Commercial Fisheries Research Articles

Implicaciones de la alimentación continua sobre la demanda de oxígeno en un pez agástrico con intestino corto (Teleostei: Atherinopsidae)

Continuous illumination and increased feeding periods have enhanced growth in commercial fish species. However, oxygen consumption under these conditions has yet to be previously assessed in agastric short-intestine fish. This study evaluated Chirostoma estor (Atherinopsidae) oxygen consumption under three specific feeding and light regimes: resting-unfed, routine-fed, and continuous light/feeding. Fish in the continuous light/feeding condition presented oxygen consumption levels 60 and 20% higher than resting-unfed and routine-fed fish, respectively. The latter implies that constant high oxygen supply levels are required to satisfy the demand for C. estor raised under these high growth rate conditions. The present study shows the relevance of determining oxygen consumption levels during continuous illumination and extended feeding periods to consider optimal oxygen levels required to achieve better performance indicators, such as the growth and welfare of atherinopsids and species with similar digestive configurations.

Microplastics Contamination of Mackerel and Red Snapper as Commercial Fish from the Takalar Fish Landing, Indonesia

Highlight Research 1. Microplastics were counted and identified based on their shape, size, and color 2. The particles were clarified using FTIR and confirmed to be microplastics based on the type of polymer. 3. The tissue destruction method is more effective with heating treatment. 4. Methods to prevent contamination are implemented so that the research results are guaranteed to be accurate. Abstract Microplastics can be ingested by marine organisms, including fish. Although it has been widely reported, further information regarding microplastic contamination in commercial fish is still needed. This study aimed to analyze the presence and concentration of microplastics in the digestive tract of the mackerel R. kanaguarta and red snapper L. gibbus and to identify the shape, size, color, and type of microplastic polymer. Digestion of the organic materials was performed using a 10% KOH solution, which was then filtered using a vacuum filtration system. The particles were observed using an Olympus microscope and clarified using FTIR. The results of the research showed that R. kanaguarta and L. gibbus landed at the Beba Fish Landing Base (PPI Beba) Takalar were contaminated with microplastics with a microplastic concentration in R. kanaguarta 0.21 ± 0.06 particles/g and L. gibbus 0.11 ± 0.04 particles/g. The microplastics found were fiber and fragment of varying colors, such as black, white, red, and yellow. The size of microplastics was dominant in the size class < 2 mm. The FTIR analysis confirmed the presence of polypropylene (PP), Ethylene/Propylene Copolymer, Nylon, Polyethylene terephthalate (PET), and polyester (PES). This study showed that both commercial fish species were contaminated with microplastics. These findings suggest that microplastics are widespread and contaminate commercial fish caught from Takalar waters. Further research is still needed on other seafood from this region, and analysis of polymer types such as FTIR is important to carry out as one of the standard methods in microplastic research.

Recruitment of European sea bass (Dicentrarchus labrax) in northerly UK estuaries indicates a mismatch between spawning and fisheries closure periods.

European sea bass (Dicentrarchus labrax) is a species of high commercial and recreational value, but it exhibits highly variable recruitment rates and has been subject to recent declines. Emergency management measures put in place to protect spawning stocks include the annual closure of commercial and recreational fisheries over a 2-month, February-March, window. Whether this protection measure is having the desired outcome for this data-poor species remains unclear. Otolith microstructural analyses (counts and widths of daily growth rings and check marks indicative of settlement) were used to estimate (1) spawn timing, (2) pelagic larval duration and settlement timing, (3) growth rate and condition, and (4) the otolith-fish size relationship for juvenile European sea bass caught from two estuaries in Wales (Dwyryd, Y Foryd), located at the northern edge of the species range. We observed a significant mismatch between the timing of fisheries closures and the spawning, with 99.2% of recruits having been spawned after the fishery had reopened (back-calculated median spawn date = May 5 ± 17 days SD), suggesting that the closure may be too early to adequately protect this population. Further, we present the first empirically derived estimates of pelagic larval duration for sea bass recruits settling in UK habitats, which showed a strong negative relationship with spawn date. Finally, we found significant differences in fish condition between the two estuaries, suggesting local variation in habitat quality. The results suggest that the timing of current fisheries closures may not be adequately protecting the spawners supplying these northernmost estuaries, which are likely to become increasingly important as sea bass distributions shift northward in our climate future.

Addition of Caulerpa racemosa on Commercial Goldfish Ornamental Fish Feed to Increase Color Saturation

The brightness and high color saturation determine the selling price of ornamental goldfish. Color saturation is the color intensity visible to the naked eye from the appearance of goldfish. Caulerpa racemosa seaweed contains β-carotene, a type of carotenoid that is a red, yellow, and orange pigment. The research aimed to determine the effectiveness of adding C. racemosa flour to artificial goldfish (Carrasius auratus) feed. The experimental design used was three treatments of adding C. racemosa flour to artificial feed, namely 0%, 1%, and 1.5%. The experiment was carried out for 45 days with intensive fish care in an aquarium. Observation of color intensity using M-TCF (toca color finder) at the beginning and end of the study by three panelists. The results showed that increasing the color saturation of goldfish with the addition of 1.5% C. recomosa seaweed flour gave the best results. Caulerpa racemosa; Carrasius auratus; artificial feed; carotenoids; M-TCF. Abstrak Nilai jual ikan hias mas koki salah satunya ditentukan oleh kecerahan dan tingginya saturasi warna. Saturasi warna merupakan intensitas warna yang secara kasat mata tampak dari performans ikan mas koki. Rumput laut Caulerpa racemosa mengandung β-karoten yaitu jenis karotenoid yang merupakan zat pigmen warna merah, kuning dan jingga. Tujuan penelitian untuk mengetahui efektifiktas tepung C. racemosa yang ditambahkan pada pakan artifisial untuk ikan mas koki (Carrasius auratus). Rancangan percobaan yaitu 3 perlakuan penambahan tepung C. racemosa pada pakan artifisial: 0%, 1%, dan 1,5%. Percobaan dilakukan selama 45 hari dengan perawatan ikan secara intensif dalam akuarium. Pengamatan intensitas warna menggunakan M-TCF (toca color finder) pada warna awal dan warna akhir penelitian oleh 3 panelis. Hasil penelitian menunjukkan bahwa peningkatan saturasi warna ikan mas koki dengan penambahan tepung rumput laut C. recomosa sebanyak 1,5% memberikan hasil terbaik. Kata kunci: Caulerpa racemosa; Carrasius auratus; pakan artifisial; karotenoid; M-TCF.

Assessing the Health of South Kalimantan Coastal Swamp Wetlands using Measurements of Heavy Metals in Commercial Fish Species

Heavy metals pollution damages coastal swamp ecosystems. This study’s primary purpose was to determine the amounts of heavy metals in coastal swamp waters and the tissues of three fish species (Mugil cephalus, Arius sagor and Plotosus lineatus). This study determined that the water in the coastal swamps of South Kalimantan was contaminated with heavy metals in the following order: Fe > Cu > Zn > Cr > Pb > Cd > Hg. The heavy metal concentrations found in the three commercial fish species are as follows: Fe > Zn > Cu > Cr > Pb > Cd > Hg. The bioaccumulation of heavy metals was highest in Mugil cephalus, followed by Arius sagor and Plotosus lineatus. The Fe, Cu and Cr concentrations in Mugil cephalus, Arius sagor and Plotosus lineatus exceeded the international and national MPLs. The liver tissue has the highest capacity to bioaccumulate heavy metals. Regular monitoring of these metals in fish and water sources is recommended to ensure the safety and conservation of coastal swamp wetlands.

The silent threat of plastics along the coastal frontiers of Bangladesh: Are we concerned enough?

Globally plastic pollution is posing a significant threat to the health and integrity of coastal ecosystems. This study aimed to provide a comprehensive overview of plastic pollution in the coastal areas of Bangladesh by examining land-based macroplastic distribution, exploring microplastic (MP) contamination in the coastal aquatic ecosystem and enhancing our understanding of the potential risks associated with MP contamination. Citizen science based monitoring approach using the android application was applied to understand the land-based plastic pollution in the coastal area of Bangladesh. From December 2022 to December 2023, a total of about 3600 photographs of plastic items from 215 citizen scientists were received from the coastal area of Bangladesh covering 580 km long coast line. Polymer Hazard Index (PHI) and Pollution Load Index (PLI) were also calculated to understand the risk of plastic pollution in sediment, water, aquatic organism, dried fish and sea salt. A total of 43 land-based plastic items reported from the coastal area of Bangladesh. Among these plastic items single use items contributed 58.2 % while disposable plastic items contributed 41.8 %. A strong spatial variability in the distribution of these plastic items was observed. PHI and PLI values suggested hazard category-I for MP contamination in sediment, sea salt, water, commercial fishery resources and dry fish. This study highlighted that coastal land area, sea salt, dried fish, water, sediment and organisms are contaminated with plastics which might have the potential threats to human health. Findings from this study will serve as reference data and also baseline for future research to combat the plastic pollution.

