Trawl Surveys Research Articles

Results of trawl surveys in the Bering and Okhotsk Seas in autumn 2023

Results of trawl surveys in the Bering and Okhotsk Seas in autumn 2023

Results of the trawl survey of nekton and macroplankton during preanadromous migrations of pacific salmon in the North-West Pacific in 2023

Results of the trawl survey of nekton and macroplankton during preanadromous migrations of pacific salmon in the North-West Pacific in 2023

Pink salmon fishery in the Far-Eastern fishing basin in 2023: preliminary studies, forecast, interpretation of the fishing season results

Data of the trawl surveys for counting of pink salmon in 2022 and 2023 and results of pink salmon fishery in the main areas of the Russian Far East in 2023 are presented and the studies for understanding the state of the main pink salmon stocks and regional complexes are overviewed. The total catch in the Far-Eastern fishing basin was 478.5.103 t in 2023, including 182.4.103 t in the Bering Sea (total run — 247.1.106 ind.) and 280.8.103 t in the Okhotsk Sea (total run — 292.4.106 ind.). These values slightly exceed the forecasts of pink salmon run and catch in the Bering and Okhotsk Seas (estimated catch rates 140–150.103 t and 240–255.103 t, runs 210.106 ind. and 260–270.106 ind., respectively). For the forecast for the Okhotsk Sea, materials on differentiation of mixed pink salmon assemblages were analyzed by specialists of the Kamchatka branch of VNIRO, using both traditional methods (as morphological express- method and genetic method based on mt-DNA analysis) and a new method based on SNP-locus variability.

On features of the life cycle of humpback shrimp Pandalus hypsinotus (Decapoda, Pandalidae) in the Tatar Strait

The study is based on biological analyses of > 80,000 ind. of Pandalus hypsinotus collected in trawl surveys and trap fishery in the Tatar Strait in 2010–2022. Due to the lack of age-recording structures, the size-age structure of shrimp is usually determined by various statistical methods, each of which has some limitations and drawbacks. The modal analysis of size-sex composition dynamics is used in this study, including tracing the growth of strong year-classes. The analysis takes into account the dynamics of major seasonal events such as group molting, spawning, and larval hatching. The reproductive cycle of females is assumed to be 2 years. Based on results of the analysis, the life cycle of humpback shrimp in the Tatar Strait is as follows. After the larvae hatch from eggs in April-May, immature shrimp spend the first year of their life at the depths < 70 m, where they reach the carapace length of 9–15 mm, with a modal size of 11–12 mm. In the second year, they grow to the length of 20–22 mm, on average, then become males and migrate to deeper layer where join the adults. Further growth is described on the data for the strong year-class of 2010: the modal size of males reaches 26–27 mm at age 3 years, 29–30 mm — at age 4, 32–33 mm — at age 5, and 35–36 mm — at age 6. Gender transition of shrimp begins at age 5+, but most males become hermaphroditic at the age 6+. The modal size of intersex hermaphrodites ranges from 37 to 39 mm. At the age of 6 years and 9 months, the intersexes spawn en masse and transform into females. The first larval hatching of new females occurs after 15 months, i.e. at exactly 8 years of age. At least three cycles of spawning (larvae release) are assumed for females, taking into account their polymodal size composition and dynamics of their size increments per molt by age. In assumption of 2-year reproductive cycle, the female stage lasts 6 years. Thus, the total life span for the most of humpback shrimps is estimated to be 12 years (6 years before gender transition and 6 years after). Apparently, a small number of them live 14 years and spawn four times, and some can live up to 16 years and spawn five times.

Distribution of pacific cod Gadus macrocephalus (Gadidae) and functional structure of the habitat in the northern Japan Sea and some issues on regulation of the fishery

