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An important food-producing sector in Egypt is aquaculture and fisheries; however, several pathogenic microorganisms lead to high mortalities and significant economic losses. The occurrence of Psychrobacter glacincola infection among 180 wild marine fishes collected from the Red sea at Hurghada, Egypt were investigated in the present study. The disease prevalence rate was 6.7%. The recovered isolates were subjected to biochemical and molecular identification. The study also investigated pathogenicity and the antibiogram profile of the recovered isolates. The clinical examination of the infected fish revealed various signs that included lethargy and sluggish movement, hemorrhages and ulcers on the body and the operculum, scale loss, and fin congestion and rot, especially at the tail fin. Furthermore, during postmortem examination, congestion of the liver, spleen, and kidney was observed. Interestingly, 12 isolates were recovered and were homogenous bacteriologically and biochemically. The phylogenetic analysis based on 16S rRNA gene confirmed that MRB62 identified strain was closely related the genus Psychrobacter and identified as P. glacincola and was pathogenic to Rhabdosargus haffara fish, causing 23.3% mortality combined with reporting a series of clinical signs similar to that found in naturally infected fishes. The present study also showed that P. glacincola isolates were sensitive to all antibiotics used for sensitivity testing. Our findings add to the body of knowledge regarding the occurrence of pathogenic P. glacincola infection in Egyptian marine fishes and its potential effects on fish. Future large-scale surveys exploring this bacterium among other freshwater and marine fishes in Egypt would be helpful for the implementation of effective strategies for the prevention and control of this infection are warranted. [ABSTRACT FROM AUTHOR]

A recent study was performed to assess the morphometric variation of otoliths of the Decapterus kurroides collected in the northern Sulu and southern Sibuyan seas in delineating fish stocks. Seven of the otolith morphometric descriptors (otolith length, OL; otolith height, OH; otolith weight OW; otolith area, OA; otolith perimeter, OP; ellipticity, EL; and aspect ratio, AR) demonstrated a significant positive correlation with fish length and six (rectangularity, RE; squareness, SQ; roundness, RO; circularity, CI; compactness, CO; and form factor, FF) demonstrated a significant negative correlation. In terms of intraspecific comparisons, almost all the otolith morphometric descriptors were significantly different between the two sites (except RE and OH). Further, principal component (PC) analysis showed that direct otolith morphometric descriptors such as OL, OH, OW, OA, and OP explained 61.71% of the differences (PC1). In contrast, derived otolith descriptors such as EL, AR, and CO explained 22.00% of the variations (PC2) for a total of 83.71% explained variations with the eight otolith morphometric descriptors. Statistics reveal that D. kurroides from the Sibuyan Sea have significantly larger, heavier, and more elliptical otoliths than those from the Sulu Sea. Results suggested that the D. kurroides from Sulu and Sibuyan seas are two different phenotypic stocks. Further studies such as otolith microchemistry, genetics, other life history-based studies, and present exploitation levels should be carried out to supplement the results of this study to fully establish the D. kurroides stock structures within Philippine waters. [ABSTRACT FROM AUTHOR]

Erysipelothrix rhusiopathiae is a Gram-positive bacillus that infects animals such as pigs, sheep, cattle, fish, and crustaceans. This microorganism's reports of infection have recently increased in fishers, handlers of fish products, and people who clean ponds. This bacterium remains in the slime and scales of the fish, without harming them. However, it has been shown to cause septicemia in eels and ornamental fish. This research aimed to detect the presence of E. rhusiopathiae in scales of various species of freshwater and saltwater fish. 390 samples of the red snapper, salmon, mojarra, lisa, and corvina species from different states of the Mexican Republic were collected. The bacterium isolation was carried out in a modified packer medium and agar blood, and its identification was performed in the API Coryne system. A second identification was performed by amplifying of the rRNA 16s genes and the spa A gene by multiplex PCR assay. The results obtained by the API Coryne system showed 15% identification for E. rhusiopathiae, while only 10% were positive by the multiplex PCR technique. The most notable detection of this bacterium was found in mojarras. The presence of E. rhusiopathiae in the scales of these fish represents a potential risk for fish handlers, such as in the formulation of balanced feed for the development of aquaculture, poultry, and pig farming activities. [ABSTRACT FROM AUTHOR]

Growth patterns and hatch-date distributions of two mesopelagic Red Sea fishes, Vinciguerria mabahiss and Maurolicus mucronatus, were inferred from otolith microstructure analysis. Estimated somatic growth rates were lower than other mesopelagic fish at similar tropical and subtropical latitudes. Low zooplankton concentrations and high Red Sea water temperatures may explain the low growth rates observed. Maurolicus mucronatus grew faster (0.15 ± 0.005 mm day−1) than V. mabahiss (0.13 ± 0.003 mm day−1). Growth differences could be attributed to different vertical distributions and migration patterns. Significant differences in somatic growth between locations were also observed for V. mabahiss. Individuals at Kebrit (24°48' N) grew significantly faster (0.16 ± 0.005 mm day−1) than those at the warmer, more southern (21°27' N) Atlantis II station (0.12 ± 0.003 mm day−1). For V. mabahiss, otolith increment width at age was similar at hatching times throughout the late spring/summer and autumn. However, for M. mucronatus, growth trajectories were hatch-date dependent, with the earliest cohorts displaying the highest maximum growth rates. This study provides baseline data which will be essential for a better understanding of their population dynamics. [ABSTRACT FROM AUTHOR]

This research focused on discovering parasites in the fish Carangoides bajad (orange-spotted trevally) (Forsskal, 1775) that were captured from the Red Sea off Saudi Arabia. Carangoides bajad (n = 120) were collected during the spring and summer of 2019. Internal parasites were extracted and subjected to parasitological analyses and fish intestines were subjected to histopathological analyses. The average length and weight of Carangoides bajad were 39.88 ± 8.7 cm and 1.68 ± 0.58 kg, respectively. We identified Anisakis (17.5%), Lecithocladium (23.33%), and Bucephalus spp (29.17%) in the infected fish. Female fish outnumbered males, suggesting that sex significantly influence the prevalence of parasitic infections. Parasites, or evidence of parasitic infection, were not detected in small fish (weighing 0.5-0.90 kg or 1.0-1.49 kg, and 20.0-29.9-cm long). Similarly, the values of Fulton's condition factor (K) ranged between 3.0-3.99 and 4.0-4.99, supporting the conclusion that these small fish were not infected with parasites. The data on larger fish (weighing 1.5-1.90 kg or 2.0-2.49 kg or 2.5-2.99 kg and length 20.0-29.9 cm or 30.0-39.9 cm or 40.0-49.9 cm or 50.0-59.9 cm) reveal that parasitic infections significantly influenced the length, weight, and Fulton's condition factor (K) according to the prevalence and intensity of infection of Carangoides bajad. Histopathological examination revealed intestinal tissue damage; and 45% of inflamed tissues involved swelling of the intestinal villi. Further, we observed separation of the mucosal epithelia from the submucosa, proliferation of goblet cells, and lymphocyte infiltration accompanied by atrophy and lysis of intestinal villi. The present study demonstrates infection of Carangoides bajad with three types of parasites and documents their deleterious effects. [ABSTRACT FROM AUTHOR]

Eicosapentaenoic acid and docosahexaenoic acid are n-3 fatty acids that are highly available in sea-fishes. Many studies have revealed that n-3 fatty acids play antidiabetic activity. In this study antidiabetic activity of the three sea fishes oils, 'volavetki' (Panna microdon, Bleeker 1849), 'ruli' (Coilia dussumieri, Valenciennes 1848), and 'tapra' (Opisthopterus tardoore, Cuvier 1829), as well as three fresh-water fishes oils, 'bata' (Labeo bata, Hamilton 1822), 'folui' (Opisthopterus tardoore, Cuvier 1829), and 'mourala' (Amblypharyngodon mola, Hamilton 1822) evaluated high lipid diet (HLD) and STZ-induced type 2 diabetes mellitus (T2DM) rats. The GC-MS analysis revealed high n-3 fatty acid content in volavetki oil. Supplementation of sea-fish oils and antidiabetic effect was monitored by fasting plasma blood glucose and HbA1c. Also, insulin, c-peptide, glucagon-like peptide-1, dipeptidyl peptidase-4, free fatty acid receptor 1, glucokinase, glucose-6 phosphatase, superoxide dismutase, glutathione peroxidase, catalase, malondialdehyde, plasma total cholesterol, low density lipoprotein, triglycerides, high density lipoprotein, c-reactive protein, total protein, alkaline phosphatase, and histopathology of pancreatic tissues were evaluated. Out of six fish oils, oral supplementation with volavetki oil resulted in significant reduction of plasma blood glucose, HbA1c of T2DM rat. All other parameters in T2DM rats were returned to near normally by treatment of volavetki oil. These findings strongly indicate that volavetki oil possess antidiabetic activity. [ABSTRACT FROM AUTHOR]

Sea-cage fish farms cause wild fish to aggregate nearby. Nevertheless, it is still not clear to what extent the attraction effect around sea-cage fish farms varies according to the type and size of the reared species. We examined this attraction effect in six sea-cage fish farms across the Aegean Sea using an integrated approach combining these variables with seasonal and spatial factors. Six 5-minute rapid visual counts were conducted on each farm complex for comparing the wild fish aggregations around the sea-cages concerning both cultivated species (seabass and seabream) and their sizes (adult and juvenile). We counted a total of 509,061 fishes, representing 36 species and 18 families. While 292,377 fish belonging to 34 species were counted in seabass cages, 216,684 fish belonging to 27 species were counted at seabream cages. In addition, 160,192 fish belonging to 28 species were counted around the juvenile cages, while 348,869 fish belonging to 34 species were counted at adult fish cages. The study shows that wild fish communities are formed around the sea-cages where seabass and seabream are reared in both adult and juvenile sizes in the Aegean Sea. According to our results, the fish species reared in the cages do not have a statistically significant effect on the wild fish community structure around the cages, whereas fish size, which was correlated with cage biomass and a longer history of feeding, had a strong effect. Other factors affecting the wild fish community structure around the cages are the season and the location of the cages. [ABSTRACT FROM AUTHOR]

Despite playing a critical role in oligotrophic ocean food webs, relatively little is known about the diet of mesopelagic fishes in the Indian Ocean. These fishes are an abundant component of the micronekton assemblages and are a major energy- and nutrient-rich food source, linking the plankton which they feed on to marine predators at higher trophic levels. DNA metabarcoding, a molecular method to identify species from mixed assemblages, has not been commonly used in studies of mesopelagic fish diet, but using it to analyse gut contents can greatly improve the understanding of mesopelagic fish feeding ecology. In this study, we apply DNA metabarcoding (18S rRNA and COI) to gut contents from Stomiiformes and Myctophiformes species from 20 sampling stations covering 30° of latitude on the 110°E meridian in the Indian Ocean. In total, 174 fish specimens from 13 genera were examined. Differences in the gut contents among fish families, geographic areas and fish stages were identified. Specimens within the family Myctophidae had the most diverse diet, more so in the northern sampling stations than the south. Gonostomatidae had the least diverse diet. Overall, the most frequently identified prey items from the gut contents were calanoid copepods and halocyprid ostracods. The proportion of halocyprids were also identified to be significantly different among Myctophidae larvae and juvenile specimens, which is a potential ontogenic shift in diet towards a higher ostracod contribution in juveniles as mouth gape increases. In comparison with other plankton abundance data, Copepoda were the most abundant plankton in the gut contents of all fishes sampled throughout the latitudinal gradient, allowing them to be a potential food resource through the region. There are indications that other less abundant plankton, such as Ostracoda and Malacostraca, may be preferentially targeted by some mesopelagic fish families. • DNA metabarcoding captured a range of dietary items from mesopelagic fishes. • Gene region targeted substantially influenced taxa detection. • Fish families, geographic areas and fish stages have different diets. • Calanoid copepods and halocyprid ostracods were the most frequently consumed prey. • Halocyprids were significantly more frequent in myctophid juveniles than in larvae. [ABSTRACT FROM AUTHOR]

