Assessing the number of moored fishing aggregating devices through aerial surveys: A case study from Guadeloupe

Abstract

Moored fish aggregating devices (MFADs) are increasingly being used in small-scale tropical fisheries to access pelagic fish species that are otherwise difficult to harvest in large numbers. Little attention has yet been paid to monitoring MFADs in coastal areas, however. This is most likely due to the small-scale nature of most fisheries that utilize them and the presumed lower impact of those fisheries on fish stocks and their ecosystems. In this paper, we examined the abundance and density of MFADs around Guadeloupe, using aerial line transect surveys. Estimated MFAD densities were found to be high compared with previously reported densities in this area, especially within the 22-45 km range offshore. We examine and discuss possible reasons for these high densities. The main drivers appear to be the target species dolphinfish (Coryphaena hippurus) and yellowfin tuna (Thunnus albacares) and related fishing behaviour. We present different approaches for reducing and monitoring MFADs densities, including the co-management of MFAD territorial use rights by fishing communities.

Existing Territories and Formalization of Territorial Use Rights for Moored Fish Aggregating Devices: The Case of Small-Scale Fisheries in the La Désirade Island (France)

“…This open access to space and fishery expanded in the 1990s resulting in an increasing number of vessels, an extension of fishing areas from nearby coastal waters to more distant coastal areas and a growing number of conflicts between fishers because of MFADs congestion (Diaz et al 2005;Mathieu et al, 2013). An aerial survey carried out in 2012 around Guadeloupe to estimate MFADs numbers found high densities of MFADs compared with previously reported densities in this area, especially around the northeastern coasts of Guadeloupe off the La Désirade Island (Guyader et al 2017). According to Guyader et al (2013), there is no effective MFAD management system nor are there any specific formal rights known associated with territorial usage in this fishery.…”

“…The current degree of nomadism is high but lower than in the pre-MFADs period where fishers sought out dolphinfish in 'free' schools. However, the degree of nomadism is higher compared to the Martinique (closed French overseas island) MFADs fishery where fishers visit one or two MFADs per day with high and predictable tuna aggregations (Guyader et al 2017).…”

“…In many parts of the world, including the Caribbean, Moored Fish Aggregating Devices (MFADs) are being used by small-scale fishers to access migratory species (e.g. tunas, dolphinfish) to improve pelagic yields (Rey-Valette et al 2000;Taquet et al 2011;Alvard et al 2015;Guyader et al 2017). MFADs are human made structures that are tethered to the ocean floor, with a buoy that floats on or near the surface that attract fish (Dempster and Taquet 2004).…”

“…In the case of Guadeloupe (FAO area 31), individual MFADs were installed in the latter of the 1980s without any accurate knowledge of their number or location (Diaz, 2007;Guyader et al, 2017). This open access to space and fishery expanded in the 1990s resulting in an increasing number of vessels, an extension of fishing areas from nearby coastal waters to more distant coastal areas and a growing number of conflicts between fishers because of MFADs congestion (Diaz et al 2005;Mathieu et al, 2013).…”

Tuna Fisheries Sustainable Management: Assessing of Indonesia Fish Aggregating Devices (FADs) Fisheries

“…Besweni [42] suggested alternative policy management of FADs through zoning, improvement of financing mechanisms and investment, setting the number of fishers and the number of the fleet. Expected impact from good management of FADs can improve food security [43].…”