Blue Crab Fishery Research Articles

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.

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.

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.

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.

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.

Socio-Economic Aspects of the Blue Swimming Crab Fisheries (BSC, Portunus pelagicus) in Maginti Island, West Muna Regency, Indonesia

Socio-Economic Aspects of the Blue Swimming Crab Fisheries (BSC, Portunus pelagicus) in Maginti Island, West Muna Regency, Indonesia

Trophic role and predatory interactions between the blue crab, Callinectes sapidus, and native species in open waters of the Ebro Delta

The Ebro Delta has become a major blue crab (Callinectes sapidus) fishery area in the NW Mediterranean, but there is limited information on factors controlling the abundance of populations in open waters, a crucial habitat for ovigerous females. Here, we use a stable isotope approach (δ15N and δ13C), to assess blue crab trophic position, the potential consumption of food items using mixing models, and the isotopic niche overlap with local commercial species. For Octopus vulgaris, a potential blue crab key predator, a trophic enrichment experiment was also conducted to further assess predation control in wild populations. The blue crab showed 1.6 times higher trophic position than in other habitats of the Ebro Delta, and similar to that found in the harbor crab, Liocarcinus depurator, and several predatory fish. Additionally, the isotopic niche of blue crabs showed overlaps from 46.2 to 14.9% with native predators, and mixing models also suggest even dietary contributions throughout the food web. For O. vulgaris, field results showed a trophic position of 3.93, lower than that of blue crab, and lower δ15N signatures were also obtained in a captivity experiment drawing negative fractionation (−1.1‰). We conclude that high dietary contribution of animal prey might provide a high protein diet that could be crucial for allowing the maintenance of a large local population, but the overall functional trophic similarity could also disfavor local native species. The similarity between experimental fractionation and field differences between predator and prey (−1.6‰) suggests that predation of blue crab is possible, but further research is needed to clarify the metabolic routes involved in octopus δ15N fractionation.

The Shadow Blue Economy: Optimizing non-target Catch of the Blue Swimming Crab Fisheries in North Coast of Central Java, Indonesia

Blue Economy is the concept of sustainable use and management of resources, including small-scale blue swimming crab (BSC) fisheries. The coastal area of Pati District is one of the BSC landing bases on the north coast of Central Java (part of Indonesian Fisheries Management Area/IFMA 712). However, there has been no study of non-target composistion as a complement to exploratory analysis to better understand the complexity of the social-ecological systems in the BSC fisheries in this region. The purpose of this study is to identify of economically non-target species, Correlation between economically non-target with target species and trend of their proportions, optimizing non-target catch value during Covid-19 pandemic. The biological data was collected from the daily logbooks of BSC middleman, which included catches from 368 individual fishers from January 2019 - March 2021. The socio-economic data was obtained by structured interviews and group discussion. The analytical methods were used such as identification, correlation and trend analysis, and descriptive analysis. The economically non-target species found include Scylla serrata, Charybdis feriatus, squid and cuttlefish (cephalopods), Charybdis afinis, Podopthalmus vigil, Portunus sanguinolentus, and Babylonia spirata (mollusc). Significant correlation between BSC catches decreased, while the catch of Scylla serrata and Charybdis feriatus are increased. The trend of economically non-target BSC fisheries decreased for sale during the Covid-19 pandemic and shadow economic occurred with the changed of fishermen behaviour who were previously commercial fishers to be subsistence fishers. The other shadow blue economy also occurred since mud crab were frequently caught as the non-target species.

