Commercial Catch Research Articles

Non‐Native Invasive Fish Species (NIFS) in Inland Waters of India: Management Issues, Strategies and Suggestions

ABSTRACTIn India, there are 626 non‐native invasive fish species (NIFS), with 16 becoming invasive in inland waters, adversely impacting native biodiversity, and fisheries by altering the abundance of NIFS in commercial catches. Scientific findings highlight that the movement of NIFS interacts with agricultural activities and the evolving environment, facilitating their spread and establishment. The scenario of NIFS invasion disrupts biological communities, ecosystem services and fisherfolk livelihoods. Despite the implementation of existed guidelines, issues related to NIFS have persisted and escalated over time scale putting increased pressure on indigenous aquatic biological resources in inland waters. This paper suggests the need of framing a new management plans, guidelines and regulatory policies to control NIFS invasions, protecting riverine fish biodiversity and ecosystem services. Proposed management strategies include functional response (FR) and adaptive response (AR)‐based approaches, which are discussed to address NIFS management in inland waters.

Estimates of life-history and growth parameters of exploited fish species in lakes Edward and George: Implications on exploitation status, population dynamics, management, and conservation of native species.

Adequate knowledge is essential for responsible inland fisheries. However, many inland fisheries lack monitoring, and therefore, decision-making for fisheries management is not reliable. In this paper, we used data from surveys and literature to estimate the life-history and growth parameters of 16 exploited fish stocks in the Ugandan part of Lake Edward and Lake George (East Africa). The estimated parameters are pivotal indicators of fish stock status, particularly in data-poor fisheries. The estimated parameters included maximum length (Lmax) and mean length (Lmean) as indicators of size structure in experimental and commercial catches, coefficients of length-weight relationships, length at 50% maturity (Lm50), fecundity, von Bertalanffy parameters, total mortality (Z), and natural mortality (M). These parameters were estimated using empirical formulae, statistical methods, and analyses of length frequencies. Only two stocks of semutundu Bagrus docmak exhibited significant and increasing trends in Lmax (Lake Edward) and Lmean (Lake George). The estimates for the remaining parameters were consistent with those in FishBase and other literature resources, either for the same species or related species. This consistency indicates their reliability for application in decision-making and further assessments. Some parameters showed evidence of unsustainable fishing. For example, estimates of Lm50 for four of the assessed stocks belonging to two species (Nile tilapia Oreochromis niloticus and marbled lungfish Protopterus aethiopicus) were lower than baseline estimates in the studied waterbodies. Furthermore, the Lmean in catches for all the stocks were less than the optimum lengths (Lopt), which maximize catches with a minimal impact on biomass and size structure. No significant changes in Lmean, length-frequency distributions, and size at maturity could be attributed to the management changes implemented in 2018, probably because it is too early to observe changes in these parameters. However, there are positive signs attributable to the changes in management as shown by a high proportion of mature individuals in commercial catches for most of the stocks for which the proportion was calculated, and an increase in Lmean and Lmax for some stocks, such as B. docmak, in commercial or experimental catches. New estimates from this study will enhance decision-making and further assessments of fisheries. Routine monitoring is recommended to update and improve the estimates.

Ocean conditions influence the quality of recruiting benthic marine invertebrate larvae—Insights from fatty acids