Information about stomach content composition of fish species of a temperate coastal fish community (western Dutch Wadden Sea) over the period 1930–2019 was analysed to reconstruct long-term trends in trophic position of individual species. Stomach data were not evenly distributed but clustered both with respect to years as well as fish species. For 18 fish species, all being omnivorous and belonging to different functional groups (pelagic, benthopelagic, demersal) and guilds [(near)-resident, juvenile marine migrants, marine seasonal visitiors], prey consumption and trophic position over time could be analysed. Prey occurrence in the stomachs of different fish species showed variability over time, most likely due to fluctuations in prey abundance, but without a trend. For all species, individual fish showed variablity in trophic position in the order of 1 unit or even more both within and between years. However, in all 18 species, no significant trend in mean trophic position over time could be found, despite the serious anthropogenic stress (pollution, eutrophication events, climate change) and the decrease in fish abundance in the area during the last 50 years. The present study does not indicate any changes in trophic position of individual species in the western Dutch Wadden Sea over the last 80 years. At the community level, trophic structure varies due to interannual fluctuations in species composition and year-to year fluctuations in the relative abundance of the various fish species. At the ecosystem level the trophic role of the fish community has been degraded due to the decrease in total fish biomass in the area. • This study indicates stability any changes in trophic position of individual species in the western Dutch Wadden Sea over the last 80 years. • Most species caught appear omnivorous over the large time scale. • Local and interannual differences were found in the abundance of demeral fish in the Wadden Sea. • General patterns in TP of Wadden Sea fish were found. Therefore, at the community- and ecosystem level the TP of the fish community might differ. [ABSTRACT FROM AUTHOR]

Seasonal harvest restrictions are a common strategy in fisheries management, designed to mitigate fishing pressure on economically and recreationally valuable fish and invertebrate stocks. However, uncertainty regarding recreational fishing effort responses to seasonal closures can lead to unintended consequences for target and non-target species. This is especially true in the Gulf of Mexico reef fishery, where anglers can switch among multiple target species and discard mortality for co-occurring species is high. Therefore, understanding the drivers of recreational fishing effort is needed to support management decisions. This study addresses knowledge gaps by employing a statistical model to analyze the relationships between recreational reef fish effort (measured in angler-trips) and species-specific seasonal management in the Gulf of Mexico along the west coast of Florida. We focused on ecological and management variables surrounding gag (M. microlepis), red grouper (E. morio), and red snapper (L. campechanus), which are among the most recreationally sought-after species targeted along the west coast of Florida. We also considered environmental covariates such as seasonal patterns, inter-annual changes in species abundance, and socioeconomic factors (i.e., numbers of saltwater fishing licenses sold and economic trends). Our analysis indicated considerable variation in effects of seasonal, environmental, and management predictors on recreational effort that were region-specific. Notably, management predictors related to both red snapper and gag, such as the fraction of a month open to harvest (both species) and the length of the red snapper season, directly influenced recreational effort. Given recent substantial reductions in the Gulf of Mexico gag season, we were particularly interested in the effect of gag management on angler-trips, but we did not find strong evidence that effort concentration has taken place for this species at this time. This information provides foundational insights into the seasonal, biological, and anthropogenic drivers of recreational angler reef fish effort along the west coast of Florida. This model, or related frameworks, could be valuable in forecasting future trends in recreational effort along the west coast of Florida specifically and the Gulf of Mexico more generally, and may be instrumental for managers seeking to comprehend the consequences of changes to seasonal reef fishery management. • Red snapper and gag temporal management influenced recreational effort along the west coast of Florida. • The fraction of months open to harvest for both red snapper and gag were both positively associated with effort. • Red snapper season length was negatively associated with effort, suggesting effort concentration. • Gag season length was not correlated with effort, suggesting effort concentration is not (yet) occurring for this species. [ABSTRACT FROM AUTHOR]

Australia used to be an active law enforcer in the Southern Ocean in the 2000s and manifested its fulfillment of multiple roles and duties in exercising jurisdictions effectively to deter the Illegal, Unreported and Unregulated (IUU) fishing in this region. This paper provides an updated review of Australia's maritime enforcement against IUU fishing. Australia's approach to combating IUU fishing in the Southern waters has been reflected in its legislation, institutional arrangements, as well as judicial cases. This paper examines international and national laws relevant to Australia's jurisdictions in the Southern Ocean, as well as critically reviews Australia's institutional arrangements and availability of military resources in maritime enforcement. A analysis of enforcement programs and judicial practices is also provided by this paper. [ABSTRACT FROM AUTHOR]

Tracking large-scale movements of fishes in the ocean's midwaters, below the euphotic zone and above the seafloor, is extremely challenging. Archival satellite telemetry devices rely on light, sea surface temperature, or bottom depth data to estimate location. Consequently, geolocation of fishes inhabiting the twilight (mesopelagic: 200–1000 m) and midnight (bathypelagic: 1000–4000 m) zones has been restricted to hypothesized movement routes, thereby precluding a baseline ecological understanding against which to assess potential anthropogenic impacts. We assessed the viability of comparing depth-temperature profiles measured by animal-borne satellite tags against those from 3D ocean-resolving models and incorporated known locations from acoustic telemetry to enable a quantitative framework for deep-sea geolocation. Testing of alternative, data-driven likelihood scenarios on a deep-water shark species assemblage with marked variation in modal depth distributions confirmed that the methodological frontier of geolocation can be advanced into the twilight and midnight zones. We identify key limitations in deep-water geolocation, and ways to overcome them, identifying a viable path for robust location estimates that can help address the knowledge gap on fish movement ecology in the deep sea. Our findings suggest that leveraging state-of-the-art geolocation approaches, in combination with novel technologies, raises new opportunities for studying enigmatic deep-ocean ecosystems. • Methods for geolocation of fishes in the ocean's midwaters are assessed. • Alternative, data-driven likelihoods are tested as inputs to a movement model. • Results confirmed midwater geolocation as viable, but with key limitations. • Novel tracking methods and technologies can surmount deep-sea fish knowledge gaps. [ABSTRACT FROM AUTHOR]