Diversity of non-targeted species on blue swimming crab Portunus pelagicus collapsible trap fishery in Pemalang, Central Java

A collapsible trap is one of the fishing gears commonly used by fishermen to catch blue swimming crabs. However, non-target species or by-catch are often caught by fishing gear. This study aimed to determine the diversity of non-target species caught by collapsible traps used in the blue swimming crab fishery. This study was conducted in Pemalang waters from January to June 2020. The Shannon-Wiener diversity, the evenness, and the Simpson dominance indices were analyzed. The results showed that the non-target species comprised seven crustaceans, six fish species, and four mollusks. The highest number of by-catches was observed in June from the mollusk group (5,762 ind of tiger snails), while the lowest catches were observed in Jan-March from the groups of fish, crustaceans, and mollusks. The predominated by-catch from collapsible traps in Pemalang was Babylonia sp. (87.64%), Podophthalmus vigil (9.74%), Charybdis feriatus (1.5%), and Portunus sanguinolentus (0.36%). The highest diversity index value was estimated in Jan at 1.73%, while the lowest was in June at 0.05%. The evenness index was highest in May and lowest in June. The by-catch biodiversity of blue swimming crab fishery in Pemalang was classified as low diversity category, low evenness, and moderate dominance.

Growth and survival rate of blue swimming crab enlargement in the south coast of Pamekasan, Madura Island

Indonesia has fishery commodities favoured by the world market, especially blue swimming crab fisheries. Fishing activities that continue to increase have caused the blue swimming crab population in nature tend to decrease. Therefore, it is necessary to develop aquaculture in ponds and coastal waters. However, blue swimming crab enlargement has technological constraints that have yet to be widely known by the wider community. The study aimed to determine the survival rate of blue swimming crabs in coastal waters using ponds conducted in Pamekasan, East Java. The parameters measured were the width of the blue swimming crab’s carapace using a ruler and the growth of the blue swimming crab’s weight using a digital scale. The experimental results on blue swimming crabs obtained an absolute growth of 9.8 cm and a survival rate of 3.96%. The high rate of cannibalism in blue swimming crabs can indicate the cause of the low survival rate of blue swimming crabs. This research is expected to increase the choice of blue swimming crab enlargement to reduce the pressure of catches and be another alternative to reduce the level of blue swimming crab fishing in nature.

Composition of lost and discarded fishing gear (ghost fishing) in the blue swimming crab fishery in Rembang, Central Java

Ghost fishing is the ability of fishing gear to catch fish continuously for a certain period when the fishing gear has been lost. Some passive fishing gear will most likely be lost due to material degradation of gear components and other factors. Therefore, it is necessary to study the composition of fishing gear left in the sea to find out the cause of ghost fishing. The study aimed to determine the composition of materials from fishing gear left in the waters of the Rembang Sea. This is done by collecting fishing gear found by fishermen and then weighing per material to get the composition of the fishing gear. As many as 86% are metal, and 14% are plastic. This shows that metal and plastic materials are difficult to decompose in marine waters, so fishermen still find these fishing gear in Rembang waters. This also shows that metal is the dominant constituent of the fishing gear used by fishermen in Rembang waters. This research provides information about what fishing gear materials are likely to be a source of ghost fishing so that it can be a suggestion for using fishing gear.

Diversity of non-targeted species on blue swimming crab Portunus pelagicus gillnet fishery in Grogol, Cirebon

Non-targeted Species (NTS) data and research is needed in the management and development of the blue swimming crab fishery ecosystem. The NTS were divided into two groups, namely the retained and the discarded. This study aims to explain the diversity of NTS caught by blue swimming crab fishermen that used gillnet in the Cirebon Regency. This study uses exploration and enumeration methods to analyze the catch of NTS catched by blue swimming crab fishermen for 7 months in 2021. Shannon-Wiener diversity, Evenness, and Simpson’s dominance index were further analyzed. Results showed the diversity of NTS caught by blue swimming crab fishermen with gillnets in Cirebon Regency consisted of 29 species from 23 families (9 fish, 16 crustaceans, and 4 mollusc species). The highest diversity index was observed in December (2.16) and the lowest was October (1.29). The highest population uniformity or evenness was observed in September (0.83) and the lowest in October and November (0.59). The dominance index had the highest value in August at 0.41 and the lowest in July at 0.15. The non-target species biodiversity of P. pelagicus fishery in Cirebon was classified as moderate diversity category, moderate to high evenness, and low dominance. These results provide information for fishermen to reduce catches of non-targeted species which requires fishermen to return and release the non-targeted species within 5 minutes and maintain the diversity of marine biota.