AbstractMany marine benthic invertebrates have a pelagic life stage, during which larvae need to accumulate enough reserves to complete metamorphosis to a settled benthic juvenile. Currently, very little is known about how ocean conditions affect quality of the larvae. We studied this for three settlement seasons (2017–2019) by collecting returning Dungeness crab (Metacarcinus magister) megalopae at the Oregon coast and analyzing them for fatty acid biomarkers. We found that the larvae are omnivorous and have versatile diets. The daily larval abundance was positively correlated with larval quality. Despite the relatively high day‐to‐day variation, we found pronounced seasonal and inter‐annual differences in the body condition (size and total fatty acid content) and biomarker composition of megalopae. Especially, the early season recruits of 2017 had lower content of lipids and polyunsaturated fatty acids known to be beneficial to crustaceans. This is likely related to lingering effects of the eastern Pacific marine heat wave (2014–2016) on pelagic communities. The larvae were rich in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) with lower levels in benthic juveniles, indicating an ontogenetic diet shift and likely lower availability of DHA and EPA in the benthic environment. The pulsed megalopa recruitment may provide substantial carbon and lipid inputs to the nearshore ecosystem as a form of pelagic subsidy. Our results reveal that ocean conditions may have an effect on the quality of returning larvae, which likely influence their recruitment performance and early juvenile success, and thus potentially also the population size and commercial catch 4 yr later.

On the problem of annual overfishing of the silver bream Blicca bjoerkna (Cyprinidae) in industrial fishing in the Astrakhan region

The silver bream Blicca bjoerkna and the small-sized common bream Abramis brama are characterized by external similarity, which contributes to manipulations with the substitution of one species (common bream) by another (silver bream) when taking into account the volume of industrial fishing in the Astrakhan region. This is due to the fact that in the period of spring fishing season during common bream spawning migration, the share of non-commercial common bream in commercial catches increases (to 20–30 %), the catch of which is limited in accordance with the Fishing Rules. In order not to exceed the allowable volume of by-catch of non-large common bream, fish producers register en masse catches of small-sized bream as a catch of silver bream, which causes significant damage to common bream fish stocks through oversampling of first-time maturing individuals of the population. In recent years, the share of non-commercial common bream recorded as a silver bream in May alone is 13–28% of its official catch during this period. In order to reduce the catch of first spawning common bream producers of non-commercial length on the water bodies of the Astrakhan region in the period from April 21 to May 20, it is recommended to introduce a ban on industrial fishing of silver bream.

Status of the fish stocks and fisheries of the main commercial fish species of Lake Ladoga in the XXI century

In the 21st century, there has been decrease in stocks and catches of aquatic biological resources in Lake Ladoga as well as a change in the structure of the fish population in the Lake, primarily due to changes in the trophic capacity of the reservoir. Smelt dominates in the commercial catches. Stocks and catches of autumn-spawning whitefish and lakecisco show obvious downward trend. Biological and commercial indicators of the pike-perch population are at a low level. Stocks of bream, roach and perch are in good condition.

Industrial fishing on Lake Ilmen, Novgorod region: catch dynamics in the XX century and the current status

The long-term dynamics of commercial catches on Lake Ilmen in the Novgorod region for the period from 1912 to 2023 was traced. The structure of catches and the fishing base is described, taking into account the affecting factors. Specifics of organizing fishing at present stage are given.

Population Genomics of the Blue Shark, Prionace glauca, Reveals Different Populations in the Mediterranean Sea and the Northeast Atlantic.

Populations of marine top predators have been sharply declining during the past decades, and one-third of chondrichthyans are currently threatened with extinction. Sustainable management measures and conservation plans of large pelagic sharks require knowledge on population genetic differentiation and demographic connectivity. Here, we present the case of the Mediterranean blue shark (Prionace glauca, L. 1758), commonly found as bycatch in longline fisheries and classified by the IUCN as critically endangered. The management of this species suffers from a scarcity of data about population structure and connectivity within the Mediterranean Sea and between this basin and the adjacent Northeast Atlantic. Here, we assessed the genetic diversity and spatial structure of blue shark from different areas of the Mediterranean Sea and the Northeast Atlantic through genome scan analyses. Pairwise genetic differentiation estimates (F ST) on 203 specimens genotyped at 14,713 ddRAD-derived SNPs revealed subtle, yet significant, genetic differences within the Mediterranean sampling locations, and between the Mediterranean Sea and the Northeast Atlantic Ocean. Genetic differentiation suggests some degree of demographic independence between the Western and Eastern Mediterranean blue shark populations. Furthermore, results show limited genetic connectivity between the Mediterranean and the Atlantic basins, supporting the hypothesis of two distinct populations of blue shark separated by the Strait of Gibraltar. Although reproductive interactions may be limited, the faint genetic signal of differentiation suggests a recent common history between these units. Therefore, Mediterranean blue sharks may function akin to a metapopulation relying upon local demographic processes and connectivity dynamics, whereby the limited contemporary gene flow replenishment from the Atlantic may interplay with currently poorly regulated commercial catches and large-scale ecosystem changes. Altogether, these results emphasise the need for revising management delineations applied to these critically endangered sharks.

Population dynamics of the flathead grey mullet (Mugil cephalus Linnaeus 1758) in the Narmada estuary on the west coast of India

The population dynamics of flathead grey mullet, Mugil cephalus, were evaluated using length-frequency data collected from the Narmada estuary monthly between January 2018 and December 2019. The population parameters were assessed and calculated using the FiSAT-II software tool (FAO-ICLARM Stock Assessment Tools) after the estimation data were divided into 10 mm class intervals. A total of 419 specimens were collected, with an average length range of 171.14±58.15 mm and an average weight of 58.15±45.65 g, respectively. The length-weight relationships were established as W = 0.0105 L2.979. Length-frequency data revealed that length groups 140–149 (15.75 %) and 130–139 mm (13.37 %) dominated the commercial catches of M. cephalus at the Narmada estuary. Different growth parameters were estimated as L∞ = 309.75 mm, K = 0.41 yr−1 and t0 = −0.0013 years. The estimated values of mortality coefficients Z, M, and F were 1.06 yr−1, 0.52 yr−1 and 0.54 yr−1, respectively. The value of exploitation ratio (E) by using the length-converted catch curve method was established as 0.51, which was found to be a little high from the optimum value (0.50). The recruitment was found to be continuous almost throughout the year, with two peaks, once during February to May and another during August to October. The maximum sustainable yield (MSY) was estimated at 970.218 t if the suggested length at first capture (Lc = 123.44 mm TL) is maintained throughout the capture periods. The fishing pressure was found to be slightly excessive for the current stocks, which should be considered for proper management of the fishery in the Narmada estuary.

Disentangling bottom-up and top-down controls on fish consumption of key prey in the Northeast US Shelf ecosystem

Abstract Exploited forage fishes serve a dual role in marine ecosystems by supporting directed fisheries and predator productivity, and thus both harvest and predatory removals should be accounted for when developing stock assessments and evaluating management trade-offs. Predator catch and stomach content data collected on the Northeast US Shelf from 1978 to 2019 by two fisheries-independent surveys were combined within multivariate spatiotemporal models to estimate time-series of consumptive removals during spring and fall for four commercially exploited prey; Atlantic herring (Clupea harengus), silver hake (Merluccius bilinearis), butterfish (Peprilus triacanthus), and longfin squid (Doryteuthis pealeii). Seasonal consumption trends were mostly synchronous for Atlantic herring and silver hake, asynchronous for butterfish and longfin squid, and predatory removals were generally greater during fall. Consumption has increased since the 1990s for all prey except Atlantic herring and butterfish during fall, which coincides with the widespread implementation of harvest constraints meant to rebuild predator and prey populations. These time-series were linked to hypothesized drivers using state-space regression models; prey availability (bottom-up; positive relationships) and commercial catch (top-down; primarily negative relationships) were the strongest predictors of consumption. Although the mechanisms underlying these relationships remain unresolved, these linkages highlight connections among the systemic drivers of productivity on the Northeast Shelf.