Can upwelling regions be potential thermal refugia for marine fishes during climate warming?

Species are expected to migrate to higher latitudes as warming intensifies due to anthropogenic climate change since physiological mechanisms have been adapted to maximize fitness under specific temperatures. However, literature suggests that upwellings could act as thermal refugia under climate warming protecting marine ecosystem diversity. This research aimed to predict the effects of climate warming on commercial and non-commercial fish species reported in official Mexican documents (>200 species) based on their thermal niche to observe if upwellings can act as potential thermal refugia. Present (2000–2014) and Representative Concentration Pathway (6.0 and 8.5) scenarios (2040–2050 and 2090–2100) have been considered for this work. Current and future suitability patterns, species distribution, richness, and turnover were calculated using the minimum volume ellipsoids as algorithm. The results in this study highlight that beyond migration to higher latitudes, upwelling regions could protect marine fishes, although the mechanism differed between the innate characteristics of upwellings. Most modeled species (primarily tropical fishes) found refuge in the tropical upwelling in Northern Yucatan. However, the highest warming scenario overwhelmed this region. In contrast, the Baja California region lies within the Eastern Boundary Upwelling Systems. While the area experiences an increase in suitability, the northern regions have a higher upwelling intensity acting as environmental barriers for many tropical species. Conversely, in the southern regions where upwelling is weaker, species tend to congregate and persist even during elevated warming, according to the turnover analysis. These findings suggest that tropicalization in higher latitudes may not be as straightforward as previously assumed. Nevertheless, climate change affects numerous ecosystem features, such as trophic relationships, phenology, and other environmental variables not considered here. In addition, uncertainty still exists about the assumption of increasing intensity of upwelling systems.

Concentration and Characterisation with Spectroscopic Technique of Microplastics in the Surface Sediment and Commercial Fish Species of Gemlik Bay (Marmara Sea)

In this study, we aimed to evaluate and characterise the microplastic pollution in the sediment and commercial fish species in the Gemlik Bay, the Marmara Sea. Our results showed that the highest concentration of microplastics in the sediment was at the station in the Gemport Harbour (9.73 pieces.kg-1) and the lowest concentration was at the Kurşunlu offshore (3.33 pieces.kg-1). The highest microplastic concentration per individual was in the gills of Synapturichthys kleinii (Risso, 1827) (14.5 pieces.ind-1) and the lowest in Diplodus annularis (Linnaeus, 1758) (0.33 pieces.ind-1). The highest concentration (8.75 pieces.ind-1) was indicated in the gastrointestinal tract of Chelidonichthys lucerna (Linnaeus, 1758), but the lowest concentration (0.88 pieces.ind-1) was in that of D. annularis species. The fiber-type particles were the most determined microplastics in both the sediment and fish samples. The Micro-Raman Spectrometer revealed that Polyvinyl chloride and polypropylene were dominant in the sediment, and polyoxymethylene and polyphenylene sulfone polymers were dominant in fish species.

A Study of Age, Sex Ratio, Gonado-Somatic Index, Fecundity, and Breeding Season, of Nile Tilapia (Oreochromis niloticus Linnaeus, 1758) from Khashm El-Girba Reservoir and Atbara River, Eastern Sudan

This study aims to investigate some reproductive aspects of Nile tilapia, Oreochromis niloticus in the Khashm El-Girba reservoir and Atbara River, eastern Sudan. The study was conducted during December 2015 to November 2016. Samples were collected bi-monthly basis from three localities, namely; Um Aswad (Atbara River), El-Remila, and El-Monaba (Khashm El-Girba reservoir), using beach seine nets of 1.2 cm 4.0 cm and 7.0 cm stretched mesh. A total of 1595 O. niloticus specimens were collected from all sampling sites. The age of O. niloticus was estimated using five anterior vertebrae of fish body; The results indicate that the age ranged between 0+ to 4+ years. Most of the collected fish specimens were of age 1+, with females most dominant at this age. Sex ratio was 1:1(M: F). Gonado-somatic index (GSI) of females of O. niloticus ranged between 1.965 – 2.620, and from 0.434 – 0.439 for males. Two periods of increase of GSI were observed reflecting two breeding seasons of this species. Used gravimetric method to estimate the average fecundity of O. niloticus ranged between 481 eggs in Um Aswad sampling site, and 638 in El-Remila site. The fecundity of O. niloticus has a high correlation with gonadal weight (r=0.82708) but a low correlation with standard length (r=0.47612) and total weight (r=0.50874). The results of this investigation on O. niloticus indicate that the age of the fish ranged from 0+ to 4+ years, with a sex ratio of 1:1. The Gonado-somatic Index (GSI) indicated two spawning seasons, and fecundity was found to be strongly correlated with gonad weight, and moderately correlated with total length and standard length. This results can be used formulate management policies and procedures for protecting and conserving the fisheries resources and to regulate and improve the catches of the most important commercial fish species in that region.

