USING AGGREGATING DEVICES TO SAMPLE FISH RECRUITS AROUND DEEP SHIPWRECKS: EXPERIMENTS AND SUGGESTIONS

José Renato Mendes De Barros Correia,Tiago Hilário Pedrosa Campello,Carlos Augusto França Schettini,Erandy Gomes Da Silva,J C P Dos Santos ,Maria Elisabeth De Araújo

doi:10.32360/acmar.v53i1.42376

Abstract

Fish aggregating devices (FAD) are an ancient fishery technique that benefits from the gregarious behavior of many species. They represent alternatives to usual census approach to study fish recruits. Based on this, we test two FAD models built for fish recruitment research, Standard monitoring unit for the recruitment of reef fishes (SMURF) and Artificial Reef Mooring (ARM) moored for the first time close to deep shipwrecks inBrazil Northeastern coast. We compared fish recruits’ abundance sampled by both models at two depths, bottom and mid-water (6 meters from the bottom). SMURFs sampled seven times more fish recruits than ARM with no difference between depth. We discovered that SMURFs mooring tilted 24º in mean with local marine currents. A long-term study with SMURFs tested immersion time influence in recruit’s sampling, and explored recruit’s abundance and standard length at two depth from the bottom. Increasing immersion timefrom 14-28 days did not influence recruit’s abundance. Bottom and Mid-water SMURFs sampled equal recruit’s number and fish sizes were significantly larger at the bottom. FADs, specially SMURFs, showed good tool to sample fish recruits in deeper shipwrecks,however standardization of FAD deployment is indicated to maximize work time and security in unstable sea conditions.

Highlights

A historical review of these devices found that the earliest known use of Fish aggregating devices (FAD) dates back to 200 AD in the Mediterranean, and that it has been used for hundreds of years by traditional fishermen in Japan, Indonesia, Malaysia and the Philippines (Dempster & Taquet, 2004) This fishery is known for names such as “kannizzati”, “capcer” and “’cannizzi” in Mediterranean (Galea, 1961; Morales-Nin et al, 2000), and the FADs known as “tsuke” in Japan (Francois, 1991), “rumpon” in Indonesia and “unjang” in Malaysia (Bergstrom, 1983) and “payao” in Philippines (Murdy, 1980)
Compilation of fish recruitment researches using FAD Comparing the 31 studies that collected fish recruits with FAD’s methods (Table I), approximately 71% used SMURF, 19% Benthic collector, 10% Artificial Reef Mooring (ARM), and 39% did not give the information about the FADs used
Concerning the dive method used in the FAD collections, only 10 of them reported it, and 60% of these studies using Scuba

Summary

Introduction

A historical review of these devices found that the earliest known use of FADs dates back to 200 AD in the Mediterranean, and that it has been used for hundreds of years by traditional fishermen in Japan, Indonesia, Malaysia and the Philippines (Dempster & Taquet, 2004) This fishery is known for names such as “kannizzati”, “capcer” and “’cannizzi” in Mediterranean (Galea, 1961; Morales-Nin et al, 2000), and the FADs known as “tsuke” in Japan (Francois, 1991), “rumpon” in Indonesia and “unjang” in Malaysia (Bergstrom, 1983) and “payao” in Philippines (Murdy, 1980) Their constructions were (and still are) basically made by vegetal material such as trunks and trees, bamboo, palm leaves, cork, grass (Gooding & Magnuson, 1967; National Research Council, 1988; Dempster & Taquet, 2004). Your system allowed select individuals’ sizes, as well as facilitate your collection

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