Atlantic Mackerel

The impacts of climate change on marine ecosystems can be seen in the changing distribution, migration, and abundance of species in the oceans. For some species this changing environment may be beneficial and can support population expansions. In the northeast Atlantic (NEA), the Atlantic mackerel (Scomber scombrus) is undergoing an increase in stock size accompanied by changing summer migration patterns, which have resulted in an expansion further north and north west than previously recorded. This study uses microsatellite loci to confirm the differentiation among NEA and northwest Atlantic (NWA) mackerel spawning populations and to assess the level of structuring within these populations. In addition, to enable population-specific exploitation rates to be factored into fisheries management, we identified the origin of individuals composing the expanding feeding aggregations in the central north Atlantic (Greenland, Iceland, Faroes), with all aggregations tested originating from s...

The impacts of climate change on marine ecosystems can be seen in the changing distribution, migration, and abundance of species in the oceans. For some species this changing environment may be beneficial and can support population expansions. In the northeast Atlantic (NEA), the Atlantic mackerel (Scomber scombrus) is undergoing an increase in stock size accompanied by changing summer migration patterns, which have resulted in an expansion further north and north west than previously recorded. This study uses microsatellite loci to confirm the differentiation among NEA and northwest Atlantic (NWA) mackerel spawning populations and to assess the level of structuring within these populations. In addition, to enable population-specific exploitation rates to be factored into fisheries management, we identified the origin of individuals composing the expanding feeding aggregations in the central north Atlantic (Greenland, Iceland, Faroes), with all aggregations tested originating from s...

In this work, a total of 1331 fish samples belonging to 15 species and commercialized in Sicily were examined for the detection of Anisakidae larvae and their morphological and molecular identification. All the fish samples came from FAO zone 37, 27, 41, and 87. The initial inspection of the fish samples was carried out according to the EC Regulation 2075/2005. The larvae detected underwent morphological identification by optical microscopy. A PCRRFLP of the nuclear ITS region (ITS1, ITS-2 and 5.8 S subunit) was carried out for the identification of the Anisakidae larvae. While the species belonged to the Hysterothylacium spp. were recognized at species level by sequencing of cytochrome oxidase 2 (cox2) region. A total of 3700 larvae were detected during the inspection. A statistically significant number of 370 larvae were subjected to molecular analysis; 330 were identified as Anisakis pegreffii Campana-Rouget et Biocca, 1955 (Nematoda Anisakidae), 23 as Anisakis simplex (Rudolphi,...

The study focused on assessing quality parameters of haddock and mackerel minces subjected to a high-pressure treatment (HP) at 200 and 300 MPa and frozen storage at -40 °C. Dry matter, water-holding capacity, protein solubility and oxidation, lipid oxidation, microbiological parameters, low molecular weight metabolites (LMW) and color parameters, were analyzed. The texture of fishcakes prepared on the basis of these fish minces was also studied, showing a decrease in firmness along with an increase in pressure. A marked inhibition of microbial growth was observed in fish minces when increasing the pressure level of HP-treatment. However, no significant effect (p < 0.05) on the content of primary and secondary lipid oxidation products was observed between untreated and 300 MPa-pressurized fish samples. The results suggested that HP-treatment could be successfully applied to both lean and fatty fish samples for reduction of microbial growth with minor changes in product quality. Industrial relevance. The application of high pressure (HP) treatment of 200 and 300 MPa could be successfully applied to both lean and fatty fish species before freezing for reduction of microbial growth. The degree of lipid oxidation is decreasing with an increase in pressure as a result of inactivation of prooxidative endogenous enzymes. Fish minces become slightly lighter and softer after HP-treatment conducted at 200 MPa due to denaturation of proteins, thus enhancing sensory properties of fishcakes prepared thereof.