Modification of a commercial fish feeder for use in small rearing ponds

AbstractObjectiveAutomatic feeders are commonly used in aquaculture, but the feed delivery pattern cannot be adjusted to accommodate a variety of rearing unit sizes. For those few feeders that can be adjusted, their use has been limited because of initial costs, availability, and other issues. This paper describes modification to a commercially available fish feeder (Texas Hunter Products 31.75‐kg [70‐lb] Lake and Pond Directional Fish Feeder) to effectively provide feed to different‐sized ponds.MethodsThis feeder has a 14‐m fish feed distribution pattern, making it unusable for smaller ponds. To reduce the distance of fish feed projected from the feeder, a resistor (rheostat) was installed in series with the fan motor.ResultThe rheostat reduced the power to the fan motor, thereby decreasing the feed projection distance. In addition, because the rheostat was adjustable, the resistance—and the resulting power to the fan motor—could be easily changed, making it possible for the same feeder to be used in different‐sized ponds while using approximately the same amount of power from the battery and solar panels.ConclusionThis modification was inexpensive and relatively easy to perform. The feeders reliably dispensed feed in a number of small ponds during an 8‐month evaluation period.

High resolution assessment of commercial fisheries activity along the US West Coast using Vessel Monitoring System data with a case study using California groundfish fisheries

Commercial fisheries along the US West Coast are important components of local and regional economies. They use various fishing gear, target a high diversity of species, and are highly spatially heterogeneous, making it challenging to generate a synoptic picture of fisheries activity in the region. Still, understanding the spatial and temporal dynamics of US West Coast fisheries is critical to meet the US legal mandate to manage fisheries sustainably and to better coordinate activities among a growing number of users of ocean space, including offshore renewable energy, aquaculture, shipping, and interactions with habitats and key non-fishery species such as seabirds and marine mammals. We analyzed vessel tracking data from Vessel Monitoring System (VMS) from 2010 to 2017 to generate high-resolution spatio-temporal estimates of contemporary fishing effort across a wide range of commercial fisheries along the entire US West Coast. We identified over 247,000 fishing trips across the entire VMS data, covering over 25 different fisheries. We validated the spatial accuracy of our analyses using independent estimates of spatial groundfish fisheries effort generated through the NOAA’s National Marine Fisheries Service Observer Program. Additionally, for commercial groundfish fisheries operating in federal waters in California, we combined the VMS data with landings and ex-vessel value data from California commercial fisheries landings receipts to generate highly resolved estimates of landings and ex-vessel value, matching over 38,000 fish tickets with VMS data that included 87% of the landings and 76% of the ex-vessel value for groundfish. We highlight fisheries-specific and spatially-resolved patterns of effort, landings, and ex-vessel value, a bimodal distribution of fishing effort with respect to depth, and variable and generally declining effort over eight years. The information generated by our study can help inform future sustainable spatial fisheries management and other activities in the marine environment including offshore renewable energy planning.

Trends in pinniped interactions with commercial passenger fisheries vessels in California

Trends in pinniped interactions with commercial passenger fisheries vessels in California

Abundance, patterns, and taxa associations of anthropogenic marine debris on reefs in the middle Florida Keys

The Florida Keys reef tract has rapidly shifted from a structurally complex, hard coral-dominated reef to a less rugose, soft coral-dominated reef. This transition has been facilitated by persistent anthropogenic stressors including recreational and commercial fishing and increased anthropogenic marine debris. During the summers of 2020–2022, benthic censuses were conducted to identify substrate and marine debris composition for 30 reefs in the middle Florida Keys. Inshore reefs contained higher rugosity, coral cover, and marine debris abundance primarily comprised of monofilament and rope from fishing traps. Plastic items (e.g., ropes and monofilament) overall had the highest species diversity. Additionally, marine debris appears to promote turf algae growth on inshore reefs. While is it not yet possible to determine if this pattern of high debris nearshore is due to proximity to onshore debris sources, accumulation due to higher rugosity snagging debris, or increased debris removal efforts offshore, these differences in marine debris types and abundances suggest variability in potential impacts of debris on marine biota on inshore versus offshore reefs. Therefore, the differential use of marine debris by associated biota should be considered in marine debris management practices.

