The scientific campaign, undertaken with two vessels, has enabled an evaluation of the entire Gulf of Biscay to be carried out and the presence of juvenile anchovies there to be determined – even in shallow waters less than 50 metres deep where the greatest part of the anchovy population is to be found. The results of the evaluation campaign using sonar indicates an estimated abundance of juvenile anchovies between 30 and 50 % inferior to that estimated in 2005.
The JUVENA campaign was started with the aim of evaluating the abundance of juvenile anchovies in the Gulf of Biscay at the beginning of Autumn of each year and of establishing a relation between this index of abundance of juveniles and the abundance of one-year-old adults the following Spring.
To date, there are only three points of reference for the relation between a) the abundance of juvenile anchovies in the Autumn and b) recruitment of one-year-old adults in the following Spring: Autumn 2003-Spring 2004; Autumn 2004-Spring 2005, Autumn 2005-Spring 2006. Following on from this recent campaign – carried out this Autumn – and, once the Method of Daily Production of Eggs campaign was undertaken in the Spring of 2007 (BIOMAN 2007), an additional data reference will be available (Autumn 2006- Spring 2007).
The validity of the series relating the abundance of recruitment with the adult stock depends mainly on the range of the series and also, to a great extent, on the scope of the observations in the period studied. In this case, the series, apart from still being very short (given the fact that we only have three pairs of values), is restricted to medium-low values for the potential range of observations. Consequently, for the moment, the series only serves as a guideline.
A short history of the events over the last two years in relation to anchovy fishing is as follows:
- Failure of French fishing season in the first term of 2005.
- Zero hauls of the Cantabrican inshore seiner vessel fleet in the Spring of 2005.
- Non activity of the inshore seiner vessel fleet since 12 May and request for cessation of commercial fishing activity.
- The undertaking by AZTI-Tecnalia of the scientific campaign in May 2005, obtaining an estimate of biomass indicating the fact that the population might be, with all probability, below the biomass limit.
- Pooling of scientific data in July 2005, to review the biomass level of the population, confirming that it is below safe levels.
- Closure of the fishing ground in July 2005.
- The undertaking by AZTI-Tecnalia of a new scientific campaign in Autumn 2005, showing a slight recovery of the juvenile biomass, but at levels insufficient to recover stock and, thereby, indicating values of high biological risk.
- Recommendation from CIEM to continue with closure of grounds for 2006, recommendation accepted by the European Commission’s Scientific, Technical and Economic Committee for Fisheries (STECF).
- Proposal by the Commission to the European Union’s Council of Ministers for Fisheries for the closure of the fishing grounds in 2006 until recovery of stock in the Spring 2006 campaigns ascertained.
- Decision by the Council of Ministers in December 2005: Total Allowable Catch (TAC) set at 5,000 tons, regulating opening and closure of grounds – if biomass in Spring is less than 28,000 tons it closes; if greater, there is a proportional increase in activity.
- Coastal fishing for 2006 very deficient (some 1,800 t) – the allocated quota not being reached.
- The undertaking by AZTI-Tecnalia of a new scientific campaign in May 2006, obtaining an estimate of biomass indicating the fact that the population might be below the biomass limit, reconfirming the risk situation for the fishing ground.
- Pooling of scientific data in in June 2006, to review the biomass level of the population, confirming that it is below safe levels.
- Closure of the fishing ground in July 2006.
- The undertaking by AZTI-Tecnalia of a new scientific campaign in Autumn 2006 finding that the level of abundance of the new generation to be insufficient to ensure the recovery of the biomass.
Knowledge of the biology of this recourse reveals that its short life (maximum 3 years) its high death rate – due both to natural causes and fishing - and the dependence of the adult biomass level on the abundance of new generations make the anchovy a highly vulnerable species and one which shows high fluctuations from one year to another, giving rise to deep crises in the sector. Suitable management of anchovy fishing based on scientific criteria is what all government administrations – and the sector itself - have to be involved in order to guarantee the recovery of the anchovy stocks.
As a consequence, and based on this data:
1. The level of biomass estimated in this campaign undertaken by AZTI-Tecnalia indicates once again the need to protect stocks until the recovery of the resource has been verified as being above the precaution levels to assure a healthy reproductive stock capable of producing abundant generations.
2. Although the data from the JUVENA campaign are only valid as a guideline, they nevertheless confirm the current scientific advice for stock management – provided by CIEM and ratified by the European Commission STECF, recommending the closure of fishing grounds until sufficient recruitment enables the recovery of the biomass of reproductive stock.
3. The need to maintain the closure of the anchovy fishing grounds until new scientific reports – drawn up after the coming evaluation campaigns are undertaken inn the Spring of 2007 - indicate otherwise.
Egoitz Etxebeste | alfa
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
The disappearance of common species
01.02.2018 | Technical University of Munich (TUM)
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy