Distribución espacio-temporal de la edad 1 de anchoa del golfo de Bizkaia (Engraulis encrasicolus) en el momento de puesta

To efficiently manage and maintain fish stock abundance and age structure, it is necessary to understand variability in its spatial distribution. The main objective of this study was to describe the demographic structure of the Bay of Biscay anchovy during the main spawning period based on adult samples from 15 daily egg production method surveys. The proportion of age-1 individuals was modelled using generalized additive models with a binomial distribution and a logit link in relation to geographical and environmental covariates. The possibility of obtaining different models depending on the average age-1 proportion (low or high) was also explored. In general, age-1 individuals were found in shallow waters close to the coast, especially associated with the Gironde and Adour river plumes, whereas older individuals were prevalent on the shelf break and in oceanic waters. However, in years with a high age-1 proportion the younger individuals were also dominant in oceanic waters. These results could be used for management purposes, such as defining protected areas for particular age groups.Con el fin de gestionar eficientemente la abundancia y la estructura espacial de un stock es necesario entender su distribución espacial. El objetivo principal de este trabajo es describir la estructura demográfica de la anchoa del golfo de Bizkaia durante el periodo de desove a partir de las muestras de adultos recogidas en 15 campañas del método de producción diaria de huevos. La proporción de individuos de edad 1 se modeló en función de variables geográficas y ambientales por medio de un modelo aditivo generalizado con distribución binomial y función enlace logit. Además se estudió la posibilidad de obtener diferentes modelos dependiendo de si la proporción de edad 1 promedio es baja o alta. En general, los individuos de edad 1 se encontraron en aguas poco profundas cerca de la costa, especialmente en las plumas de los ríos Garona y Adur, mientras que los individuos de mayor edad prevalecieron en el cantil y en aguas oceánicas. Sin embargo, los años con una alta proporción de edad 1, los individuos jóvenes fueron también predominantes en aguas oceánicas. Estos resultados podrían utilizarse para fines relacionados con la gestión, tales como la definición de áreas protegidas para determinados grupos de edad

a4a short research project. Spatial effects on the stock dynamics of European Atlantic sardine stocks

Under the scope of the a4a Initiative a workshop dedicated to studying spatial effects on the stock dynamics of European Atlantic sardine took place in Ispra, Italy, the 14th to the 18th of December 2015, with the objectives of (i) explore a4a methods to assess the Southern sardine stock (Atlanto-Iberian stock) and compare the results with the current ICES assessment carried out with SS3; (ii) explore a4a methods to assess the Northern stock of sardine stock; and (iii) apply a4a to assess putative sub-stock units; discuss local depletion and mixing among sub-units of the stock. Sardine is fished mainly by UK, Netherlands France, Spain and Portugal across ICES areas VII, VIII and IXa. In France, Spain and Portugal sardine has significant social and economic importance to the fishing and canning industries. Sardine shows a complex population structure characterized by spatial heterogeneity in phenotypic characters and life-history traits. Evidence of spatial variability in dynamics does not preclude some fish mixing across the whole region, in agreement with both genetic homogeneity and the similarity in otolith element composition in larger fish. Current knowledge on sardine biology and dynamics is consistent with the hypothesis of a meta-population composed of three populations recruiting in the Bay of Biscay, off northern Portugal, and in the Gulf of Cadiz. The workshop looked into three options of spatial structures (i) current stock structure Bay of Biscay stock (BB; VIIIa,b) and Ibero Atlantic stock (IB; IXa and VIIIc); (ii) three separate sub-units Bay of Biscay, Northwest stock (NW; VIIIc, IXa-North to IXa-Central South) and South stock (S; IXa South); and (iii) a single stock. The a4a stock assessment model was used to estimate the dynamics of each sub-units in each option. To carry out the comparison across sub-units the models used were kept as similar as possible, to mitigate the effect that the choice of model can have on the final results. Uncertainty was estimated using MCMC with the ADMB implementation, which, in the most recent version, can be assessed through the FLa4a package. In the case of the overall stock, a sensitivity analysis about survey's data processing options was carried out, to investigate the robustness of the assessment results. For the Bay of Biscay a bayesian approach has also been implemented. In order to compare both methods (a4a and bayesian) a very simple separable model was selected. A visual evaluation of the consistency between the spatial hypothesis was done based on the SSB estimates, showing that both trends are remarkably similar until 2012, when they start to diverge. In 2012 the Iberian stock (sub-units NW and S) was at a very low level and the migration rates between the Iberian and the Bay of Biscay sub-units may have increased. In such case, the stock assessment model assumption of closed population is less likely to be maintained and the two estimates of SSB diverge. One of the advantages of the approach proposed is to make it possible to look into sub-units of the stock with regards to their productivity and exploitation. These results are shown as time series of fishing mortality and recruitment for each sub-unit.JRC.E.6-Demography, Migration and Governanc

Reference points for the Iberian sardine stock (ICES areas VIIIc and IXa)