Dynamics of catches and state of stocks the European perch Perca fluviatilis in rivers in the middle Ob basin (in the Tomsk region)

European perch Perca fluviatilis Linnaeus, 1758 — is a mediumsized representative of the Percidae. It distributed in lowland rivers, lakes and artificial reservoirs, as well as in desalinated coastal areas of the seas of Northern Eurasia, with the exception of the Far East and the coast of the Arctic Ocean. This species is numerous almost everywhere. It is one of the main objects of industrial and amateur fishing. In the Middle Ob basin, a significant part of the life cycle of perch is associated with the floodplain system. There is, during the spring flood, its spawning and subsequent feeding of juveniles and producers take place. Therefore, the regulation of the Ob’s flow by the Novosibirsk hydroelectric power station dam served as one of the important factors that had a negative impact on the state of its reserves. Thus, within the Tomsk region, commercial catches of perch before the regulation of the Ob flow (1946–1961) averaged 354 tons per year, and after regulation (during the period of stable fishing pressure, in 1960–1985) — 157 tons. In recent years (2018–2022), the catch of perch has increased slightly and, according to official fisheries statistics, amounts to 211 tons per year, providing 5.9% of the total fish production in the region. Currently, the reserves of perch are in a relatively stable state, the estimated indicators of its biomass in rivers within the Tomsk region in recent years range from 1190.9 to 2277.5 tons, with an average number of 10.6 million pieces. The development of the perch’ reserves is satisfactory, averaging 94.2% of the recommended catch. Amateur fishermen do not have a significant impact on the state of perch stocks.

Elasmobranch Mark–Recapture Experiment off the Balearic Islands: Insight into Scyliorhinus canicula Growth, Mobility, and Population Size

Despite the high diversity of elasmobranch fishes in the Balearic Islands, knowledge of their biology and population dynamics is still scarce. A recent mark-and-recapture experiment off the Balearic Islands tagged 3738 individuals of 23 shark and batoid species during MEDITS and CANAL bottom trawl scientific surveys from June 2021 to August 2023. Retrieval was reported for the sharks Scyliorhinus canicula and Mustelus mustelus, revealing relatively small home ranges for these species (0.2–38.5 km and 7.8–15.3 km for S. canicula and M. mustelus, respectively). Recapture efficiency was higher from scientific surveys than from commercial catches, highlighting potential challenges in collaboration with fishermen and recapture reports. Density estimates obtained from the MEDITS bottom trawl survey suggest a much larger population for S. canicula than estimates from the mark–recapture data, indicating MEDITS density estimates for this species may be overestimated due to its scavenger behavior perhaps favoring individuals searching for discards aggregated in the fishing grounds. This study emphasizes the importance of monitoring, collaborative efforts, and improved reporting mechanisms to enhance our understanding of elasmobranch populations and provide support for sustainable management of these vulnerable marine species.

Investigating fish reproduction phenology and essential habitats by identifying the main spatio-temporal patterns of fish distribution

Abstract Fish spawning phenology is a major concern for conservation and fisheries management. New intensive data sources, such as GPS-based tracking data and high-resolution catch declaration data, are becoming increasingly available in the field of marine ecology. These data benefit from high spatiotemporal resolution and open new research avenues for investigating the interannual variability in fish phenology. In this paper, we demonstrate how an integrated species distribution model informed by commercial catch data combined with spatiotemporal dimension reduction methods known as empirical orthogonal functions (EOFs) can be used to synthesize spatiotemporal signals in fish reproduction phenology. Specifically, we address the following questions: (1) Can we identify seasonal spatial patterns that can be interpreted in terms of reproductive phenology and essential habitats? (2) Can we identify changes in reproductive phenology over time? (3) Are these changes related to environmental drivers? The analysis illustrates the reproductive phenology of three key commercial species in the Bay of Biscay (sole, hake, and sea bass). The EOF analysis emphasized strong seasonal spatiotemporal patterns that correspond to reproduction patterns and feeding patterns. Based on this methodology, we identified seasonal variations in the timing of reproduction, and we related these variations to sea surface temperature, a key driver of fish reproduction.

