Progress on the revision of the Iberian sardine assessment for the benchmark

This working document presents work progress on the revision of the assessment model of the Iberian sardine. Data and model exploration were carried out to address some of the issues outlined in the last sardine benchmark in 2012. Specifically, we address assumptions about initial equilibrium catch, recruitment modelling and time varying selectivity. The aim is to promote discussion in WGHANSA 2016 and to define guidelines for further work to be undertaken until the benchmark assessment scheduled for early 2017

ICES. 2016. Report of the Workshop on Atlantic Sardine (WKSAR), 26–30 September 2016, Lisbon, Portugal. ICES CM 2016/ACOM:41. 351 pp.

The Workshop on Atlantic Sardine (WKSAR), chaired by Alexandra Silva (Portugal) and Lionel Pawlowski (France), met in Lisbon, 26–30 September to (i) review infor-mation on stock identification, connectivity and migrations of sardine within European Atlantic waters (Area 7 to Subdivision 9.a)and, (ii) collate, standardize and analyse survey, fishery and biological data collected in the region, (iii) propose scenarios of stock structure and dynamics and (iv) methods/models for stock assessment (ToRs, Annex 5). There were 18 participants from the UK, France, Portugal and Spain, including one representative from PONG-PESCA (NGO, Portugal) and two chair-invited experts on genetics (Annex 1). A WebEx meeting was organized with stakeholders to facilitate their effective involvement in the benchmark process, clarifying what their role is, and to promote their contribution. To that purpose a questionnaire was written, translated into French, Spanish and Portuguese, and sent to stakeholders with questions regard-ing their perception of the various aspects of the Northern and Southern stocks, the fisheries, the monitoring and their management (Annex 2). Information on stock identification, connectivity and migrations has been compiled in Section 3 to be reviewed by SIMWG. The group agreed to set the deadline to compile final datasets (all) at 5th December in order for people to start running assessment in preparation for the ICES benchmark meeting in February 2017

Preliminary results of the PELACUS0316 survey: estimates of sardine, anchovy and horse mackerel abundance and biomass in Galicia and Cantabrian waters

PELACUS 0316 has been carried out between 13th March and 16th April, covering the north Spanish continental self between the Miño river (Spanish/Portuguese border) and the Bidasoa one (Spanish/French border). Unexpectedly, weather and oceanographic conditions found were those of the winter time rather than the incipient spring ones. Consecutive deep W/NW storm fronts have affected the survey plan; five days were lost due to the bad weather conditions and even during part of the survey either strong south wind (up to 45 knots) or a persistent swell of about 2-4 m height have also made problems to achieve clean echograms (i.e. without bubbles) and good performance at the fishing station. These conditions might have been also affected the availability of the fish. This seems clearer in the southern part (IXaN), where a stronger winter poleward current led the continental self almost empty of plankton and with a very scarce concentration of fish. Abundance of the main pelagic fish species was lower than that of the previous year. For sardine the abundance was very low, practically below of an acceptable threshold for an acoustic assessment. Only the presence of a very thick school with acoustic and morphological characteristics being compatibles to those of sardine, thus being possible sardine but not ground truthed. In total the assessed biomass was very low, and excluding this school only 3 thousand tons were estimated, the lowest record in the time series (13 thousand tons including this school but still at a very low level) Horse mackerel showed also an important decrease while anchovy has been mainly detected at the inner part of the Bay of Biscay, although as it was observed for sardine, the presence of thick schools in the western part, presumably being anchovy, had an important impact in the final assessment

CRUISE REPORT INTERPELACUS 0414

An intercalibration survey aiming at to verify if the PELACUS survey time series could have been affected by the change from R/V Thalassa to R/V Miguel Oliver has been carried out off the Garonne mouth. To do that, the inter-ship variability in some sampler devices (mainly acoustics, CUFES and fishing gears) have been compared with the intra-ship variability in order to give coherence to the time series (i.e. small vessel effect). Accordingly, the null hypothesis the characterisation of the pelagic ecosystem by means of an acoustic-trawl survey would give significant differences on account the vessel effects was tested. Acoustic sampling consisted in two tracks 2.5 espaced and divided in two areas, shallower, with 22 nmi from 40 to 60 m, and deeper , with 10 nmi, from 110 m to the slope. These four track were surveyed three times for each vessel, first in parallel and the others with one of the vessels leading. In the same way 15 parallel fishing station were also perfomed. However, the intercalibration has been made in a small area and only during the light hours of four days and a half of effective work. It is, therefore, complicateto extract conclusions for a large scale survey such as PELACUS time series. In spite no significant diffences in mean backscattering energy was found, it seems that R/V Miguel Oliver, although showed worse noise spectra than R/V Thalassa specially at higher frequencies (200 kHz), consistently accounted higher cumulated backscattering energy values than Thalassa. In addition. Contradictory, the high level of cavitation showed by R/V Miguel Oliver would not result in a higher fish avoidance and the low cumulated backscattering energy values ahchieved by R/V Thalassa could be related with a higher fish avoidance or more presumably with a higher diving response to R/V Thalassa. This kind of response changes the tilt angle and TS becomes lower than expected, which in turn results in an underestimation of the fish abundance. This contradictory response has been already observed in other ship comparisons. Fish reactions cannot be explained only by considering noise spectra but also sound pressure fields and particle acceleration. This later feature would explain the results obtained. In the same way the different fishing gear used for both vessels would not result in significant differences between catch composition and length structure as the intra-ship variability was similar to the inter-ship one. However it should be mention that R/V Miguel Oliver has had higher accessibility to horse mackerel and hake than R/V Thalassa. Finally CUFES performance was similar for both vessels as the intra-ship variability is of the same order as the inter-ship one. Given these results, it seems that the PELACUS time series would not be affected by the change from R/V Thalassa to R/V Miguel Oliver

