Experimental research and fish aggregating devices (FADs) in French Polynesia (original) (raw)
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Recent resolutions of the Indian Ocean Tuna Commission (IOTC) have been implemented to improve scientific knowledge on the effects of drifting fish aggregating devices (DFADs) through increased data collection and reporting. Here, we report information on DFADs collected from three distinct data sources to describe the use of DFADs and buoys by the French PS fleet of the Indian Ocean over the last decade. First, archives of buoy purchase orders during 2002-2014 were provided by fishing companies to give insight into the historical use of DFADs. Data show an homogeneity of the numbers of buoys available to each purse seiner and a steady increase of about 10 buoys per year per vessel, from 50-60 in the early 2000s to 200 in 2013. Second, information derived from satellite transmission data was made available for the period 2010-2013 based on quarterly reports that are produced by buoy supplier companies on a vessel basis. Data show an overall relative stability of the number of French...
Report on Fish Aggregating Devices (FADs) deployed at Andaman & Nicobar Islands
Executive Summary The National Institute of Ocean Technology and the Department of Fisheries, Andaman & Nicobar (A&N) Administration signed an M.O.U for the deployment of 10 Nos of Fish Aggregating Devices (FADs) in Andaman & Nicobar Islands marine waters. NIOT agreed to deploy FADs at following places; Off Diglipur, Mayabunder, Rangat, Chidiyatappu, Neil Island, Hut Bay, S. Sentinel, Car Nicobar, Nancowry and Campbell Bay as requested by the Department of Fisheries, A & N Administration. NIOT team along with the Officials of the Department of Fisheries visited several Islands and discussed with fishermen community before the FADs deployment. The final FAD locations were selected at the meeting by incorporating the opinion of the local fishermen and concerned fisheries officials. NIOT designed and fabricated 10 FADs and tested them for buoyancy and stability at Acoustic Testing Facility lab of NIOT, Chennai and also in the open sea before deployment. The buoyancy of FADs was fixed w...
Aquatic Living Resources, 2007
We adapted a visual census method, mainly used in demersal and reef fish studies, to characterize fish communities associated to drifting fish aggregating devices (FADs) in the Western Indian Ocean. Drifting FAD associated fishes from both equatorial (Seychelles) and tropical waters (Reunion Island) were examined by divers. A total of 32 species (belonging to 16 families) were observed associated with drifting FADs in equatorial waters, and 24 species (14 families) were found around FADs in tropical waters. Twenty species were found in both regions. The highest number of species observed at a single FAD was 18 (12 ± 2, mean ± SD) in equatorial and 13 (10 ± 3) in tropical waters, not counting circumnatant species loosely associated with the FAD. Some species like Kyphosus vaigiensis, Canthidermis maculata, Elagatis bipinnulata, Acanthocybium solandri and Coryphaena hippurus were observed on all or most of the surveys. In this study, the contribution in biomass of the 18 common species associated with drifting FADs (but excluding circumnatant species), represents more than 98% of the biomass. The overall biomass values of closely associated species remains well below tuna biomass estimates for circumnatant tuna schools at FADs, estimated as high as 200 tons. The species that most significantly contribute to the by-catch in tuna purse-seines logically match those that showing the highest biomass values in our surveys (Carcharhinus spp., Elagatis bipinnulata, Coryphaena hippurus, Canthidermis maculata, and Acanthocybium solandri). One of the most abundant and ubiquitous species in our study was the spotted oceanic triggerfish Canthidermis maculata that sometimes formed massive schools of many thousands individuals around the drifting FADs. Future research is needed to explore the role of such non tuna species in the attraction and aggregation processes of tuna around drifting FADs.
