Crab Fishery Research Articles

The Feasibility of a Claw‐Only Fishery for the Red Rock Crab, Cancer productus

ABSTRACTThe red rock crab, Cancer productus, is primarily harvested by a recreational fishery, with a small commercial harvest in California. Although relatively large, meat yields are low because the legs are small, and meat is largely confined to the claws. We investigated the potential for a claw‐only harvest for this species. Although hand removal is used in the stone crab fishery, it caused > 90% post‐harvest mortality in red rock crabs. Inducing autotomy by inserting a spike into the arthrodial membranes or by cutting into the autotomy plane resulted in a high post‐harvest survival. We recommend a minimum harvest size of 35 mm claw height to produce a claw size similar to medium‐sized stone crabs and standard‐sized brown and Jonah crabs and to ensure that severed claws are unlikely to have come from female crabs, which is important for regions that mandate a male‐only harvest.

The economic impacts of living habitat changes in the Virginia Middle Peninsula, Chesapeake Bay

Living habitats support ecologically and commercially important species but are threatened by anthropogenic stressors, including climate change. The populations of two living habitats in the Chesapeake Bay, Eastern Oyster (Crassostrea virginica) and Eelgrass (Zostera marina), are depleted compared to historical levels, but recent Oyster restoration efforts have created new reef habitat and enhanced existing Oyster reefs. Other animals (e.g., commercially important fish and invertebrates) consume organisms that associate with these living habitats, suggesting the regional economies that rely on the commercial fishing industry may be impacted by changes in living habitat coverage. Ecosystem models were developed for two rivers that have undergone Oyster restoration in the Virginia Middle Peninsula, and simulations were conducted to estimate the potential influence that changes to living habitats may have on commercial fisheries harvests. Additionally, commercial fishers were interviewed to document expenditures needed to link ecological model estimates to an economic input-output model via IMPLAN that estimated the regional economic impacts of these changes. Increases to Oyster and Eelgrass populations are predicted to enhance commercial fisheries populations and in turn, harvests, while decreases to living habitats are predicted to have negative effect on fisheries harvests. The driving factor behind landed value trends is changes with the lucrative Blue Crab (Callinectes sapidus) fishery. The primary expenses of watermen are repairs/maintenance, fuel, and bait, but greater than 37 % of the annual revenue is retained as proprietor and crew income. Oyster reef restoration alone is predicted to increase the regional economic impact of the commercial fishing industry by $1.1 M yr-1 and support 12 more full-time jobs at the end of a 20-year simulation. Oyster restoration in combination with a continued decline of Eelgrass led to a negligible increase (∼$150 K yr-1) in the regional economic impact. Eelgrass restoration to the current management goal without the influence of Oyster restoration is anticipated to elevate the regional economic impact to $16.8 M yr-1 and 152 full-time jobs, and smaller increases to the Eelgrass population, relative to current levels, will still have a positive impact on the regional economy. Combined Oyster and Eelgrass restoration are predicted to enhance economic impacts to the greatest extent, while continued Eelgrass decline is likely to minimize these benefits.

Feeding Behavior and Bait Selection Characteristics for the Portunidae Crabs Portunus sanguinolentus and Charybdis natator