Utilizing DNA barcoding approach to study the diversity of the blue swimming crab from Tuban District, East Java, Indonesia

Abstract. Joesidawati MI, Nursalim N, Kholilah N, Kurniasih EM, Cahyani NKD, Ambariyanto A. 2023. Utilizing DNA barcoding approach to study the diversity of the blue swimming crab from Tuban District, East Java, Indonesia. Biodiversitas 24: 4731-4737. Blue swimming crabs are one of the economically significant fisheries resources in Indonesia. However, Indonesia's blue swimming crab fisheries still depend on wild catches that lead to a non-target species harvest, especially the cryptic swimming crabs. This study aims to investigate the genetic diversity of blue swimming crab specimens and other cryptic species using a molecular approach (DNA Barcoding). The samples were caught from the waters of Tuban District, East Java, Indonesia, using traditional foldable traps or "bubu lipat". This study utilized the Polymerase Chain Reaction (PCR) method targeting the Cytochrome c Oxidase Subunit I (COI) gene. The sequences were then compared to the NCBI database to get the closest species based on the sequences. 21 out of 23 samples were identified as Portunus pelagicus, and two samples were identified as Charybdis feriata with percentage of similarity ranging from 99.68% to 100%. The phylogenetic trees were constructed using Neighbor Joining and Maximum Likelihood method with sequences from Scylla serrataas an outgroup. The genetic distance between P. pelagicus and C. feriata was 16%, whereas the genetic distance between P. pelagicus and C. feriata to the outgroup was 20%. The molecular method is crucial for species identification and population stock assessment. This information helps in determining stock boundaries, estimating population sizes, and understanding the genetic health of populations. Genetic data will help the government to have a better management of the fisheries activities in Indonesia by providing the diversity and population data.

A Concept of Open-Closed Season Approach for Indonesian Blue Swimming Crab (Portunus Pelagicus) Management on the North Coast of Java

The open-closed season approach has not been widely used in fisheries management in Indonesia, including blue swimming crab (BSC) fisheries that created ecological and economic balance. This research aims to illustrate the characteristics of BSC fishers, examine the application of the concept of the open-closed season in blue swimming crab fisheries, and predict the sustainability of fishermen's livelihoods. Data collection was conducted in 2020 and 2022 in four regencies: Rembang, Demak, Cirebon, and Lampung. However, Lampung is excluded in 2022. The primary data were obtained from structured questionnaires sent to 520 fishermen and 63 mini plants and collectors, then analysed by descriptive analysis, Likert scale, and business sustainability index. The findings showed that blue swimming crab fishing characteristics at four research sites showed different conditions. Working as fishermen cannot contribute sufficiently to improving the household economy. The factor influencing the blue swimming crab fishing business is the size of the fishing boats. The open-closed season (OCS) policy is worthy of short-term goals consisting of fishermen's welfare and business justice in business actors and long-term goals, namely the sustainability of blue swimming crabs. Institutional schemes are proposed for the OCS model to maintain the sustainability of resources and businesses.

Syndication of sink-source and area-based resource management as a remedy to sustain a small-scale fishery: The case study of blue swimming crab fishery from Sri Lanka