The aim of the present study is to assess the influence of different sous-vide time-temperature regimes and use of two types of commercial antioxidants (rosemary extract and rosmary extract with ascorbyl palmitate) on quality parameters of Atlantic mackerel (Scomber scombrus) during chilled storage. The mackerel fillets were treated with the antioxidants, exposed to sous-vide cooking at 70 and 80 °C for 10 and 20 min, and further stored for 1, 3, 9 and 15 days at (0±1) °C. Changes in dry matter and ash, cook loss, protein oxidation and solubility, as well as texture parameters in sous-vide cooked mackerel during storage, were assessed by application of multiple regression analysis. It was revealed that duration of chilled storage had the highest contribution to the decrease in cook loss due to a possible reabsorption of water released during cooking by unfolded proteins. At the same time, this parameter increased protein carbonylation in mackerel samples, resulting in a decreased pro...

The impacts of climate change on marine ecosystems can be seen in the changing distribution, migration, and abundance of species in the oceans. For some species this changing environment may be beneficial and can support population expansions. In the northeast Atlantic (NEA), the Atlantic mackerel (Scomber scombrus) is undergoing an increase in stock size accompanied by changing summer migration patterns, which have resulted in an expansion further north and north west than previously recorded. This study uses microsatellite loci to confirm the differentiation among NEA and northwest Atlantic (NWA) mackerel spawning populations and to assess the level of structuring within these populations. In addition, to enable population-specific exploitation rates to be factored into fisheries management, we identified the origin of individuals composing the expanding feeding aggregations in the central north Atlantic (Greenland, Iceland, Faroes), with all aggregations tested originating from s...

Background: An abundance of vitamins, minerals, and vital amino acids can be found in fish. The parasitic zoonotic disease anisakiasis is caused by ingesting the third larval stage of Anisakis spp., which is carried by nematodes called anisakids. Serious health problems, such as abdominal pain, nausea, vomiting, and allergic reactions that could approach anaphylactic level, are brought to the human body by ingesting undercooked fish, where this parasite is present. Aim: Raw herrings, smoked herrings, raw sardines, salted sardines, raw mackerel, and raw saurus were all tested for the presence of Anisakis larvae. Methods: Fish samples were purchased from Sharkia Governorate, Egypt, with half of the samples from all species being collected in the spring and the other half being collected in the autumn. Parasitic examination of fish was done morphologically and confirmed using PCR. Results: The detection rates of Anisakis larvae in raw herrings, smoked herrings, raw sardine, salted sardine, raw mackerel, and raw saurus fish were 40%, 25%, 15%, 0%, 25%, and 10%, respectively. No muscle samples were found to be infested with Anisakis spp. Based on the findings, it was discovered that the fish that were sampled in spring had a higher infestation rate with Anisakis larvae than that collected in autumn. The hazards associated with Anisakis larvae were further discussed. Conclusion: The examined fish species in the present study were found to be infested with Anisakis larvae at variable rates except for salted sardine. Therefore, efficient cooking of fish before serving to human is highly recommended.

In order to improve the capacity of bottom trawl fishing gears to reduce catches of young fish and discards in a highly exploited demersal trawl fisheries in the Mediterranean, the size-selection performance of a 36-mm square-mesh codend and two sorting grids with 20 and 15 mm bar spacing was assessed. Alternate hauls were used to assess the selectivity of 36mm square-mesh codend. Selectivity of sorting grids was assessed using a double codend in which fish that escaped through the grid were captured in the lower codend while other fish were guided into the upper codend. The mean selection length (L 50 ) for European hake was 18.5 cm and that for the Atlantic horse mackerel was 14.0 cm with the 36-mm square-mesh codend . These values are close to their current minimum landing sizes (20 cm for hake and 12 cm for horse mackerel). The sorting grid with 20-mm bar spacing showed L 50 value of 13.3 cm for hake, suggesting that a larger grid-spacing would be needed to obtain sufficient sorting performance. Similarly, for Atlantic mackerel the estimated L 50 of 14.3 cm indicates that larger grid spacing is required to attain an L 50 that would be close to the current MLS (18 cm). For Atlantic horse mackerel and red mullet, the L 50 obtained with the sorting grid with 20-mm bar spacing was close to the MLS of these species (the MLS of red mullet is 11 cm). The selectivity of the sorting grid with 15-mm bar spacing was generally very poor. Size-selection performance of sorting grids was assessed for the first time in the local fisheries. In order to effectively improve size-selection, seasonal and depth-dependent differences between target and by-catch species must be taken into account, which is a good indicator of the difficulty of implementing a single mesh size or grid spacing in the Mediterranean demersal trawl fishery.

