The Anisakis larvae presence in fish for human consumption is a health risk that needs to be monitored. The anchovy is a fish that is highly appreciated by consumers and that can harbour Anisakis. It ...is thus necessary to periodically evaluate the presence of anisakid larvae in them. So, anchovies from Iberian Peninsula coasts were analysed. Fish examination for macroscopic nematodes showed L3s of both Anisakis type I and Hysterothylacium aduncum. The Anisakis prevalence varies with the catching area and the fish size. The muscle prevalence was 7.45% (mean intensity 1.75; range 1–5). Molecular analysis showed 110 A. simplex s.s. (17 in muscle), 22 A. pegreffii (3) and 7 hybrid genotype individuals (1). Considering that most of the Iberian Peninsula coasts are a sympatry area between these two Anisakis species, it has been observed that A. simplex s.s./A. pegreffii ratio increases from south to north in a clockwise direction. Also, 19 larvae were detected on the fish surface from the Bay of Biscay, indicating the ability of these larvae to migrate after the fish death. The A. simplex s.s./A. pegreffii larvae proportion found on the anchovy surface is similar to the found in viscera and lower than in muscle, suggesting that most of the larvae migrating to the surface must have come from the visceral package. This confirms the importance of removing fish viscera immediately after capture, for those fish species where this is possible. As both species cause anisakiasis/anisakidosis, these data show a real risk to human health, especially in dishes highly prized in Mediterranean countries prepared with raw or semi-raw anchovies.
•Anisakis prevalence increases clockwise in the Atlantic waters of the Iberian Peninsula.•The catch area and size of the anchovies are risk factors for Anisakis infection.•Anisakis infection prevalence in sampled anchovies muscle was 7.45%.•Anisakis on the marketed anchovies' surface seem to originate from the fish viscera.•Anisakis on the anchovies' surface seem to be related to poor fish preservation.
•Differentiation of fresh and frozen-thawed fish samples was accomplished.•Discrimination of fish spies was performed using Raman spectroscopy.•Analysis time was reduced by taking the advantages of ...Raman spectroscopy and PCA.
The potential of Raman spectroscopy was investigated in terms of its capability to discriminate the species of the fish samples and determine their freshness according to the number of freezing/thawing cycles they exposed. Species discrimination analysis was carried out on sixty-four fish samples from six different species, namely horse mackerel (Trachurus trachurus), European anchovy (Engraulis encrasicolus), red mullet (Mullus surmuletus), Bluefish (Pomatamus saltatrix), Atlantic salmon (Salmo salar) and flying gurnard (Trigla lucerna). Afterwards, fish samples were exposed to different numbers of freezing/thawing cycles and separated into three batches, namely (i) fresh, (ii) once frozen-thawed (OF) and (iii) twice frozen-thawed (TF) samples, in order to perform the freshness analysis. Raman data collected were used as inputs for chemometric analysis, which enabled us to develop two main PCA models to successfully terminate the studies for both species discrimination and freshness determination analysis.
In this study, the population dynamics of European anchovy (Engraulis encrasicolus) was evaluated from the present to the past 30 years in the Black Sea and is intended to contribute to the creation ...of the Black Sea anchovy fishery management system. In the present study, catch composition, growth parameters, the average length values in ages, the mean length values in general, mortality rates and exploration rates were evaluated in the fishing seasons and five-years periods. 0 years of age composition of individuals not reached sexual maturity was estimated as 27.4 plus or minus 3.6% (n=26 studies), and this ratio was calculated as 32.7 plus or minus 9.04% for 1985-1990 period (n=7 studies), 39.6 plus or minus 7.76% for 1990-1995 (n=5 studies), 24.2 plus or minus 3.56% for 1995-2000 (n =7 studies), 14.5 plus or minus 4.55% for 2000-2005 (n=5 studies) and 22.1 plus or minus 1.1% for 2005-2010 (n=2 studies). Zero-year-old age composition was not significantly difference in the five-years periods (one-way ANOVA; P>0.05). The von Bertalanffy growth function (VBGF) parameters; asymptotic length (L infinity ) values were ranged between 14.1-23.5 cm (mean: 17.0 plus or minus 0.38 cm) and brody growth coefficient (K) values were ranged between 0.139-0920 year super(-1) (mean: 0.331 plus or minus 0.031 year super(-1)). The VBGF was calculated as L sub(t)=17.0 plus or minus 0.4(1-e-0.331 plus or minus 0.031(t+2.344 plus or minus 0.233) (n=26 studies). A relationship between L infinity and K values was calculated as K=1105.3L infinity -2.8958 (r super(2)=0.6224, n=26). The relationship between natural mortality ratio (M) and K values was determined as M=0.7171K0.3073 (r super(2)=0.2982; n=26). Regression coefficients of this equations were found to be statistically different from zero (P<0.05). Anchovy grew quickly and reached at the age of 1 year of 60-70% in the value of L infinity and Lmaximum length values. The instantaneous mortality ratio (Z) of anchovy was designated by fishing mortality ratio (F). The exploration ratio (E) consistently show an increase from 1985-1990 period to 2000-2005 period and it was determined as above the optimum value (E>0.5; F>M). The creation of the Black Sea anchovy fishery management system for sustainable anchovy fisheries in the Black Sea has been proposed.