Multidisciplinary acoustic survey PELACUS0314: preliminary results on fish abundance estimates and distribution

PELACUS 0314 was characterised by relative stable weather conditions along the surveyed area. Besides, there was an important increase in backscattering energy as compared with the previous year. This resulted in an increase of the biomass estimated for the majority of the fish species, but still sardine is at lowest productivity ever recorded. Good recruitment would be observed in horse mackerel, but for the rest of the fish species, no strong signals for age group 1 have been detected. The reasons for this increase would be related to the weather stability which could have increased the fish availability either for a change in the behaviour (i.e. spatial pattern distribution) or for an increase in the food availability. This is relevant accounting the increase of the occurrence of mackerel subsurface layers observed this year. As PELACUS is a multidisciplinary survey series (we collect environmental and biological ancillary information, stomach contents, including CTD cats, plankton tows or continuous records of plankton, eggs, S, T and flourometry), we will try to explain this change of behaviour. Our main hypothesis is that these species could follow mackerel when is undertaking vertical migration, probably related with the spawning activity, just for feeding eggs and, therefore, changing the expected schooling behaviour by the dispersed one, used during the feeding activity

Preliminary results of the PELACUS0315 survey: estimates of sardine abundance and biomass

A total of 10 384 tons of sardine (191 million fish) was estimated to be present in northwest and northern Spanish waters by the Spanish spring acoustic survey PELACUS0315, carried out from 13th March to 16th April 2015. These values are virtually identical to those recorded in 2014, which shows a stable trend at the lower level of the time series. Sardine distribution was wider than previous years, but the energy allocated to this species was in general very low. Sardine was presented throughout the whole sampled area, but the energy attributed to this species was in general very low. Higher sardine concentrations were detected in Galicia and in the Vasque Country area. Most fish in the entire surveyed area were assigned as belonging to the age 1 (29% of the abundance and 20% of the biomass), age 2 (28% of the abundance and 26% of the biomass) and age 3 (27% of the abundance and 29% of the biomass) years classes. By sub-area, IXa subdivision represents 21.1%, VIIIc West 0.3%, VIIIcEast-West 25.4% and VIIIcEast- East 53.1% of the total abundance. Galicia populations (IXaN and VIIIcW subdivisions) were dominated by age 1 fish whilst the Cantabrian area was mainly composed by older individuals. The distribution of sardine eggs indicates a coastal distribution, agreeing with that observed in previous years. Sardine eggs showed a widespread distribution in the surveyed area, with higher percentage of positive stations than in earlier years

Preliminay results of the PELACUS0314 survey: estimates of sardine abundance and biomass in Galician and Cantabrian waters.

A total of 9,023 tons of sardine (147 million fish) was estimated to be present in northwest and northern Spanish waters by the Spanish spring acoustic survey PELACUS0314, carried out from 9th March to 8th April 2014. That represents an important increase in relation to 2013 abundance and biomass, but still at the lower levels of the time series. Fish were mainly found in Cantabrian area (mainly in VIIIc East-West subdivision) and inside Rias Baixas (South Galicia, ICES sub-areas IXa-N) and was almost absent from the rest of the surveyed area. Most fish in the entire surveyed area were assigned as belonging to the age 2 (38% of the abundance and 43% of the biomass) and age 3 (24.5% of the abundance and 25.5 % of the biomass) years classes. By subdivisions, the IXaN (South of Galicia) population was dominated by age 1 fish whilst the Cantabrian area was mainly composed by a population of age 2 and age 3 individuals. The distribution of sardine eggs (obtained from the analysis of 358 CUFES stations) indicates a very coastal distribution, agreeing with that observed in previous years The percentage of positive stations was very similar in both surveys, but total number of sardine eggs detected in Spanish waters was 4214, which represents an important decrease from the 2013 value

Report of the Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA), 20-25 June 2014, Copenhagen, Denmark.

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