Lobster Catch Research Articles

Spillover and competitive exclusion in the crustacean community following the implementation of a marine reserve

Abstract Flamanville marine protected area (MPA) located in Normandy, France, was created in 2000 to sustain the local crustacean fishery. In 1985, an annual survey targeting crustacean populations (e.g. European lobster Homarus gammarus, edible crab Cancer pagurus, and European spider crab Maja brachydactyla) that include the future MPA started. The MPA implementation effects were investigated in this study. The sampling design allowed the integration of spatial and temporal covariances to estimate the MPA effects. With respect to the initial objective, the MPA significantly improves the most economically valuable species, H. gammarus, abundance. Lobster catch per unit effort increased by 597% in the MPA, whereas outside it only increased by 156%. The MPA creation also led to an increase in lobster size inside the protected area. Furthermore, a few years after the MPA implementation, lobster catches showed a significant non-linear decline with distance from the centre of the reserve, suggesting a spillover effect. However, the edible crab catches were halved following the MPA implementation suggesting an opposite effect. Spider crab abundance seemed unaffected. Finally, the MPA implementation had no effect on edible crab and spider crab sizes. These differential responses appear to result from these species’ variable movement and competitive abilities.

THE USE OF A MAGNETIC SENSOR TO DETECT LOBSTER (Panulirus spp.) CATCHES ON THE LABORATORY SCALE

Problems in operating trap fish tool are that fishermen do not know the actual condition of the traps. Thus, it causes the effectiveness of time and number of catches to be not optimal. Based on the conditions and problems above, the writer concluded that an innovation in the operation of the trap to design a magnetic sensor-based system/tool to detect lobster catches that can be accessed via smartphone is required. The aim of this study is to design and observe the performance of using a magnetic sensor to detect lobsters' (Panulirus spp.) movements on a laboratory scale (in the aquarium). Data analysis in this study used the Confusion Matrix method, where this method divides the test results into 4 common conditions: TP (True Positive), TN (True Negative), FP (False Positive), and FN (False Negative). From the 4 conditions, Recall, Specificity, Precision, Accuracy, and F1 Score can be calculated. From 16 tests with the 16 lobsters of 60-190 grams/individual, it obtained conditions of TP of 25 times, TN of 109 times, FP of 11 times, and FN of 15 times. From the four conditions, it was obtained a Recall value of 0.625 or 62.50%, Specificity of 0.9083 or 90.83%, Precision of 0.6944 or 69.44%, Accuracy of 0.8375 or 83.75%, and F1 Score of 0.6579 or 65.79%. Based on the observations and test results of the actual detection and application system in this study, performance reference for using magnetic sensors was by using Accuracy with a score of 83.75%.

Review of Sharia Economic Law Regarding Prices and Sizes in Buying and Selling Empang Crabs

This study aims to find out the practice of buying and selling crabs at different prices and sizes and to review Sharia economic law regarding the practice of buying and selling crabs. This research uses descriptive and qualitative research methods. The author's data collection technique involves conducting observations, interviews, and documentation. The results of the research show that the practice of buying and selling pond crabs in Watu village, Cenrana subdistrict, Bone Regency is carried out by the collector contacting the fisherman, and the collector usually gives the fisherman a down payment so that when the fisherman gets the sea lobster catch, he immediately gives it to the collector. The practice of determining prices and sizes is that before selling to buyers, collectors have sorted and divided the sizes of crab types with predetermined price differences. Meanwhile, collectors get crabs from fishermen with crabs that have not yet been sorted by type and size, while all those involved in the practice of buying and selling crabs do not understand the existence of ministerial regulations governing the size of crabs. Buying and selling crabs according to Sharia economic law is legal because it complies with the provisions of Islamic law. However, in the practice of buying and selling crabs, buyers only feel burdened by the high prices set. Because in buying and selling, both parties must be equally sincere and willing without anyone feeling disadvantaged.

