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Bianchetto ["white" late-larval and juvenile stages ('fry') mainly of sardine (Sardina pilchardus)] was fished traditionally along most of the Italian coast. The Gulf of Manfredonia (southwest Adriatic Sea) hosts a sardine nursery which was historically exploited by the bianchetto fishery using trawlnets; the fishery was banned in 2010. Here, we model this larval fishery under different assumptions of catch and natural mortality to assess its impact on the adult sardine stocks in the Adriatic Sea. The results show that the impact of the fishery is heavily dependent on the choice of early-stage natural mortality. The model proposed by Pepin (1991). Effect of temperature and size on development, mortality, and survival rates of the pelagic early life history stages of marine fish. Canadian Journal of Fisheries and Aquatic Sciences, 48: 503-518. was selected as the most plausible. Under this assumption, the direct effect of the bianchetto fishery in the Gulf of Manfredonia on the Adriatic adult sardine stock appears to be low, but not negligible, with impacts estimated as a 0.1-2% increase in the numbers of sardine at age 1 in the absence of a bianchetto fishery. Projections show that a 5% impact on age 1 sardine may be sufficient to bring the adult stock below safe levels. Therefore, given the uncertainties surrounding the impact assessment and the current status of the stock, if this fishery were to be resumed, catches should be kept at the lowest possible level until the underlying processes are better understood. [ABSTRACT FROM AUTHOR]

Bernal, M., Stratoudakis, Y., Wood, S., Ibaibarriaga, L., Uriarte, A., Valdés, L., and Borchers, D. 2011. A revision of daily egg production estimation methods, with application to Atlanto-Iberian sardine. 1. Daily spawning synchronicity and estimates of egg mortality. – ICES Journal of Marine Science, 68: .Assumptions of daily spawning synchronicity and estimation of egg mortality for Atlanto-Iberian sardine are revised in the context of daily estimators of egg production. An extensive database of ichthyoplankton surveys from 1985 to 2008, aggregated at different levels, is used, a set of mortality models is derived, and a comparison among them is carried out using standard statistical techniques. Analysis of the database shows Atlanto-Iberian sardine to be a late-evening spawner, in agreement with previous knowledge, but suggests a lengthier daily period of spawning. Comparison among the set of mortality models used suggests that estimates of mortality from single surveys for Atlanto-Iberian sardine are often unreliable, and that the mean estimates obtained after aggregating data from various years are statistically significant, more robust, and in line with existing information gathered from the literature. [ABSTRACT FROM PUBLISHER]

In this study the spatial distribution of eggs, larvae and juveniles of European anchovy ( Engraulis encrasicolus) was followed in 2004 and 2005 during three consecutive cruises each year in spring–summer to test what the limits of retention are in a non-upwelling area. Eggs, small larvae and large juveniles were mainly distributed over the shelf, whereas large larvae and small juveniles were found mainly off the shelf. Although overall distributions were similar, the 2 yr differed in that there was more of a coastal distribution of individuals in 2004, whereas in 2005 more individuals were found off the shelf. There were no significant differences in the length–weight relationships for individuals found on and off the shelf or between years. The correspondence in circulation patterns and the lack of difference in the length–weight relationships suggest that a single population is present, larvae drifting off the shelf due to currents and returning as mobile juveniles. Quantile regression analysis of the long-term recruitment index suggests that transport off the shelf may favour good recruitments. This would suggest that in non-upwelling regions the retention area resulting in good recruitment may not be restricted to the shelf. [ABSTRACT FROM AUTHOR]