Large-scale serial replacement of invasive tench (Tinca tinca) by invasive carp (Cyprinus carpio) in the presence of redfin perch (Perca fluviatilis) in the Murray-Darling River system, Australia

Ecosystems worldwide are increasingly being invaded by multiple species, and the rate of biological invasion is accelerating, leading to more interactions among invasive species. One such interaction that has received little attention is the phenomenon of ‘serial replacement’ or ‘over-invasion’, where an established invasive species is supplanted by a second invasive species. Understanding this interaction is important as controlling the second species could inadvertently lead to an increase in the abundance of the first species. We used a hierarchical state-space model to analyse changes in annual abundances (commercial catch-per-unit-effort) of three invasive fish species, tench (Tinca tinca), common carp (Cyprinus carpio) and redfin perch (Perca fluviatilis), in the Murray-Darling River system (MDRS), Australia between 1954–2002. Tench were present at low abundances until the mid-1970 s, before declining to the point of no commercial catch post-1989. This rapid decline coincided with a significant increase in carp abundance, suggesting that carp may have driven the tench decline through habitat modification (particularly the destruction of aquatic plants), consistent with findings from European studies that show the disappearance of tench from ponds with intensive carp farming. Redfin perch populations, were inferred to be much less impacted by the invading carp population. While carp were present in the MDRS for the duration of the study, the rapid increase in carp abundance in the early 1970 s coincided with the introduction of a specific genetic lineage—the “Boolarra strain”. Our analysis provides compelling evidence of serial replacement of long-established tench by invading common carp triggered by the introduction of a novel carp strain.

Reproductive Biology of Red Pandora (Pagellus bellottii Steindachner, 1882) from the Coast of Ghana and Implications for Management

A total of 933 samples of Pagellus bellottii were obtained from the coast of Ghana between January and December 2019, from commercial catches to determine the sex ratio, maturity stages, spawning period, and length at first maturity. The male to female ratio was 1.39:1. July and May were the main spawning peaks for female individuals of the assessed fish species. Two spawning periods were observed with a minor spawning period from November to January and major spawning from March to September. Female individuals matured slightly earlier than male individuals at 20 cm and 20.8 cm respectively. The results of this study could help to revise the existing minimum capture size of Red Pandora in Ghana.

The Impact of the COVID-19 Pandemic on the Commercial Catch of Marine Fish

The Impact of the COVID-19 Pandemic on the Commercial Catch of Marine Fish

Біологічна характеристика білого (Hypophthalmichthys molitrix Valenciennes, 1844), строкатого (Hypophthalmichthys nobilis Richardson, 1845) та гібрида товстолобиків (Hypophthalmichthys sp.) як обʼєктів випасної аквакультури в Кременчуцькому водосховищі