Atlantic mackerel (Scomber scombrus) were recorded in Isfjorden, Svalbard (78˚15ʹ N, 15˚11ʹ E) in late September 2013. This record is the northernmost known occurrence of mackerel in the Arctic and represents a possible northward expansion (of ca. 5˚ latitude) of its distributional range. The examined specimens of mackerel were between 7 and 11 years old, with a mean size of 39 cm and a mean weight of 0.5 kg. Examination of stomach contents indicated that the mackerel were feeding mainly on juvenile herring (Clupea harengus). The occurrence of mackerel in the Arctic is discussed in relation to the recent increase in mackerel population size in the North Atlantic and the expansion of other North Atlantic fishes into the Svalbard region during the last decade. Using a decadal record of water temperature, we conclude that the occurrence of Atlantic mackerel in Svalbard waters is a result of a continued warming of the ocean in the region and that it follows a general trend of species' extending their distributional ranges northward into the Arctic.

Zoonotic larvae of the family Anisakidae found in several fish species represent a serious risk in public health since they may cause food-borne anisakidosis in humans. Chile has culinary preferences including eating raw fish in many traditional preparations. In the present study, a total of 180 fish specimens representing three different fish species, i.e., Chilean hake (Merluccius gayi), snoek (Thyrsites atun), and sea bream (Brama australis), were caught at central coast of Chile. Parasitological examination was performed on musculature and abdominal cavity for subsequent extraction and quantification of anisakid larvae. Estimation of infection parameters, such as prevalence, was performed indicating 100% (CI: 0.94–1.0) prevalence of anisakid L3 in Chilean hakes and snoeks. Moreover, sea breams reached a prevalence of 35% (CI: 0.23–0.48). Prevalence of anisakid larvae in muscle was also analyzed showing values of 18.6% (CI: 0.097–0.309) in Chilean hakes, 15% (CI: 0.07–0.26) in sn...

This study reports on diseased Chelidonichthys spinosus¯sh that were originally obtained from the Taiwan Strait for exhibition in an aquarium. These¯sh showed abnormal swimming behavior, eye damage and skin lesions. Gross examination and histopathology revealed that the C. spinosus was su®ering from severe nematode infections in the pyloric caeca, liver and mesentery. Marine nematodes from internal organs were veri¯ed by partially sequencing the § §

Se realizó la identificación molecular de larvas de nemátodos en el tercer estadío del Scomber colias Gmelin, 1789 recogidos en la costa norte de Argentina, y la caracterización morfológica y morfométrica de estos parásitos. Los órganos internos y los músculos de 31 muestras de S. colias fueron analizadas. La identificación genética de larvas se realizó por PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism) mediante la amplificación de un fragmento de ADN nuclear (ITS1, ITS2 y 5,8S) y el escote con enzimas de restricción específicas (HinfI, HhaI) para la identificación. Para el análisis morfológico y morfométrico, los especímenes se observaron en el microscopio trinocular y en microscopía electrónica de barrido. Alrededor de 369 nematodos fueron recolectados en el 68% de los peces analizados. Todos los parásitos se encontraron en los órganos internos del huésped, y no se detectó formas larvarias en los músculos. La identificación molecular produjo cuatro...

