119 research outputs found
Program for Training Spanish Scientific Observers in the SIOFA Convention Area. IEO (Spanish Institute of Oceanography)
The purpose of this document is to explain the steps involved in the training of observers on board the Spanish fleet within SIOFA waters. This program includes a wide range of aspects related to scientific observation both target and bycatch species in the SIOFA convention area, quantification of invertebrates by main taxa, marine mammals (MMs) and seabirds interactions/accidental catches and MMs depredation. A manual is provided to the observers to help them plan their work
Information about tagged Patagonian toothfish (Dissostichus eleginoides) tagged in the CCAMLR Convention Area and recovered in the SIOFA management area by two Spanish vessels in 2017/18
Research plan for the Spanish exploratory longline fishery for Dissostichus spp. in Divisions 58.4.1 and 58.4.2: preliminary results of stage 1 (2012/13 season)
During the 2012/13 season Spain started the approved multi-year research survey in Divisions 58.4.1 and 58.4.2 in order to obtain information to better understand the population dynamics of both species of Dissostichus in areas off the Antarctic continent close to the Ross Sea and Banzare Bank, and to implement the use both local depletion and tag-recapture methods in areas described so as to estimate local abundance.
The research plan, as it was stated in the proposal, takes several years to be completed. It has started in the SSRUs closest to the Ross Sea, 58.4.1H and G, during the 2012/13 season. In order to fix the protocols and ascertain the viability and suitability of the study, it was establish the return to the same areas the two-three subsequent years along with the movement to new places and westwards to SSRUs 58.4.1D, C, B and 58.4.2E is expected.
The vessel Tronio has started the research plan after the exploratory fishing season in the Subarea 88.1, using the Spanish bottom longline system. A total of 42 research sets were performed within the SSRUs 58.4.1H and 58.4.1G. Two depletion experiments were completed and three prospecting-phase clusters of sets did not reach the established threshold to start the depletion.
A prospective estimation of the local biomass (BLOC) of the two localized areas where the depletion experiments were performed is done and regarding the maximal and minimal biomass for the SSRUs (BSSRU) considering areas with high and low densities.
This study will be reviewed and completed the upcoming years with the new data obtained revisiting the same areas as well as with the tag-recapture data in order to estimate the local abundance using two different approaches, depletion and tag-recapture methods.
A summary of the activities and results from the survey is also presented related to the sampling scheme, collected samples and species
Research plan for the exploratory fisheries for Dissostichus spp. in Divisions 58.4.1 and 58.4.2 in 2013/14
The Spanish vessel Tronio started the research plan in the 2012/13 season using the Spanish bottom longline system. One depletion experiments was completed in each of the SSRU surveyed (58.4.1H and 58.4.1G). Three prospecting-phase clusters of sets did not reach the established threshold to start the depletion.
A prospective estimation of the local biomass (BLOC) of the two localized areas where the depletion experiments were performed is done as well as an estimation of the biomass of the SSRUs (BSSRU), maximal and minimal, considering areas with high and low densities.
A summary of the activities and results from the survey is also presented related to the sampling scheme, collected samples and species involved
Results of the Spanish exploratory longline fishery for Dissostichus spp. in divisions 58.4.1 and 58.4.2 in the 2013/14 season.
Following the Spanish research plan approved by the SC-CCAMLR XXXII, during the second year of the multi-year research survey in Divisions 58.4.1 and 58.4.2, the F/V Tronio has returned to the same places surveyed in the 2012/13 season, as well as expanded the experience westwards to the 58.4.1D and 58.4.1C SSRUs.
A prospective estimation of the local biomass (BLOC) of one localized area that was visited for the commercial Spanish fleet along five seasons in the SSRU 58.4.1C is made, together with the estimation of the total Biomass in the entire SSRU using a depletion model.
There have been some Antarctic toothfish recaptured that would allow, in successive years, to estimate the local abundance by tag-recapture models.
The IEO is starting the process of reading otoliths with ageing purposes, data to be added in order to carry out a robust assessment of Dissotichus eleginoides stock in these divisions.
Results of other data collected such as fish bycatch, incidental catch of benthic taxa or otoliths collection for ageing purposes are also presented
Patagonian toothfish in the South Indian Ocean outside CCAMLR waters: a preliminary analysis of the SIOFA Patagonian toothfish population
Results of the Spanish exploratory longline fishery for Dissostichus spp.
We addressed the revisions requested by the WG-SAM-14 regarding the results of the second
year of Spanish research experience and ongoing research plan presented in WG-SAM- 14/12
and WG-SAM-14/09.
A summary of the results of the Spanish research that took place in the 58.4.1 division during
the last two fishing seasons is presented.
A prospective estimation of the local biomass (BLOC) of three SSRUs visited using the local
depletion method, together with the extrapolation to the total Biomass in the entire SSRUs, as
well as an estimation of the Biomass in SSRU 58.4.1H using the mark-recapture Petersen
model is made
Continuation in the 2015/16 season of the research plan initiated in 2012/13 for stocks of Dissostichus spp. in Divisions 58.4.1 and 58.4.2
In the 2012/13 fishing season Spain began implementing a multi-annual Research Plan for
Divisions 58.4.1 and 58.4.2 in order to estimate local biomass of Dissostichus spp. by means of
two methods: depletion and tagging. In 2014/15 the vessel was unable to conduct the proposed
research experience due to problems with a blade of the propeller, During the season 2015/16
is intended to make the same proposed research with some minor changes, always subject to
the ice conditions, fulfilling Spain's commitment to return to the same fishing areas in order to
study inter-annual variability and maximize tag recovery, as well as, to progress research in
these SSRUs (58.4.1H, G, D and C). Two research surveys have been already implemented in
Division 58.4.1 and preliminary estimates of local biomass using Leslie depletion analyses
have been obtained. Some recoveries of tagged toothfish have been made, both within-season
and between-seasons recaptures and a preliminary Age-Length Key of Dissostichus mawsoni
has been built after otholits reading from 58.4.1 division specimens. All these data will allow a
robust stock assessment attempt by the end of this multiyear research survey
Update of ongoing work on age and growth of Antarctic toothfish (Dissostichus mawsoni) (2013-14 season) from Division 58.4.1 by Spain
Preliminary Age-length key by reading otoliths of antarctic toothfish (Dissostichus mawsoni)We present preliminary results on age and growth of Dissostichus mawsoni for the
second season (2013/14) of the Spanish research fishing in the 58.4.1 Division
obtained for growth rings on otolith readings. It is included the age-length key and
growth parameters estimates by sex. Growth parameters obtained using length-age
pair values are: L∞: 175.7, k: 0.1078 and t0: 1.528 for females; L∞: 150.3, k: 0.1491
and t0: 1.809 for males; and L∞: 169.8, k: 0.1087 and t0: 1.168 all combined. These
results are very similar to those reported previously for the first season (2012/13)
although they differ slightly with the values used in the Ross sea assessment for
males
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