Search Results (78)

Introduction: Fish consumption in Portugal (53.61 kg/year) and Spain (40.68 kg/year) remains the highest in the European Union, highlighting the nutritional and economic relevance of small pelagic species. However, fish composition is highly dynamic and influenced by biological and environmental factors, including reproductive cycle, seasonality, and feeding patterns. European anchovy (Engraulis encrasicolus, EE) and European sardine (Sardina pilchardus, SP) exhibit complementary spawning periods, summer and winter breeders, respectively, making them ideal models to study seasonal nutritional variability. A systematic evaluation of their proximate composition is essential not only for quality control but also to support sustainable fisheries management and nutritional recommendations. Objective: This study aimed to comparatively assess the seasonal variation in proximate composition of EE and SP fillets in early autumn and early spring, identifying species-specific nutritional advantages linked to their reproductive cycles. Methodology: Twelve composite samples (six per season) were analysed, each comprising multiple specimens of the same species (EE or SP). Standard proximate analyses were performed to determine moisture, ash, protein, and lipid content, and energy values were calculated. Statistical comparisons were conducted using SPSS (Version 21) to evaluate seasonal and interspecific differences. Results: Sardines showed higher ash, lipid, and energy values, whereas anchovies exhibited higher protein overall. Marked seasonal differences (p < 0.05) were observed: sardine (SP)—autumn: higher lipid (10.00 g/100 g) and energy (176.22 kcal/100 g); spring: higher protein (21.69 g/100 g) and ash (1.96 g/100 g); and anchovy (EE)—spring: higher protein (23.18 g/100 g), lipid (2.44 g/100 g), and energy (117.68 kcal/100 g). Notably, in early spring, anchovies surpassed sardines in protein, lipid, and energy content, highlighting a seasonal inversion of nutritional value between species. Conclusions: Results demonstrate a clear seasonal complementarity in the nutritional value of anchovies and sardines, directly linked to their reproductive cycles. Sardine reaches its peak nutritional quality in autumn, while anchovy becomes nutritionally superior in spring. The alternating pattern suggests that seasonally targeted consumption and fisheries management strategies could optimise both nutritional intake and resource sustainability. These findings provide a strong basis for developing evidence-based recommendations for consumers, industry, and policymakers. Future research should expand this approach by incorporating fatty acid profiles, micronutrients (vitamin D, selenium), and contaminants (e.g., mercury), enabling a more comprehensive evaluation of nutritional quality and food safety. Full article

Introduction: Microplastic (MP) contamination can endanger marine ecosystems and indirectly affect the well-being of humans through the ingestion of marine species. While most research investigates the digestive system, such as the gills and gastrointestinal tract of fish, it still fails to address a major oversight in understanding MP deposition in edible tissues, which is the primary route of human exposure. The differences in contamination levels among pelagic, demersal, and benthic fish in Malaysian waters remain poorly understood. This preliminary study uses Laser Direct Infrared Imaging (LDIR), a new, high-resolution, automated technique, to examine synthetic MP contamination in the edible portion of fish. Materials and Methods: The MPs were extracted from the edible tissue of three fish species representing pelagic (Fish A), benthic (Fish B), and demersal (Fish C) using KOH and sieved onto a gold mesh filter before analysis using LDIR. Results and Discussion: LDIR identified 162 MP particles, revealing clear differences by polymer type and habitat. Pelagic species mostly contained polyethylene (PE) and rubber (n = 8). Demersal species had mostly polyethylene terephthalate (PET) with small amounts of PE and rubber (n = 57). Benthic species showed the highest load, dominated by PET and polypropylene (PP) (n = 97). The morphological assessment of the MPs indicated that the polymers in pelagic fish were smaller, with an area of 2047.82 µm² and a circularity range of 0.14–0.74, indicating consistent shape. Conversely, MPs are irregular and larger in benthic fish, with areas up to 38,837.50 µm² and circularities ranging from 0.02 to 0.81. This pattern reflects specific accumulation related to habitat and potential environmental degradation processes. Conclusions: This preliminary study demonstrates the effectiveness of LDIR for detecting MPs in edible fish tissues. The findings provide a fundamental dataset on MP contamination in edible tissue and emphasize its distribution across ecological zones. Nevertheless, broader research is required to substantiate these data and assess the implications of MP contamination for the environmental stability of human and marine well-being. Full article