Purpose: Determination and analysis of parameters, which characterize the biological and fishery aspects of the formation and exploitation of the commercial stock of silver and bighead carps of the Kremenchuk Reservoir. Methodology. As primary materials, the results of field studies at the Kremenchuk Reservoir carried out in 2019-21 and 2023 have been used. Data collection and processing was carried out in accordance with generally accepted methods. Ichthyological material was collected from catches of commercial fishing nets with mesh sizes a=38-140 mm; in total, during the study period, catches of 2,254 fishing nets were examined, of which 652 individuals of silver and bighead carps as well as their hybrids were analyzed.. Predicted survival rate was assessed based on the annual natural mortality rate, which was determined based on the the Bertalanffy equation parameters. Statistical data processing was carried in MS Excel. Findings. In recent years, the basis of the commercial catches of silver, bighead carps and their hybrids in the Kremenchuk Reservoir was composed of age-7-10 fish, which was due to their predominant catch due to specialized fishing with nets with mesh sizes of a=100-140 mm, which accounted for up to 96.7% of the total catch of these species; the share of native species in the catches of these nets did not exceed 10%. The average annual absolute linear growth of these species in modal age groups was 6.0...9.6 cm, relative - 8.7...14.5%; the weight gains were 1416...3829 g and 28.1...43.5%, respectively, which indicated satisfactory grazing conditions in the Kremenchuk reservoir. The parameters of the Bertalanffy equation, which characterize the growth rate of silver, bighead carps and their hybrids in the Kremenchuk Reservoir, were: K = 1.08 (year-1), L∞ = 115.7 (cm) to = 0.17 (years). Based on the calculated natural mortality rates and 30% removal starting from age-5 fish, the fish return rate from stocking age-1+ fish into the Kremenchuk Reservoir is 10.2%. The peak culmination of ichthyomass of silver, bighead carps and their hybrids falls on age-4-6 fish; the optimal legal length of 55 cm allows ensuring the catch rates of 751 kg per 1,000 stocked age-1+ juveniles. Originality. Original data on the current state of commercial stocks of the main objects of pasture aquaculture in the Kremenchuk Reservoir were obtained from the point of view of the theoretical foundations of the formation and exploitation of their commercial stock. New methodical approaches to the assessment of fish return rate are proposed, as the main criterion for the effectiveness of measures for the artificial reproduction of ichthyofauna. Practical value. It has been established that the conditions for the formation of the commercial stock of the Kremenchuk Reservoir can be considered as satisfactory, i.e. the main limiting factor limiting the growth of their catches is the insufficient stocking volume. The obtained actual coefficients, which characterize the survival of fish seeds, can be used to forecast the volume of stocking and catch of silver, bighead carps and their hybrids. The shortcomings of the organization of modern fishery from the point of view of ensuring the maximum catch per recruitment unit have been established. The advisability of increasing the legal length for silver, bighead carps and their hybrids to 55 cm has been confirmed. Key words: Kremenchuk reservoir, pasture aquaculture, silver carp, bighead carp, organization of fishery.

Early arrival of spring-spawning Atlantic herring Clupea harengus at their spawning ground in the Kiel Fjord, western Baltic, relates to increasing winter seawater temperature.

The disturbance of marine organism phenology due to climate change and the subsequent effects on recruitment success are still poorly understood, especially in migratory fish species, such as the Atlantic herring (Clupea harengus; Clupeidae). Here we used the commercial catch data from a local fisher over a 50-year period (1971-2020) to estimate western Baltic spring-spawning (WBSS) herring mean arrival time Q50 (i.e., the week when 50% of the total fish catches had been made) at their spawning ground within the Kiel Fjord, southwest Baltic Sea, and the duration of the spawning season for each year. The relationship between the seawater temperature in the Kiel Bight and other environmental parameters (such as water salinity, North Atlantic and Atlantic multidecadal oscillations) and Q50 was evaluated using a general linear model to test the hypothesis that fish arrived earlier after warm than cold winters. We also estimated the accumulated thermal time to Q50 during gonadal development to estimate the effects of seawater temperature on the variations of Q50. The results of this study revealed a dramatic decrease in herring catches within the Kiel Fjord since the mid-1990s, as documented for the whole southwestern Baltic Sea. Warmer winter seawater temperature was the only factor related to an earlier arrival (1 week for one January seawater temperature degree increase) of herring at their spawning ground. The relationship was found for the first time on week 52 of the year prior to spawning and was the strongest (50% of the variability explained) from the fourth week of January (8 weeks before the mean Q50 among the studied years). A thermal constant to Q50 (~316°C day) was found when temperatures were integrated from the 49th week of the year prior to spawning. These results indicate that seawater temperature enhanced the speed of gonadal maturation during the latest phases of gametogenesis, leading to an early fish arrival under warm conditions. The duration of the spawning season was elongated during warmer years, therefore potentially mitigating the effects of trophic mismatch when fish spawn early. The results of this study highlight the altering effects of climate change on the spawning activity of a migratory fish species in the Baltic Sea where fast global changes presage that in other coastal areas worldwide.