Escape gaps in wire lobster traps reduce bycatch of coral reef fish while maintaining catch of harvestable lobsters in Florida’s Caribbean spiny lobster (Panulirus argus), fishery

Escape gaps are a tool commonly used to reduce the catch of sublegal-size animals and bycatch in crustacean trap fisheries. In Florida’s Caribbean spiny lobster (Panulirus argus) commercial trap fishery, traps are baited with live, sublegal-size lobsters, which precludes the use of escape gaps sized to exclude capture of undersize lobsters. Both wood and wire traps are used in the fishery, but wire traps capture more fish as bycatch than do wood traps. This project was developed and executed cooperatively with commercial fishers to evaluate, for wire lobster traps, the effect of escape gaps on catch rates of bycatch and harvestable lobsters. We tested five wire-trap configurations that included a control trap without escape gaps (i.e., an unmodified commercial trap) and four configurations consisting of a narrow (3.81 cm) or wide (5.40 cm) escape gap, oriented either vertically or horizontally. All traps were fished in the Atlantic Ocean at a deepwater site (ca. 30 m) and a shallow-water (ca. 10 m) site. Control traps and traps with a narrow escape-gap configuration were baited with a live, sublegal-size lobster; traps with a wide escape-gap configuration were baited with a live, legal-size lobster. We compared the number of lobsters caught and coral reef fish bycatch, as well as size frequency distributions of lobster and compressiform fish species, which include fish in the snapper and grouper families, in each trap configuration. Escape-gap traps caught statistically similar numbers of legal-size lobsters in all configurations except the wide horizontal configuration at the deep site. The catch of sublegal-size lobsters was significantly reduced in the wide horizontal and wide vertical escape-gap trap configurations at both sites. Fish bycatch was dominated by compressiform fish of the Haemulidae family and fish bycatch was significantly reduced in all escape-gap trap configurations. Our results suggest that the wide vertical escape-gap configuration maximized both the retention of harvestable lobsters and the escape of sublegal-size lobsters and fish bycatch. Inclusion of any of the escape-gap configurations tested could reduce discard mortality of fish and undersize lobsters, but baiting and trap fishing methods may need to be adjusted to maximize lobster harvest.

A novel method for quantifying the attractiveness of lobster trap baits

We developed a new method for quantifying the attractiveness of bait in traps used for crustacean fisheries by using accelerometers in bait containers to assess the amount of time animals spend interacting with the baits. We validated our approach in the laboratory by using time-lapse video recordings to verify that the accelerometry data accurately reflected when, and how much, American lobsters (Homarus americanus) interacted with bait. We then conducted a field experiment comparing traps baited with traditional herring, crushed green crabs (Carcinus maenas), or an inert control. We found that during 48-h trap sets, the number of minutes in which the accelerometers recorded movements of the bait bags was correlated with lobster catch. Although the traps baited with herring did not catch significantly more lobsters than traps baited with crushed green crabs, the accelerometer data revealed differences in bait attractiveness over time. Lobsters interacted less with the green crab bait on the second day of the set, while no such decline was observed with the herring bait. This technique is inexpensive, easy to use, and the data obtained can be more rapidly analyzed than the video data traditionally used for these types of studies, making it well suited for future work on bait choice and attractiveness.