This study evaluated diet variation of European anchovy, Engraulis encrasicolus, in productive and oligotrophic areas. The diet of the European anchovy was studied at 13 different sites along its ...geographic distribution range. In all sites, the diet was mainly based on copepods that represented 33 to 98% of the prey identified and were found in over 80% of the stomachs analyzed. The dominant copepod species and the various secondary preys such as ostracods, gastropods, and eggs varied among locations. Multivariate analyses (AFC, CAH, nMDS) distinguished three groups according to sites: group 1 in the Northwestern Mediterranean, Atlantic, Channel/North Sea; group 2 in the Algero-Provencal Basin (Ghazaouet, Benisaf and Bejaia); and group 3 in the Eastern Mediterranean (Lebanon and Turkey). The differences among groups were based on the presence of specific prey types, such as, zooplankton, cyprid larvae, barnacles in the first group, bivalves and amphipods in the second group, and ostracods, mysids, and euphausiids in the third group. These groupings reflected the dissimilarities of hydrographic characteristics and biological productivity between regions. Examination of the stomach contents highlights the significant presence of plastic (13-16% of the content in some sites), where the vast majority came from fishing gear filaments.Original Abstract: Cette etude represente la variation du regime alimentaire de l'anchois europeen Engraulis encrasicolus entre les regions productives et les regions oligotrophes. Le regime alimentaire de l'anchois, a ete etudie au niveau de 13 sites repartis le long de son aire de distribution. Quel que soit le site, le regime alimentaire est base essentiellement sur les copepodes qui representent entre 33 et 98% comme frequences numeriques des proies identifiees et qui se retrouvent dans plus de 80% des estomacs analyses. Les especes de copepodes dominantes et le type de proies secondaires tels que les ostracodes, gasteropodes, oeufs, different selon les sites. Des analyses multivariees (AFC, CAH, nMDS) permettent de distinguer trois groupes de sites: groupe 1 Nord-Ouest de la Mediterranee, Nador, Atlantique, Manche/ mer du Nord, groupe 2 bassin Algero-provincale (Ghazaouet, Benisaf et Bejaia) et, groupe 3 Mediterranee orientale (Liban et Turquie). Les differences entre les groupes sont basees sur la presence de groupes zooplanctoniques specifiques comme les larves cypris cirripedes dans le premier groupe, les bivalves et les amphipodes dans le groupe 2 et les ostracodes, mysidaces-euphausiaces dans le groupe 3. Ces groupements refletent les dissimilarites de productivite biologique et hydrographiques qui existent entre les regions. L'examen des contenus stomacaux met en exergue la presence non negligeable de plastiques (13-16% des contenus a certains sites) dont la grande majorite est constituee de fils de peche.