Tropical small-scale fisheries (SSF) have become more vulnerable to over-exploitation due to: delayed alarming stock status, consequences of implementing deprived management strategies, data-poor scenarios, ambiguous assessment approaches and failures in a comprehensive understanding of the context of specific resource users. Hence, the current study on the blue swimming crab (BSC) fishery off the northern coast of Sri Lanka (September 2017 to November 2018), reveals the evidence of the SSF's requirement for a precise management and decision approach for sustainability. Therefore, here we intended, to evaluate The TropfishR package of the electronic length frequency (ELEFAN) method with new optimization techniques for data-limited fisheries analysis with length frequency (LFQ) data. Further multivariate techniques were used for the follow-up analysis. Results of LFQ data obtained through scrutinized ELEFAN methods and followed-up analysis showed that all studied fishing grounds are overexploited (E > 0.5) due to the “effort-creep” in post-war context and higher economic demand of BSC, which were collectively drive the prevailing behaviour of fishers. Further, due to cultural constraints such as caste-based gear choices and fishing ground choices, the small and immature stages of BSC become more susceptible to gears with low selectivity, which frequently operated in the estuary (ES) and shallow coast (SC). So under this multi-gear, complex SSF scenario banning or restricting the harmful gears becomes socially impossible. Hence, area-based management through a sink-source approach that characterizes the fishing ground with respect to the gear, seems to be promising. Therefore, we conclude that through a such robust approach, we could able to replenish a similarly overfished fishery scenario in the SSF.

Bycatch of bottlenose dolphins in South Carolina, USA, and an evaluation of the Atlantic blue crab fishery categorisation

In the USA, commercial fisheries that interact with marine mammals are categorised according to the number of incidental takes of marine mammals relative to the defined Potential Biological Removal (PBR) for the population. Three categories exist for such commercial fisheries: Category I, II and III, each varying in the degree of regulation. Fishery categorisation is based on a five-year running average of the number of incidental entanglements in that fishery and is published annually in the Federal Register. The Atlantic blue crab (Callinectes sapidus) fishery is one of South Carolina’s largest commercial fisheries in terms of volume and value and was recently re-categorised as a Category II fishery, resulting in heightened regulation. The Atlantic blue crab fishery exists in known areas of bottlenose dolphin (Tursiops truncatus) habitat; therefore, interaction between the two is probable. This study uses historical marine mammal stranding data and on-board investigations of the blue crab fishery in South Carolina to investigate the degree of fishery and dolphin interaction. Analysis of historical strandings showed that approximately 24% of the 42 entanglement cases in South Carolina from 1992-2003 resulted from the blue crab fishery. In nine of the 12 years examined, bottlenose dolphin mortality rates were found to be greater than or equal to 10% of the South Carolina Management Unit’s PBR, which is significant according to the US Marine Mammal Protection Act’s (MMPA) definitions for the Atlantic Coastal Stock of bottlenose dolphins. In addition, results from this study showed that the average number of bottlenose dolphin entanglements per year in the South Carolina blue crab fishery has exceeded 1% of PBR across a five-year period (1999-2003), which defines a Category II fishery. Thus, entanglement data from South Carolina from 1992-2003 support the re-categorisation of the blue crab fishery and the introduction of heightened regulations under the MMPA.

Compliance in recreational fisheries: Case study of two blue swimmer crab fisheries.

Comparing two Australian regions, Western Australia (WA) and South Australia (SA), this research investigates official noncompliance datasets of recreational blue swimmer crab (Portunus armatus) fishing between 2009 and 2019. These recreational fisheries in both jurisdictions are license-free and therefore participating fisher information is limited. Analyses provide a glimpse at the (noncompliant) fisher population profiles against the application of management strategies. The data provide (1) an evidence-base to optimize regulatory strategies by balancing education and enforcement activities with recreational fisher enjoyment. The results of this research enable application within and beyond these fisheries and jurisdictions; and (2) drawing from the criminology discipline, deterrence theory offers insight to enhance compliance tools. Further, it shows the importance of a multi-disciplinary approach to assessing compliance and identifies some practical approaches to data collection that can be readily undertaken to assist with more detailed analysis and enhance compliance strategies.

Bycatch Composition and Ecological Status of Trap and Gillnet Blue Swimming Crab Fisheries in Bone Gulf, Southeast Sulawesi, Indonesia

Bycatch Composition and Ecological Status of Trap and Gillnet Blue Swimming Crab Fisheries in Bone Gulf, Southeast Sulawesi, Indonesia