Identification and productivity of lobster catching (Panulirus spp) in Aceh Jaya

Lobster is a leading commodity in Aceh Province and it is one of the commodities with a high economic price. Besides, it is believed that Aceh Jaya Regency has superior fisheries commodities. This study aims to describe the composition of the catch, the relationship between the length and the weight and the productivity of the catch on six different types of lobster in Aceh Jaya. The study was conducted from June to August 2022 in the waters of Aceh Jaya, Setia Bakti District, Lhok Rigaih Village. The study focuses on the catch composition, length-weight relationship, and the measurement of the catch productivity. The types of samples taken were six species including Panulirus homarus, P. longipes, P. penicillatus, P. versicolor, P. ornatus and P. polyphagus. The composition of the total lobster catch was dominated by Panulirus penicillatus 23.94%, followed by P. versicolor 19.71%, P. homarus 18.30%, P. longipes 18.30%, P. ornatus 18.30%, and P. polyphagus 1.40%. The composition of the weight of the catch was dominated by Panulirus versicolor 23.20%, followed by P. longipes 22.79%, P. homarus 19.41%, P. penicillatus 17.42%, P. ornatus 17.02%, and P. polyphagus as 0.13%. The relationship between the length and the weight of these six types of lobster catch were allometric negatives. The productivity of lobster catch using gillnet fishing gear averaged 226.66 kg in April 2021, 293.51 kg in June, and 141.53 kg in December. The catch in January 2022 was 437.26 kg, meanwhile in February was 77.87 kg, followed by April 358.85 kg.

Species Composition, Relative Abundance, Distribution, and Size Structure of Spiny Lobsters (Panulirus spp.) in Eastern Visayas, Philippines

Spiny lobsters are an important resource of the artisanal fishery in Eastern Visayas, Philippines. It has long been harvested and contributes to the region's local economy. Despite being a high-value species, the spiny lobster resource has not been monitored and regulated for decades. This study aimed to assess the spiny lobsters in Eastern Visayas and provide recent information to support local resource management. Spiny lobsters were assessed from 2018 to 2019 in four major sampling areas in Eastern Visayas: (1) Guiuan and (2) San Policarpo in Eastern Samar province, (3) San Jose in Northern Samar, and (4) Silago-Hinunangan in Southern Leyte. Species composition, relative abundance, geographical and seasonality distribution, and size structure of spiny lobster resource in the region were described. Six species and subspecies of the genus Panulirus were observed in the catch landings: P. penicillatus (65%), P. ornatus (18%), P. versicolor (2.8%), P. femoristriga (5.3%), P. longipes longipes (6.1%), and P. longipes bispinosus (1.7%). Incidental catches (1.3%) of the ambiguous forms of P. longipes were also observed. P. penicillatus were more prevalent in areas exposed to the Pacific, such as Guiuan and San Policarpo, while adult P. ornatus were chiefly harvested in Northern Samar and Southern Leyte. The other lobster species were either occasional or rare in some areas. Calmer waters and good weather during dry months in Eastern Visayas allow fishers to sail and gather lobsters. The surge in the abundance of P. ornatus and P. penicillatus from July to December was also affected by market demand. Panulirus femoristriga, P. versicolor, and P. longipes subspecies generally peaked from April to June in Eastern Samar and July to September in Northern Samar and Southern Leyte areas. These species would decline in abundance towards the end of the year. The general size structure of spiny lobster catches in Eastern Visayas revealed extreme harvesting of juveniles and sub-adults (< 77.5 mm CL), except for P. ornatus. The fishery could be on the verge of growth overfishing since 50-90% of the catch have CL below their size at first maturity. Panulirus ornatus is targeted at larger sizes (96–107 mm CL) and as a live catch due to its high value and marketability. Raising awareness of the species, reinforcing existing regulations on minimum size limits, and prohibiting the use of compressor diving as a hazardous collection method should be prioritized by fishery managers to protect both the spiny lobster resource and the gatherers in Eastern Visayas.