Whole genome resequencing of sablefish at the northern end of their range reveals genetic panmixia and large putative inversions

Abstract Sablefish (Anoplopoma fimbria) are a highly mobile species that support important commercial fisheries in the North Pacific Ocean. Information on the genetic stock structure of sablefish is vital for constructing management strategies that ensure the long-term viability of the species. Most previous genetic studies on sablefish have found panmixia throughout the majority of their range, but a recent study suggested that a population structure may exist. Here, we use low-coverage whole genome resequencing to investigate genetic structure in the northern end of the species’ range (from Washington State, USA to the Bering Sea and Aleutian Islands, AK, USA). Additionally, we reanalyzed an existing genomic dataset containing 2661 markers to test specific hypotheses about genetic structure by sex. Genome resequencing data from 119 individuals screened at 7 110 228 markers revealed no evidence of population structure, and reanalysis of the existing genomic dataset supported the same conclusion. Differentiation across the genome was largely driven by variation at two putative inversions located ∼1 megabase apart, which did not display any signals of geographic differentiation. Our study further supports the conclusion of genetic panmixia in sablefish throughout its northern range.

Disappearing fish: Grey seal depredation in a Baltic net fishery

Grey seals (Halichoerus grypus) in the Baltic Sea commonly attempt to steal fish captured in net fisheries. Seal depredation reduces economic yields for small-scale net fishers in a region already highly impacted by the collapse of important fish stocks. Visible damages in looted nets consist of injured fish with bite marks, or holes in the gear, but additional losses from seals eating entire fish without leaving a trace can often remain unnoticed. In this study, we estimated the daily rates of injured and of stolen fish in a commercial gillnet fishery operating off coast of Bornholm in the Central Baltic Sea in 2021–2022. Our results show that the Atlantic cod (Gadus morhua) is generally preferred over other target species [here, European plaice (Pleuronectes platessa), European flounder (Platichthys flesus), and turbot (Scophthalmus maximus)]. Although the observed ratio of 5.65 cods disappearing for each cod retrieved with seal bite marks is similar to a study from the 2000’s, we show that average daily cod disappearance rates are linked to the duration a gear is left soaking in the same location.

Microplastics weaken the digestion and absorption functions in the golden pompano (Trachinotus blochii) by affecting the intestinal structure, bacteria and metabolites

Microplastics are difficult to degrade and widespread environmental pollutants. Coastal areas are hardest hit of microplastic pollution as they receive significant amounts of microplastics discharged from inland sources. Golden pompano (Trachinotus blochii) is a high commercial valuable marine aquaculture fish species, most of the golden pompano are raised in coastal areas, which means they are at significant risk of exposure to microplastics. Therefore, we exposed golden pompano to 10 μg/L, 100 μg/L and 1000 μg/L of 5 μm spherical polystyrene microplastics and conducted a 14-day stress experiment. Histopathology results showed the intestinal villi shrank. The 16s sequencing analysis revealed that microplastics significantly impacted the abundance and community structure of intestinal microorganisms, which may affect the metabolic function of the gastrointestinal tract. Metabolomics sequencing of the intestinal contents showed that microplastics caused disruptions in lipid, glucose, and amino acid metabolism, thus compromising the normal digestion and absorption functions in the intestinal system. In addition, the activation of various pathways, including the intestinal endocrine system, proline metabolism, and signal transduction, which can lead to the occurrence of several diseases. This study combined various methods to investigate the adverse effects of microplastics on intestinal digestion and absorption, and provided new insights into the toxic mechanisms of microplastics.