Species distribution models predict a poleward migration for marine ectotherms with ocean warming. However, a key limitation in current species distribution models (SDM) is that they do not account for population-specific heterogeneity in physiological responses to temperature change resulting from local adaptations and acclimatization. To address this gap, we developed a novel, Physiology Integrated BioClimate Model (PIBCM) that combines habitat-specific metabolic thermal physiological tolerance of a species into a bioclimate envelope model. Using a downscaling approach, we also established a fine-resolution coastal sea-surface temperature data set for 2050–2080, that showed a high degree of location-specific variability in future thermal regimes. Combining predicted temperature data with the PIBCM model, we estimated habitat distribution for a highly eurythermal intertidal minnow, the Atlantic killifish (Fundulus heteroclitus), a species that likely presents a best-case-scenario for coastal vertebrates. We show that the killifish northern boundary shifts southwards, while distinct habitat fragmentation occurs in the southern sub-population (due to migration of adjacent fish populations to the nearest metabolically optimal thermal habitat). When compared to current SDMs (e.g., AquaMaps), our results emphasize the need for thermal physiology integrated range shift models and indicate that habitat fragmentation for coastal fishes may reshape nursery habitats for many commercially and ecologically important species. [ABSTRACT FROM AUTHOR]

The regulation of high sea fishing would not be successful without cooperation among the states in the current international society, without a world government. However, the ongoing quest for cooperation in the field of fishery governance focuses too much on the unilateral responsibility of a state to cooperate with a RFMO, overlooking the responsibility of state parties of an RFMO or the state seeking to regulate IUU fishing. This essay reveals that the equitable consideration of fishery governance is sometimes prejudiced in the name of conservation. Fishery governance involves food security, employment, free trade, and the environment. An ideal regime of high sea fishing is expected to balance the conflicting values and bring an end to the fragmentation of international law. The systemic interpretation approach, which is based on Article 31, paragraph 3(c) of the Vienna Convention on the Law of Treaties, contributes to a fairer governance of high sea fishing. Such an approach revives the obligation of the state to cooperate in the fishery sector by referring to external legal sources, including human rights laws, WTO laws, and environmental laws. [ABSTRACT FROM AUTHOR]

The population dynamics of many colonially breeding seabirds are characterized by large interannual fluctuations that cannot be explained by environmental conditions alone. This variation may be particularly confounded by the use of skipped breeding by seabirds as a life‐history strategy, which directly impacts the number of breeding pairs and may affect the accuracy of breeding abundance as a metric of population health. Additionally, large fluctuations in time series may suggest that the underlying population dynamics are heavy tailed, allowing for a higher likelihood of extreme events than expected under Gaussian dynamics.Here, we investigated the effect of demography on time series for abundance of the Adélie penguin Pygoscelis adeliae and explored the occurrence of heavy‐tailed dynamics in observed Adélie time series. We focus this study on the Adélie penguin as it is an important bellwether species long used to track the impacts of climate change and fishing on the Southern Ocean ecosystem and shares life‐history traits with many colonial seabirds.We quantified the impacts of demographic rates, including skipped breeding, on time series of Adélie abundance simulated using an age‐structured model. We also used observed time series of Adélie breeding abundance at all known Antarctic colonies to classify distributions for abundance as Gaussian or non‐Gaussian heavy tailed. We then identified the cause of such heavy‐tailed dynamics in simulated time series and linked these to spatial patterns in Adélie food resource variability.We found that breeding propensity drives observed breeding fluctuations more than any other vital rate, with high variability in skipped breeding decoupling true abundance from observed breeding abundance. We also found several Antarctic regions characterized by heavy‐tailed dynamics in abundance. These regions were often also characterized by high variability in zooplankton availability. In simulated time series, heavy‐tailed dynamics were strongly linked to high variability in adult survival.Our results illustrate that stochastic variability in abundance dynamics, particularly the presence of variable rates of skipped breeding, can challenge our interpretation of fluctuations in abundance through time and obscure the relationship between key environmental drivers and population abundance. [ABSTRACT FROM AUTHOR]

Increasing pressure of sea lice, development of multi‐resistance to chemotherapeutants, and alternative delousing strategies have been raising concerns about the environmental impacts of salmon farming. Ectoparasitic sea lice and its treatments represent a major bottleneck for the development of the Norwegian salmonid aquaculture. The environmental impacts of different treatments and their contribution to the salmon footprint remain unknown; these processes have been excluded from life cycle assessment (LCA) of farmed salmon. In this work, we apply LCA to quantify the impacts of three different value chains expressed per ton of cleaner fish farmed/fished, distributed, and used. The impacts of farmed lumpfish, farmed wrasse, and fished wrasse are then combined to calculate the footprint of the Norwegian biological lice treatment mix, expressed per ton of salmon produced. We found that wrasse fishing generates considerably lower impacts than farmed lumpfish and, a fortiori, farmed wrasse. The direct comparison of these value chains is compromised since LCA is unable to quantify ecosystem impacts and because cleaner fish delousing efficiencies remain unknown. Overall, the impacts of biological lice treatments have a low contribution to the salmon footprint, suggesting that using this treatment type could be a sound approach to treat salmon. However, such favorable results depend on three critical factors: (1) the efficiency of biological lice treatments needs to be confirmed and quantified; (2) ecosystem impacts should be accounted for; and (3) cleaner fish welfare issues must be addressed. This article met the requirements for a gold‐gold JIE data openness badge described at http://jie.click/badges. [ABSTRACT FROM AUTHOR]