Seasonal and bathymetric distribution of the main age groups of pacific cod in the northern Japan Sea are considered on the data of bottom trawl surveys in 1980–2023. The main wintering and spawning accumulations, where the fish concentrate from December to January and then spawn in February-March, are formed on the external shelf and the upper continental slope along the western coast approximately between Peter the Great Bay and 47о N and along the eastern coast between Cape Krillon and 47о 30′N. The juveniles have feeding migrations from April to May, while older age groups complete the migrations a month later. They migrate in three main directions: from the areas at the mainland coast – southwestward and northeastward and from the areas at western Sakhalin — southward. The juveniles feed on shallows in Peter the Great Bay, northern Tatar Strait, and on southwestern shelf of Sakhalin between the Nevelsky Bay and Cape Krillon, whereas the feeding grounds for older groups occupy two vast areas including Peter the Great Bay with the adjacent southeastern shelf of Primorye and the shelf of northern Primorye in the Tatar Strait (to the north from 47о N) with the whole shelf of Sakhalin. In the northern Tatar Strait (northward from 48о N), the cod belonged to the Primorye and Sakhalin stocks can feed together. The feeding season lasts from June to September. The older cod feed usually deeper that the juveniles. Back migrations of cod for wintering occur from October to November. Because of a joint feeding area where the mainland and Sakhalin stocks are able to mix, the bottom trawl surveys at Primorye coast cannot be used for correct assessment of the total available catch (TAC) in this fishing district. To improve quality of the cod fishery forecasts, the methods of cohort or production analyses should be used, with the control by bottom trawl surveys data, as alternative information about the state of cod stocks, taking into account the abovementioned patterns of seasonal distribution and migrations.

Combined stomach contents and stable isotope analysis reveal feeding habits of Japanese jack mackerel (Trachurus japonicus) in the East China Sea

Japanese jack mackerel (Trachurus japonicus) is an economically important pelagic fish in the East China Sea. Knowledge is still limited regarding the feeding habits of this species in this area. Based on bottom trawl surveys conducted in the southern coastal area of Zhejiang during August in 2019 and 2020, we analyzed the feeding ecology of T. japonicus using stomach contents analysis and the stable isotope approach. The results indicated that the δ13C value for T. japonicus ranged from − 17.72 % to ;−14.30 %, and the δ15N value ranged from 10.89 % to 13.03 %. Two-way analysis of variance indicated significant annual and ontogenetic variations in the δ13C value, thereby suggesting changes in the final nutrient sources for T. japonicus in different growth stages and years. The trophic level of T. japonicus was estimated as from 3.35 to 4.46. In general, the trophic level of T. japonicus increased with growth, although the ontogenetic variation was not significant. The main food groups identified for T. japonicus based on stomach contents analysis were fish, shrimp, crabs, cephalopods, and small crustaceans. The results obtained by stable isotope analysis showed that the nutrient contribution rate of small crustaceans to the diet of T. japonicus was highest in both years, followed by shrimp. The feeding habits of T. japonicus had obvious ontogenetic variations, and the average contribution of fish species increased as the size of the predator increased. The results obtained in this study provide detailed feeding information about T. japonicus in the East China Sea.

Ethical issues in Lake Malawi fisheries: a case of Karonga District

ABSTRACT The fisheries sector, exemplified here by Malawi’s Karonga District, illustrates the global consequences of insufficient ethical considerations, leading to the depletion of fisheries resources. Using data spanning from 2012 to 2021, including frame surveys and catch assessment surveys, this study employs ethical theories and the ethical matrix to identify and analyse ethical issues. The observed concerns include illegal fishing, heightened investment in a limited resource fishery, consumption of the critically endangered Chambo species, the environmental impact of trawl surveys, technological overreliance, and inadequate resource support from local politicians. Recommendations encompass ending open-access fisheries, revising biomass assessment methods, promoting mindset change, implementing poverty alleviation programmes, promoting aquaculture development, and enhancing the establishment of freshwater protected areas as sites for biodiversity conservation.

Variation in energy density of northwest Atlantic forage species: Ontogenetic, seasonal, annual, and spatial patterns