TWO EXPERIMENTAL FISH AGGREGATING SYSTEMS (FADs) IN THE AEGEAN SEA: THEIR DESIGN AND APPLICATION
Two steel spar buoys were constructed and moored in 50 and 100 m deep of water in the Aegean Sea to support recreational fisheries. The first FAD was deployed at coordinates 38°01´48´´N 26°58´02´´E and at a distance of 3 nautical miles from the shoreline. The other FAD was moored at 1.1 nautical miles from the shoreline at coordinates 38°03´11´´N; 26°59´01´´E. An anchor (1.2x1.2x0.8 m3) weighing approximate 2.76 metric ton, made of reinforced concrete, was used to hold a FAD weighing approximate 1.5 metric ton. Hardware and connections of FADs, ropes, mooring calculation and anchor design were made. The interaction between the forces of wave and current and FADs in those waters was investigated. In the experiment, all forces (drag force, buoyancy force etc.) acting on FADs were calculated. It is proposed that the construction of the FADs should take the following design criteria into consideration: wave and current, forces related to the FADs, deployment depth, mooring hardware and ropes. This knowledge provides an important reference for stakeholders performing projects aiming to increase the performance and service life FADs. R E S U M O Duas bóias de aço spar foram construídas e ancoradas em 50 e 100 m de profundidade nas águas do Mar Egeu para dar apoio à pesca recreativa. O primeiro FAD foi implantado nas coordenadas 38°01'48''N 26°58'02''E, a uma distância de 3 milhas náuticas da costa. O outro ficou ancorado a 1,1 milha náutica da costa nas coordenadas 38°03'11''N; 26°59'01''E. Uma âncora (1.2x1.2x0.8 m3), pesando aproximadamente 2,76 toneladas, feita de concreto armado, foi usada para prender um FAD de peso aproximado de 1,5 toneladas. Foram realizados cálculos para determinação das conexões dos FADs, dos cabos e da ancoragem. A interação entre as forças de ondas e correntes com os FADs foi também investigada. No experimento, todas as forças (força de arrasto, força de empuxo, etc) atuantes sobre os FADs foram calculadas. É proposto que para a construção dos FADs deverão ser levados em consideração os seguintes fatores: ondas e correntes, forças relacionadas com os FADs, profundidade de implantação, sistema computacional dos moorings e cordas de amarração. Esse conhecimento proporcionará referência importante para os interessados em realizar projetos que visem aumentar o desempenho e a vida útil dos FADs. Descriptors: Fish aggregating system, FADs, Wave current and effects, Aegean Sea. Descritores: Sistema de concentração de peixes, FADs, Efeito das correntes e ondas, Mar Egeu.
The National Institute of Ocean Technology and the Department of Fisheries, Lakshadweep Administration signed an M.O.U for the deployment of 10 Nos of Fish Aggregating Devices (FADs) in Lakshadweep Islands marine waters. NIOT agreed to deploy FADs at following places; Kavarati, Aggati, Minicoy, Kalpeni, Bitra, Chetlet, Kilton, Kadamat, Amini, and Androth Islands as requested by the Department of Fisheries, Lakshadweep. NIOT team along with the Officials of the Department of Fisheries visited several Islands and discussed with fishermen community before the FADs deployment. The final FAD locations were selected at the meeting by incorporating the opinion of the local fishermen and concerned fisheries officials. NIOT designed and fabricated 10 FADs and tested them for buoyancy and stability at Acoustic Testing Facility lab of NIOT, Chennai and also in the open sea before deployment. The buoyancy of FADs was fixed with 2 m draft and 1.6 m free board. NIOT carried out bathymetry survey ...
Marine Biology, 2017
in the NW Seychelles associated with DFADs to a greater degree during daytime. In the Mozambique Channel, large tuna showed daytime associative behaviour, while small tuna showed a maximum biomass at sunrise, decreasing over the day. The associative behaviour of non-tuna species was slightly variable, being uniform near the equator or showing two peaks when increasing latitude. This study shows the importance and effect of biological factors on the associative behaviour of the fish and serves as a first step towards improving pre-set selectivity of purse seine fisheries using DFADs. The fish presence and density may improve DFAD attraction and detectability and the observed periodicity by species and area shows both similarities and differences with published literature.
Spanish Fish Aggregating Device Management Plan. Preliminary data in the Indian Ocean
2014
This document analyzes the Fish Aggregating Device National Management Plan undertaken by the Spanish General Secretariat of Maritime Fisheries (Ministry of the Environment, Marine and Rural Affairs), in collaboration with the Spanish Institute of Oceanography (Ministry of Economy and Competitiveness), and presents preliminary data obtained in 2013 on the number of FADs deployed by quarter, number of active FADs by quarter, FAD characteristics, types and materials used in its construction and activities on objects and geographical distribution of these activities.