European anchovy (Engraulis encrasicolus) age structure and growth rate in two contrasted areas of the Mediterranean Sea: the paradox of faster growth in oligotrophic seas

Abstract

Copyright © 2017To cite this article: BASILONE, G., MANGANO, S., PULIZZI, M., FONTANA, I., GIACALONE, G., FERRERI, R., GARGANO, A., http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 12/05/2018 11:19:51 | ARONICA, S., BARRA, M., GENOVESE, S., RUMOLO, P., MAZZOLA, S., & BONANNO, A. (2018). European anchovy (Engraulis encrasicolus) age structure and growth rate in two contrasted areas of the Mediterranean Sea: the paradox of faster growth in oligotrophic seas. Mediterranean Marine Science, 18(3) IntroductionThe European anchovy (Engraulis encrasicolus, Linnaeus, 1758) is an important commercial resource and constitutes almost 30% of the total Mediterranean fish production (Lleonart & Maynou, 2003). Landing statistics including both Mediterranean and Black Sea waters, noting that among small pelagic fishes, anchovy is the most important species contributing approximately 50% of total landings (FAO, 2011). Clupeoid fish populations, especially anchovies and sardines, exhibit large fluctuations in abundance in several areas around the world (Crawford, 1987;Schwartzlose et al., 1999;Palomera et al., 2007). In the Strait of Sicily (Geographical Sub Area -GSA 16, as defined by the General Fisheries Commission for the Mediterranean; GFCM, 2009), the average annual catches have been estimated at around 5000 tons, while approximately 100 vessels of different types employing different fishing gears are actively exploiting anchovy in this area (Data Collection Framework, years 2007; http://stecf.jrc.ec.europa.eu/reports/dcf-dcr). In the same area, acoustic and ichthyoplankton-based biomass evaluation methods showed that the high interannual variability in biomass is largely controlled by environmental variability Bonanno et al., 2014a).In the Tyrrhenian and Ligurian seas (GSAs 10 and 9), anchovy and sardine landings in the period [2009][2010][2011][2012] were in the ranges 8000 -12000 tons and 2000 -9000 tons, respectively (IREPA, 2012). Although some acoustic surveys in the Tyrrhenian Sea during the last years highlighted the consistent presence of these resources, the management of small pelagic fishes in this area is impeded by the considerable lack of information independent of the fishery . The present study provides the first set of observations on the biology and ecology of anchovy in the Tyrrhenian Sea and compares them with data acquired in other areas. Comparative studies at the species-level are very important as they reveal the effect of habitat conditions on growth and recruitment of fishes (Brander, 1995;Planque & Frédou, 1999). Indeed, pooling data from a number of populations broadens the range of conditions and helps to detect general patterns (Brander, 1995;Brunel & Boucher, 2006), allowing a modelling of the species' responses to climate change (Clark et al., 2003;Drinkwater, 2005).Knowledge on the fish's growth is historically fundamental for fishery sciences. Growth information provides an integrated assessment of habitat suitability because it reflects the prevailing environmental conditions...

Current and Future Influence of Environmental Factors on Small Pelagic Fish Distributions in the Northwestern Mediterranean Sea

“…However, other studies pointed out that sardine juveniles prefer areas with moderate primary productivity values (Giannoulaki et al, 2011;Tugores et al, 2011) and negative relationships were also found between anchovy adults and primary productivity in other Mediterranean areas (Giannoulaki et al, 2008(Giannoulaki et al, , 2013Martín et al, 2008;Quattrocchi et al, 2016). Recent studies point out that primary productivity concentration is negatively correlated with anchovy individuals of age −1 (Bacha et al, 2010;Basilone et al, 2017). Overall, areas with high primary productivity concentration could affect water transparency, increasing the difficulty of finding prey (Fernández-Corredor, 2018).…”

“…This result is consistent with a comprehensive literature review (Fernández-Corredor, 2018). Temperature seems to affect the size of anchovy at the end of the first year of life, and was found positive related with anchovy at age-1 (Bacha et al, 2010;Basilone et al, 2017), and with anchovy body condition factors (Basilone et al, 2006).…”

First annulus formation in the European anchovy; a two-stage approach for robust validation

“…In both these areas the habitat conditions are characterized by higher riverine input nutrients and higher productivity 25,31 than the oligotrophic waters of the study area and of the most part of the Mediterranean Sea 26 . The Strait of Sicily is considered an oligotrophic area 34,35,64 , where the enrichment of the upper water layers is associated with upwelling phenomena, which allow nutrient inputs from deeper waters 27,65 . Literature widely reported the variability in somatic growth linked to habitat variability e.g.…”

“…Literature widely reported the variability in somatic growth linked to habitat variability e.g. 24,28,29,64,66,67 . The growth rate of the anchovy in the Strait of Sicily was at the low end of the range observed for this species among different areas, also including the Bay of Biscay and NW Mediterranean 24,31 .…”

Marine ecosystems and living resources in the Central Mediterranean Sea: an introduction

“…Both the permanent and non-permanent character of the recognized physical features of the Central Mediterranean, as well as its degree of variability, have been studied (e.g., Olita et al, 2007;Gasparini et al, 2008;Drago et al, 2010;Placenti et al, 2013;Ben Ismail et al, 2014;Bonanno et al, 2014a;Jouini et al, 2016). Some studies singled out the influences of environmental variability on the biological resources in the Central Mediterranean (e.g., Levi et al, 2003;Garofalo et al, 2010;Rjeibi et al, 2010;Basilone et al, 2013Basilone et al, , 2015Basilone et al, , 2017Bonanno et al, 2013Bonanno et al, , 2014bBonanno et al, , 2015Fiorentino et al, 2013;Khoufi et al, 2014;Barra et al, 2015;Jaziri et al, 2015;Lauria et al, 2016;Gargano et al, 2017). However, only part of the main features affecting the ecosystems and living resources in the Central Mediterranean has been fully understood.…”