AbstractObjectiveEnergy density (ED) estimates for marine forage species have been limited, impeding our understanding of this important trophic level. We studied the EDs of eight key forage species: Alewife Alosa pseudoharengus, Atlantic Herring Clupea harengus, Silver Hake Merluccius bilinearis, Northern Sand Lance Ammodytes dubius, Atlantic Mackerel Scomber scombrus, Butterfish Peprilus triacanthus, northern shortfin squid Illex illecebrosus, and longfin inshore squid Doryteuthis pealeii (also known as Loligo pealeii).MethodsSamples were obtained during spring and fall bottom trawl surveys across five regions (Gulf of Maine, Georges Bank, southern New England, northern Middle Atlantic Bight, and southern Middle Atlantic Bight) from 2017 to 2019. In the laboratory, we developed predictive relations between the percent dry weight (%DW) and ED (kJ/g wet weight) determined by proximate composition analysis (n = 606; r2 = 0.76–0.98) to estimate the ED of additional samples (n = 4583). For each species, we modeled ED as a function of size, depth, season, and year (as factors) as well as location (latitude, longitude) using generalized additive models (GAMs).ResultAlewife, Atlantic Herring, Northern Sand Lance, Atlantic Mackerel, and Butterfish were classified as high‐quality prey (ED > 6 kJ/g), although Atlantic Herring ED was nearly half the values reported in earlier studies. Silver Hake, northern shortfin squid, and longfin inshore squid were classified as moderate‐quality prey (4 kJ/g < ED < 6 kJ/g). Most species had higher EDs in the fall following summer feeding than in the spring after spawning and/or reduced winter feeding. The best‐fitting GAMs included weight, depth (by season), season, and year effects for most species. Location (by season) explained significant amounts of variation.ConclusionObserved variation in ED across regions, species, seasons, and years provides the empirical data necessary to consider hypotheses related to “upstream” regulation of ED (via environmental drivers and productivity) and “downstream” effects on recruitment for these forage species as well the species that prey on them.

Thirty years of change: Assessing the dynamics of fish communities in Daya Bay, a semi-enclosed coastal ecosystem of the South China sea

Daya Bay is a semi-enclosed bay in the South China Sea which is a coastal ecosystem with significant ecological and economic value that is subjected to a variety of anthropogenic disturbances. However, long-term variation in fish community structure in this Bay remains uncertain. In this study, we aimed to explore the changing characteristics of fish species composition and community structure in Daya Bay during the past 30 years using data from 1989 to 2021 from bottom trawl surveys and historical literature data. As of now, a total of 544 species of fish have been identified in the Bay, belonging to 24 orders and 125 families. The structure of the fish community in the bay has changed over time. Firstly, there has been a clear decrease in the number of species and biomass of large fish. Secondly, the number of fish constituent orders and families has decreased. Moreover, both the average taxonomic distinctness and variation in taxonomic distinctness decreased from 1989 to 2021. Thirdly, there is low similarity among fishes at different time phases and distinct changes in the composition of dominant species. Present results indicate that the fish community structure in Daya Bay has tended to reflect a decline in diversity, shifts in composition, and shrinking of fish body size in the past 30 years. This study improves our understanding of fish species composition and its drivers over time in Daya Bay, providing important knowledge to support the protection and restoration of this ecosystem and the important ecosystem services it provides.

The distribution of the juvenile stages and eggcases of skates (Rajidae) around the British Isles

Abstract Skates (Rajidae) include species of conservation and commercial importance, but there is limited information regarding their ecologically important habitats, including spawning and nursery areas, in northern European seas. Data on the distribution, relative abundance and length composition of skates were collated from scientific trawl surveys, and based on length‐frequency information, length‐at‐hatching and length‐at‐maturity, skates were allocated to length‐based categories representing early‐juvenile stages (EJS) and mid‐juvenile stages (MJS). Citizen science data were used to inform on the occurrence of eggcases. The Great Eggcase Hunt (starting in 2003) citizen science recording project collects georeferenced data for elasmobranch eggcases, primarily from around the British Isles. This provided verified species‐specific data for a total of 227,407 specimens from 11 skate species. Purse Search Ireland (starting in 2005) provided a further 2491 records of 10 skate species from around Ireland. The most frequently observed skate eggcases were from the genus Raja and occurred around much of the British Isles. The EJS and MJS of such species were observed most frequently in inshore waters. Data for EJS were more limited for Raja microocellata and Raja undulata, indicating that the EJS of these species occur in shallower (<20 m) waters. Juveniles of the genus Leucoraja occurred further offshore. Only the eggcases of Leucoraja naevus were recorded regularly, with the eggcase of Leucoraja fullonica described here. The data collated here provide an overview of skate spawning and nursery areas, thus informing fisheries management and marine spatial planning, including the identification and delineation of Important Shark and Ray Areas (ISRAs).