Understanding the feeding behavior of Portunidae crabs with different baits can improve bait selection and is crucial for improving the effectiveness of crab fishing gear. This study, conducted in indoor experimental tanks, used trajectory tracking software and two types of natural baits (mackerel (Scomber australasicus) and squid (Uroteuthis chinensis)) to understand the behavior of Portunus sanguinolentus and Charybdis natator. Spatial distribution results showed that P. sanguinolentus was frequently present in the starting area (S1) and bait area (S3) in the control and treatment groups. However, C. natator was frequently present and concentrated in the S1 area compared to the middle areas S2 and S3, and only in the mackerel treatments were they observed to move to the S3 areas. The spatial distribution results indicate that P. sanguinolentus shows a stronger willingness to explore its surroundings, while C. natator is generally in a stationary, wait-and-see state. The swimming speeds of P. sanguinolentus and C. natator showed different trends. P. sanguinolentus showed continuous movement with no fixed speed when no bait was present in the control groups. However, when treated with mackerel and squid, the average swimming speed of P. sanguinolentus was faster (>5 cm/s) in the first 10 min and showed a more stable movement speed when searching for the baits. C. natator showed a stationary or low movement speed when no bait was present in the control groups. However, when C. natator perceived the presence of the baits in the treatment groups, their movement speed increased in the first 10 min. In addition, there was no significant difference between male and female crabs of P. sanguinolentus and C. natator in movement speed in the control and treatment groups. Compared to C. natator, P. sanguinolentus might be more sensitive to natural baits, as shown by its movement from S1 to S3. The results indicate that the species of Portunidae crabs show different bait selections. Natural baits (mackerel and squid) are recommended for catching P. sanguinolentus in crab fisheries.

Fisher poverty, value chain equity, and resilience: The case of the Indonesian Blue Swimming Crab and the Peruvian Mahi-Mahi

Many marine fishery supply chains are becoming increasingly global and export oriented. Simultaneously, academic discussions around fisheries and poverty have often construed fishers as being among the poorest and most marginalised people in society. However, how value accrues along these supply chains, and how that affects fisher wellbeing, remains understudied. If fishers are indeed impoverished and relevant stakeholders wish to address the causes of impoverishment, then understanding how the value of a fish accrues along a value chain is essential. This research seeks to more clearly understand the existence, nature, and extent of fisher poverty through case studies of the Peruvian Mahi-Mahi and the Indonesian Blue Swimming Crab fisheries. It examines how value accrues along export-oriented fishery supply chains in country of origin and the prevalence of underearning at the fisher level. The value accrued at each domestic value chain step (fishers, middlemen/aggregators, processors) is estimated and used to calculate the level of underearning experienced by fishers within the value chains. Underearning is understood here as falling below a living income threshold, rooted in a rights-based approach to human rights. It is found that while fishers earn a significant percentage of the value of a fish that accrues in the country of origin, differences in number of actors per value chain step and labour intensity per kg of product handled mean that fishers still typically earn significantly less than other value chain groups. Underearning is found to be present in both value chains, with 69 % of Blue Swimming Crab fishers and 38 % of Mahi-Mahi fishers earning less than the rural living income. The outcomes of the research indicate that while fishers, particularly in export-oriented fisheries, are not the poorest of the poor, they still face significant challenges to their well-being and the stability of their livelihoods. It is recommended that future research incorporate more multi-faceted approaches to poverty and well-being in their analysis.

Molecular Evaluation of the Mating Dynamics of Snow Crab (Chionoecetes opilio) in the Eastern Bering Sea

ABSTRACTSnow crab (Chionoecetes opilio) in the eastern Bering Sea (EBS) supports a valuable crab fishery that harvests large males. To better understand the potential impact of the presence of snow‐Tanner hybrids (C. opilio × C. bairdi) on snow crab mating dynamics, the maternal lineage of hybrids was evaluated using single nucleotide polymorphisms (SNPs). Contrary to results from a previous study that indicated hybrids result only from crosses between Tanner crab (C. bairdi) males and snow crab females, results from this study showed hybrids result from bidirectional parental crosses. SNP and microsatellite markers were used to evaluate the species and number of males detected as mates in female sperm reserves acquired during mating and as sires among embryos in brooded clutches. The incidence of interspecies mating between female snow crab and Tanner crab or hybrid males was low (2%), suggesting interspecies mating is not currently a pressing fishery management concern. Most females had stored sperm from either a single mate (59%) or two mates (32%), which reflects fewer mates than observed for other snow crab populations. Few females were observed with either no stored sperm (5%) or sperm from three to four mates (4%). Single (82%) or dual (18%) paternity was found among embryos in brooded clutches. Sperm from some mates appeared to be fully utilized for fertilization of the brooded clutch for 35% of females. In contrast to findings for other snow crab populations, no significant differences were detected in the numbers of mates or sires between primiparous and multiparous females. The low extent of polyandry observed may suggest that female snow crab in the EBS have limited mating opportunities, potentially leading to insufficient sperm reserves to fertilize subsequent clutches without remating.