Research background. It is desirable to increase the consumption of pelagic fish rich in long-chain omega-3 fatty acids. Partial replacement of traditionally used white fish species by pelagic fish will increase the content of omega-3 fatty acids, and thus improve the nutritional value but it may also affect the consumer acceptance. The aim of this study is to assess the physicochemical and sensory quality of novel fish cake prototypes prepared from haddock and mackerel mince. Experimental approach. Fillets of haddock and Atlantic mackerel were used as raw material for preparation of fish cakes. The fish fillets were minced, mixed together (in haddock/mackerel mass ratio of 100:0, 75:25 and 50:50) with salt, potato starch, pepper and full fat milk. Physicochemical and sensory analyses were further performed. Results and conclusions. The fatty acid composition analysis showed that the recommended daily intake of 250 mg of eicosapentaenoic acid and docosahexaenoic acid can easily be r...

The aim of this study was to assess lipid oxidation development in sous-vide cooked Atlantic mackerel during chilled storage by fluorescence microscopy coupled with chemical, physical and data analysis methods. Sous vide-cooking at 70°C and 80°C for 10 and 20 min was performed with and without use of antioxidants. Fluorescence micrographs of lipids extracted from the fish samples on 1st, 3rd, 7th, and 9th day of chilled storage at 4 ± 1°C, were acquired in the wavelength region of λex 475/40 and λem 530/50 (44 FITC filter). The obtained images were numerically processed and the resulting data correlated with 2-thiobarbituric acid reactive substances (TBARS) determined by conventional chemical method of lipid oxidation analyses. Total lipid content and color characteristics of mackerel fillets were analyzed as well. The yellowness of the fish flesh significantly correlated (p < 0.05, R = 0.859) with conjugated trienes generated from thermal polymerization of lipids during chilled storage of sous-vide cooked mackerel. Results showed that higher temperature and cooking times generally accelerated lipid oxidation in mackerel samples prepared both with and without addition of antioxidants in terms of conjugated trienes and tetraenes. However, the addition of antioxidants enhanced the lipid oxidation stability of cooked mackerel fillets.

The aim of this study was to investigate the potential of fluorescence microscopy coupled with chemical, physical and data analysis methods for reliable and non-invasive detection of changes in texture parameters of sous-vide cooked Atlantic mackerel during chilled storage. Fluorescence micrographs of cook loss and connective tissue of the fish samples after sous-vide treatment at 60°C and 75°C for 10, 15 and 20 minutes taken in the 1 st , 3 rd and 7 th day of chilled storage were acquired. The obtained images were numerically processed and the resulting data was directly correlated (R=0.960) with the total collagen content determined by a chemical method. Partial least squares analysis was applied to derive statistically significant regression models revealing the influence of each of sous-vide regime parameters on changes in total collagen content and texture parameters of Atlantic mackerel during chilled storage. Results showed that both collagen integrity and firmness of mackerel flesh were significantly (p<0.05) affected by the temperature of sous-vide treatment and duration of chilled storage, leading to gradual softening of the fish tissue due to degradation of collagenous tissue.

SummaryChanges in quality characteristics in relation to protease activity and protein oxidation in chilled, superchilled and frozen mackerel fillets during storage were studied. The solubility of sarcoplasmic proteins was quite stable in mackerel samples for all storage experiments, whereas the solubility of myofibrillar proteins decreased in both superchilled and frozen samples. A significant correlation (r = 0.983, P &lt; 0.05) between the increased activity of cathepsin B+L in chilled fillets and softening of the fish flesh during storage was revealed. Contrary with chilled samples, the texture of superchilled mackerel fillets became tougher along the storage period, which can be explained by a higher rate of myofibrillar oxidation (r = 0.940, P &lt; 0.05). The hardness and drip loss decreased slightly at the end of frozen storage. Superchilling preserved the quality of mackerel fillets with the least side effects in relation to protein solubility, drip loss and softening of the...

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The impacts of climate change on marine ecosystems can be seen in the changing distribution, migration, and abundance of species in the oceans. For some species this changing environment may be beneficial and can support population expansions. In the northeast Atlantic (NEA), the Atlantic mackerel (Scomber scombrus) is undergoing an increase in stock size accompanied by changing summer migration patterns, which have resulted in an expansion further north and north west than previously recorded. This study uses microsatellite loci to confirm the differentiation among NEA and northwest Atlantic (NWA) mackerel spawning populations and to assess the level of structuring within these populations. In addition, to enable population-specific exploitation rates to be factored into fisheries management, we identified the origin of individuals composing the expanding feeding aggregations in the central north Atlantic (Greenland, Iceland, Faroes), with all aggregations tested originating from s...

