Spiny Lobster Stock Research Articles

Multi Connectivity Social-Ecological System of Spiny Lobster Fisheries (Case Study: Gunungkidul Regency, Yogyakarta, Indonesia)

Spiny lobster fisheries production, provides a fairly high economic value compared to other fisheries commodities in Gunungkidul Regency. The high selling value of spiny lobsters is one of the main factors that encourage fishermen to carry out their fishing activities massively, so it can have a negative impact on the environment and spiny lobster stocks in the waters. This study aims to map the interaction and connectivity of the social-ecological system (SES) of lobster fisheries on the coast of Gunungkidul Regency. The analysis method utilized is Social-Ecological Network Analysis (SENA) with R stundio tools and Cytoscape version 3.9.1. Data were obtained from in-depth interviews using questionnaires with key informants based on purposive sampling techniques. The results of the analysis showed that there were 94 elements and 216 relationships in the basic network model of multi SES lobster fisheries. The key variables that most affect the lobster fishing network are fishing season, fishing activity, lobster stock, and fishermen's income. There needs to be synergy between the resources system (RS), resources unit (RU), resources actor (RA), and resources governance (RG) such as monitoring and evaluation from RG to other systems in order to create optimal and sustainable lobster fisheries management.

Spawning potential ratio of comercially important spiny lobster in Donggala Waters Central Sulawesi

Currently, spiny lobster fishery in Indonesia ranks third as an export commodity from the crustacean subphylum after shrimp and blue swimming crab – mud crab. Most of the spiny lobster export needs still rely on wild population resulting in fishing pressure. To ensure the sustainability of spiny lobster stocks, information of the Spawning Potential Ratio (SPR) is needed. This study aims to analyze SPR of spiny lobsters of Panulirus femoristriga and P. versicolor species. The research was conducted in May − November 2022 in Donggala Regency waters. SPR analysis uses the Length-Based SPR method. The results showed that the stock status of P. femoristriga and P. versicolor had experienced growth overfishing and recruitment overfishing with estimated SPRs of 17 and 11%, respectively. Fishing regulations are needed to maintain a sustainable spiny lobster fishery through increased participation of stakeholders in the implementation, monitoring and evaluation of the regulations set by the government. In addition, it is necessary to reduce of efforts 27 − 33% from the current exploitation rate to E50 0.28.

Inferring Stock Status of Painted Spiny Lobster (Panulirus versicolor) in Aru Islands Waters, Indonesia

Three of six commercial spiny lobster species in Indonesian waters was found in Aru Islands waters which exploited continuously using drift gillnet and the catch was dominated by painted spiny lobster (Panulirus versicolor). To ensure the sustainability of the lobster stock, fisheries should be managed properly based on the best available science. In data-limited fisheries, length composition data are most common form information available for researchers and managers since its relatively cheap and simple to collect. In this study, we evaluate the stock status of P. versicolor in Aru Islands waters using three length-based methods: 1) length-converted catch curve (LCCC), 2) length-based spawning potential ratio (LB-SPR) and 3) length-based Bayesian biomass (LBB). The result showed that the mean length at catch of P. versicolor was 80.9 mm in carapace length. Furthermore, the three methods agree that the current status of painted spiny lobster stock seems to be fully exploited where the exploitation rate, the spawning potential ratio, and relative stock size (B/BMSY) were 54%, 35%, and 85%, respectively. Thus, for sustainability of this stock, it is highly recommended to catch P. versicolor at size greater than 80 mm in carapace length.

Towards the rebuilding of spiny lobster stocks in Brazil: a review

Abstract In this study, we used the Monte Carlo model (CMSY) to estimate fisheries reference points based on annual lobster landings. During the period 2012-2018, fishing pressure on lobster stocks decreased and a tendency for recovery was observed, despite the low biomass levels of approximately 29%. In 2019, the stock size was capable of producing yields close to the maximum sustainable yield (5770 t), with a probability of 58.1%. The enforcement of management measures should be continued in order to eliminate sources of negative externalities and rebuild stocks. We also demonstrate that the closed season does in fact protect the main events of the lobster life cycle. Responsible and efficient management should focus on life cycle studies and reliable monitoring of fishing data.