A Cross-Decadal Change in the Fish and Crustacean Community of Lower Yaquina Bay, Oregon, USA

Natural environmental change, anthropogenic development, and inter-annual variability can affect the ecology of estuarine fish and invertebrates. Yaquina Bay, Oregon, a well-studied estuary, has undergone intense development, as well as deep-draft dredging during the latter half of the 20th century, resulting in the alteration of ~45% of the lower estuary’s natural shoreline. In 1967, the United States Environmental Protection Agency (USEPA) conducted a 21-month survey of Yaquina Bay to characterize the demersal fishes and epibenthic crustaceans that occupy the bay. From 2003 to 2005, we conducted a 25-month survey to replicate that work and provide a comparative snapshot of the demersal fish and epibenthic crustacean community in the bay. A comparison of the trawl survey datasets reveals a 91% decline in total catch per unit effort (CPUE) between surveys, as well as a decline in multiple measures of biodiversity. Furthermore, the fishes and crustaceans of Yaquina Bay have experienced a shift in species dominance from demersal fishes in the late 1960s to epibenthic crustaceans in the 2000s, marked most notably by a nine-fold increase in the Dungeness crab CPUE. While this work does not establish a causal relationship between changes in the demersal communities of this West Coast estuary and human or natural events, it does document substantial changes in both the diversity and total abundance of animals in that community over a three-plus decade period of development and environmental variability. Hence, this forms a second baseline for continued long-term monitoring.

Stock Assessment of the Commercial Small Pelagic Fishes in the Beibu Gulf, the South China Sea, 2006-2020.

Long-term variations in population structure, growth, mortality, exploitation rate, and recruitment pattern of two major commercial small pelagic fishes (CSPFs) (Decapterus maruadsi and Trachurus japonicus) are reported based on bottom trawl survey data collected during 2006-2020 in the Beibu Gulf, South China Sea. All individuals collected during each sampling quarter over a period of 15 years were subjected to laboratory-based analysis. In this study, the stock of D. maruadsi and T. japonicus inhabiting the Beibu Gulf was assessed using length-based methods (bootstrapped electronic length frequency analysis (ELEFAN)) to complete stock assessment in different fishery management periods (the division of fisheries management periods was based on China's input and output in the South China Sea offshore fisheries over 15 years, specifically divided into period I (2006-2010), period II (2011-2015), and period III (2016-2020)). The results showed that the mean body length, dominant body size, and estimated asymptotic length of two CSPFs decreased, whereas their growth coefficient decreased, indicating miniaturization and slower growth, respectively. Estimated exploitation rates and catching body length for two CSPFs indicated that both stocks in the Beibu Gulf were overexploited in period I and moderately exploited after 2011. These stocks were taking a good turn in status in period III, with the exploitation rate much lower than the initial period and reversing the downward trend in catching body length. Furthermore, the variations in the spawning season of the two CSPF stocks and their barely satisfactory expected yield indicated the complexity of the current fishery management in the Beibu Gulf. These results suggest that management measures to reduce fishing pressure may have a positive influence on the biological characteristics of those CSPFs in the Beibu Gulf; however, the stock structure already affected by overfishing will be a huge challenge for the conservation and restoration of fisheries resources in the future. Given that the current stocks of D. maruadsi and T. japonicus in the Beibu Gulf still have low first-capture body length (Lc) and high fishing mortality (F) (compared to F0.1), we identify a need to refine population structure by controlling fishing efforts and increasing catchable size, and more consideration should be given to the local fishery resource status in fisheries management.

Spatio-temporal patterns of whiting (Merlangius merlangus) in the Adriatic Sea under environmental forcing.

Understanding how environmental factors affect species distribution is crucial for the conservation and management of marine organisms, especially in the face of global changes. Whiting (Merlangius merlangus) is a demersal cold-temperate fish, considered a 'relict species' in the Adriatic Sea. Despite its significance to commercial fisheries in the region, the specific drivers behind its spatial and temporal patterns have not been thoroughly examined. Here, we fitted a set of Generalized Linear Mixed Effects Models to data collected in the Northern and Central Adriatic from 1999 to 2019 during the Mediterranean International Trawl Survey to investigate the potential influence of depth, seafloor temperature and seafloor dissolved oxygen on the annual biomass density and spatial distribution of whiting in the spring-summer season. Our results showed that depth, and to a lesser degree temperature and oxygen, are important predictors of whiting distribution in this period, with preferences for depths of ~ 45 m, temperature of ~ 15.4°C and dissolved oxygen > 5.5 ml L-1. We predicted a persistent core area of distribution in front of the Po River Delta, in the Northern Adriatic Sea, while the density progressively declined towards the Central and Southern Adriatic Sea along the Italian coast. Additionally, the temporal trend exhibited high fluctuations over the years, occurring in cycles of 3 to 4 years. Finally, by comparing the biomass density estimates obtained under optimal conditions with those derived from the actual values for each variable, our analysis revealed that temperature had a pronounced and general impact on biomass density in the northern survey area (predictions revealed a density reduction of approximately two-thirds), while oxygen displayed a minor and more localized influence. This work deepens the current knowledge about the ecology of whiting in the Adriatic Sea and provides support for the conservation and management of this species.

