A Method for Measuring Fishing Effort by Small-scale Fish Aggregating Device (FAD) Fishers from the Commonwealth of Dominica

Abstract

We used global positioning system (GPS) technology and tracking analysis to measure fishing effort by marine, small-scale, fish aggregating device (FAD) fishers of the Commonwealth of Dominica. FADs are humanmade structures designed to float on the surface of the water and attract fish. They are also prone to common pool resource problems. To identify free riders with respect to specific FADs, we need to compare the cost expended for FAD construction versus the benefit fishers extract from their use of the FADs. From August to December 2012, we placed GPS devices on a sample of fishing trips to track movement and measure Downloaded from variation in fishers' fishing efforts at a set of seven FADs off the Atlantic east coast of central Dominica. The method produces high-resolution data to determine how much time different fishers use different FADs.

Using a Partial Sum Method and GPS Tracking Data to Identify Area Restricted Search by Artisanal Fishers at Moored Fish Aggregating Devices in the Commonwealth of Dominica

“…There is good reason to believe that the relatively small sample of observations provides a sufficiently accurate description of FAD trips to generalize the method to other boats and captains. Visual analysis of tracks from the larger sample of FAD trips indicates a general pattern of directed, higher speed travel between patches and slower and sinuous movement at FAD locations and other presumed patches [ 33 ]. Discussions with fishers confirm that the pattern of movement at FADs identified during the observed trips as ARS is a general feature of FAD fishing at Desa Ikan.…”

“…During the data collection period, 505 fishing trips were observed leaving and returning to the landing site at Desa Ikan. We placed GPS devices aboard the boats and collected movement data from a sample of 351 of these trips [ 33 ]. For 25 of these trips, along with the GPS data, ground truth data were simultaneously collected during time-synchronized focal follows where one of us joined the crew and recorded behavioral data during the course of the trip.…”

“…The deep water FADs deployed from Desa Ikan are anchored to the ocean floor with halved 55 gallon drums filled with concrete ( Fig. 1 ; see also [ 33 ]). A length of polypropylene rope joins the anchor to the FAD’s head at the surface which usually consists of a number of round floats in addition to the FAD’s attraction.…”