Cooperative Research Units
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Estimating detection and occupancy coefficients for the Pacific Islands coral reef fish species


January 2019 - June 2020


Data-limited stock assessment models are used to determine the status of the coral reef fish species in the western Pacific. Estimates of standing stock biomass are based on an expansion of the species biomass density with known hard bottom substrate from 0-30m depth from underwater visual census surveys. The expansion to generate estimates of standing stock biomass includes implicit assumptions of uniform distribution and perfect detection. These assumptions are rarely met as variations in fish behavior, areas surveyed with varying fishing pressure, habitat type, diver survey experience affect the ability to detect species and individuals and have repercussions to the population estimators. Therefore, quantifying the detectability and occupancy coefficients of each coral reef fish species can refine the standing stock biomass estimates and reduce bias. The overall aim of this project is to analyze the National Marine Fisheries Service Coral Reef Ecosystem Program Reef Fish Dataset to estimate detection and occupancy coefficients for species listed in the Western Pacific Regional Fishery Management Council’s Fishery Ecosystem Plans to refine the standing stock biomass estimates used in stock assessment.

Research Products and Activities


  • Suarez B & TB Grabowski. Estimating detection and occupation coefficients for reef fish in the western Pacific. 11th Annual Tropical Conservation Biology and Environmental Science Research Symposium. Hilo, HI. 11-12 April 2019.

Current Staff

Federal Staff: 1

Masters Students: 4

Phd Students: 1

Post Docs: 0

University Staff: 1

5 Year Summary

Students graduated: 1

Scientific Publications: 18

Presentations: 33



Funding Agencies

  • Western Pacific Regional Fishery Management Council


Hawaii Cooperative Fishery Research Unit Cooperators

  1. Hawaii Department of Land and Natural Resources
  2. U.S. Fish and Wildlife Service
  3. U.S. Geological Survey
  4. University of Hawaii