The present study examined fish biodiversity, livelihood dependence, cultural importance, and genetic connectivity in two ecologically linked habitats of the Sylhet region, Bangladesh: Hakaluki Haor and the Surma River. Surveys documented 60 fish species with distinct assemblage patterns between sites. Hakaluki Haor was dominated by floodplain spawners and small indigenous species that contribute to year-round subsistence harvests, whereas the Surma River supported a greater proportion of migratory and pelagic species, most notably Tenualosa ilisha. These ecological contrasts reflected differences in hydrology, habitat diversity, and fishing intensity. Household surveys confirmed the central role of fisheries in sustaining income and food security, while cultural practices surrounding hilsa consumption reinforced local stewardship norms. Mitochondrial cytochrome b sequence analysis of T. ilisha revealed low genetic differentiation between sites, indicating a single, well-connected stock maintained by seasonal flooding and the absence of major migration barriers. This convergence of ecological and genetic evidence supports treating the two sites as an integrated management unit. Effective conservation will require protecting hydrological connectivity, safeguarding dry season refugia, coordinating seasonal fishing restrictions across habitats, and incorporating cultural values into policy frameworks. The findings strengthen the scientific basis for national and regional conservation strategies and demonstrate the value of combining biological, socio-economic, and cultural dimensions in managing connected wetland–river systems. This approach can serve as a transferable model for other tropical floodplain–river complexes facing similar ecological and livelihood challenges. Full article

Understanding the reproductive physiology of marine fish is critical for sustainable fisheries management, particularly under environmental variability. This study evaluated seasonal changes in body parameters (condition factor, Kn, and gonadosomatic index, GSI, as proxies for body condition and reproductive status, respectively) and biochemical composition (P, proteins; G, glucose; L, lipids; fatty acids; and bioenergetic ratios L/P, LG, all as proxy of integrated biochemical condition) of female gonads in Strangomera bentincki, a key pelagic species in the Humboldt Current System (HCS) off south-central Chile. Moreover, environmental factors (sea surface temperature and chlorophyll-a) were also analyzed to explore their influence on the FA profile of gonads. Female body parameters showed significant seasonal variations, with high values of Kn and GSI in autumn and spring, respectively. The biochemical composition also revealed significant seasonal variation in protein and glucose content, with the highest protein levels in winter and elevated glucose in autumn. While total lipid and energy content remained relatively stable across seasons, the L/P and L/G ratios presented seasonal variations. Similarly, the fatty acid composition showed pronounced seasonal differences, particularly with increased polyunsaturated fatty acids (e.g., DHA) in winter. The SST was the environmental factor with the greatest influence on the seasonal variations in the gonadal FA profile. Altogether, these findings suggest a partial capital breeding strategy in S. bentincki, where reproductive investment depends on both accumulated reserves and environmental conditions during reproduction. This study underscores the importance of incorporating reproductive biochemical indicators into ecosystem-based fisheries management models to improve assessments of stock health and reproductive potential. Full article

Small pelagic fish are nutrient-dense foods, but whether domestic cooking alters their capacity to modulate probiotic adhesion is unclear. We prepared sardines and sprats using five household techniques (raw, cooked, steamed, baked, and fried) and generated in vitro digestates using the INFOGEST method. We tested two concentrations in two intestinal co-cultures—Caco-2/HT29 and mucin-producing Caco-2/HT29-MTX. Adhesion of Lacticaseibacillus rhamnosus, Lactobacillus gasseri, and Lactobacillus brevis were quantified. Digestates altered adhesion in a probiotic strain species in a process-dependent manner. Sprat digestates from fried or baked preparations produced the strongest stimulation, exceeding 150% in Caco-2/HT29; responses in HT29-MTX were directionally similar but attenuated. In contrast, cooked or steamed sardine digestates frequently inhibited adhesion, particularly at 0.5% (e.g., L. gasseri < 50%). Raw preparations yielded divergent outcomes across models. A two-way ANOVA confirmed significant effects of processing, concentration, and their interaction, with the interaction explaining up to 21% of the observed variance. Across conditions, L. rhamnosus adhered most consistently, whereas L. brevis and L. gasseri were more environmentally sensitive. These findings suggest that standard cooking practices alter the bioactivity of fish-derived digestates and, consequently, the adhesion of beneficial lactobacilli in intestinal cell models, selecting sprats and employing dry-heat methods may favor probiotic–host interactions under in vitro conditions. Full article

