Contents lists available at ScienceDirect Ocean and Coastal Management journal homepage: www.elsevier.com/locate/ocecoaman The use of echo-sounder buoys in Mediterranean Sea: A new technological approach for a sustainable FADs fishery Tiziana Cillari a,* , Alessandro Allegra b , Franco Andaloro a,c , Michele Gristina b , Giacomo Milisenda b , Mauro Sinopoli a a ISPRA - Institute for Environmental Protection and Research, S.T.S. Palermo, Lungomare Cristoforo Colombo n. 4521 (Ex Complesso Roosevelt) Località Addaura, 90149 Palermo, Italy b IAMC - Institute for Coastal Marine Environment, CNR - National Research Council, Via Luigi Vaccara 61, 91026 Mazara del Vallo, TP, Italy c Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy ARTICLE INFO Keywords: Fishing technology Anchored FADs Drifting FADs Biomass estimates GAM ABSTRACT In the Mediterranean Sea, dolphinfish fishery has employed a great number of anchored Fish Aggregating Devices (FADs) arranged in lines, that represents a threat to navigation and to the marine environment and is economically disadvantageous to fishers. In this research, echo-sounder buoys were tested for the first time in the Mediterranean, and it was evaluated if this technological method can be useful to studies aimed to reduce the impact of FADs from the perspective of sustainable fishery. The study was carried out in November and December 2015 in a Tyrrhenian area where echo-sounder buoys were tied to anchored and drifting FADs and aggregated biomass estimates were recorded daily. Comparisons were made to evaluate whether there are: a relation between the number of anchored FADs and associated biomass; and differences, in terms of aggregated biomass, between anchored and drifting FADs. No clear correlation was found between the number of anchored FADs and biomass, while the drifting FADs showed a greater power of attraction than the anchored FADs. Anyway, the echo-sounder buoys may be suitable for future studies. It was highlighted that their simple use in the Mediterranean FADs fishery could facilitate a reduction of the high number of anchored FADs. 1. Introduction The distribution of some marine fish species is influenced by floating objects (Hilborn and Medley, 1989). High fish-densities have been observed to aggregate around drifting algae (Dooley, 1972; Kingsford and Choat, 1985), driftwood (Hunter and Mitchell, 1967), jellyfish (Janssen and Harbison, 1981; Mansueti, 1963), carcasses of large animals (Kojima, 1966) and man-made objects such as rafts (Gooding and Magnuson, 1967). For this reason, flotsam and other fish aggregating devices (FADs) have been used by fishers throughout his- tory to improve pelagic fish yield (Kojima, 1966; Massutí and Vidal, 1997). There are two basic categories of FADs used in fishery mainly tar- geting tuna-like fish species: anchored (a-FADs) and drifting (d-FADs) (Dagorn et al., 2013). The first are used, in the western and central Pacific(Cabral et al., 2014 and literature therein), in the Indian (Beverly et al., 2012) and Atlantic oceans (Dempster and Taquet, 2004 and literature therein) mainly at small-scale. At industrial level, catches of tuna were increased by introducing the use of d-FADs since the '90s (Fonteneau et al., 2013 and literature therein). The main differences between the two types of FADs are in terms of fishing gear used and biomass caught (Beverly et al., 2012). Recently, an increasing amount of these devices has been equipped with echo-sounder buoys that pro- vide fishermen with rough estimates of aggregated biomass, together with accurate geolocation information improving fishery yields. (Moreno et al., 2016a; Lopez et al., 2014). These technological systems also allow a reduction in fuel and operational costs and an increase in yields (Lopez et al., 2014; Taquet et al., 2012). In the Mediterranean Sea, FADs fishery is an artisanal activity tar- geting mainly common dolphinfish (Coryphaena hippurus Linnaeus, 1758) also having different species as by-catch, among which greater amberjack (Seriola dumerili) and Bluefin tuna (Thunnus thynnus) (Andaloro et al., 2007; Sinopoli et al., 2012) with only the use of a- FADs. This activity is widespread in Greek waters, southern Italy, Tu- nisia, Malta and Spain where it has historical roots in the Balearic Is- lands (Massutí and Vidal, 1997; Morales-Nin et al., 2000). https://doi.org/10.1016/j.ocecoaman.2017.11.018 Received 13 September 2017; Received in revised form 21 November 2017; Accepted 24 November 2017 * Corresponding author. E-mail address: tiziana.cillari@isprambiente.it (T. Cillari). Abbreviations: a-FADs, anchored FADs; d-FADs, drifting FADs Ocean and Coastal Management 152 (2018) 70–76 0964-5691/ © 2017 Published by Elsevier Ltd. T