Three Yield-Per-Recruit/stock-recruitment approaches (deterministic, stochastic with plotMSY and stochastic with HCS) were used to explore reference points for the management of the Iberian sardine. The sensitivity of reference points was evaluated in relation to alternative scenarios of productivity, growth and selectivity. Growth and selectivity scenarios had a small impact on stock projections whereas productivity scenarios were very influential. The three approaches gave coherent results, but the approach using HCS, assuming uncertainty in stock biology and recruitment dynamics, was preferred to derive reference points for sardine. In this approach, the risks of the stock fa lling below some low biomass level can also be taken into account. This possibility was considered to be useful in the case of the sardine for which exploitation at maximum YPR or F0.1 resulted in values above historical exploitation and higher than Floss, therefore unsuitable as precautionary management targets. Bloss (306 thousand t) is proposed as a proxy for Blim but given no indication that recruitment is impaired below this biomass level, the group considers that the level of risk of falling below this candidate for Blim acceptable in the evaluation of a management plan should be higher than the standard ICES value (5%).The stock productivity has declined over time; therefore a scenario of low productivity was assumed (recruitment in the period 1993-2010). Under this productivity scenario, the Fmsy value for the sardine stock is 0.34, a value associated with a high probability (45%) of the biomass falling below the proposed Blim and therefore, incompatible with precautionary considerations. The WG proposes an F= 0.27, corresponding to a Prob(B<Blim)<15% under equilibrium, as the best available candidate for an F management target (proxy for Fmsy) assuming the low productivity scenario (since 1993) will continue in the future. This F provides high yield conditional to a low probability that the biomass falls below Blim=Bloss in equilibrium, thus incorporating precautionary considerations

ICES. 2019. Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA).

The Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA1) met by correspondence from 3 to 7 June 2019, and in Madrid from the 25 to the 28 of November 2019, and was chaired by Alexandra Silva (Portugal). There were 13 participants from France, Portugal, Spain and UK. The main task of WGHANSA was to assess the status the stocks of sardine in the Celtic Seas and English Channel (pil.27.7), sardine in the Bay of Biscay (pil.27.8abd), sardine in the Cantabrian Sea and Atlantic Iberian waters (pil.27.8c9a), anchovy in the Bay of Biscay (ane.27.8), anchovy in Atlantic Iberian waters (ane.27.9a; components west and south), horse mackerel in Atlantic Iberian waters (hom.27.9a) and jack mackerel in the Azores (jaa.27.10). Assessments and short-term forecasts were updated according to the stock annexes. There is no assessment method adopted for pil.27.7 due to the lack of data. The stock of pil.27.8abd was assessed as category 1 for the first time, following an interbenchmark. Recruitment has been above the average, the spawning–stock biomass declined and fishing mortality steeply increased in 2010–2012. SSB is fluctuating above MSY Btrigger and F2018 is above FMSY and below Fpa. This year, the DEPM datapoint for 2017 was included in the pil.27.9a assessment for the first time, following a revision of the survey data. The stock has decreased since 2006 and stabilized to a historical low since 2012. The biomass of age 1 and older fish has been decreasing since 2006 and reached the lowest historical value in 2015. It has since increased slightly but is below Blim since 2011. Recruitment has been below the time-series average since 2005. Recruitment in 2018 was around the geometric mean of the last five years. Fishing mortality has been decreasing from a peak in 2011. In 2018, it was the lowest in the time-series and below Fpa and Flim. The stock size indicator for anchovy in 9a.west decreased 90% from 2018 to 2019 (4129 t), after a period of an increasing trend since 2014. The harvest rate decreased 67% from management year 2017 to 2018 being below the median of the historical time-series.The relative spawning–stock biomass of the south component of the anchovy 9.a stock has fluctuated without a trend over the time-series, with most of the values above Bpa. From 2018 to 2019, the relative SSB decreased 5% but is still well above Bpa. Relative Fishing mortality (F) has fluctuated with no clear trend. From management year 2017 to 2018, relative F decreased 93%. The SSB of horse mackerel in Division 9.a fluctuated from 1992, the beginning of the assessment period, to 2012–2013 and afterwards increased continuously to a historical maximum, in 2018. The consistently high recruitment since 2011 has contributed to the SSB increase. Fishing mortality was 0.029 year -1 in 2018, showing a 29% decrease compared to 2017. Fishing mortality has been below FMSY over the whole time-series. The spawning–stock biomass has been above MSY Btrigger over the whole time-series. The exploration of data on anchovy abundance-at-age from juvenile surveys IBERAS-JUVESAR and ECOCADIZ-RECLUTAS indicated the series are still short to conclude about their future incorporation into the assessments. The analyses of internal consistency of the indices and of their consistency with spring acoustic surveys showed promising results for ECOCADIZ-RECLUTAS and pointed out the need to revisit the results of some of the surveys, particularly the IBERAS_JUVESAR series. For sardine, 0-group abundance from IBERAS-JUVESAR (2013–2019) combined with data from an earlier autumn survey, SAR-PT-AUT (discontinued in 2008) covering the northwestern Iberian waters, showed a significant correlation with the abundance of age 1 individuals in surveys carried out in the following spring

