33 research outputs found
Directory of Atmospheric, Hydrographic and Biological datasets for the Canary Current Large Marine Ecosystem. 3rd Edition
Directory of Atmospheric, Hydrographic and Biological datasets for the Canary Current Large Marine Ecosystem
Environmental and biological data-sets were recovered from oceanographic surveys and other
observation sources (e.g. tide gauges) since the 40s. This rescue and mining exercise was
carried out in cooperation with the countries bordering the CCLME and other nations
undertaking research in the region (i.e. Morocco, Mauritania, Senegal, Gambia, Guinea, Guinea
Bissau, Cape Verde, Spain, Norway, Germany and France). A total of 425 data-sets, 27 databases
and 21 time-series sites have been identified in the area. A substantial part of them were
rescued from archives supported in paper copy. Finally, a directory of meta-data referring 99
data-sets and data-bases has been published. This catalogue and the recovered data offer an
exceptional opportunity for the researchers in the CCLME to study the dynamics and trends of a
multiplicity of variables, and will enable them to create their own time-series, baselines and
climatologies under a spatial and temporal perspective. It will produce new and valuable
information on changes produced during the last 35 years in this region, going from climatic
changes to shifts in species diversity and populations due to natural and human induced
factors. This directory is the first result of the project “Enhancing oceanography capacities on
Western Africa Countries” funded by the Spanish Agency for International Development
Cooperation (AECID) and coordinated by the IOC-UNESCO and the IEO. The project aims to
reinforce transboundary cooperation in the CCLME and to facilitate access and data flow to
existing scientific information and its utilization by the scientists, politicians, industry and civil
society.http://unesdoc.unesco.org/images/0023/002314/231430E.pd
LACK OF GENETIC DIFFERENTIATION IN THE ALTANTIC DISTRIBUTION OF WAHOO
SUMMARY
In this study we present the analysis of the stock structure of Wahoo (Acanthocybium solandri) using the mitochondrial control region as genetic marker. We analyzed 276 individuals distributed in four locations int eh east and west Atlantic. Samples were from: Northeast Atlantic (AT-NE/BIL94B) (Canary Islands, Spain), from Southeast Atlantic (AT-SE/BIL97) (Côte d’Ivoire and Gabon) and Southwest Atlantic (AT-SW/BIL96). Four of individuals from Southwest Atlantic (AT-SW/BIL96) were genetically identified as Scomberomorus cavalla. The genetic comparison of the four locations failed to show genetic differences. This result suggests a single genetic pool of the Wahoo in the whole Atlantic. Based on these results, ICCAT should reconsider their management strategies for this species in the area studied.
RÉSUMÉ Dans cette étude, nous présentons l’analyse de la structure du stock de thazard-bâtard (Acanthocybium solandri) en utilisant la région de contrôle de l’ADN mitochondrial comme marqueur génétique. Nous avons analysé 276 spécimens répartis dans quatre zones de l’Atlantique Est et Ouest. Les échantillons provenaient de : l’Atlantique Nord-Est (AT-NE/BIL94B) (îles Canaries, Espagne), l’Atlantique Sud-Est (AT-SE/BIL97) (Côte d’Ivoire et Gabon) et l’Atlantique Sud-Ouest (AT-SW/BIL96). Quatre spécimens provenant de l’Atlantique Sud-Ouest (AT-SW/BIL96) ont été génétiquement identifiés comme Scomberomorus cavalla. La comparaison génétique des quatre zones n’a pas révélé de différences génétiques. Ce résultat donne à penser à un patrimoine génétique du thazard-bâtard dans l’ensemble de l’Atlantique. En se fondant sur ces résultats, l’ICCAT devrait revoir ses stratégies de gestion pour cette espèce dans la zone à l’étude.
RESUMEN
En este estudio presentamos el análisis de la estructura del stock del peto (Acanthocybium solandri) utilizando la región de control mitocondrial como marcador genético. Hemos analizado 276 ejemplares distribuidos en cuatro localizaciones en el Atlántico este y oeste. Las muestras procedían de: Atlántico nororiental (AT-NE/BIL94B) (islas Canarias, España), del Atlántico suroriental (AT-SE/BIL97) (Côte d'Ivoire y Gabón) y del Atlántico sudoccidental (AT-SW/BIL96). Cuatro de los ejemplares del Atlántico sudoccidental (AT-SW/BIL96) fueron genéticamente identificados como Scomberomorus cavalla. La comparación genética de las cuatro localizaciones no mostraba diferencias genéticas. Este resultado sugiere un único acervo genético del peto en todo el Atlántico. Basándose en estos resultados, ICCAT debería reconsiderar la estrategia de ordenación para esta especie en la zona estudiada.Versión del edito
Bycatch of the European purse-seine tuna fishery in the Atlantic Ocean for the period 2010-2016
This paper presents an update for the period 2010-2016 of the bycatch estimations for the European tuna purse seine fishery operating in the Atlantic Ocean. Bycatch data were collected by observers onboard. Observer coverage increased progressively from 15 trips in 2010, to 114 and 107 trips in 2015 and 2016 respectively. Bycatch data, as collected by the observers, were stratified by quarter and fishing mode (free school and floating object sets). The ratio of total to observed catches of the target species (skipjack, bigeye and yellowfin tunas) in each stratum was then used as raising factor. The average of the annual total bycatch estimated for the studied period was 9,515 t. Tunas (neritic tunas and small size tunas) represent the major part of the bycatch, followed by fin fish, sharks, billfishes, rays and turtles.En prens
A NOVEL INDEX OF ABUNDANCE OF JUVENILE YELLOWFIN TUNA IN THE ATLANTIC OCEAN DERIVED FROM ECHOSOUNDER BUOYS
The collaboration with the Spanish vessel-owners associations and the buoy-providers
companies, has made it possible the recovery of the information recorded by the satellite linked
GPS tracking echosounder buoys used by the Spanish tropical tuna purse seiners and associated
fleet in the Atlantic since 2010. These instrumental buoys inform fishers remotely in real-time
about the accurate geolocation of the FAD and the presence and abundance of fish aggregations