Geographic redistribution of living natural resources changes access and thereby harvesting opportunities between countries. Internationally shared fish resources can be sensitive to shifts in the marine environment and this may have great impact on the economies of countries and regions that rely most heavily on fisheries to provide employment and food supply. Here we present a climate change‐related biotic expansion of a rich natural resource with substantial economic consequences, namely the appearance of northeast Atlantic mackerel (Scomber scombrus) in Greenlandic waters. In recent years, the summer temperature has reached record highs in the Irminger Current, and this development has expanded the available and realized mackerel habitat in time and space. Observations in the Irminger Current in east Greenland in 2011 of this temperature‐sensitive epipelagic fish were the first records so far northwest in the Atlantic. This change in migration pattern was followed by a rapid dev...

Research background: Fresh cheese varieties represent an important share of the whole cheese market. Although with great variability in terms of composition and method of preparation, fresh cheese varieties are bland in flavor and their production originates whey drainage. On the other hand, the cheese market is also responsible for a significant amount of food waste. These motivated the development of a novel fresh cheese incorporating ripened cheese, which can then represent a valorization of ripened cheese surpluses. Experimental approach. A variable amount of ripened cheese was dispersed in a paste of gelatinized starch (normal corn or waxy rice) in milk, producing melted cheese bases. These cheese bases were diluted with milk, sometimes enriched with skim milk powder, and then renneted. The resultant fresh cheese was characterized for macronutrients content, and physical properties. Sensory analyses of samples incorporating mature Cheddar, goats’, or ewes’ cheese were carried o...

Anisakidosis is a foodborne zoonotic infection induced by members of the family Anisakidae via the consumption of raw or undercooked fish such as sushi and sashimi. Identifying anisakid larval species is critical for the epidemiology and diagnosis of diseases caused by them. This study aimed at identifying Anisakis larvae collected from marine fish in Egyptian waters based on morphological characteristics and molecular analysis. Thirty marine fish coral trout, Plectropomus areolatus, were collected from Hurghada, Red Sea, Egypt, to investigate larval nematodes of the genus Anisakis. The larvae were detected encapsulated in the peritoneal cavity and muscle of the fish host. This examination revealed that anisakid larvae naturally infected 19 fish specimens with a prevalence of 63.33% and a mean intensity of 4.1 ± 0.40. Most of them (68 larvae: 71.57%) were found in the musculature. Morphological and morphometric analyses using light and scanning electron microscopy revealed a head re...

The aim of the present study was to evaluate the effects of various sousvide time-temperature regimes and their interactions on quality parameters of Atlantic mackerel (Scomber scombrus) during chilled storage. The mackerel fillets were exposed to sous-vide treatment at 60, 75, and 90°C for 10, 15, and 20 min and further stored for 1, 3, and 7 days at 4 ± 1°C before analysis. Changes in pH, water content and cook loss, amount of water-and salt-soluble proteins, texture, and color parameters, as well as accumulation of lipid oxidation products in sous-vide-cooked mackerel were assessed. Sous-vide cooking time and temperature had the lowest contribution to the formation of primary and secondary products of lipid oxidation, as well as increase in yellowness of the fish flesh due to their accumulation; whereas duration of chilled storage led to a significant increase in oxidation and yellowness (p < 0.05). Duration of chilled storage also affected structural and textural properties of the fish muscle, leading to a decreased cook loss. At the same time, sous-vide cooking decreased the firmness of the fish muscle. Duration of chilled storage was found to have the highest significant effect (p < 0.001) on all physicochemical characteristics of sous-vide-cooked mackerel.