Population dynamics and sustainability of the spiny lobster (Panulirus meripurpuratus Giraldes & Smyth, 2016) fishery on the Amazon continental shelf

The assessment of fishery resources is key to the development of management strategies for exploited stocks. Analysis of specific parameters provides information regarding the state of the stock and indicators of exploitation levels. The aim of the present study was to analyse the growth and mortality parameters, as well as investigate the exploitation status, of Panulirus meripurpuratus caught on the Amazon coast, northern Brazil. Growth parameters and stock assessment were estimated using R with bootstrapping and FISAT II, based on cephalothorax length–distribution frequency. Specimens were collected by the commercial lobster fishery off the coast of the states of Pará and Amapá between 2001 and 2002. The results indicate that the P. meripurpuratus stock assessed is composed of individuals with low growth rates and high estimates of maximum asymptotic length, with relative longevity of 21.37 years. The exploitation rate was operating at near the maximum limit of sustainability in 2001 and 2002. This is the first estimate of the exploitation status of P. meripurpuratus on the Amazon coast. We strongly recommend new monitoring efforts and further studies to support the conservation and management of the spiny lobster stock.

European spiny lobster recovery from overfishing enhanced through active restocking in Fully Protected Areas

Fully protected areas (FPAs) help preserving biodiversity and reversing the global decline of fishery resources. Stocks of the European spiny lobster Palinurus elephas (Fabr. 1787), among the most precious gourmet seafood worldwide, are currently facing a dramatic decline. Previous attempts of recovery based on fishery restrictions or active post-larval restocking in marine reserves provided unsuccessful outcomes. Here we present results of a 5-year restocking program carried through a Collaborative Fishery Research (CFR) project, in three ad-hoc established FPAs replenished using below-legal size wild juveniles. Results showed that Catch per Unit Effort (CPUE) in terms of both density and biomass burst (by ca. 300–700%) just 2 years since FPAs establishment, regardless of location. We also report tangible spillover effects (ca. 30–50% increase in density and biomass CPUE outside the FPAs) by the end of the program. Data from a 15-years lasting monitoring of a pilot FPA established in 1998, where the restocking protocol was conducted and protection kept in force once restocking ceased, demonstrated the persistence in time of restocking’ benefits. We foster that creation of FPAs assisted with local restocking under oriented CFR programs can represent an option for the recovery of European spiny lobster stocks from overfishing.

Age and growth of the commercial spiny lobsters Panulirus argus (Latreille, 1804) and Panulirus laevicauda (Latreille, 1817) (Decapoda, Palinuridae) in Northeast Brazil: a review

Abstract The two spiny lobster fisheries targeting Panulirus argus (Latreille, 1804) and Panulirus laevicauda (Latreille, 1817) have made an important marine resource in Northeast Brazil since 1955. The Von Bertalanffy age and growth parameters of the spiny lobster started being studied in 1960 and the last assessment was performed over 20 years ago. The objective of this review is to analyse the type of input data and the methods historically used to assess age and growth of the spiny lobster stock in Northeast Brazil. Our study reviews and updates the research on the subject and proposes relative values for the Von Bertalanffy growth parameters for P. argus and P. laevicauda as provisional reference. We recommend further age and growth research on spiny lobsters to create a new and updated growth function for commercial lobsters in Northeast Brazil.

Investigating temporal variation in stable carbon and nitrogen isotope values of Florida Caribbean spiny lobster (Panulirus argus) recruits

The limited information available on the recruitment dynamics of the Caribbean spiny lobster, Panulirus argus (Latreille, 1804), has long been an issue for biologists. The long pelagic larval stage and the surface circulation in the Caribbean Sea have led many researchers to hypothesize that Caribbean lobster stocks are demographically open, implying connectivity among stocks in this region. Multiple approaches have been applied to investigate potential stock connectivity in this species, including biophysical modeling and genetic markers. Stable isotope analysis has proven to be a useful tool to study animal movement, and has been widely applied in studies of both terrestrial and aquatic species. However, this method has never been applied to Caribbean spiny lobster recruits. In the present study, we performed carbon and nitrogen stable isotope analyses on three sub-stages of the non-feeding pueruli (clear, semi-pigmented, and pigmented), as well as on the feeding, first juvenile stage that settled in the Florida Keys from August 2014 to July 2016. Results indicated that the stable isotope values differed between the feeding and non-feeding stages. The δ13C and δ15N values of the lunar monthly samples displayed notable temporal variation and oscillated during the 2-yr sampling period. Cluster analyses of the stable isotope values suggested that four clusters could have contributed to the observed Florida recruits. The results of our study reveal the possibility that the Florida spiny lobster stock receives recruits from multiple source populations outside Florida in addition to self-recruitment.