Fishing methods and fishing season of the tropical lobster fisheries of Southern Java, Indonesia

Abstract. Setyanto A, Sumarno, Wiadnya DGR, Prayogo C, Kusuma Z, West RJ, Tsamenyi M. 2023. Fishing methods and fishing season of the tropical lobster fisheries of southern Java, Indonesia. Biodiversitas 24: 778-783. Tropical lobster fisheries represent a relatively small-scale but valuable export industry in Indonesia, but in many ways may fall within the category of Illegal, Unreported and Unregulated (IUU) fisheries. The absence of useful fisheries information means the management strategies and plans to manage the fisheries is severely limited. This research aimed to provide information about the fishing gear, methods, and fishing season of the fisheries, as a precursor to the development of fisheries management strategies. The study was conducted at Watukarung, Pacitan (East Java) and Baron, Gunungkidul (Yogyakarta). Fisheries data on lobster catch, fishing methods and fishing effort were collected through direct observation and interviews with fishers, fishery officers and port managers. Catch data were analyzed using ordinations technique to determine the fishing season. Lobsters were captured in various fishing gears throughout the year, but fishers targeting lobsters primarily used specialized lobster nets deployed by small boats and “krendet” (traps) deployed from clifftops as well as from small boat. The main fishing season for lobsters was from November to February each year. Future research needs to investigate fishing capacity and population parameters before any comprehensive fisheries management can be undertaken.

Understanding the impact of environmental variability and fisheries on the red sea urchin population in Baja California

IntroductionThe red sea urchin fishery is one of the most important fisheries in Baja California and the only urchin fishery in México; yet little is known on understanding how local, regional, and oceanic environmental variability may affect red sea urchin populations. MethodsWe analyzed how food availability, predator abundance and environmental variability could affect red sea urchin populations developing generalized linear models under different temperature conditions: Pre-heat wave, heat wave, and post–heatwave, including sites where sea surface temperature was above, below, and on average. Models included: a) biological variables: Macrocystis pyrifera (kelp) biomass, red sea urchin (Mesocentrotus franciscanus) density, sheephead (Semicossyphus pulcher), kelp bass (Paralabrax clathratus) and spiny lobster (Panulirus interruptus) catches, and b) oceanographic variables: sea surface temperature, wave power, upwelling index, multivariate El Niño index and North Pacific Gyre Oscillation index. ResultsBetween 65 and 82% of the variability observed in red sea urchin populations was explained by different combinations of variables, depending on the thermal condition analyzed. We observed that local environmental variability, such as food availability and predator harvest are highly important factors in determining red sea urchin population changes, compared to regional and oceanic scale variables such as upwelling, El Niño, or the North Pacific Gyre Oscillation. Results show that the relative importance of these variables changed depending on the spatial and temporal scale being analyzed, meaning that under “normal or average” conditions one set of variables is important, compared to extreme environmental conditions such as El Niño or “the Blob” when a different set of variables explained the observed variability. Urchin predators’ catches were correlated with urchin density during the pre-heatwave scenario, suggesting that under “average temperature” conditions the effect of fishing on predators, and consequently on urchin density is higher than local temperature, the most important variable during warm conditions. DiscussionThis study suggests that in Baja California, red sea urchin harvest has become the most important red sea urchin population control, so efforts should be encouraged and supported by state and federal agencies to promote more resilient ecosystems in the face of environmental uncertainty. Improving management of the commercial species that inhabit kelp forest, could yield benefits for the entire ecosystem, fishers, and the red sea urchin population in Mexico.

Fishers can optimize gear design if the management system allows for enough flexibility: A modified SELTRA codend can reduce fish catch in the Danish trawl fishery for Norway lobster

Through an industry-science collaboration, a modified SELTRA codend consisting of a grid with scaring floats (GSF) was successfully developed by the fishing industry, and tested in a scientific trial on board a twin-rig demersal trawler. The selectivity of the gears used in the fishery needs to be tailored to each vessel and season, as quota availability differs across vessels and seasons. The modified gear aims at avoiding catching unwanted fish when targeting Norway lobster. The use of the modified codend showed good potential for effectively reducing catches of unwanted fish without affecting the catch of the target species Norway lobster. With respect to a standard SELTRA codend, the GSF design led to a significantly lower retention of unwanted fish, with 71 (61–79) % less cod, 94 (73–100) % less saithe and 22 (14–37) % less plaice being retained. The results show that fishers have the knowlegde to develop more selective gears. The authors argue that fisheries management should support such industry driven innovation through more flexible management approaches.

