018+), State of the Ecosystem - Mid-Atlantic (2018+)
Indicator category: Synthesis of published information; Published methods
Contributor(s): Kristin Precoda, Christopher D. Orphanides, Debra Palka
Data steward: Debra Palka debra.palka@noaa.gov
Point of contact: Debra Palka debra.palka@noaa.gov
Public availability statement: Source data are available in public stock assessment reports.
22.1 Methods
22.1.1 Data sources
Reported harbor porpoise bycatch estimates and potential biological removal levels can be found in publicly available documents; detailed in Marine Mammal Protection Stock Assessments. More detailed documentation as to the methods employed can be found in NOAA Fisheries Northeast Fisheries Science Center (NEFSC) Center Reference Documents (CRDs) found on the NEFSC publications page.
22.1.2 Data extraction
Annual gillnet bycatch estimates are documented in the CRDs. These feed into the Stock Assessment Reports which report both the annual bycatch estimate and the mean 5-year estimate.
22.1.3 Data analysis
Bycatch estimates as found in stock assessment reports were plotted along with confidence intervals. The confidence intervals were calculated from published CVs assuming a normal distribution (\(\sigma = \mu CV\); \(CI = \bar{x} \pm \sigma * 1.96\)).
Data were analyzed and formatted for inclusion in the ecodata R package using the R code found here, Harbor Porpoise.
catalog link https://noaa-edab.github.io/catalog/harborporpoise.html