Ecological connectivity is one of the most important processes that shape marine populations and ecosystems, determining their distribution, persistence, and productivity. Here we use the synergy of ...Lagrangian back-trajectories, otolith-derived ages of larvae, and satellite-based chlorophyll-a to identify spawning areas of European anchovy from ichthyoplanktonic data, collected in the Strait of Sicily (Central Mediterranean Sea), i.e., the crucial channel in between the European and African continents. We obtain new evidence of ecosystem connectivity between North Africa and recruitment regions off the southern European coasts. We assess this result by using bio-energetic modeling, which predicts species-specific responses to environmental changes by producing quantitative information on functional traits. Our work gives support to a collaborative and harmonized use of Geographical Sub-Areas, currently identified by the General Fisheries Commission for the Mediterranean. It also confirms the need to incorporate climate and environmental variability effects into future marine resources management plans, strategies, and directives.
European anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are southern, warm water species that prefer temperatures warmer than those found in boreal waters. After about 40years of ...absence, they were again observed in the 1990s in increasing quantities in the North Sea and the Baltic Sea. Whereas global warming probably played a role in these northward migrations, the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO) and the contraction of the subpolar gyre were important influences. Sardine re-invaded the North Sea around 1990, probably mainly as a response to warmer temperatures associated with the strengthening of the NAO in the late 1980s. However, increasing numbers of anchovy eggs, larvae, juveniles and adults have been recorded only since the mid-1990s, when, particularly, summer temperatures started to increase. This is probably a result of the complex dynamics of ocean–atmosphere coupling involving changes in North Atlantic current structures, such as the contraction of the subpolar gyre, and dynamics of AMO. Apparently, climate variability drives anchovies and sardines into the North and Baltic Seas. Here, we elucidate the climatic background of the return of anchovies and sardines to the northern European shelf seas and the changes in the North Sea fish community in the mid-1990s in response to climate variability.
Pelagic fishes are among the most ecologically and economically important fish species in European seas. In principle, these pelagic fishes have potential to demonstrate rapid abundance and ...distribution shifts in response to climatic variability due to their high adult motility, planktonic larval stages, and low dependence on benthic habitat for food or shelter during their life histories. Here, we provide evidence of substantial climate‐driven changes to the structure of pelagic fish communities in European shelf seas. We investigated the patterns of species‐level change using catch records from 57 870 fisheries‐independent survey trawls from across European continental shelf region between 1965 and 2012. We analysed changes in the distribution and rate of occurrence of the six most common species, and observed a strong subtropicalization of the North Sea and Baltic Sea assemblages. These areas have shifted away from cold‐water assemblages typically characterized by Atlantic herring and European sprat from the 1960s to 1980s, to warmer‐water assemblages including Atlantic mackerel, Atlantic horse mackerel, European pilchard and European anchovy from the 1990s onwards. We next investigated if warming sea temperatures have forced these changes using temporally comprehensive data from the North Sea region. Our models indicated the primary driver of change in these species has been sea surface temperatures in all cases. Together, these analyses highlight how individual species responses have combined to result in a dramatic subtropicalization of the pelagic fish assemblage of the European continental shelf.
European anchovy, a small pelagic fish, plays a significant role in the blue economy, with remarkable commercial, ecological and culinary values. In this study, the variability in the shapes of the ...body and sagitta otoliths was examined to identify the different anchovy stocks in the Black Sea (26.5°E–39.9°E, 38.7° N–42.1°N) and adjacent regions, i.e., the Sea of Marmara and the Aegean Sea. The body shape was assessed with geometric morphometrics, while shape indices and elliptic Fourier analysis were used to evaluate the shape of the sagitta otoliths. The data were analysed using multivariate and univariate analysis of variance, discriminant function and principal component analysis. The anchovy population could be divided into five distinct stocks based on body shape, with an overall leave‐one‐out cross‐validated correct classification of 85.6%. The geometric morphometrics revealed significant differences in body depth, snout, lower jaw and caudal fin. The differences in sagitta otolith shape also revealed the existence of four distinct stocks with an overall leave‐one‐out cross‐validated correct classification of 46.5%–69.3%. The elliptic Fourier analysis revealed two main stocks of anchovy from the Black Sea as the Eastern–Middle Black Sea stock and the Western Black Sea stock. Based on the elliptic Fourier analysis, the differences in the sagitta otoliths increase in magnitude with increasing geographic separation, first manifested at the otolith anterior notch, followed by changes in the otolith width. The findings affirmed the existence of distinct stocks that should have important implications for effective management of this pelagic fish in the Black Sea and adjacent regions.
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