Standardization of the swordfish Xiphias gladius catch per unit effort data caught by the Hawaii-based longline fishery from 1994-2016 using generalized linear models

Details

• Personal Author:
  Sculley, Michelle ; Yau, Annie ; Kapur, Maia
• Corporate Authors:
  Pacific Islands Fisheries Science Center (U.S.)
• NOAA Program & Office:
  NMFS (National Marine Fisheries Service) ; PIFSC (Pacific Islands Fisheries Science Center)
• Description:
  The swordfish (Xiphias gladius) catch per unit effort for the Hawaii-based longline fishery was standardized from the Pacific Islands Regional Observer data set. The fishery was divided into the tuna-targeting deep-set sector and the swordfish-targeting shallow-set sector. Additionally, the shallow-set sector was standardized in two time periods: an early period (1995-2000) and a late period (2005-2016) because the shallow-set fishery was closed from 2001 to 2004, and regulations caused changes in the fleet operations thereafter. Four different models were evaluated to standardize the CPUE for each time series: the delta-lognormal model, the negative binomial model, the zero-inflated negative binomial model, and the Poisson model. The delta-lognormal model provided the best model fits and explained the most percent deviance of those evaluated. The models explained between 26 and 65% of the deviance in the shallow-set sector and 35% of the deviance in the positive catches for the deep-set sector, but only 4% of the proportion of positive catches in the deep-set sector. The shallow-set standardized annual CPUE values show an increase in catch rates in the early period followed by a peak in 2006 after the closure. CPUE values increased again from 2010 to the present. The CPUE values for the deep-set sector were relatively flat and had high variability.
• Content Notes:
  Michelle Sculley, Annie Yau, Maia Kapur.
  
  "Issued 18 May 2018."
  
  Includes bibliographical references (pages 8-10).
  
  
• Keywords:
  Catch Effort Fisheries Fish Stock Assessment Swordfish Catch Effort Fish Stock Assessment
• Series:
  PIFSC working paper   WP-18-001
• DOI:
  http://doi.org/10.7289/V5/WP-PIFSC-18-001
• Document Type:
  Working Paper
• Place as Subject:
  Hawaii ; Pacific Ocean
• Rights Information:
  Public Domain
• Compliance:
  Library
• Main Document Checksum:
  urn:sha256:3f3b1eb5fbb0de52ad7c1309756ea10e52d8936f401a0d135c6465beaa63cfd7
• Download URL:
  https://repository.library.noaa.gov/view/noaa/17612/noaa_17612_DS1.pdf
• File Type:
  [PDF - 2.41 MB ]