Bycatch characterization in the Pacific halibut fishery: A field test of electronic monitoring technology


A North Pacific Research Board Grant to
     Dr. William Karp, National Marine Fisheries Service
     Dr. Bruce Leaman, International Pacific Halibut Commission
     Ms. Jennifer Cahalan, Pacific States Marine Fisheries Commission




Links


Contact Information

Jennifer Cahalan, PSMFC,
(206) 526-4185
jennifer_cahalan@psmfc.org

Gregg Williams, IPHC,
(206) 634-1838
gregg@iphc.washington.edu

Brian Mason, NMFS
(206) 526-4227
brian.mason@noaa.gov

Acknowledgements
Funding provided by North Pacific Research Board
Research is cooperative with the commercial halibut fleet; vessel participation is voluntary

Photos curtesy of Bill Monheimer, IPHC and NOAA Fisheries Service.

The goal of this research is to test the ability of electronic monitoring (EM) systems to operate in a commercial setting by comparing estimates of bycatch based on video monitoring and standard NOAA Fisheries Service observer sampling with a known census of harvest.

We have been using EM alongside standard NOAA Fisheries Service sampling methods, and comparing catch estimates to a known census of catch. In 2008 we successfully recruited 4 vessels to participate in the study. This resulted in data collected for 13 trips and over 150 monitored longline sets. Fishing occurred in three different IPHC regulatory areas over a four month period. .

We expect study results to be available in early 2010.

Research Objectives:
This study has two main objectives:
1. Estimation of catch and bycatch rates from data collected on commercial longline vessels using several methods
  1. Electronic (video) monitoring
  2. Standard NMFS observer monitoring
  3. Hook-specific documentation (by a second observer) of fish species (Census of Catch)
2. Evaluations of the relative efficiency, cost, and bias of each of the two bycatch estimation methods (EM, NMFS Observers) relative to a known standard (census)
Background

Bycatch rates of non-target species in the Pacific halibut fishery operating off Alaska are not well estimated. The majority of the vessels operating in the halibut longline fishery in Alaska are not currently subject to at-sea harvest monitoring; hence, estimates of bycatch are not based on direct observation of the fishery.


We will be comparing and evaluating the effectiveness of electronic monitoring (EM) and the currently utilized National Marine Fisheries Service (NMFS) monitoring methods to operate effectively in a commercial longline (hook-and-line) setting. This is a cooperative study with the commercial fishing industry and relies on our ability to sample on various vessel configurations.


Previous research documented successful EM of Pacific halibut longline fishing from chartered research vessels (Ames, 2005; Ames et al., 2007). While this work supported the use of EM to monitor bycatch, the research was not conducted under commercial fishing conditions where a much broader range of environmental and physical factors affect the vessel operations.


Research Methods
  • Monitor catch using three methods, simultaneously when possible
    • Census of catch, electronic monitoring, standard NOAA Fisheries Service sampling
    • One or two observers on each vessel
    • Video equipment on each vessel
  • Time periods and locations chosen to reflect major fishing patterns
Electronic Monitoring
  • Sensors recording vessel activities and GPS positions
  • Video cameras mounted on an outboard boom, ~ 4.5 meters from incoming gear.
  • Hook specific data can be aligned with hook-status data
  • Aggregated data can be aligned with NOAA Fisheries Service data
North Pacific Groundfish Observer Program
  • Currently, standard methods used to monitor groundfish catches
  • Well documented in the NMFS Observer Sampling Manual (NMFS, 2008)
  • Systematic random sampling
  • Gear segment-specific data can be aligned with EM data and hook-status data
Hook-Status Monitoring
  • Provides a census on the number of fish caught, by species
  • Sequentially record the status of each hook retrieved
    • Empty hook, Landed catch, species
  • Hook-specific data can be aligned with EM data
  • Aggregated data can be aligned with NOAA Fisheries Service data