The spread of the non-indigenous species Bregmaceros nectabanus Whitley, 1941 (Osteichthyes: Bregmacerotidae) in the eastern Mediterranean

This study reports the first record and some features of two individuals of the Lessepsian migrant species smallscale codlet, Bregmaceros nectabanus, found in the stomachs of two individuals of European hake, Merluccius merluccius, sampled in the northern Ionian Sea (eastern Mediterranean) during the MEDITS International Bottom Trawl Survey. The two European hake were collected on muddy bottoms in September 2021 at 63 m depth (39.34950 ºN; 16.52350 ºE) and at 240 m depth (39.07156 ºN; 17.12626 ºE). Their morphological traits together with otolith and scale characteristics allowed the identification of the two specimens found in the stomachs as B. nectabanus. The analysis of the stomach contents for the larger individual is also reported. This finding underlines the utility of stomach content analysis as an indirect method to study the biodiversity of deep-sea ecosystems, including the spread of non-indigenous species as indicators of global warming.

On the biology of blackbellied angler, Lophius budegassa Spinola, 1807, in the north-western Mediterranean

In the Mediterranean Sea, the blackbellied angler, Lophius budegassa Spinola, 1807, represents a relevant fraction of the commercial by-catch of bottom trawling and small-scale fisheries that use passive gears (e.g., set nets, bottom longlines, etc.). Despite its importance, there are no comprehensive studies on the population dynamics of this species, and there is still scarce and scattered knowledge of its biology and ecology. Biomass, morphometric, and biological data of the blackbellied angler were collected from 1994 to 2021 by means of the Mediterranean International Bottom Trawl Survey (MEDITS) programme in the Ligurian and northern Tyrrhenian Seas, and in the EU Data Collection Framework during the period of 2006-2021. Furthermore, ageing was performed on specimens collected from 2013 to 2021 during the MEDITS programme. There were high values for the density indices and the spatial distribution of biomass in the central sector of the investigated area (the Tuscan Archipelago), mostly on the continental shelf. The length-weight relationship showed negative allometric growth when considering the sexes together, and no difference between the sexes. The size at first maturity (L50) was estimated at 39.4 cm total length (TL) in females and at 29.2 cm TL in males. The obtained Von Bertalanffy growth parameters were: in females, L∞ = 74.50 cm, k = 0.10 years-1, and t0 = -0.40 years; in males, L∞ = 61.30 cm, k = 0.14 years-1, and t0 = -0.38 years. There were differences in growth between males and females for L∞ (χ2 = 10.04; p < 0.05) and k (χ2 = 6.12; p < 0.05).

An updated checklist of bony fishes from the Persian Gulf

This study provides an updated and comprehensive checklist of bony fishes occurring in the Persian Gulf based on a recent survey of the region. This study was conducted from 1995 to 2020 by research trawl survey for identification and biomass estimation of the demersal species each year from autumn to late winter, covering all waters of Iran in the Persian Gulf. In addition to the research cruises, routine field visits were conducted at major fishing ports to identify pelagic species captured through gillnet and trap fisheries. Among the over 700 species reported in previous studies conducted in the Persian Gulf, the occurrence of 486 species has been confirmed. Several species were omitted from the revised checklist due to insufficient evidence supporting their occurrence in the region or due to taxonomic confusion. Throughout the study, 486 species of bony fishes, representing 101 families, were identified, and a critical review of relevant literature was conducted. This checklist serves as a reliable reference to address existing contradictions in the scientific literature on bony fishes of the Persian Gulf and establishes a foundation for future stock assessment studies in the region.

Variable trends in the distribution of Atlantic cod (Gadus morhua) in the Celtic seas.