Changes in the Scalloped Spiny Lobster, Panulirus Homarus Biological Structure after a Shift of the Fishing Season

During 2010, the spiny lobster (Panulirus homarus) fishing season of Oman along the Arabian Sea coast was shifted from 15 October-15 December (2003-2008) to March-April (2010-2014) by the decision of the Ministry of Fisheries. The current status of the spiny lobster stock in the main fishing regions (Dhofar, Al-Wusta and Al-Sharqiyah) was examined based on monthly samples and surveys during the fishing season carried out from 2012 to 2014. An analysis of biological indicators such as size structure, number of undersized individuals captured, size at first maturity, sex composition shows that due to the new fishing season, the state of the lobster stock is improving. However, landings are still relatively low, therefore additional enforcement is needed to control the fishery out of the permitted season.

Measures for a sustainable lobster fishery

Lobsters; the crustaceans have four varieties as spiny, slipper, clawed and coral reeflobsters. Althoughall the species have a biological and environmental importance only two varieties; spiny and slipperlobsters have acqu ired the market and attribute for the fishery. Lobster fishery is a paramount componentwhich contributes more than five percent foreign exchange from total fish earnings in Sri Lanka. Thishas an export oriented market with attractive high prices, around 2000 LKRkg-J. The fishery hasexplained as a capture fishery. Therefore, the resource is subjected to over exploitation due tounattainable demand. That means, the fishery is currently in a period of transition era of open accessto a period oflimited access. In fact, it needs a well managed, monitoring plan and functioning rulesand regulations towards a sustainable lobster fishery that would be discussed through this study.The data were collected from five lobster process-ing companies and three purchasing centers inGampaha district. Informal discussions were held with officers at NARA and ministry of fisheries.The sustainability was calculated using surplus yield model (Schaefer, 1954 - 1957)_During 1980s to early 1990s, the only lobster variety exported was spiny lobsters: but with the absenceof enough spiny lobster stock, marketers and buyers tend to demand 51ippcr lobster also, Therefore,the catch also declined up to mid 1990s and slightly increased in a decreasing manner where the catchdrop from 375 mt in 1996 to 247 mt in 2004 with slight variation during the period. So as the Catch PerUnit Effort (CPUE) also decreased from 0.33 percent to 0.09 percent during the period of 1986 -1998. The decreasing is mainly due to the over exploitation. Therefore, new remedies, rules andregulations should be implemented.Habitat enhancement, minimize near shore pollution, usage of appropriate gears. conduct larvalsettlement and lobster fattening programmes, and facilitate training, extension work cum awarenessprogrammes are some suggestions that could be implemented. Also the primary regulations on lobsterfishery should be implemented with restrictions on the fishing efforts (traps) and a quota system. Thecalculated yield levels permit to harvest only within the range of359 mt - 388 mt annually.

Assessment of wild spiny lobster stocks on the Brazilian continental shelf

The red spiny lobster Panulirus argus (Latreille, 1804) and the green spiny lobster Panulirus laevicauda (Latreille, 1817) are the most abundant and commercially valuable lobster species on the Brazilian continental shelf. Though sold on the domestic market, the painted spiny lobster (Panulirus echinatus Smith, 1869) and the slipper lobster (Scyllaridae) are of little economic importance and have been the object of very little research. Brazilian spiny lobster fisheries have been in decline for many years due to growth overfishing, including the capture of undersized specimens (>50%). Furthermore, fishing berried females and older lobsters from deeper waters (≥50 m), compromising the reproductive potential of the species and increasing the risk of low recruitment and fishing collapse. The setting of quotas on catches is in itself insufficient to protect Brazilian lobster stocks. Management efforts should instead focus on the enforcement of control measures in order to increase lobster stocks. In this study we make several recommendations: (i) lobster traps should be furnished with escape gaps for undersized lobsters, (ii) the use of undersized lobsters (decoys) in traps should be avoided, (iii) gillnets (“cacoeira”) and artificial shelters (“marambaia”) should be eliminated, (iv) an optimal minimum legal size should be established (80 mm CL for all spiny lobster species and 85 mm CL for slipper lobsters), (v) a maximum legal size should be established (135 mm CL for P. argus and 100 mm CL for P. laevicauda of both sexes), (vi) the capture of berried females should be prohibited, (vii) a closed season should be instituted to protect ovigerous females and ensure recruitment, (viii) establishment of marine reserves or a total closed season to protect the juveniles in nursery areas, (ix) a monitoring program collecting catch and effort data should be implemented to help assess lobster stocks adequately, and, (x) stratified random sampling must be implemented.