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There is a need for improved understanding of how climate-change driven rises in sea level and increased ocean temperatures will affect fish assemblages in rocky shore tidal pools. Rising sea levels are predicted to alter habitat availability and increasing ocean temperatures will drive tropicalisation, both of which are likely to alter tidal pool fish assemblages. Consequently, we examined changes in fish assemblages in tidal pools at four sites in Coffs Harbour, Australia, using baited video sampling. Data were collected seasonally at each site, in pools at differing tidal elevations. We identified significant differences in tidal pool fish assemblages among elevations and found that assemblages exhibited cyclic seasonal patterns. Modelling identified that ocean temperature was the most powerful factor for explaining variations in assemblages, followed by pool area and pool elevation. Results highlight that distinct fish assemblages occur in tidal pools at different elevations and indicate that assemblages at higher elevations could be squeezed out by rising sea levels and by increased competition from tropical fish species. Future conservation assessments are needed to determine whether latitudinal and vertical range shifts for tidal pool fishes are possible, with facilitation of these range shifts needed to address displacement of tidal pool fishes by rising sea levels and ocean temperatures. [ABSTRACT FROM AUTHOR]

This Formal Comment uses re-analysis after appropriate corrections to claim that the extreme decline effect reported by Clements et al. is a statistical artefact caused by the way they corrected for zeros in percentage data, exacerbated by errors in data compilation, selective data inclusions and missing studies with strong effects. [ABSTRACT FROM AUTHOR]

(d) The contacted fish exhibited severely attenuated and flattened epithelium (yellow arrow) and alteration in their pigment layer on the dorsal skin (black arrow, H&E stain) gl Field observations suggested that the sea anemone may be the cause of the acute death of the snubnose pompano and permit. Keywords: broodstock; mortality; permit; red drum; snubnose pompano EN broodstock mortality permit red drum snubnose pompano 1799 1803 5 10/14/22 20221101 NES 221101 In February 2022, unusual acute mortalities were observed in snubnose pompano ( I Trachinotus blochii i ) and permit ( I T. falcatus i ) broodstock held in sea cages in Nha Phu lagoon, Khanh Hoa, Vietnam. Thirty fish ( I n i = 30) were divided evenly among three groups: high density (25 sea anemones per 100 ml), low density (5 sea anemones per 100 ml) and control (no sea anemone). [Extracted from the article]

Out of 2,168 respondents who answered a question about participation in tournament fishing, 323 (15%) self-identified as tournament anglers (i.e., tournament anglers), whereas the other 1,845 (85%) indicated not participating in tournament fishing (i.e., non-tournament anglers). Tournament Participation On average, tournament anglers participated in 8.54 tournaments in 2019, traveled 44 miles one-way from the residence, and reported spending $193 per trip during tournament trips. While all anglers seek more fishing experience, the differences between tournament and non-tournament anglers suggest that participation motivations may differ between the groups. [Extracted from the article]

To investigate the plastic sources and aging, the number and weight ratios of 4 main plastic categories, namely hard plastics, membranous plastics, fibrous plastics, and foam plastics in the Shanghai coast were determined. Aging of polyvinyl chloride, polyethylene, and polystyrene includes the appearance of scratches and damage and even the forming of cracks and micropores. Composite packaging plastics were cracked from the external surface. Aging plastics showed new bands at around 1700 cm−1 for carbonyl functional groups, and 1000 cm−1 for C–O bonds, indicating the surface oxidation and adsorption of organic matter. The number of foam plastics was the highest among the different types of plastics, probably due to their lowest density. The sources of foam plastics varied because they are used in both the daily life of the city resident and ocean fishing and farming. This study provides scientific data for the management of Shanghai marine plastics. [ABSTRACT FROM AUTHOR]

This study investigated the fish fauna diversity of the Shimokita and Tsugaru peninsulas in the northernmost part of the main island of Japan. Since ocean currents influence brackish and saltwater fish distribution and dispersion, it is assumed that in the target area where ocean currents are complex, the ichthyofaunal diversity of river estuaries may vary significantly between rivers. In addition, the target area is located on a peninsula with complex topography, and topographical factors are also considered major factors influencing the fish fauna. During the field survey, 6879 individuals of fish from 34 species were collected from 25 river estuarine areas. Furthermore, the cluster analysis results indicated that the Tsugaru Warm Current, which flows from the warm current (Tsushima Current) on the Sea of Japan side to the Pacific Ocean side, strongly influences the presence of fish fauna in the regional river estuarine areas. Moreover, the wave exposure was marginal in rivers flowing into the Tsugaru Strait (7.4 ± 5.8), and saltwater fishes were absent, whereas fishes that depend on the gravel bed were observed. The bed slope of the estuarine river area of this group was large (1.65 ± 0.99%). The riverbed comprised stone and gravel, suggesting that in addition to biogeography, environmental factors strongly influence the presence of fish fauna. Furthermore, compared with previous studies conducted in the Shimokita Peninsula, the distribution area of the southern Gymnogobius species expanded, possibly due to the increase in seawater temperature caused by climate change. In the target area, where currents and topography are complex, it became clear that the area into which the river flows and topographical factors determine the fish fauna of river estuaries, suggesting that elucidating the relationship between complex environmental factors and biota is important for riverine environmental management and conservation ecology. [ABSTRACT FROM AUTHOR]

Simple Summary: Every year an estimated 1.5–2.7 billion wild fish are caught by UK commercial sea fishing fleets subjecting most to severe stressors. Scientific research shows that fish are sentient beings, but UK animal welfare laws do not protect commercially caught wild fish. For example, stunning fish before slaughter is rare and gutting them alive is a common practice. There are therefore major welfare issues in wild capture sea fisheries, no laws to protect the welfare of wild fish at sea, and great potential to reform practice to improve the lives of billions of sentient fish. The article investigates this through reporting findings from interviews with 18 experts with a stake in wild fish welfare. The article reviews the UK fishing industry, policy context and scientific evidence that fish are sentient, linked to stakeholder views about what fish experience during wild capture. The article then analyses industry practices, resultant welfare harms and stakeholder attitudes towards them. No participant disputed that fish are sentient and all were able to identify key stressors to fish in different stages of the capture process, together with potential mitigations. Interviews revealed that harms can be worsened by their hidden nature along with conservative industry attitudes towards brutal practices which would be unacceptable in other areas of animal food production. The article raises awareness of an under-researched welfare problem in UK wild capture sea fisheries but should have wider significance to many fishing nations. An estimated 1.5–2.7 billion wild fish are caught by UK commercial sea fishing fleets annually. Most are subjected to severe stressors during capture; stunning is rare and gutting alive is common practice. Fish are recognised in UK law as sentient beings, but commercially caught wild fish are excluded from welfare protections. Animal welfare impacts in wild capture sea fisheries are therefore on a massive scale, with major potential for legislative and market-based reforms. Interviews were conducted with 18 experts working within the fishing and seafood industry, fisheries management, scientific research and animal/fish advocacy organisations. The findings reveal a significant welfare gap between societally acceptable ways to treat sentient animals and the reality of capture fisheries. The participants pointed to harms caused to fish throughout different stages of the capture process caused by combinations of variables from fishing gear and methods to biological, environmental and other factors, noting that all require mitigation. Interviews revealed that the nature of harms may be exacerbated by conservative attitudes towards brutal practices in the industry, driven by profit and efficiency and free from legal restraint. To address the welfare gap, stakeholders favour engagement with the industry to improve understanding of harms and to identify mutually beneficial and shared objectives through alleviating stressors to fish in the capture process. This empirical research is focused on UK wild capture sea fisheries. However, given the dearth of welfare legislation globally, it has significance for fishing nations and the many billions of wild sea fish captured each year around the world. [ABSTRACT FROM AUTHOR]

