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Experimental surveys for the assessment of juveniles.

Objective

One of the most basic steps in the advice for fishery management is the assessment of the strength of the year classes before they entry the fishery. It seems that the strength of the recruitment of many pelagic species is already established 5 or 6 months after the spawning (Smith 1985). In that sense, if an assessment of those early juveniles could be done at that phase, it could be used to predict, at least in relative terms, the strength of the future recruitment to the fisheries. However the assessment of early juveniles iy is not an easy task due to the fact that many of the juveniles display an epipelagic distribution, remaining in the upper layers of the water and they are commonly found in shallow waters close to coast

The major goal of JUVESU project is to evaluate the possibilities and problems for scientific direct surveying of the spatial distribution and relative abundance of early juveniles (of about 6 months old) of several pelagic species by means of Airborne systems for fish detecting in comparison with the usual shipborne acoustic systems. The radiometric LIDAR (Light I2etecting and Ranging) will be used from an airplane for the detection of juveniles occupying the upper layers of waters, while a concurrent acoustic (Sonar and Echosounding) and fishing survey will expand the surveying to deeper waters and will serve to check for the performance of the LIDAR system regarding the spatial (horizontal and vertical) distribution of juveniles, and providing, at the same time, the identification of the species composition. The experimental surveys will be carried out for two consecutive years at the south of Europe, in the Bay of Biscay and Atlantic coasts of the Iberian Peninsula, where significant recruitment of sardine, anchovy, mackerel and horse mackerel are known to occur.

A second goal of the project will be the study of the role of marine environment and its variation in the spatial distribution of the early juveniles of the different species. To that purpose some simple oceanographic parameters (water temperature, salinity and colour, and pigment concentration) in the upper water layers will be measured at different scales from shipborne instruments (CTD and Fluorometer) to airborne and satellite remote sensors (Daedalus, AVHRR, SeaWiFS), in order to detect shelf processes (up welling) and ocean structures (stratification and fronts) which may determine the spatial distribution of juveniles SeaWiFS), in order to detect shelf processes (upwelling) and ocean structures (stratification and fronts) which may determine the spatial distribution of juveniles.

The simultaneous use of acoustics and Radiometric LIDAR in the South of Europe will serve to check and compare the weakness and robustness of these two technologies to survey the schools of early juveniles of pelagic species. This together with the acquired knowledge on the relationship between distribution and environment will serve to define improved and efficient methods for the assessment of these early juveniles (and thus of recruitment), which may benefit the management of pelagic fisheries.

The goals of the project are completed with a training on the application and processing of the LIDAR system for the scientific surveying of close to surface fish resources, which will be managed by menas of a course on the Lidar techniques and a training stay in USA.

The project is basically structured in two years of field surveys (1998 and 1999) and a third year for final analysis and synthesis with the edition of final report. The surveys will take place for about 12 days of continuous work in August/September 1998 and 1999, with the participation of all the teams involved in the project. The 2 target areas are the Iberian Atlantic coasts from Cape Ortegal to Cape Espichel (from 44°N. to 38°24 N) and the south east part of the Bay of Biscay (mainly South of 46°N. and East of 3 ° W up to coast). The coverage will be made continuously during day and night in order to check for the differences in the availability of the juveniles to the different detector devices, in relation to the variation of vertical distribution of the schools.

The field work is clearly structured according to the disciplines and natural areas or work of participants. Nevertheless a strong standardization by discipline of work for the data acquisition, storage and processing is foreseen in order to come up with parallel and compatible outputs. This will allow the inclusion of all data in a common geographic information system, which would facilitate all subsequent discussions and synthesis work.

The Scientific teams involved in the project, with their major commitments, are: AZTI, Instituto Tecnologico Pesquero y Alimentario (Basque Country, Spain) is the Coordinator of the project. Its major role, apart from the coordination, is the standardization of the exchange data files and the implementation of the Geographic information system GIS. Concerning the direct surveys on juveniles, AZTI will carry out the shipborne hydrographic and fishing surveys in the Bay of Biscay. In addition, AZTI will receive by means of its satellite antenna station the raw data of the images coming from AVHRR and SeaWiFS satellites concerning both the Bay of Biscay and the Atlantic coasts of the Iberian peninsula, which will be processed by it self and by IPIMAR. Finally AZTI will coordinate the synthesis on the environment and the Ecology of juveniles. A person of this team will make an stay in USA to acquire the knowledge of the Lidar technologies

IFREMER Institute Francaise pour la Recherche et l'Exploration de la Mer (France) This team will be mainly in charge of the acoustic surveys in the Bay of Biscay (Echointegration and sonar surveying). In addition it will cooperate with the IEO in the comparison and analysis of the relative performance of the different fish sensors in surveying the juveniles distribution and abundance indexes. It will also help in the discussion on the Ecology of juveniles in their environment and in relation to other species.

INTA, the Instituto Nacional de Tecnica Aerospacial (Spain), will be in charge of the Airborne surveys carried out in all areas. They will make the Daedalus survey over the agreed tracks in the Bay of Biscay and Iberian Atlantic Coasts to characterize the upper layers of seawater in terms of Temperature, turbidity and pigment concentrations. They will install on board the same plane the Daedalus and the Lidar equipment of Subcontractor 1 in order to apply at the sarne time both technologies together. They will help in the standardization of data storage and processing for the airborne surveys. A person of this team will make a stay in USA to acquire the knowledge of the Lidar technologies.

IEO, Instituto Espafiol de Ocenograffa (Spain). It will take care of all research activities concerning the North-western Iberian Atlantic waters. It will carry out all shipborne direct surveying in this area, comprising the Acoustic, fishing and hydrographic surveys. A second major role of this institute is related to the comparison and analysis of the relative performance of the different fish sensors in surveying the juvenile distribution and relative abundance. With the rest of the teams it will help in the synthesis on the ecology of juveniles concerning the environment and in relation with other species.

IPIMAR, Instituto de Investigacao das Pescas e do blar (Portugal)
IPIMAR will take care of all research activities concerning the central Iberian Atlantic waters. It will carry out all shipborne direct surveying, comprising the Acoustic and hydrographic surveys in those waters. In addition, they will help AZTI in the processing of the images from AVHRR and SeaWIFS satellites for the Atlantic coasts. A second major role of this institute is related to the production of a Synthesis of the Oceanographic conditions and events occurring during the cruise surveys in August September of each year (Subtask 3.3). Finally it will collaborate with the rest of the teams in the synthesis on the ecology of juveniles concerning the environment and in relation with other species.

The implementation of the Lidar surveys will be organized by AZTI, IEO and IPIMAR by means of a subcontract with an expertise team: the Environmental Research Laboratories (Boulder, Colorado) of the National Oceanic and Atmospheric Administration (NOAA) of the United States Department of Commerce of USA. The reason for this is that this is the first time this type of surveys are applied in Europe to epipelagic fish resources. The project will finish by October 2000.

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Call for proposal

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Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Fundacion AZTI - AZTI Fundazioa
EU contribution
No data
Address
Avda de Satrustegui 8
20008 Donostia (Gipuzkoa)
Spain

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Total cost
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Participants (4)

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Last update: 10 March 2023

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Permalink: https://cordis.europa.eu/project/id/FAIR973374

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