Estimation of abundance and spatial distribution of Panulirus argus using different methodologies in artificial shelter, trap and coral reef fisheries

Estimates of spiny lobster stocks (Panulirus argus Latreille, 1804) represent a fundamental input for population assessment models and are, therefore, indispensable for proper management. In this study we analysed methodologies employed in the Gulf of Batabanó (Cuba) and Providencia and Santa Catalina (Colombian Caribbean) to estimate abundance (N) and stock productivity. We found evidence that the relative abundance (CPUE) for trap-like jaulones and skin diving in natural shelters was likely to remain high despite the decline in abundance (hyperstability). In contrast, the proportionality between CPUE and N was satisfactory in artificial shelters (Cuban pesqueros). Stock productivity was greater for jaulones (22 288 kg/km2) than for pesqueros (1309 kg/km2) or natural shelters (15.25 kg/km2), reflecting differences in the productive capacity of each type of fishing gear. In natural shelters the exploitable biomass is under great fishing pressure and the reproductive stock is likely to decrease. Thus, the West zone of Providencia and Santa Catalina, characterized by high-density seagrass and mangrove, should be designated a marine protection area to prevent a lobster fishing collapse. The most effective measure to revert the lobster fishing collapse in Cuba would be to ban the use of jaulones and liftable pesqueros, thereby reducing fishing intensity.

Historical changes of sediments and mollusk assemblages in the Gulf of Batabanó (Caribbean Sea) in the twentieth century

The first paleoecological reconstruction of the biogeochemical conditions of the Gulf of Batabanó, Caribbean Sea was performed from (210)Pb-dated sediment cores. Depth profiles of 20 major elements and trace metals, organic compounds, grain size, and mollusk assemblage composition were determined from 9 stations encompassing unconsolidated sediments in the gulf. Spatial heterogeneity was evident for the geochemistry of sediments and for the mollusk assemblage composition. Our reconstruction indicates that pollution is not a critical threat to the ecosystem, although a slight historical increase of lead enrichment factor was detected probably due to long-range atmospheric fallout. Mollusk assemblages were composed by 168 species belonging to 59 families and no temporal trends in the species diversity or assemblage composition were detected, suggesting no depletion of diversity or habitat loss. Other signals of habitat loss such as changes in organic budget or increase of fine sediment fraction were absent or weak. Nitrogen retained in sediments changed by <1% in the century, indicating no historical events of eutrophication or oligotrophication in the gulf. Historical decrease of fine sediment fraction in the eastern sector would be linked to modifications in sedimentation rate, land use, and/or particle transport from the shelf border; this also suggests that both sectors have different sedimentary dynamics. Although, on theoretical grounds, historical fishery may have caused deleterious ecosystem effects by overexploitation of spiny lobster stocks, no evidence of habitat degradation or loss, caused by fisheries, could be detected.

Dependence of recruitment on parent stock of the spiny lobster, Panulirus argus, in Florida

AbstractDespite management practices to achieve sustainability, commercial landings for Florida spiny lobster (Panulirus argus) have experienced a drastic decline (57%) since 2000. This is cause for concern not only for economic reasons, but for issues of sustainability. An annual index of P. argus post‐larval (puerulus) abundance, estimated with a generalized linear model with significant mean sea‐level effects, shows a 36% decrease in annual puerulus supply since 1988. In addition, local Florida spawning stock biomass estimated from an age‐structured sequential population analysis decreased 57% since 1988. Puerulus abundance follows a highly correlated (R = 0.76) trend with a 12‐month delayed spawning stock abundance, which supports the contention that the Florida spawning population is a significant contributing factor to post‐larval recruitment in Florida. Residuals about the puerulus on spawning stock abundance function follow closely an interannual North Atlantic Oscillation Index signal. This residual effect is thought of as a secondary regional population effect on Florida puerulus recruitment. The Florida spiny lobster stock is exploited with no fishing mortality controls due to the Pan Caribbean recruitment concept adopted in Florida spiny lobster management. Therefore, the potential of recruitment overfishing exists if fishing mortality controls to protect local spawning stock abundance, such as catch quotas, are not introduced.