Background: Anisakiasis is a zoonotic disease caused by accidental ingestion of live Anisakis spp. third-stage larvae present in raw or undercooked seafood. Symptoms of this emerging infectious disease include mild-to-severe abdominal pain, nausea, and diarrhea. Some patients experience significant allergic reactions. Aims: In order to better understand the onset of anisakiasis, we aimed to: (i) histopathologically describe severe inflammatory/hemorrhagic infection site lesions in Sprague-Dawley rats experimentally infected with Anisakis pegreffii larvae; and (ii) qualitatively and quantitatively characterize the transcriptomes of affected tissues using RNA-Seq. Methodology: The experiment was performed on 35 male rats, sacrificed at 5 time points (6, 10, 18, 24, and 32 h post-infection). Gastric intubation was performed with 10 A. pegreffii larvae (N = 5 infected rats per time point) or 1.5 ml of saline (external control N = 2 rats). 16 pools, seven for muscle tissues and nine for stomach tissues, were created to obtain robust samples for estimation of gene expression changes depicting common signatures of affected versus unaffected tissues. Illumina NextSeq 500 was used for paired-end sequencing, while edgeR was used for count data and differential expression analyses. Results: In total, there were 1372 (855 up and 517 down) differentially expressed (DE) genes in the Anisakis-infected rat stomach tissues, and 1633 (1230 up and 403 down) DE genes in the muscle tissues. Elicited strong local proinflammatory reaction seems to favor the activation of the interleukin 17 signaling pathway and the development of the T helper 17-type response. The number of DE ribosomal genes in the Anisakis-infected stomach tissue suggests that A. pegreffii larvae might induce ribosomal stress in the early infection stage. However, the downstream pathways and post-infection responses require further study. Histopathology revealed severe inflammatory/hemorrhagic lesions caused by Anisakis infection in the rat stomach and muscle tissues in the first 32 h. The lesion sites showed infiltration by polymorphonuclear leukocytes (predominantly neutrophils and occasional eosinophils), and to a lesser extent, macrophages. Bušelić et al. Rat Response to Anisakis Infection Conclusion: Understanding the cellular and molecular mechanisms underlying host responses to Anisakis infection is important to elucidate many aspects of the onset of anisakiasis, a disease of growing public health concern.

Atlantic mackerel (Scomber scombrus) were recorded in Isfjorden, Svalbard (78˚15ʹ N, 15˚11ʹ E) in late September 2013. This record is the northernmost known occurrence of mackerel in the Arctic and represents a possible northward expansion (of ca. 5˚ latitude) of its distributional range. The examined specimens of mackerel were between 7 and 11 years old, with a mean size of 39 cm and a mean weight of 0.5 kg. Examination of stomach contents indicated that the mackerel were feeding mainly on juvenile herring (Clupea harengus). The occurrence of mackerel in the Arctic is discussed in relation to the recent increase in mackerel population size in the North Atlantic and the expansion of other North Atlantic fishes into the Svalbard region during the last decade. Using a decadal record of water temperature, we conclude that the occurrence of Atlantic mackerel in Svalbard waters is a result of a continued warming of the ocean in the region and that it follows a general trend of species' extending their distributional ranges northward into the Arctic.

Research background. It is desirable to increase the consumption of pelagic fish rich in long-chain omega-3 fatty acids. Partial replacement of traditionally used white fish species by pelagic fish will increase the content of omega-3 fatty acids, and thus improve the nutritional value but it may also affect the consumer acceptance. The aim of this study is to assess the physicochemical and sensory quality of novel fish cake prototypes prepared from haddock and mackerel mince. Experimental approach. Fillets of haddock and Atlantic mackerel were used as raw material for preparation of fish cakes. The fish fillets were minced, mixed together (in haddock/mackerel mass ratio of 100:0, 75:25 and 50:50) with salt, potato starch, pepper and full fat milk. Physicochemical and sensory analyses were further performed. Results and conclusions. The fatty acid composition analysis showed that the recommended daily intake of 250 mg of eicosapentaenoic acid and docosahexaenoic acid can easily be r...