Small pelagic fish, including sardines, are essential to global fisheries and aquaculture feed production. However, these species are increasingly exposed to intense exploitation. In Chile, the common sardine (Strangomera bentincki), endemic to the Humboldt Current System, supports major industrial and artisanal fisheries. Landings are expected to reach 300,000 tons by 2025, mostly for fishmeal production. As a keystone species, S. bentincki is highly sensitive to environmental variability during early development, which can reduce recruitment and threaten long-term population sustainability. This interdisciplinary approach integrates ecological and biotechnological perspectives to assess the feasibility of controlled juvenile sardine production in land-based Ecological Aquaculture (EA) systems, including Recirculating Aquaculture Systems (RAS) and Integrated Multi-Trophic Aquaculture (IMTA), which are designed to reduce environmental impacts. These systems enable precise control of temperature, feeding regimes, and water quality, facilitating investigations into larval and juvenile survival, growth performance, and physiological responses under variable thermal and nutritional conditions. Emphasis is placed on fatty acid metabolism during ontogeny, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which are essential for somatic growth, reproductive development, and thermal tolerance. Developing standardized protocols for juvenile S. bentincki culture addresses key gaps in husbandry and physiology (temperature threshold, nutrient density, larval growth rate, etc.) while introducing a novel ecological–aquaculture integration framework. This approach links early-life ecology with applied rearing techniques to support stock enhancement, strengthen artisanal fisheries, and promote sustainable aquaculture diversification under increasing environmental variability. Full article

The Japanese chub mackerel (Scomber japonicus) is a small pelagic economically important fish species in the northwest Pacific Ocean, and its abundance and distribution are influenced by water temperature changes. In recent years, frequent marine heatwaves (MHWs), defined as prolonged anomalously warm sea surface temperature events, in this region have significantly impacted marine ecosystems and fishery resources. The effects of MHWs on Japanese chub mackerel remain poorly understood. This study analyzed the relationship between Japanese chub mackerel abundance and MHW characteristics in the northwest Pacific Ocean from 2014 to 2021. It includes comparative analyses on the spatiotemporal patterns of catch per unit effort (CPUE) and MHWs, an exploration of CPUE distribution under varying MHW intensities and durations, and an assessment of the relationship between MHW characteristics and CPUE using a Generalized Additive Model (GAM) approach. Additionally, CPUE variations before, during, and after MHWs in 2016, 2018, and 2021 across different regions are measured. Results reveal significant interannual variability in MHWs, with increasing trends in the frequency, intensity, and duration of MHWs. As the frequency, intensity, and duration of MHWs increased, the abundance of Japanese chub mackerel decreased, particularly in years with higher intensity and longer lasting MHWs. The study concludes that MHWs negatively impact Japanese chub mackerel, highlighting the urgent need for climate-adaptive fishing and management strategies. Full article

This review examines the animal welfare implications associated with the purse seine fishing method as applied to the following small pelagic species: Atlantic herring (Clupea harengus), Peruvian anchoveta (Engraulis ringens), Atlantic chub mackerel (Scomber colias), and Atlantic mackerel (Scomber scombrus). The analysis is based on synthesized data from the purse seine Method Profile, recently introduced in the catch branch of the fair-fish database—an open-access platform dedicated to compiling, evaluating, and systematically categorizing technical and/or scientific literature on aquatic animal behaviour and welfare. The Method Profile is a novel tool that outlines the commercial relevance of the respective fishing method, its target species, and general operational setup. It provides a structured overview of welfare hazards encountered across the main phases of the fishing process, including prospection, setting, capture, hauling, emersion, gear release, sorting, storage, and stunning and slaughter. In addition, this profile also addresses bycatch and discarding issues as well as environmental hazards associated with the fishing method. Identified welfare concerns in purse seining for the four small pelagic species include high stress levels resulting from intense crowding—primarily leading to hypoxia, mechanical injuries, and mortality—as well as issues related to scooping or pumping fish on board, (live) storage, and the lack of effective stunning and slaughter protocols. Furthermore, the bycatch rate of (undersized) target and diverse non-target species, as well as ghost fishing from abandoned, lost, or discarded gear, pose significant risks requiring effective mitigation. In this review, we critically evaluate factors influencing the welfare outcomes of the four pelagic species caught by purse seine and discuss potential mitigation strategies, such as operational improvements, gear modifications, and management measures. Full article