Movements and residence time of spiny lobsters, Palinurus elephas released in a marine protected area: an investigation by ultrasonic telemetry

Marine reserves and restocking initiatives are sometimes used as a tool to enhance spiny lobster stocks. In such initiatives it is crucial to follow the movement of lobsters once they are released at sea in restocking experiments.This paper presents the results of the application of an ultrasonic telemetry system to the monitoring of 11 lobsters (90±14 mm mean carapace length) released in the Capo Gallo-Isola delle Femmine Marine Reserve in north-western Sicily, central Mediterranean. The system comprised transmitters glued onto the lobster carapace, and manual as well as automated receivers to locate tagged animals. The data (i.e. number of detected signals) were tested to assess any difference in the diel activity of lobsters. The field study lasted 79 days in total. Lobsters remained in the study area for periods ranging from a few hours to the entire duration of the study. The longest distance travelled by a tagged lobster was 2.2 km. The number of signals varied significantly across the day, with the highest value recorded in the full-light hours (1000–1500), but they were not sufficient to assess clearly the diel activity of the released lobsters.The interpretation of data suggests that: (1) released lobsters preferred a deeper habitat than that of the release site; and (2) the lobsters that reached a rough rocky area with available shelters settled there, while those that did not meet such a habitat soon moved out of hydrophone detecting range.

Survival and movement of naïve juvenile spiny lobsters returned to the wild

Using multistate Arnson–Schwartz (AS) mark-recapture models, we show that naïve (captive reared) juvenile southern rock lobsters ( Jasus edwardsii, Hutton 1875) survived as well as wild-caught lobsters when released to an area of coastal reef. Lobsters captured as pueruli were ongrown in tanks for 12 to 18 months where they were fed to satiation in the absence of predators. Lobsters were marked with antennal tags each carrying a unique code, and released to coastal reef along with tagged wild-caught lobsters of similar size. During 8 dive surveys of the release reef and 3 surveys of adjacent reefs over a 28 day period, divers resighted 40.3% of the naïve lobsters and 70.2% of the wild lobsters. We show that this discrepancy is a function of differing movement rates and spatial differences in resighting probability. The probability of naïve lobsters moving from the release reef to adjacent areas in the first 4 days post-release (0.72 ± 0.04 S.E.) was almost twice that of wild-caught lobsters (0.38 ± 0.08 S.E.). This behavioural difference did not influence daily apparent survival (0.98 ± 0.016 S.E.), which was constant between groups and over time. Our results are encouraging for the potential of enhancing spiny lobster stocks by releasing juveniles, and demonstrate the utility of AS mark-recapture models as a tool for evaluating medium-term survival of mobile marine species.

Patterns in Landings and Size Composition of Jasus Verreauxi (H. Milne Edwards, 1851) (Decapoda, Palinuridae), in Waters Off New South Wales, Australia

Available information suggests that the relative abundance of the New South Wales' spiny lobster stock, exploited since at least 1873, has declined over the past 20 years. Annual landings fluctuated until 1948-49 but have fallen in most years since. Data on fishing effort and CPUE were available only for years from 1969-70 onwards. Fishing effort was stable over most years to 1978-79 but has continued to rise since then. CPUE declined over the period for which data were available; this was attributed to a fall in the abundance of Jasus verreauxi, since this species comprises around 97% of the commercial catches of lobsters in New South Wales. The lengths of J. uerreauxi in catches from commercial vessels between 1986 and 1988 varied between locations. The spatial pattern in annual distributions of lengths suggests that this species may move along-shore. When data from all sites were combined, only 10% of the J. verreauxi sampled were longer than the smallest length at which 50% of females carry eggs (166.5 mm CL). Although the optimum level of fishing effort could not be determined from the available data, the patterns in landings, effort, and CPUE suggest that measures are necessary to conserve this resource until estimates of maximum sustainable yield and optimum fishing effort can be determined.

Patterns in Landings and Size Composition of Jasus Verreauxi (H. Milne Edwards, 1851) (Decapoda, Palinuridae), in Waters Off New South Wales, Australia

Available information suggests that the relative abundance of the New South Wales' spiny lobster stock, exploited since at least 1873, has declined over the past 20 years. Annual landings fluctuated until 1948-49 but have fallen in most years since. Data on fishing effort and CPUE were available only for years from 1969-70 onwards. Fishing effort was stable over most years to 1978-79 but has continued to rise since then. CPUE declined over the period for which data were available; this was attributed to a fall in the abundance of Jasus verreauxi, since this species comprises around 97% of the commercial catches of lobsters in New South Wales. The lengths of J. uerreauxi in catches from commercial vessels between 1986 and 1988 varied between locations. The spatial pattern in annual distributions of lengths suggests that this species may move along-shore. When data from all sites were combined, only 10% of the J. verreauxi sampled were longer than the smallest length at which 50% of females carry eggs (166.5 mm CL). Although the optimum level of fishing effort could not be determined from the available data, the patterns in landings, effort, and CPUE suggest that measures are necessary to conserve this resource until estimates of maximum sustainable yield and optimum fishing effort can be determined.