Differences in catching time and baits on the catch results of Krendet in Coastal Fishing Port (CFP) Sadeng, Gunungkidul, Yogyakarta

Krendet is one of the fishing gears used to catch Lobster in the South Coast of Java. Krendet is a passive fishing gear. Lobster is a fishery commodity that has high economic value. This research was conducted to determine the difference in lobster catches based on differences in fishing time and bait types on Krendet fishing gear. The method used in this research is experimental fishing with 4 treatment combinations and 6 repetitions. The difference in fishing time used was morning – afternoon and afternoon – morning, while the bait used was trash fish and no bait as a control. This research was carried out in February 2021 in the waters around the Sadeng area, Gunung Kidul. The analysis carried out in this study used the Two Way Anova Test method. The results showed that the time difference had an effect on the number of catches. The effective time to catch Lobster is at night. This can be caused by Lobster's behavior or habits which tend to be active at night. Giving bait to Krendet is also able to increase the number of catches. The trash fish bait is able to lure the Lobster to come closer to Krendet. Giving bait to Krendet is also able to increase the number of catches. The trash fish bait is able to lure the Lobster to come closer to Krendet so that the Lobster can be trapped.Keywords:KrendetLobsterCoastal Fishing PortSadeng

Exploring the potential use of escape gaps in the Florida spiny lobster, Panulirus argus, fishery

The spiny lobster fishery in Florida uses live, sublegal-size lobsters as bait in the approximately 450,000 traps currently permitted in the fishery. Live baits increase the catch of traps, yet confinement in traps compromises lobster health and causes mortality. We conducted a field experiment to test the suitability of traps fitted with escape gaps to address a priority need for reducing catch and mortality of sublegal-size lobsters and other species in Florida’s spiny lobster trap fishery. We then modeled the potential effect of escape gaps on the Florida commercial spiny lobster trap fishery (via a Monte Carlo simulation technique) to identify the effect on fishery harvest. We measured catch rates and mortality of lobsters in traps with or without a 54 mm escape gap and baited with either a live sublegal-size lobster, a live legal-size lobster, or left unbaited. The relationship between catch in traps fitted with escape gaps vs. catch in control traps determined from the field experiment was applied to commercial fishery landings data from 2010 to 2018 and used to model changes in harvest as result of implementing escape gaps and baiting with a legal-size lobster. We found that traps with escape gaps nearly eliminated catch of sublegal-size lobsters in traps, which would lower mortality caused by such confinement and potentially allow hundreds of thousands of lobsters to remain in the population. Alternatively, replacing live bait lobsters every two weeks reduced bait mortality by half in our field experiment; thus, mortality of sublegal-size lobsters used as bait in the fishery could be reduced through frequent release of bait lobsters. Escape gaps also reduced fish bycatch, including some in the snapper-grouper management complex. Traps with escape gaps and baited with legal-size lobsters caught ~27% ± 16% fewer legal-size lobsters than control lobster traps baited with a sublegal-size lobster. However, these traps caught as many legal-size lobsters as control lobster traps baited with sublegal-size lobsters when lobster abundance was high, demonstrating that self-baiting of traps is density dependent. Although traps with escape gaps caught fewer legal-size lobsters per trap, fishery modeling indicated that increased survival of sublegal-size lobsters could increase landings by the second to fourth year after implementation of escape gaps, depending on which model assumptions are used to predict landings.