Long‐lived top predators shape biodiversity structure in their ecosystems and predator–prey interactions are critical in decoding how communities function. Studies on the foraging ecology of seals and Eurasian otters in Western Europe are outdated and most studies solely performed traditional hard part analysis. Molecular metabarcoding can be used as an innovative noninvasive diet analysis tool, which has proven efficient and complementary to hard part analysis, however, lacking application in the wider North Sea area. In this study, DNA from digesta, collected between 2014–2020, were used to identify fish species in the diet of 47 Eurasian otters, 54 harbour seals and 21 grey seals by applying a next‐generation metabarcoding approach. A newly designed 16S rRNA primer, providing the best coverage of >130 local marine and freshwater fish species, was used to amplify prey DNA from seal scats and otter gut content sampled from the North Sea and regional freshwater bodies. Frequent fish species included tench, ninespine stickleback and white bream in otters; hooknose and common roach in grey seals and Pleuronectidae and sand gobies in harbour seals. Bipartite network analysis showed a strong overlap of harbour and grey seal diets. Otter diet intersected with both seal species in terms of freshwater species. This study provides new knowledge about dietary composition and community assemblage of fish prey in otters and seals in the North Sea and regional freshwaters, and a new molecular tool to elucidate predator–prey interactions and interspecies competition in complex and changing ecosystems under pressure from anthropogenic activities. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes, characterized by a high mortality rate in humans, is a bacterium that causes listeriosis and is found in various aquatic products. The aim of this research was to investigate the presence, serotype distribution, virulence factor genes, and antibiotic susceptibility of L. monocytogenes strains isolated from a total of 500 fish samples of whiting (Merlangius merlangus euxinus) (n:243) and striped red mullet (Mullus surmuletus) (n:257) caught in the Black Sea between the years 2013-2014. Only one (0.2%) L. monocytogenes strain (striped red mullet) was isolated according to the cultural method (EN ISO 11290-1) and confirmed by PCR analysis. The L. monocytogenes strain was identified as serogroup 4b-4d-4e. Furthermore, the strain harboured hlyA, inlA, inlC, inlJ, plcA, plcB, prfA, mpl, actA, monoA-B, flaA, lip 1-2a, fri, iap, and gtcA genes except the dltA gene. On the other hand, L. monocytogenes strain susceptibility to ampicillin, meropenem, erythromycin, trimetophrim/sulfamethoxazole, and penicillin G was evaluated with the disc-diffusion method. According to the results, serogroup 4b-4d-4e isolated from striped red mullet was found to be unique to raw fish and susceptible to all tested antibiotics. In addition, it is considered that carrying out this research in different seas and with different fish species would be appropriate for determining the prevalence and virulence characteristics of L. monocytogenes. [ABSTRACT FROM AUTHOR]

This study investigated the pollution characteristics, exposure levels and health risk assessments of seven kinds of biogenic amines (BAs) in eight varieties of canned sea fish products (n = 131) on the Chinese market. Carbon spheres QuEChERS mixed dispersion solid phase extraction combined with HPLC was used for the classification and analysis of batch samples. The average recovery of single BAs obtained by this method is 92.3~97.7%, and the relative standard deviation is 1.9~4.8%. Different varieties of samples have different degrees of pollution, the mass concentration of single BAs range 0.45~27.74 mg/kg, and the total concentration of ΣBAs range 18.77~368.50 mg/kg, of which the concentration of Σ4BAs range 11.53~368.50 mg/kg. The composition of four BAs is mainly putrescine, cadaverine, histamine and tyramine, which always play an important role in the exposure level and risk assessment of samples. The exposure level of BAs in the human body ranges 67.03~209.52 μg∙kg−1∙d−1. The health risk assessment shows that the gender trend of exposure risk level of BAs is male > female (young age), female > male (middle and old age), the age trend is young age > old age > middle age, and the regional trend is city > countryside. The food safety index of BAs in samples is 0.0062~0.0195, which is far less than 1, so the risk is within the controllable range. [ABSTRACT FROM AUTHOR]

One marine biota containing various proteins supporting enamel maturation is saltwater fish. Protein is transferred from a mother to her child through the placenta, an organ that plays a critical role in fetal growth and development. The placenta with fatty acid-binding proteins (FABPs) expression serves as an interface for exchanging substances, producing proper hormones during pregnancy, and as a barrier. Early dental enamel formation is generally known as amelogenesis. Type 1 collagen is one of the ameloblasts' proteins in amelogenesis. This research aims to examine the effect of saltwater fish powder on the increase in the expression of FABPs in trophoblast cells and the increase in expression of type 1 collagen in ameloblasts. This research belongs to true experimental with a completely randomized design. The sample consisted of 24 female house mice (Mus musculus) which were pregnant and received saltwater fish powder administration made of sardines (Sardinella Fimbriata), pony fish (Leiognathus splendens), and mackerel tuna (Euthynnus affinis). The mice were divided into three concentration groups: Group 1 with 1.07 mg/0.5 ml concentration, Group 2 with 2.14 mg/0.5 ml concentration, and Group 3 as the control group. The samples were stained to see FABP expression and the KLK-4 expression a. Data were analyzed using an independent sample t-test and pathway analysis. The research results showed a significant difference in enamels between the Control Group and Group 1 and Group 2, and there was no significant difference between Group 1 and Group 2. In mother mice that consumed saltwater fish powder, there was an increase in expression of FABPs and a decrease in expression of type 1 collagen. [ABSTRACT FROM AUTHOR]