underneath them. Apart from its unquestionable impact in the conception of a reliable CPUE
index from the tropical purse seine tuna fisheries fishing on FADs, echosounder buoys have also
the potential of being a privileged observation platform to evaluate abundances of tunas and
accompanying species using catch-independent data. Current echosounder buoys provide a
single acoustic value without discriminating species or size composition of the fish underneath
the FAD. Therefore, it has been necessary to combine the echosounder buoys data with fishery
data, species composition and average size, to obtain a specific indicator. This paper presents a
novel index of abundance of juvenile yellowfin tuna in the Atlantic Ocean derived from
echosounder buoys for the period 2010-2018
Final report of the short-term contract for ICCAT SMYTP for the biological samples collection for growth, maturity and genetics studies – Year #2
This document is the final report of the second year of the short-term contract of the Small Tuna
Year Program by ICCAT. In 2018, the Small Tuna Species Group decided to prioritize Little
tunny (LTA) (Euthynnus alletteratus) Atlantic bonito (BON) (Sarda sarda) and Wahoo (WAH)
(Acanthocybium solandri), based on their economic importance and the deficiency of knowledge
of their biology. The objectives of the contract for three species were: i) Collect biological
samples for estimating growth parameters, assessing the maturity and stock structure analysis
(populations genetics), and ii) Conclude the analysis of the stock structure for at least one of the
three species and provide preliminary results for the remaining. The obtained samples for
growth, maturity and stock structure analysis was almost completed for Little tunny and Atlantic
bonito, whereas for Wahoo the samples are scarce. The analysis of stock structure for Little tunny
and Atlantic bonito revealed that the observed dif
Best standards for data collection and reporting requirements on FOBs: towards a science-based FOB fishery management.
A major concern for tropical tunas, on these last years, has been the worldwide increasing use of drifting FOBs
by purse seiners, which are equipped with satellite buoys and echo-sounders. The use of these floating objects
has contributed to increase the catch of skipjack tuna, but also of juveniles of yellowfin and bigeye tunas.
Moreover, it has increased the amount of by-catch (including some species classified as vulnerable or
endangered) and has likely resulted in adverse effects on the ecology of fish and on vulnerable areas (e.g.
beaching events on coral reef areas). Despite the increasing FOB use and concerns, little information is
available on FOB use worldwide for an appropriate monitoring and management. Thus, FOB monitoring has
become a priority in all tuna t-RFMOs. However, the data collection and reporting requirements around FOBs
are not standardized and there are significant data gaps. The aim of this document is to review current
requirements and procedures in place and propose standards for data collection and submission on FOBs to tRFMOs. The proposals included in this document are the result of a collaborative work between scientists and
the fishing industry
Biodegradable DFADs: Current status and prospects
Until recently, dFAD structure, materials and designs have remained quite rudimentary and
virtually the same since their discovery, characterized by the increase of the dimensions and
prevailing heavy use of plastic components. Biodegradable materials are called to be an
important part of the solution, as they can faster degrade in the environment, free of toxins
and heavy metals, reducing their lifespan, and preventing them from accumulating in
sensitive areas once they are abandoned, lost or discarded. During last decades, regulatory
measures at tRFMOs have advanced in the gradual implementation of biodegradable
materials in dFAD constructions together with other measures limiting the number of active
dFADs and the use of netting materials. However, more clarity is needed starting with a
standardised definition of biodegradable dFADs among tRFMOs, to provide operational
guidance. Research with those natural and synthetic materials is required, along with
updated data collection for monitoring standards, as well as alternative and
complementary actions need to be explored to contribute to minimising dFAD adverse
effects on environment. Acknowledging the current difficulties for the implementation of
fully biodegradable dFADs a stepwise process towards the implementation of fully
biodegradable dFADs should be considered.Postprin
Report on the 2020 ICCAT workshop on small tunas biology studies for growth and reproduction
This report describes the 2020 ICCAT workshop on small tunas biology studies for growth and
reproduction, hosted by the Instituto Español de Oceanografía, Málaga, Spain. The major
objectives of the workshop were: 1) starting the creation of ageing and reproduction reference
sets and, 2) providing more training for the ongoing sample collection and processing to the
teams involved in these studies. As approved by the SCRS in 2017, the Small Tuna Species
Group intersessional meeting decided to prioritize the collection of biological samples aiming
at growth, maturity and stock structure studies on three species: little tunny (Euthynnus
alletteratus), Atlantic Bonito (Sarda sarda) and wahoo (Acanthocybium solandri), based on
their economic importance and the lack of knowledge on their biology. This work will
contribute to the next major advance in the assessment of these three species
Estudio de las pesquerías de atún tropical a través de los casos de las conservas y el faux poisson en África Oriental
Este proyecto tiene como objetivos principales mejorar la comprensión del sistema alimentario global asociado a los recursos marinos a través del ejemplo de la lata de atún y de la pesquería de cerco de túnidos tropicales en África Oriental y dar a conocer los retos a los que se enfrenta la industria alimentaria para reducir su coste medioambiental y desigualdades norte-sur