Assessment for All initiative(a4a) - Workshop on development of MSE algorithms with R/FLR/a4a

The a4a approach to Management Strategies Evaluation ( MSE ) is to develop a set of common methods and procedures to build a minimal standard MSE algorithm. This has the most common elements of both uncertainty and management options. Such a tool set should allow for the development of MSE simulations for many fisheries in an operational time frame. Between the 30th of January and the 3rd of February, in Ispra, Italy, the JRC organized a workshop on development of MSE algorithms with R/FLR/a4a. The workshop was a mix of hands-on coding and discussion/implementation of concepts associated with MSEs. The participants used the most recent version of the a4a MSE code, modularized the most important processes and developed their own version of several processes so that the MSE could model and test alternative management procedures to the one initially coded.JRC.D.2-Water and Marine Resource

ICES. 2020. Working Group on Acoustic and Egg Surveys for Sardine and Anchovy in ICES areas 7, 8 and 9

he Working Group on Acoustic and Egg Surveys (WGACEGG) coordinates pelagic surveys for a number of stocks and provides monitoring for the two major sardine and anchovy stocks in ICES areas 6, 7, 8, and 9. The group evaluated small pelagic fish biomass indices derived from acoustic and Daily Egg Production Method (DEPM) surveys in ICES areas 6, 7, 8 and 9. These indices have been provided to the ICES Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA), the Working Group on Widely Distributed Stocks (WGWIDE) and the Herring Assessment Working Group for the Area South of 62ºN (HAWG) stock assessment group, to serve as fishery-independent input for analytical assessment purposes. DEPM and acoustic indices were derived based on data collected using independent methods. Acoustic- and DEPM-derived biomass indices from quasi-synoptic surveys conducted in the Bay of Biscay in spring were compared, to assess the presence of potential bias and to improve the precision of fish stock biomass estimates. The DEPM-based anchovy biomass index was 22% higher than the acoustic index in 2019. Unusual concentrations of anchovy in Eastern Cantabrian Sea, an area not covered by the acoustic survey, and the presence near the sea surface of actively spawning individuals possibly under-sampled by acoustics in central Bay of Bay had been postulated as potential causes of this discrepancy. No significant difference was found between sardine biomass indices derived from DEPM and acoustics in 2019. The group has updated its database of standard gridded maps covering the European Atlantic area. This initiative continues to inform on the spatial dynamics of various parameters collected during the surveys coordinated under the auspices of the group (fish acoustic densities, anchovy and sardine egg abundance, surface temperature and salinity). Results of an analysis of the time series of gridded maps (anchovy and sardine acoustic density, surface salinity and temperature) showed quantitative changes in the spatial and temporal distribution of anchovy and sardine over the last 15 years, and further define their habitats in European Atlantic waters in spring. The timing and spatial coverage of DEPM and acoustic surveys that will be conducted by group members in 2020 were planned to optimise the monitoring of anchovy and sardine populations and their pelagic environment in the European Atlantic area. The synoptic nature of the survey components has been assessed for each target species. A manual describing the protocols used during the DEPM surveys coordinated by the WGACEGG group was reviewed, and writing of a manual of WGACEGG acoustic surveys continued. Both manuals will be available in 2020. The final results of the 2017 sardine DEPM assessment were endorsed by the group

Preliminary results from the ECOCADIZ 2020-07 Spanish acoustic survey (01 – 14 August 2020)

The present working document summarises a part of the main results obtained from the Spanish (pelagic ecosystem-) acoustic survey conducted by IEO between 01st and 14th August 2020 in the Portuguese and Spanish shelf waters (20-200 m isobaths) off the Gulf of Cadiz (GoC) onboard the R/V Miguel Oliver. The 21 foreseen acoustic transects were sampled. A total of 26 valid fishing hauls were carried out for echo-trace ground-truthing purposes. Four additional night trawls were conducted to collect anchovy hydrated females (DEPM). This working document only provides abundance and biomass estimates for anchovy, sardine and chub mackerel, which are presented without age structure. The distribution of all the mid-sized and small pelagic fish species susceptible of being acoustically assessed is also shown from the mapping of their back-scattering energies. GoC anchovy acoustic estimates in summer 2020 were of 5153 million fish and 44 877 tones, with the bulk of the population occurring in the Spanish waters. The current biomass estimate becomes in the second historical maximum within the time-series. The estimates of sardine abundance and biomass in summer 2020 were 1923 million fish and 50 721 t, estimates close to the historical average, but lower than the values estimated last year and the most recent maxima reached in 2018. A total of 32 854 t and 448 million fish were estimated for Chub mackerel, estimates similar to the most recent ones and very close to the time-series average