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This article discusses the challenging condition of envenomation by weever fish. The author presents data on 160 patients who were treated for weever fish stings between May 2000 and June 2022. The usual effects of envenomation include intense pain, numbness, edema, and systemic symptoms. The recommended treatment involves local injections of xylocaine or lidocaine, corticosteroid ointment, and methylprednisolone. Immediate treatment can lead to total resolution within 24 hours, although some patients may experience residual symptoms. The article also highlights the need for further research on fish venoms and the development of effective treatment protocols. [Extracted from the article]

The isopods of the family Cymothoidae are ectoparasites crustaceans that infest a wide variety of saltwater fish. This paper documented the first occurrence of Nerocila acuminata (Schiödte & Meinert, 1881) parasitizing the shortnose guitarfish Zapteryx brevirostris (Müller & Henle, 1841) (Rhinobatiformes, Rhinobatidae) in the southern Atlantic Ocean. This report can be an available tool to create a parasitology database for a species of conservation interest. It will also provide scientific data that can help the understanding of the biological factors acting in healthy populations and thus support the efforts made to preserve and conserve the species. [ABSTRACT FROM AUTHOR]

About ten specimens of the sandbar shark, Carcharhinus plumbeus, were observed beneath a fish farm sea-cage off the Arsuz coast in Iskenderun Bay, northeastern Mediterranean Sea, on 15 October 2021. Sandbar sharks have been reported to aggregate around fish farms when the seawater temperature reaches >24°C swimming around cages in groups of 10-20 individuals. During the cleaning of the bag, which is attached to the bottom part of the cage to collect the dead reared fish, sandbar sharks were observed to approach the diver and sporadically attempted to attack the cage, as well. [ABSTRACT FROM AUTHOR]

Here, we report the recent capture (October, November 2021) of the following three non-indigenous species (NIS) from the Indo-Pacific in the Mediterranean Sea: the fishes Naso annulatus and Scatophagus argus and the brachyuran Charybdis (Charybdis) natator. The record of the white margin unicorn fish N. annulatus from the island of Malta represents the first for this species from the basin. Both the spotted scat S. argus and the ridged swimming crab C. natator were found in Egyptian waters, in localities significantly far from ones previously reported. Possible vectors of introduction for these three NIS to the Mediterranean locations in question include Lessepsian migration, ship-mediated transport, aquarium release, and are briefly discussed. [ABSTRACT FROM AUTHOR]

Background: Buoyancy and balance are important parameters for slow-moving, low-metabolic, aquatic organisms. The extant coelacanths have among the lowest metabolic rates of any living vertebrate and can afford little energy to keep station. Previous observations on living coelacanths support the hypothesis that the coelacanth is neutrally buoyant and in close-to-perfect hydrostatic balance. However, precise measurements of buoyancy and balance at different depths have never been made. Results: Here we show, using non-invasive imaging, that buoyancy of the coelacanth closely matches its depth distribution. We found that the lipid-filled fatty organ is well suited to support neutral buoyancy, and due to a close-to-perfect hydrostatic balance, simple maneuvers of fins can cause a considerable shift in torque around the pitch axis allowing the coelacanth to assume different body orientations with little physical effort. Conclusions: Our results demonstrate a close match between tissue composition, depth range and behavior, and our collection-based approach could be used to predict depth range of less well-studied coelacanth life stages as well as of deep sea fishes in general. [ABSTRACT FROM AUTHOR]

The bionic robotic fish is one of the special autonomous underwater vehicles (AUV), whose path planning is crucial for many applications including underwater environment detection, archaeology, pipeline leak detection, and so on. However, the uncertain ocean currents increase the difficulty of path planning for bionic robotic fish in practice. In this paper, the path energy consumption is selected as the objective function for path planning, path safety factor, and smoothness are considered as the constraint conditions. The kinematic model is established for bionic robotic fish and, considering the uncertainty of ocean currents, a "min-max" robust optimization problem is proposed in the light of the normal optimization model of path planning for bionic robotic fish. The co-evolutionary genetic algorithm is presented to solve the robust optimization problem with two populations; one population represents the solutions and the other represents the uncertain ocean currents. The objective of the proposed algorithm is to find a robust solution that has the best worst-case performance over a set of possible ocean currents. Multiple experiments indicate that the proposed algorithm is very effective for path planning for bionic robotic fish with ocean currents. [ABSTRACT FROM AUTHOR]

The primary source of persistent organic pollutant (POP) exposure is food, especially fish. European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) are among the most eaten sea fish in Italy. Fish from lakes in Northern Italy, such as agone (Alosa agone), represent niche consumption for most people, but possibly constitute a much larger percentage of overall consumption volume for local residents. This study dealt with the presence of POPs in the above-mentioned fish species via GC-MS/MS analysis. None of the analytes for which maximum limits are in place showed concentrations above those limits. Moreover, none of the substances without maximum limits exceeded the provisional tolerable daily intake (PTDI) when given, nor did they exceed the more general values considered safe, even for 99th percentile consumers. [ABSTRACT FROM AUTHOR]