Small pelagic fish, such as sardines and sprats, are an affordable and nutritionally rich source of omega-3 fatty acids and bioactive peptides. While their nutritional value is well established, the impact of standard household cooking methods on their immunomodulatory potential and effects on intestinal integrity remains poorly understood. Fish were prepared using five culinary techniques (raw, boiled, steamed, baked, and fried), digested via the INFOGEST protocol, and applied at 1% concentration in a Caco-2 co-culture model combined with lipopolysaccharide-stimulated RAW264.7 macrophages. NO and TNF-α production, and epithelial permeability were assessed. Steamed sardines induced the highest NO levels (122%) in activated macrophages, while raw sardines inhibited NO production (73%). Baked sardines and raw sprats triggered higher TNF-α production (>400 pg/mL). Boiled sardines and baked sprats caused the strongest disruption of epithelial permeability (>13%), whereas steamed sardines and raw sprats preserved barrier integrity (<11%). Notably, digested baked and fried fish preserved suppressive effects on NO and TNF-α even after translocation across the epithelial layer. Culinary processing significantly modulates the bioactivity of fish. In general comparison, steaming is gentler than dry heat cooking methods, as it better preserves anti-inflammatory effects and barrier-promoting properties. These findings highlight the relevance of cooking practices in modulating the functional benefits of fish consumption. Full article

Fish stocks and their management are paramount for sustainable fisheries under the ongoing changes in atmosphere–sea interactions. The Aegean Sea, one of the composite seas influenced by different water masses, is characterized by a diverse ecosystem. Small pelagic fish are abundant and tend to form schools that vary in size. One of the most efficient and rapid techniques for sampling fish schools over a large area is the use of acoustic methods. Therefore, an acoustic survey was conducted in the coastal areas along the entire Turkish Aegean waters between June and August 2024, using a scientific quantitative echosounder equipped with a split-beam transducer operating at 206 kHz. During the survey, environmental parameters, including water physics, optics, and bathymetry, were measured at 321 stations. Additionally, satellite data were used to obtain water primary production levels for each sampling month across the entire study area. Using a custom computer algorithm written during the present study in MATLAB (2021a), fish schools were automatically detected to measure various morphological and acoustic features. Through a series of statistical analyses, three optimal clusters, validated with the total silhouette sum of distances (1317.38), were identified, each characterized by specific morphological, acoustic, and environmental variables associated with different areas of the study. School morphology and acoustic properties also varied with bottom depth. Cluster 1 was mostly found in open and relatively deep waters. Cluster 2 appeared in areas impacted by anthropogenic sources. Principal Component Analysis (PCA) revealed that the first component (PCA1) was correlated with school height from the bottom (HFB) and overall school height (SH), followed by minimum depth (MnD), maximum depth (MxD), and volume backscattering strength at the school edge (SvE). The second component (PCA2) was associated with school width (SW) and area (A). Cluster 1 was characterized by schools with large SW and A, and relatively high HFB and SH. Cluster 2 showed low HFB and SH, while Cluster 3 had high MnD and MxD and low SvE. Based on the descriptors for these clusters, each cluster could be attributed to fish species at different life stages inferred based on target strength (TS), namely sardine, horse mackerel, and chub mackerel, distributed along the entire Turkish Aegean coast. Full article

Mothocya parvostis Bruce, 1986 (Isopoda: Cymothoidae) is a parasite that mainly infests the branchial cavity of Japanese halfbeak, Hyporhamphus sajori (Temminck and Schlegel, 1846) (Beloniformes: Hemiramphidae) (pelagic marine fish). Although it has generally been considered to parasitize the branchial cavity throughout its life, early studies suggested that mancae (first free swimming stage) initially attach to the body surface of the host. In this study, H. sajori juveniles were collected off Ohkurokamishima Island, Hiroshima, Japan, and examined for cymothoid infestation. Of the 57 individuals that were examined, 5 were parasitized, all on the ventral surface of the fish bodies. One manca was genetically identified as M. parvostis based on the sequence of cytochrome c oxidase subunit I (100% or 99.81% identity with known sequences). These findings support the earlier claim that mancae infest the body surface of H. sajori. Due to the host’s slender body and small branchial cavity, early-stage parasites may remain external in the initial phase of infestation. Full article

