Rating the Effectiveness of Fishery Closures With Visible Infrared Imaging Radiometer Suite Boat Detection Data

Christopher D Elvidge,Nilo Selim Katada,Feng-Chi Hsu,Kimberly Baugh,Wilmon Penalosa,Bui Quang Hung,Mikhail Zhizhin,Tilottama Ghosh

doi:10.3389/fmars.2018.00132

Abstract

Fishery closures are widely used to promote the sustainability of fish stocks. Fishery agencies typically have very little data relevant to planning closure enforcement actions and evaluating the effectiveness of closures, due in part to the vast expanse and remote nature of many closures. In some cases the effectiveness of closures can be evaluated using data from GPS based beacons, such as Automatic Identification System (AIS) or Vessel Monitoring Systems (VMS) installed on fishing boats. In fisheries where few boats are equipped with AIS or VMS, the rating of closures relies on other data sources capable of detecting or inferring fishing activity. One such source comes from low light imaging data collected by the NASA/NOAA Visible Infrared Imaging Radiometer Suite (VIIRS), which can detect fishing boats using lights to attract catch. This is a widely used practice in Asia and several other regions. NOAA has developed an automatic system for reporting the locations of VIIRS boat detections with a nominal four hour temporal latency. VIIRS boat detection alerts are running for more than 900 fishery closures in the Philippines, with email and SMS transmission modes. These alerts are being actively used in the Philippines to plan enforcement actions and there is a growing list of apprehensions that occurred based on tip-offs from VIIRS. The VIIRS boat detection archive extends back to April 2012. A VIIRS closure index (VCI) has been developed to rate the effectiveness of closures on monthly increments in terms of a percentage. The VCI analysis was performed on three types of closures: an ad hoc fishery closure associated with a toxic industrial discharge, a seasonal fishery closure and a permanent closure in restricted coastal waters. The VCI results indicate that it is possible to rank the effectiveness of different closure, year-to-year differences in compliance levels, and to identify closure encroachments which may warrant additional enforcement effort.

Highlights

Fishery closures are bans on fishing activity for defined spatial regions
For rating the long term effectiveness of closure with VIIRS boat detection (VBD), we develop a Visible Infrared Imaging Radiometer Suite (VIIRS) closure index (VCI) based on the concept that changes in VBD numbers during closure periods is an expression of the compliance level
It would not be expected that VIIRS would routinely detect every type of fishing boat, only those that are deploying lights to attract catch

Summary

Introduction

Fishery closures are bans on fishing activity for defined spatial regions. The purpose is to curtail fishing effort to accomplish specific management objectives, such as to reduce interference with fish breeding or to protect stocks of juvenile fish (Gell and Roberts, 2003; Ani, 2016). Fishery closures may be seasonal, permanent, or ad hoc (Hall, 2002; Dinmore et al, 2003; Clarke et al, 2015). They may apply to a specific catch species or to an identified class of fishing gear. A number of data sources have been used to assess compliance or effectiveness of fishery closures, including: questionnaires and interviews (Bergseth et al, 2015), onboard observer data (Palka et al, 2008), biological surveys (Lewison et al, 2003; Tewfik and Béné, 2004; McClanahan et al, 2009; Diogo et al, 2016), surveys of derelict fishing nets and lines (Williamson et al, 2014), law enforcement records (Mann, 1995), vessel tracks from GPS beacons (Detsis et al, 2012; Öztürk, 2015; Petrossian, 2015), shore based camera images (Lancaster et al, 2017), aerial observations of fishing boats (Haggarty et al, 2016)

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Results

Conclusion