Molecular identification and potency of scalloped spiny lobster (Panulirus homarus) study from Kodang Merak Beach, South Malang

Lobster is one of the commodities from the fisheries sector that has high economic value. The problem faced is that there is still limited biological information on lobster species in Indonesia, including identifying genetic diversity. The purpose of this study was to determine the potential ofscalloped spiny lobster. Lobster identification was carried out morphologically and molecularly on the most dominant lobster species at Kondang Merak Beach, Malang. The method in this study used observation and experimental methods. The results of recording data on natural lobster catch from local fishermen from Kondang Merak,scalloped spiny lobster is the most dominant species compared to other types of lobster (painted spiny lobster, ornate spiny lobster). Morphologically, the most dominant lobster sample (MAL-01) obtained from this research location was Panulirus homarus. The lobster has a color pattern and meristic characteristics that are in accordance with the morphological identification reference used. Molecular identification of scalloped spiny lobster (DNA barcoding) has shown that the lobster specimen is a scalloped spiny lobster (Panulirus homarus) which has the same sequence as KF548574 (100%) in the BLASTN results with the Genbank Database.

Catch Diversity of Small Scale Lobster Fishery in Southern Coast of Sri Lanka

The lobster fishery is one of the well-established, highly valued commercial fisheries on the Southern coast of Sri Lanka. There are five spiny lobster species, Panulirus homarus, P. longipes, P. ornatus, P. versicolor and P. penicillatus are recorded in the Southern coast of Sri Lanka. However, the heavy fishing pressure and other anthropogenic interventions have caused a significant depletion of some of these species. Therefore, in order to identify the vulnerability of the lobster species, we studied the species, gender and sexual maturity compositions of the lobster catch with the data collected from nine different lobster landing sites along the southern coast of Sri Lanka during 2019 and 2020. Minitab and MS Excel software were used for the descriptive statistical analysis. According to the results, the dominant species in the sampled landings was P. homarus, with the average percentage of 73.16% in 2019 and 84.65% in 2020. However, least abundant P. ornatus species’ average percentages were 0.74% in 2019 and 0.27% in 2020. Moreover the results reveals the male:female 1:1 sex ratio of the lobster catches as 1:0.9 in 2019 and 1:0.89 in 2020. Most importantly, among all females, there were 43.01% in 2019 and 37.31% in 2020 percentages borne eggs while 48.53% in 2019 and 47.03% in 2020 percentage of females were identified with tar spots. Therefore, considerable caught of tar spotted and egg bearing female lobsters might be a major cause of lobster stock depletion in Southern coast of Sri Lanka. Thus present study would be a preliminary guide for the future studies on sustainable lobster fishery management approach.
 Keywords: Lobsters fishery, Southern coast, Panulirus homarus, Tar spots, Sri Lanka

Increasing spillover enhances southern California spiny lobster catch along marine reserve borders

AbstractThe conservation benefits of marine reserves are well established but their contribution to adjacent fisheries via spillover is less certain and context‐dependent. Theoretical predictions do not always match empirical evidence from individual reserves, so carefully designed studies are essential for accurately assessing spillover and its contribution to fisheries. Biomass buildup within reserves, and spillover from reserve borders, also usually takes time to develop. In 2003, a network of no‐take marine reserves was established in the Northern Channel Islands (NCI) of southern California (CA) to conserve biodiversity and to eventually enhance local fisheries through spillover of larvae, juveniles, and adults. The reserve network impacted the local CA spiny lobster (Panulirus interruptus) fishery by removing about 20% of fishing grounds in the NCI. In 2008, a collaborative fisheries research effort detected substantial lobster population increases within reserves, and an indication of the possible spillover of adult lobsters across reserve borders. To estimate whether and how much populations within reserves, and spillover from reserves, have increased through time, we repeated the sampling program 10 years later in 2018 at two of the three original reserves. Scientific trapping was conducted prior to the fishing season along a spatial gradient beginning deep within the reserves to reference sites located outside (≥2 km) of reserve borders. Results showed that legal‐sized lobster abundance in traps (catch per unit effort) increased by 125%–465% deep inside reserves, and by 223%–331% at sites near to reserve borders, and by nearly 400% just outside of reserve borders over the 10‐year period, thus indicating a substantial increase in spillover across reserve borders. A similar pattern was observed in lobster biomass caught in traps at the two reserves. This study demonstrates how spillover scales with biomass buildup and that collaborative fisheries research can be used to assess the efficacy of marine reserves as fishery management tools worldwide.

