17 research outputs found
Brief update on the satellite tagging of Atlantic swordfish
This paper provides a brief update of the study on habitat use for swordfish, developed within the
working plan of the Swordfish Species Group of ICCAT. A total of 9 miniPAT tags have been
deployed by observers on Portuguese and Spanish vessels and the Uruguayan research cruise in
the North and South Atlantic. Data from eight tags/specimens are available, four specimens
suffered from post-release mortality and one individual tag pop-up date has not occurred yet.
These preliminary results showed swordfish moved in several directions, travelling considerable
distances. Swordfish spent most of the daytime in deeper waters, being closer to the surface
during night-time. The main plan for the next phase of the project is to continue the tag
deployment during 2020 in several regions of the Atlantic Ocean and Mediterranean Sea
BRIEF UPDATE ON THE SATELLITE TAGGING OF ATLANTIC SWORDFISH
This paper provides a brief update of the study on habitat use for swordfish, developed within the
working plan of the Swordfish Species Group of ICCAT. A total of 9 miniPAT tags have been
deployed by observers on Portuguese and Spanish vessels and the Uruguayan research cruise in
the North and South Atlantic. Data from eight tags/specimens are available, four specimens
suffered from post-release mortality and one individual tag pop-up date has not occurred yet.
These preliminary results showed swordfish moved in several directions, travelling considerable
distances. Swordfish spent most of the daytime in deeper waters, being closer to the surface
during night-time. The main plan for the next phase of the project is to continue the tag
deployment during 2020 in several regions of the Atlantic Ocean and Mediterranean SeaEn prens
Distributional and reproductive aspects of the bigeye thresher shark (Alopias superciliosus) in the Atlantic ocean
Captura asociada a la pesquería de palangre de superficie dirigida a pez espadaThe bigeye thresher shark, Alopias supercilious is sometimes caught as bycatch in
pelagic longline fisheries targeting tunas and swordfish in the Atlantic Ocean. As part
of an ongoing cooperative program for fisheries and biological data collection, fishery
observer data from various fishing nations and projects were compiled and analyzed.
Those data sets include information on geographic location of the observations, as well
as size, sex and in some cases maturity stage. A total of 4371 bigeye threshers were
recorded throughout the Atlantic Ocean between 1992 and 2013, with the sizes ranging
from 70 to 305 cm FL (fork length). Considerable variability was observed in the catchat-
size, with particular emphasis on the tropical region where the mean sizes tended to
be smaller than in the other regions. The expected distribution of juvenile and adult
specimens also showed considerable variability, and the sex-ratios varied between
regions and size classes. Maturity ogives were fitted to data from 642 specimens, with
the median sizes at maturity estimated at 208.6 cm FL (corresponding to 349.1 cm TL)
for females and 159.2 cm FL (corresponding to 269.8 cm TL) for males. In addition, a
segmented regression model (SRM) was used for males, and two breakpoints (Bk1:
122.5cm FL, Bk2: 173.3cm FL) estimated, identifying transitions between the three
different maturity stages for male sharks (immature, maturing and mature). Only a few
pregnant females were recorded, always with the presence of two embryos (one per
uterus), and were distributed predominantly in the tropical northeast Atlantic closer the
African continent, and in the southwest region, with those regions possibly serving as
nursery areas for this species. These reproductive parameters, and especially the
estimated median sizes at maturity and low fecundity, highlight the vulnerability of this
species, reinforcing that the bigeye thresher tends to mature at a larger size than the
other species of the Alopiidae family. The biological and distributional patterns
presented can help managers adopt more informed and efficient conservation measures
for this species.En prensa0,000
Stomach contents of the pelagic stingray (Pteroplatytrygon violacea) (elasmobranchii: dasyatidae) from the tropical atlantic
Plan de acción nacional para la conservación de condrictios en las pesquerías uruguayas. (PAN - Condrictios Uruguay)
Durante las últimas décadas se ha observado un incremento de la captura (descartada y retenida) de condrictios en las pesquerías artesanales e industriales, conjuntamente con un rápido crecimiento de las pesquerías no reguladas, lo cual ha ocasionado una disminución en muchas poblaciones de este grupo de peces en todos los mares del mundo. La sobrepesca y los elevados niveles de mortalidad ocasionados por la captura incidental, asi como la degradación y contaminación de áreas costeras donde se ubican las zonas de alimentación, reproducción y cría para muchas especies de condrictios, han colocado a este grupo de peces en una situación difícil. Estos hechos, combinados con el bajo potencial reproductivo y la estrategia de vida de la mayoría de las especies de condríctios, no permiten una recuperación de las poblaciones, cuando las mismas se ven enfrentadas a períodos de sobreexplotación.
En las aguas de Uruguay ocurren aproximadamente 100 especies de condrictios, muchas de las cuales son capturadas por diferentes pesquerias, tanto de forma incidental como dirigida.
Debido a la preocupación a nivel internacional sobre la sustentabilidad de las pesquerías de tiburones, la FAO en 1998 realizó una consulta internacional a expertos y desarrolló un “Plan de Acción Internacional para la Conservación y el Manejo de los Tiburones” (PAI - Tiburones), el cual fue adoptado en 1999.
El objetivo del PAI - Tiburones es asegurar la conservación, el manejo y el uso sustentable a largo plazo de los tiburones. Al hacer referencia a “tiburones”, se incluyen a todos los condrictios (tiburones, batoideos y quimeras).
Este documento se divide en dos Capítulos y cuatro Anexos. El primer capítulo incluye los objetivos del PAN - Condrictios Uruguay y las medidas propuestas para alcanzar los mismos. El segundo capítulo contiene un diagnóstico general de los condrictios, las pesquerías y el marco jurídico. Como anexos se incluyen una lista de especies de condrictios citadas para Uruguay junto a su status en las listas rojas de la UICN, una reseña biológica de las especies consideradas prioritaras, una lista de abreviaturas, y listas de instituciones y personas que participaron de las reuniones desarrolladas durante el proceso de elaboración del PAN – Condrictios Uruguay.
Las medidas propuestas por el PAN - Condrictios Uruguay se deberán aplicar a todas las pesquerías efectuadas por buques de bandera uruguaya, incluso los que operan fuera de la zona económica exclusiva de Uruguay.Publishedchondrichthyan, legal nor
New insights into the reproductive biology of the blue shark (Prionace glauca) in the South Atlantic Ocean
Mitigating bycatch of threatened seabirds: the effectiveness of branch line weighting in pelagic longline fisheries
Brief update on the satellite tagging of Atlantic swordfish
This paper provides a brief update of the study on habitat use for swordfish, developed within the
working plan of the Swordfish Species Group of ICCAT. A total of 9 miniPAT tags have been
deployed by observers on Portuguese and Spanish vessels and the Uruguayan research cruise in
the North and South Atlantic. Data from eight tags/specimens are available, four specimens
suffered from post-release mortality and one individual tag pop-up date has not occurred yet.
These preliminary results showed swordfish moved in several directions, travelling considerable
distances. Swordfish spent most of the daytime in deeper waters, being closer to the surface
during night-time. The main plan for the next phase of the project is to continue the tag
deployment during 2020 in several regions of the Atlantic Ocean and Mediterranean SeaS