Live bait fishing, which was initiated around the 1950s on the coast of Dakar for the exploitation of tropical tunas, remains poorly studied. This study aims to examine the ichthyological diversity in Hann Bay and analyze the seasonal variation in species used as live bait. Ten experimental fishing campaigns were conducted between February and November 2023, using a beach seine and a purse seine. Captured individuals were sorted by species, counted, and weighed. Salinity and temperature drive seasonal changes in live bait fish communities in Hann Bay. Beach seine captured 389,171 individuals from 65 species, representing a biomass of 1743 kg. Purse seine yielded 9408 individuals from 62 species, representing a total of 306 kg. Ten species were identified as live bait, ten of which were caught with beach seine (Engraulis encrasicolus dominated) and eight with purse seine (Sardinella maderensis dominated). Eight of the ten live bait species were caught by both purse seine and beach seine. For beach seine, Shannon’s index was higher during the cold season, indicating a better distribution of species abundance. For purse seine, species abundance was lower in the cold season. Pielou’s evenness index indicated a more balanced assemblage in the cold season for beach seine (0.65) and in the warm season for purse seine (0.74). The number and weight of live baits did not vary significantly between seasons. These results may support the sustainable management of coastal small pelagics, whose juveniles are used as live bait. Full article

As a semi-pelagic fish with commercial value, Mediterranean horse mackerel, Trachurus mediterraneus (Steindachner, 1868), is highly important both for the ecosystem, as a link between trophic levels, and for fisheries and local livelihoods. This study investigates the T. mediterraneus stock along the Romanian coast for more than 10 years (2014–2024), reporting the following data on its bio-ecological characteristics and stock status: size, age, sex ratio, and estimated biomass. Horse mackerel at the Romanian coast revealed an initially slower growth rate followed by acceleration in later years, which may reflect local ecological influences such as resource availability, environmental conditions, or selective pressure. The spatial distribution of the species along the Romanian shelf indicates a clear pattern of coastal aggregation, highlighting the need for targeted and precautionary fisheries management measures, aiming to ensure a sustainable stock. Full article

Climate change is disrupting marine ecosystems, necessitating a deeper understanding of environmental and fishing-related impacts on exploited species. This study examines the effects of physical factors (temperature, thermal anomalies, salinity, seabed conditions), biogeochemical elements (pH, oxygen levels, nutrients, primary production), and fishing pressure on the biomass of commercially important species in the Alboran Sea from 1999 to 2022. Data were sourced from the Copernicus observational program, focusing on the geographical sub-area 1 (GSA-1) zone across three depth ranges. Generalized Additive Models were applied for analysis. Rising temperatures and seasonal anomalies have largely negative effects, disrupting species’ physiological balance. Changes in water quality, including improved nutrient and oxygen concentrations, have yielded complex ecological responses. Fishing indices highlight the vulnerability of small pelagic fish to climate change and overfishing, underscoring their economic and ecological significance. These findings stress the urgent need for ecosystem-based management strategies that integrate climate change impacts to ensure sustainable marine resource management. Full article

Fish are a valuable source of high-quality protein and essential nutrients, making them an integral component of a healthy diet. However, protein digestibility, influenced by preparation methods, is a critical factor in assessing nutritional quality. This study aimed to evaluate the impact of various thermal processing methods on the protein digestibility of two commonly consumed small pelagic fish species: sardines (Sardina pilchardus) and sprats (Sprattus sprattus). Protein digestibility was assessed using two complementary approaches: total protein digestibility and the Digestible Indispensable Amino Acid Score (DIAAS). Fish samples were subjected to different cooking methods, including boiling, steaming, baking, and frying. All thermal treatments enhanced protein digestibility compared to raw fish. Fried samples exhibited the highest total protein digestibility, with sardines reaching 92.4 ± 4.3% and sprats reaching 89.5 ± 4.4%. DIAAS values corroborated these findings, indicating superior protein quality in fried fish. While frying yielded the highest digestibility scores, steaming and boiling provided a favourable balance between improved protein quality and lower potential health risks, with baking achieving comparable results. Full article