Despite decades of active fisheries management, many stocks of Atlantic cod in its southern range are in a depleted state and mortality estimates remain high. Recovery of these stocks, as defined by management areas, could be confounded by cod distributions shifting outside of these areas. Here, we assess data from internationally coordinated trawl surveys to investigate the distribution of three cod stocks in the Celtic Seas ecoregion, Irish Sea, Celtic Sea, and West of Scotland, from 1985 to 2021. We mapped cod densities, analyzed trends in mean weighted depth and bottom temperature, and calculated the center of gravity and equivalent area of the stocks. The distribution of the West of Scotland stock shifted north and east, spilling into the North Sea, while the Irish Sea and Celtic Sea stocks shifted west. Each stock showed decreasing trends in equivalent area, but there were no clear trends in the average depth occupied by the fish. There was no apparent relationship between temperature and the distribution of cod, as bottom temperature varied little from 1993 to 2021. Although Irish Sea cod showed a shift into warmer water, this was due to changes in survey distribution. The shift in distribution of the West of Scotland cod stock towards the North Sea whilst impairing local recovery provides further justification for the recent definition of its incorporation into a larger stock unit that includes the northwest of the North Sea. The Irish Sea and Celtic Sea cod stocks are neither shifting northwards, nor into deeper waters, but remained within current boundaries. This suggests that recent temperature conditions did not affect their distribution, but this may change as temperatures increase towards the limit for reproduction.

Genetic characterization of juvenile chum salmon with otolith marks of Japanese salmon hatcheries in the catches of trawl surveys 2016–2021

Chum salmon sample from the catches of autumn trawl surveys in the Sea of Okhotsk (2016–2021), including individuals with otolith marks of Japanese salmon hatcheries (SHs), was analyzed based on microsatellite loci polymorphism. Reference database of eight microsatellite loci frequencies, created before and included 26 samples of chum salmon from major reproductive regions in the Sea of Okhotsk basin, has been updated with data on the microsatellite allele variety of chum salmon from Hokkaido and Honshu. Result s of the research indicate of strong similarity between chum salmon of the Kuril Islands and individuals released from Japanese SHs.

Catalyzing Conservation: An Analysis of Fish Stock Dynamics in a Marine Protected Area before and after Artificial Reef Deployment

The marine ecosystem’s balance is crucial for sustaining biodiversity and supporting fisheries. Marine protected areas have been increasingly used to enhance marine habitats, yet their impact on fish populations remains a topic of debate. This study focuses on a marine protected area in Kitros, Pieria, in Greece, where an artificial reef was constructed, to understand its influence on coastal fish populations. The objectives were to investigate the changes in fish biomass and abundance, comparing the data from periods before and after the construction of an artificial reef. This research compares the data between 2007 and 2008 with the data between 2016 and 2017, collected with bottom trawl surveys strategically executed prior to and after the artificial reef’s installation. Fish species captured were identified, with their lengths and masses measured. The findings indicate an increase in the biomass and abundance of certain fish species after artificial reef deployment, notably the commercially significant Mullus barbatus and Pagellus erythrinus. The artificial reef in Kitros, Pieria, with its surrounding marine protected area appears to have had a positive impact on the local fish populations over the years, suggesting that it can contribute to marine conservation and fishery enhancement. These results underscore the potential of artificial reefs as tools for marine ecosystem management, offering insights for policymakers and environmentalists into coastal resource management.

Distribution and diversity of elasmobranchs in the Sea of Marmara: A 2023 status report

Abstract Elasmobranchs, encompassing an array of sharks and rays, confront a threat of extinction on a global scale. The Sea of Marmara (SoM) stands out as a critical refuge for these endangered species. This study harnesses data derived from comprehensive trawl surveys, representing the first area‐based evaluation of the elasmobranchs inhabiting the SoM. Sampling protocols were carried out at 10 separate stations along the 980‐km coastline of the SoM, each bounded by different ecological characteristics and anthropogenic influences. A total of eight shark species and six ray species were caught in the towed area of the entire the SoM. Notably, Scyliorhinus canicula and near‐threatened Raja clavata constitute more than 50% of the total abundance. Additionally, rare, and critically endangered species, including the Oxynotus centrina, Squatina squatina, Dipturus batis, and Myliobatis aquila, were documented, expanding our knowledge of their presence in the region. Spatial distribution heterogeneity was pronounced within species. Size distributions were species‐specific, and the presence of both juvenile and adult individuals suggested successful reproduction and growth. Records expand the known size range in the SoM for six shark and three ray species. It also provides first‐size information based on the total length of the S. stellaris and D. batis. Additionally, the urgent need for field‐based conservation efforts is highlighted, citing a previously unidentified important sensitive areas located in the southern part of the SoM.