Adapting to climate change in a spiny lobster (Jasus edwardsii) fishery: A harvest strategy response

The complex lifecycle of spiny lobsters makes the species particularly vulnerable to the impacts of climate change. In south-eastern Australia, a regime shift in productivity was experienced during the late 1990s with evidence indicating that increased water temperatures had impacted on female size-of-maturity. Within the Southern Zone fishery of South Australia, this translated into low levels of egg production and sub-optimal fishery performance. In 2018, the harvest strategy for the fishery was reviewed with the primary focus of achieving a target percentage of unexploited egg production (%UEP) within an agreed timeframe. The proposed harvest strategy was based on a tabular harvest control rule, where catch per unit effort (CPUE) from the preceding season, as an indicator of lobster abundance, specified the following year’s total allowable commercial catch (TACC). To account for climate change impacts, the harvest strategy was assessed using a projection model where recruitment was sampled from post-regime shift years, thereby adopting a conservative approach to stock rebuilding. Results were assessed against projected trends in catch, CPUE and %UEP. In 2020, this harvest control rule was formally adopted and is now used in annual TACC setting. Observed values for key indicators have been closely aligned with projected estimates, with %UEP estimates approaching the target reference point. Specifically, %UEP has improved from 10% to 15% with the target projected to be achieved by the late 2020 s. Projections are sensitive to recruitment however, with a 21% lower recruitment scenario failing to reach target levels, thereby reinforcing the need to account for climate change impacts in harvest strategy testing.

Selectivity-based management for reversing overexploitation of demersal fisheries in North-western Mediterranean Sea

Bottom trawling in the Mediterranean Sea has compromised the availability of demersal fishery resources, primarily due to decades of overexploitation beyond sustainability thresholds. Low selective bottom trawl nets have exacerbated this situation by catching large numbers of under-sized or immature individuals of targeted and not-targeted commercial species that are subsequently discarded. EU legislation requires EU Mediterranean countries to recover demersal fish stocks to sustainable levels by January 2025. This is a challenging requirement under current management scenarios that mainly focus on reducing fishing hours, compromising the activity of the fleets. While social networks among fishing fleets and fisherman associations are essential for facilitating the transition to sustainable exploitation, improving the selectivity of bottom trawl gears is proposed as a viable option beyond reducing fishing hours. This study presents the benefits of improving bottom trawlers net selectivity in multi-species NW Mediterranean coastal and deep-sea fisheries to reduce the catch of non-commercial sizes and discards. Data from selectivity experiments and literature review, fish market landings and a regional monitoring program in the FAO geographical sub-area 6 were used. Results indicate that in the short term, enhanced selectivity leads to an increase in the proportion of fish that are closer to their minimum conservation reference sizes or sizes at maturity, while minimising the impact on commercial catches. Sustainability may be achieved, though beyond 2025, with measures complementing selectivity. These include the adoption of semi-pelagic otter doors to mitigate the impact of trawlers on the seabed and the expansion of no-take marine reserves to ensure habitat recovery and spillover effects.

Reducing Artisanal Fishery Impact on Marine Community: New Data from Comparison of Innovative and Traditional Gear

Fishery resources overexploitation, together with bycatch and discards, have an impact on marine ecosystems. The adoption of technologically innovative gears is a possible solution to reduce the discard and to enhance the sustainability of fishery, mainly in artisanal fisheries that represent about 80% of the EU Mediterranean fleet. In the perspective of fishery sustainability, it is necessary to study and test alternative gears to the traditional ones, also with collaboration of fishers. In the present study, results of experimental fishing activities carried out in two Mediterranean areas with traditional and innovative gears of small-scale fishing are reported. Thirty-four hauls were carried out to compare the catch of two types of trammel nets: a traditional one and experimental guarding net. Additionally, 12 hauls were carried out to compare collapsible pots and traditional pots. No significant differences were recorded between trammel nets in terms of commercial catch and discard. However, interesting differences in discard composition were recorded, with higher Elasmobranchs presence in trammel nets, including species assessed as critically endangered and vulnerable. The use of trapula pots in place of traditional ones showed a lower discard of specific resources and an advantage for fishers in terms of space occupied on board.