Bait Biomass and Caloric Contribution From the Dungeness Crab (Cancer magister) Fishery in Oregon, USA

ABSTRACTFishery discards worldwide increase the availability of organic materials on the benthos, altering trophic relationships and potentially increasing the abundance of benthic consumers. Expert knowledge from fishers is a valuable yet often underutilized source of information to understand these dynamics. We interviewed Dungeness crab fishers (n = 24) to determine the most‐used bait types and to characterize regional and seasonal bait use strategies that drive inputs of organic matter into Oregon coastal waters during the commercial Dungeness crab fishery each year. Based on bomb calorimetry measurements of caloric densities of 12 commonly reported bait species, total energetic input was 12.99 × 109 kJ (3.10 B kcal) from bait in the 2019–2020 commercial ocean Dungeness season in Oregon, USA. Fishing effort and bait inputs were strongly seasonal, with 88% of effort concentrated in the first 60 days of the 9‐month‐long season but did not vary regionally. This large, temporally concentrated caloric input suggested that bait could contribute substantially to Dungeness crab productivity. Fisher respondents indicated that bait effectiveness was the most important motivating factor in choosing a bait type, more than availability or cost.

Assessing the value of harmful algal bloom forecasts in the Pacific Northwest

Abstract Over the past three decades, fisheries and livelihoods on the coasts of Washington and Oregon have been severely impacted by the presence of harmful algal blooms (HABs) that produce domoic acid, a neurotoxin that accumulates in shellfish and endangers public health. Among others, recreational razor clams and commercial Dungeness crab fisheries along the Pacific Northwest (PNW) have been negatively affected, jeopardizing the economies of coastal communities that depend on tourist revenues and income generated through visits of harvesters in the region. The PNW HAB Bulletin, launched in 2008, publishes forecasts on incoming HAB events, which has enabled managers to increase toxin monitoring in high-risk locations and proceed with selected harvesting at safe beaches and delays or closures of fishing seasons, as required. In light of the value of the HAB Bulletin to local managers and communities and the occasional challenges of securing sufficient resources to ensure its continuation, this study attempts to assess the value of information (VOI) for the predictions provided by the Bulletin. Results of the study show that ongoing financial support of the Bulletin is economically justifiable. The value of HAB forecast is positively related to three primary factors: the frequency of HAB events, the precision of forecast, and the number of social and economic sectors benefiting from the forecast. The expected increase in HAB frequency and intensity due to climate change, coupled with advancements in forecasting accuracy through technological development, is anticipated to enhance the value of the forecast program.

Development of a stock-specific management procedure for snow crab fishery in the Sea of Japan using conditioned surplus production models in a data-moderate situation

A management procedure (MP) automatically calculates an acceptable biological catch from input data, and its performance is quantitatively evaluated by closed-loop simulations of population dynamics with their uncertainties (operating models). In snow crab in the Sea of Japan, an MP based on survey biomass estimates was adopted by stakeholders, rather than a generic MP recommended for data-moderate Japanese stocks. This was done without quantifying its performance owing to data and resource limitations. This study evaluated the performance of the existing MPs and modified the generic MP through closed-loop simulations with state-space surplus production models (SSPMs) conditioned with actual data. The survey-based MP generally worked well to achieve sustainable catch and biomass but tended to be sensitive to the bias in biomass estimates. The modified MP can be more robust to the bias than the survey-based MP with higher catches than the generic MP. This study demonstrates that, although continuing efforts of collecting composition data are inevitable, SSPM could be used as the conditioned operating models even in data-limited situations to sufficiently represent the stock status and its uncertainty.