Fish population survey based on classification and recognition is an effective means to study water ecosystem. However, the identification of fish in the sea and other waters will be interfered by corals, reefs and other organisms. The great variety of fish also make it more difficult to distinguish. In order to improve the effect of fish recognition in the complex underwater environment, this paper proposes a method based on targeted sample transfer learning. The designed CNN is used to train the simple background fish data after background re-processing to obtain the pre-training model. By using transfer learning and interlayer fusion mechanism, the feature extraction layer of the pre-training model is frozen and fused with the new feature extraction layer in parallel, then, combined with pooling layer, a new feature extractor is formed, finally, connected to the classifier and output part to construct a new network, which is used to identify 10 kinds of fish with complex background. Compared with the original CNN model, the accuracy of the new network is improved by about 5%, reaching 91.33%. The experimental results show that the model can improve the ability of fish classification and recognition in complex underwater scenes, and can provide support for the study of fishery resources distribution. [ABSTRACT FROM AUTHOR]

This research aimed to isolate lactic acid bacteria from the bowel of saltwater fish to assess their potential probiotic properties. Nineteen isolates of LAB including Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Lactobacillus acidophilus, Levilactobacillus brevis, Pediococcus pentosaceus, and Pediococcus acidilactici were recognized using molecular tools. All the isolates survived in the simulated conditions of the GI tract. Auto-aggregation ranged from 01.3 ± 0.5 to 82.6 ± 1.4% and hydrophobicity with toluene ranged from 3.7 ± 1.6 to 69.4 ± 1.3%, while the range of hydrophobicity with xylene was from 02.2 ± 1.6 to 56.4 ± 2.1%. All the isolates of lactobacilli, pediococci, enterococci, and lactococci indicated variable sensitivity and resistance towards clinical antibiotics. Non-neutralized cell free supernatant of isolates F12 and F15 showed antimicrobial activity against all the 8 evaluated enteric pathogens. Cluster analysis of identified potential probiotic bacteria based on heat-map and PCA methods also highlighted the priority of isolates F3, F7, F12, and F15 as bio-control agents in fishery industry. The findings of this study may essentially contribute to the understanding of the probiotic potential of LAB in saltwater fish, in order to access their probiotic characterization for use as biocontrol in fishery. [ABSTRACT FROM AUTHOR]

The global importance of mesopelagic fish is increasingly recognised, but they remain poorly studied. This is particularly true in the Southern Ocean, where mesopelagic fishes are both key predators and prey, but where the remote environment makes sampling challenging. Despite this, multiple national Antarctic research programs have undertaken regional sampling of mesopelagic fish over several decades. However, data are dispersed, and sampling methodologies often differ precluding comparisons and limiting synthetic analyses. We identified potential data holders by compiling a metadata catalogue of existing survey data for Southern Ocean mesopelagic fishes. Data holders contributed 17,491 occurrence and 11,190 abundance records from 4780 net hauls from 72 different research cruises. Data span across 37 years from 1991 to 2019 and include trait-based information (length, weight, maturity). The final dataset underwent quality control processes and detailed metadata was provided for each sampling event. This dataset can be accessed through Zenodo. Myctobase will enhance research capacity by providing the broadscale baseline data necessary for observing and modelling mesopelagic fishes. Measurement(s) Abundance • Standard length • Wet weight Technology Type(s) Trawl net • ruler-based body length measuring method • Motion compensated balance Sample Characteristic - Organism Actinopteri • Cephalopoda Sample Characteristic - Environment oceanic pelagic zone biome Sample Characteristic - Location Southern Ocean [ABSTRACT FROM AUTHOR]

As a ubiquitous movement in the ocean, tides are vital for marine life and numerous marine activities such as fishing and ocean engineering. Tidal dynamics are complicated in the East Asian marginal seas (EAMS) due to changing complex topography and coastlines related to human activities (e.g., land reclamation and channel deepening) and natural variability (e.g., seasonal variations of ocean stratification and river flow). As an important tool, numerical models are widely used because they can provide basin-scale patterns of tidal dynamics compared to point-based tide gauges. This paper aims to overview the development history of the numerical simulation of tides in the EAMS, including the Bohai Sea, the Yellow Sea, the East China Sea, the East/Japan Sea, and the South China Sea, provide comprehensive understanding of tidal dynamics, and address contemporary research challenges. The basic features of major tidal constituents obtained by tidal models are reviewed, and the progress in the inversion of spatially and temporally changing model parameters via the adjoint method are presented. We review numerical research on how a changing ocean environment induces tidal evolution and how tides and tidal mixing influence ocean environment in turn. The generation, propagation, and dissipation of internal tides in the EAMS are also reviewed. Although remarkable progresses in tidal dynamics have been made, nonstationary tidal variations are not fully explained yet, and further efforts are needed. In addition, tidal influences on ocean environment still receive limited attention, which deserves special attention. [ABSTRACT FROM AUTHOR]

Anisakis is a zoonotic parasite found in the stomach of marine mammals. Its eggs are released into the sea and ingested by fish and cephalopods. Humans accidently become hosts when they consume raw or undercooked fish, or cephalopods, leading them to suffer from intestinal syndromes and allergic reactions. In Europe, the officially prescribed methods for inactivation of Anisakis are heat treatment or freezing, both of which can affect fish quality. Several studies have demonstrated the effectiveness of PEF for the inactivation of Anisakis ; however, none of them have featured naturally infected samples. This study focuses on 1) the inactivation of Anisakis by PEF in naturally infected hake belly fillets (as hake is one of the most parasitized species in Europe) and 2) the evaluation of the quality of fish samples during their shelf life after PEF treatment. Results showed that it was necessary to apply higher PEF intensities of up to 5 kV/cm to inactivate Anisakis when it is naturally parasitized in comparison to artificial scenarios or when the parasite is present in water. The degree of inactivation increased over time when the samples were stored after PEF treatments in a modified atmosphere containing 50% CO 2. After PEF treatments, quality analyses during shelf-life indicated that fish microbiota evolved similarly to untreated samples; however, the modified atmosphere limited the growth of the microbiota. In PEF-treated samples, quality parameters (drip loss, moisture, water holding capacity, and cooking loss) were closer to those of fresh hake and superior, in terms of quality, to the values obtained in frozen/thawed samples during their entire shelf-life. • PEF assures 90–100% Anisakis inactivation in hake. • PEF did not affect hake quality during shelf life. • PEF an alternative to freezing for Anisakis elimination. [ABSTRACT FROM AUTHOR]