Assessment of spawning habitat suitability for Amphidromous Ayu (Plecoglossus altivelis) in tidal Asahi River sections in Japan: Implications for conservation and restoration

AbstractThe Amphidromous Ayu (Plecoglossus altivelis), vital for Japan's riverine commercial fisheries, is experiencing population decline due to habitat degradation. In response, Japan is implementing restoration efforts by releasing juvenile fish and cultivating spawning habitats. This study, focusing on the Asahi River's Heidan area, evaluates Ayu spawning habitat suitability, especially in tidal zones, and its conservation implications. Through field surveys and numerical analysis, the research identifies optimal conditions for spawning amid dwindling numbers. Observations from the 2020 peak spawning season showed that water temperatures below 20°C are conducive to spawning, with the best sites producing up to 48,817 eggs/m2. Gravel sizes between 0.85 and 53.0 mm were identified as crucial for effective spawning. Notably, artificial spawning grounds established in 2019 showed no spawning activity, likely due to saline intrusion from tides. Using the three‐dimensional hydrodynamic‐aquatic ecosystem numerical model, the study assesses flow, substrate, and water quality's impact on spawning, corroborated by sensor data. A key finding is the negative correlation between salinity and egg density in tidal sections of the Asahi River. Furthermore, an artificial intelligence (AI)‐based YOLOv5 model, trained on underwater images, effectively detected Ayu aggregations, demonstrating an F1‐score of 0.757 in differentiating Ayu from other coexisting fish species in the same aquatic environment. This AI approach provides a nonintrusive method for monitoring Ayu populations and habitat preferences. The research underlines that successful spawning habitats require minimal saline intrusion, with optimal salinity and flow conditions. These insights are critical for spawning ground development, emphasizing the management of tidal effects and riverbed conditions to bolster Ayu populations and preserve aquatic ecosystems.

Marine protected areas can increase the abundance of invasive lionfish (Pterois miles)

AbstractMarine protected areas (MPAs) can protect and restore marine biodiversity and fisheries, but there are concerns that they may also benefit invasive species. The spatial and temporal colonization of invasive lionfish (Pterois miles) in the eastern Mediterranean was compared across zones with varying fishing restrictions (no fishing, recreational and commercial fishing, and commercial fishing only), and stations where targeted removal events were conducted by volunteer SCUBA divers. Lionfish density in no fishing areas was nearly double that of areas with commercial fishing only, and over four times greater than in areas where both commercial and recreational fishing were allowed. Lionfish density increased with depth, possibly due to easier human exploitation in shallow waters (0–10 m) that are accessible to recreational spearfishers. Targeted removals by volunteer divers decreased lionfish densities by over 60%, while areas without removals had a 200%–400% increase. Along with management actions, natural and ecological processes might drive lionfish densities within MPAs, and the speed with which lionfish colonized fishery‐restricted zones, emphasized the need for a more sophisticated MPA management strategy that considers invasive species impacts and dynamics in an ecosystem‐based approach.

Molecular identification and prevalence of plerocercoid larvae (Cestoda: Diphyllobothriidae) in some commercial fish species from Peru.

Diphyllobothriosis, a fish-borne zoonosis in South America, is mainly caused by the Pacific broad tapeworm Adenocephalus pacificus Nybelin, 1931, a parasite of considerable concern in fishery resources due to its impact on public health. A new diphyllobothrid, Diphyllobothrium sprakeri Hernández-Orts et al. Parasites Vectors 14:219, 2021, was recently described from sea lions from the Pacific Coast, but marine fish acting as intermediate hosts are unknown. The objective of this study was to confirm the presence of plerocercoid larvae of Diphyllobothriidae Lühe, 1910 (Cestoda: Diphyllobothriidea) in nine fish species of commercial importance in Peru. Of a total of 6999 fish (5861 Engraulis ringens, 853 Sciaena deliciosa, 6 Sciaena callaensis, 171 Scomber japonicus, 40 Trachurus murphyi, 40 Ariopsis seemanni, 18 Merluccius peruanus, 5 Sarda chiliensis, and 5 Coryphaena hippurus), 183 were infected with plerocercoid larvae, representing a total prevalence of 2.61% and a mean intensity of 3.2. Based on mtDNA cox1 sequences of 43 plerocercoids, a phylogenetic analysis revealed that 41 belong to A. pacificus and two to D. sprakeri. These findings are first molecular data for D. sprakeri larvae, and the infections of E. ringens and T. murphyi by plerocercoid larvae represent the first records of intermediate/paratenic hosts for this species. Hence, the findings of the current study enhance our understanding of the presence of diphyllobothriid species in commercial fish from the Southeastern Pacific Ocean and their potential impact on seafood safety for local human populations.

The historical ecology of subsistence and early commercial fisheries in mangrove systems in Brazil

The historical ecology of subsistence and early commercial fisheries in mangrove systems in Brazil