Connectivity of the social-ecological system of the blue swimming crab fisheries in Rembang

Abstract The management of blue swimming crabs requires several aspects to be considered, such as social and ecological aspects for the sustainability of small crab fisheries. Fishery management is currently still focused on economic interests, so if this is allowed to continue, it will result in ecosystem degradation. This study aims to determine the components of the social-ecological system of the blue swimming crab fishery and the interrelationships of the crab management factors in Lasem District, especially in Gedongmulyo Village, Rembang from March to June 2023 using a purposive sampling method, including socio-economic data and fishermen’s interviews. Analysis of social-ecological connectivity including resource systems (RG), resource units (RU), resource actors (RA), and resource governance (RG) subsystems, and analyzes management variables using the participatory prospective analysis (PPA) method. The results show the connectivity of the social ecological system of the blue swimming crab fishery in Lasem between Resource Actors and Resource Systems, Resource Units, and Resource Governance. While Resource Governance is negatively related to the Resource System. Re-education about the regulations for the use of non-environmentally friendly fishing gear, the impact on the environment, and fishermen’s awareness of the need to comply with these regulations needs to be carried out.

The role of women in the blue swimming crab fisheries supply chain from gender perspective in Pamekasan

Abstract The blue swimming crab (Portunus pelagicus) fishery industry bring positive impact onwomen in coastal areas by providing livelihood opportunities through active involvement in various gender roles, both in preparation and post-capture processes as well as in the production chain. This study aimed to analyze the roles of women in the crab fishing supply chain. This study was conducted in June 2023 at Pagagan Village, Pademawu District, Pamekasan Regency. The research employed interview methods, field observation, and secondary data sources, including articles and journals. Six respondents participated in the study, representing fishermen’s wives, mini-plant owners, crab pickers, and crab suppliers. Results showed that fishermen’s wives play a significant role in marketing and selling the crab catch, as well as assisting their husbands in making and repairing fishing gear. In the case of crab suppliers, women or housewife contributed in weighing and boiling the crabs. At the mini-plant level, women play the main role as pickers in sorting and stripping process, while the mini-plant owner supervises the overall process. The study highlighted the substantial contribution of women in coastal areas to the local community, demonstrating a strong reliance on marine resources, which fluctuate with the seasons. Additionally, the income earned by coastal women significantly contributes to their families finances, thereby enhancing their household’s economic condition.

Susceptibility analysis of cuttlefish (Sepia recurvirostra) to blue swimming crab fisheries in Keboromo village, Pati

Abstract The coast of Pati Regency and its surroundings are one of the crab sanctuaries on the north coast of Java that have tended to increase in the last decade. The purpose of this study was to analyze the level of vulnerability of cuttlefish (Sepia recurvirostra) to crab fisheries in Keboromo Village, Pati. The sample used was the catch of cuttlefish by blue-swimming crab fishermen in Keboromo Village during the research period of June 2023. The productivity value was obtained from the literature, while the parameters of vulnerability were obtained from interviews with local fishermen, which were analyzed using productivity and susceptibility analysis (PSA). The average length of the cuttlefish was 80–125 mm, with a weight of 25–61.6 grams. While having a PSA score of 1.71 with an MSC score of 84.7 (limit > 80). The smaller PSA value indicates the level of vulnerability is still relatively low, so fishing activity pressure has not had a serious impact on the potential sustainability of cuttlefish.

Mapping the habitat distribution of horseshoe crabs (Tachypleus gigas) in Pamekasan, Madura Island, Indonesia

Abstract Horseshoe crabs, often known as Belangkas or Mimi, is one of the ancient marine faunas with protected conservation status. Horseshoe crabs are distributed in coastal waters of Indonesia of the islands of Sumatra, Java, Kalimantan, and Sulawesi, which are often caught as bycatch. Horseshoe crabs’s bloods were uniquewhich contain amebocytes as a test material for the presence of endotoxin bacteria. The purpose of this study was to identify the species of horseshoe crabs and to analyze environmental conditions, as well as the distribution of horseshoe crabs in the coastal waters of Pamekasan, Madura Island. This study was conducted in June 2023 by collecting data from crab fishers. ArcGIS was applied to delineate the distribution of horseshoe crab. The identification results showed that there was one species horseshoe crab of the Tachypleus gigas in the waters of Polagan Village, Galis District, Pamekasan Regency. The environmental condition of the waters in Polagan Village, Galis District, and Pamekasan Regency was relatively good. Habitat mapping is one way to protect these animals from the threat of extinction and support conservation efforts.

Catch composition and fishing season of blue swimming crab using a collapsible trap in Pemalang coastal water, Central Java

Abstract The blue swimming crab (Portunus pelagicus) is an economically important fishery resources that has penetrated the export market that requires proper management. Pemalang Regency is still entirely dependent on natural catches, so information on seasonal patterns of blue swimming crab fishing is essential for fishermen to support the efficiency and effectiveness of the fishing activity. This research was conducted in Danasari village, Pemalang sub-district, in January–December 2022 with the aim of determining the composition of collapsible trap catches based on the crab fishing season in the waters of Pemalang Regency. Danasari fishermen classify the blue swimming crab fishing season into two, the west season starts in November–May (high rainfall), and the east season starts in June–October (low rainfall). The survey method was performed by collecting data of blue swimming crab catch as the main target and bycatch. Carapace width of the blue swimming crab was also measured. The data obtained was analyzed descriptively using Microsoft Excel 2010 software. The results showed that the catch composition of collapsible traps in Pemalang consisted of crustaceans, fish, and mollusks. The best season to catch blue swimming crabs was during the west season because the catch is more stable than during the east season.

Exploring uncertainty of small-scale blue swimming crab fishery (Portunus pelagicus) toward local blue economy: The case of Pati Coastal Waters, Central Java, Indonesia

Abstract Blue swimming crab (BSC) fisheries are characterized as small-scale, with limited biological and socio-economic data. Information limitations, such as those related to administrative inputs, have become a pressing issue in understanding the sustainability of BSC fisheries in coastal Pati Regency. This study aimed to analyze fishery uncertainty. The research was conducted from December 2020 to March 2021 in Alasdowo Village, Dukuhseti District, Pati Regency. Biological data was collected from the daily logbooks of BSC middlemen, encompassing the catch of 368 fishermen from January 2019 to March 2021. Socio-economic data was obtained through structured interviews and focus group discussions. The production value of BSC in zone 2 was approximately 724.6 ± 889.7 kg/day, with a coefficient of variability of 1.23. The number of fishing trips was 188 ± 137, with a coefficient of variability of 0.73. The productivity value was approximately 3.2 ± 3.7 kg/trip, with a coefficient of variability of 1.16. The BSC fishery using trap-net gear in zone 2 exhibits high uncertainty, as evidenced by the high coefficients of variability. Exploring fishery uncertainty can be a valuable component of fisheries management through a social-ecological systems approach.

Social media influence on the promotion of sustainable fisheries management: Insight from Indonesian blue swimming crab

Abstract Blue swimming crab is one of potential fisheries commodities in Indonesia that has been mainly exported to America. Crab industry contributed to national economy due to high export volume and value. The use of social media has surged due to digitalization, becoming a crucial marketing strategy for maximizing business profits. The role of social media in non-profit organizations for fisheries sustainability campaigns remains unexplored. Therefore, this study aimed to analyze to the role of social media in promoting sustainable blue swimming crab fisheries programs in Indonesia. Data was collected for 14 days from 31 social media users on various platforms, such as Instagram, Facebook, LinkedIn, and YouTube. SmartPLS 3.2.9 was applied to analyze the effect of recall, recognition, alternative, and recalling on blue swimming crabs fishery programs on interaction and effectiveness consumer brand engagement (CBE). Results showed that the most recognized fisheries sustainability programs for blue swimming crabs were crab apartment and GTK-5 Minutes. Meanwhile, the crab enlargement program and APRI Youth Innovation were known through moment-open recruitment. Knowing and following APRI’s social media has significant effect on CBE’s interaction and effectiveness. Social media could also be used as a marketing strategy to promote sustainable fisheries management programs The research reveals the significance of social media in fostering consumer engagement and promoting sustainable practices in fisheries management programs by non-profit organization through effective marketing strategies.

Mud crab (Scylla spp) resources status in Hoat Sorbay Bay, Southeast Maluku Regency

Abstract Ohoi Evu is one of the villages in Southeast Maluku Regency where fishermen utilize mud crab resources. Mud crab fishing areas are concentrated in the waters of Hoat Sorbay Bay. Information on mud crab fisheries in these waters is relatively limited, so the application of sustainable management efforts is still difficult to develop. This study aims to determine the status of mud crab resources through the adoption of a fishery management model with an ecosystem approach and formulate recommendations for improving its management. Data collection was carried out through surveys of fishing operations, interviews, and participatory mapping. This research was conducted for 13 months, starting from January 2021 to January 2022, at Hoat Sorbay Bay. The research focus is on the Wear Manun Joint Business Group (KUB) in Ohoi Evu. The indicators observed included CPUE, mud crab size trends, the proportion of juveniles caught, species composition, range collapse, and endangered, threatened, and protected (ETP) species caught. Descriptive statistical analysis, CPUE, and indicator analysis were carried out using a multi-criteria analysis approach through the assessment of composite indexes and flag model visualization. The results showed that the management status of the mud crab fishermen Ohoi Evu in Hoat Sorbay Bay was in the moderate category (yellow) with a composite value of 2.50. CPUE indicators and species composition were good categories with a score of 3 (green). Trend indicators for fish size, proportion of juveniles, ETP species, and range collapse are in the moderate category with a score of 2 (yellow).

The effectiveness of crab apartment to shelter egg berried female of blue swimming crab (Portunus pelagicus) in Rembang, Central Java, Indonesia

Abstract Blue swimming crab is an Indonesian fishery commodity with high economic value for export to America, Asia, and Europe. The increase in crab fishing activities every year results in diminishing stocks in nature, in addition to predator attacks around spawning areas. The purpose of this study was to determine the growth of blue swimming crabs and identify types of fish in the crab apartment shelters in Rembang Regency, Central Java Province, from March to May 2023. The egg berried female crabs were put in a floating apartment for three months and monitored every 2 weeks to determine the growth of the hatched crab eggs. Our observations showed as many as 50 egg berried female crab with with an average size of 8–10 cm and a weight of 40–65 g. There were other marine organisms found in the shelter, including rabbit fish, shrimp, small crabs, and therapon-perch. Rabbit fish and therapon-perch often result in reduced juveniles. Therefore, add and installing shelter is highly recommended to the entry of these fish. This study found crab apartment brings positive impacts on the survival of hacthing crabs and protected them from the threat of predatory fish.

Climate risk assessment of the fisheries in Namibia

In Namibia, fisheries are important for food security and protein provisioning, income generation and trade; but they are vulnerable to the impacts of climate change. Not only does climate change impact the marine living resources crucial to fisheries; but changes in weather, currents and storminess are affecting the safety and effectiveness of fishing. Here we ask: What are the key risks from climate change to the eight large-scale fishery sectors of Namibia, and for the recreational and small-scale (artisanal) fisheries? For each fishery sector, we assessed three main risk components: (1) climate hazard exposure; (2) fish species sensitivity; and (3) socio-economic vulnerability. In combination, these three risk components are then used to calculate the overall climate risk for each fishery. Climate hazard exposure was assessed as highest for the small-scale, recreational, and rock lobster fisheries. Species sensitivities were highest for the rock lobster and crab fisheries, followed by monkfish trawlers, hake liners and hake trawlers. Socio-economic vulnerability was highest for the small pelagic fishery (linked to the collapse of pilchard). The overall climate risk emerged as greatest for the rock lobster fishery, followed by the (highly marginalised) small-scale artisanal fishery. The key risks by sector emerging from this assessment, informed five stakeholder workshops held across Namibia in 2023, attended by representatives of each sector and aimed at exploring options for climate adaptation. Based on these, we discuss potential adaptation measures that could reduce risk and minimise consequences, in support of improved climate resilience in Namibian fisheries.

A regional analysis of climate change effects on global snow crab fishery

AbstractThe snow crab fishery faces increasing vulnerability to environmental factors, yet the literature on the relationship between climate change and snow crab harvest remains limited. This study estimates snow crab harvest functions using climate change indicators with unbalanced panel data of snow crab production from the eastern Bering Sea (Alaska), the southern Gulf of St. Lawrence (Canada), the Sea of Japan, and the Barents Sea (Norway‐Russia). The relationship between snow crab biomass, stock, and catch is analyzed and the endogeneity of stock in the harvest function is also addressed using climate change indicators as instrumental variables (IVs). The results show that the extent of Arctic sea ice is effective in addressing the endogeneity, and the random effects IV model with error components two stage least squares estimator performs the best to control heterogeneity. A 1% increase in snow crab fishing effort is associated with a 0.42% increase in snow crab harvest, and a 1% increase in snow crab stock causes a 0.98% increase in snow crab harvest. The reported estimates indicate a large stock‐harvest elasticity and provide supporting evidence to prioritize stock enhancement in snow crab fishery policy designs to maintain stocks at sustainable levels and minimize government expenditures on subsidies.Recommendations This study explores how snow crab harvests are influenced by snow crab populations and fishing efforts in the context of global warming across various global regions, including the Bering Sea, the Gulf of St. Lawrence, the Sea of Japan, and the Barents Sea. A 1% increase in fishing effort is associated with a 0.42% increase in harvest, while a 1% increase in snow crab population leads to a 0.98% increase in harvest, showing a high dependency on snow crab biomass. Arctic sea ice extent is identified as a crucial climate factor affecting snow crab biomass and harvests, making it a valuable variable for understanding and managing snow crab populations. The study supports the prioritization of stock enhancement policies by fishery agencies and suggests standardizing how fishing effort is measured across different regions to improve snow crab fishery management and future research.

Biological and fishery indicators for the small-scale marble crab fishery in Northern Patagonia: recommendations for improving a monitoring program and stock assessment of a data-limited fishery

Small-scale fisheries have been typically data-limited despite their economic importance for local communities. This is especially true in zones where fishing operations occur in remote areas under harsh weather conditions. Crab fishery in Chile is exclusively artisanal, and marble crab (Metacarcinus edwardsii) has the highest landing records. This species is found in most parts of the coast of Chile, but it is mainly caught in the south of the country (including Patagonia). Fishery management is data-limited, and monitoring has not established the spatial and temporal variability baseline necessary to determine its exploitation status. This fishery is currently evaluated annually under a scheme based on reporting biological and fishery information, primarily from the landing ports and secondarily from fishing grounds. In the present study, we collected data from fishing grounds on board artisanal fishing vessels around 45°S during an annual cycle to establish indicators based on catch per unit effort (above and below minimum legal size), size, sex ratio, and the relationship between weight and size. Our results showed that fishery and biological indicators respond more to seasonal patterns than to expected spatial heterogeneity related to different fishing grounds: proportional stock density (lowest in winter), sex ratio (biased toward males in winter), retained catch (highest in autumn), and released catch (highest in winter), while the average size of the largest 10% of the sample only showed differences between males and females. Additionally, released catch varied according to soak time, which indicates the effectiveness of escape rings incorporated in the traps. These results lead to recommendations related to the current monitoring program, which should include the selection of a limited number of fishing grounds standardized by season and the incorporation of information related to soak time and the presence of escape rings. Finally, this study highlights the importance of on-board scientific monitoring for any fisheries, even those of small scale.