Reef related fisheries resources, spawning and nursery grounds of target species in Quy Nhon bay, Binh Dinh province

Coral reef-related fishery resources in Quy Nhon bay were assessed at four communes in 2016, using an investigation note with additional input from consultations with experienced local fishermen. This information was ground-truthed during field survey assessments of spawning and nursery grounds of target resources (December 2016 and April–June 2017). The total catch of reef-related target resources was about 637 tons/year, including 536 tons of fish, 130 tons of mollusks, 0.34 tons of spiny lobsters, 19 tons of collector urchins, and 3 tons/year of Gracilaria seaweeds. There were some 936,450 juveniles of fishes and lobster caught in each year, in which some 576,000 individuals of grouper juveniles (orange-spotted grouper and six-bar grouper) were mainly caught by Ghenh Rang commune, and some 360,450 individuals of lobster ‘seeds’ were caught by the four communes (Nhon Ly, Nhon Hai, Ghenh Rang and Nhon Chau). The total revenue from fishing at the 4 locations was some 90.81 billion VND (about 4,128,000 USD), with the highest value being recorded in Nhon Hai (41.23 billion VND), Nhon Ly (28.53 billion VND), Ghenh Rang (13.06 billion VND), and the lowest in Nhon Chau (7.99 billion VND). Commercial resources contributed 35.43% (32.17 billion VND) and seed collection 64.57% (58.64 billion VND). There were 16 important grounds found in Quy Nhon bay, including three spawning grounds of cuttlefishes and murex snails, and 13 nursery grounds of swimming crabs, lobster ‘seeds’, sea cucumbers, rabbitfishes, and groupers, in which Nhon Hai and Ghenh Rang supported six grounds for each.

Population structure and biological aspects of lobster (Panulirus spp.) of the Madura Strait landed in Situbondo of East Java, Indonesia

Lobster is an important economic fishery resource in domestic and international trade. The high economic value of lobster due to increasing market demand has led to its intensive exploitation. The enactment of specific regulations on lobster proves the urgency of its management. Madura Strait is one of the unique biogeographical sea regions of East Java. This research was conducted in January-March 2021 at Pasir Hitam Beach, Situbondo. The purpose of this study was to determine the species composition of lobsters, the frequency distribution and the growth form, and the sex ratio. The analysis applied is class distribution of length and weight classes, regression analysis, and chi-square. The lobster catches consist of 4 species, namely Scalloped spiny lobster (Panulirus homarus), Ornate spiny lobster (P. ornatus), Painted spiny lobster (P. versicolor), and Mud spiny lobster (P. polyphagus). P. homarus is the most dominant species. The frequency distribution of carapace length and weight of P. homarus, P. ornatus, and P. versicolor has met the minimum size limits rules. The length and weight relationship of P. Homarus and P. ornatus were negative allometric, while P. versicolor isometric. Lobster sex ratio is in a balanced condition.

Captura de Langosta en Baja California y su relación con la Actividad Solar

Es creciente el interés por conocer los vínculos entre el comportamiento de la Actividad Solar (AS) y del Clima Espacial con numerosos procesos de la biosfera y en particular, los relacionados con la extracción de especies marinas. En este trabajo se relacionó la serie de tiempo anual (1959-2018) de captura de langosta por varias cooperativas pesqueras a lo largo de la Península de Baja California, México, con los ciclos multianuales de la AS, con el objetivo de revelar si se cumple la hipótesis de asociación entre estas variables. La relación estadística y análisis espectral entre las dos series muestran un marcado sincronismo entre las series de tiempo y la presencia en los volúmenes de captura del período principal de 11 años de la AS. Se explica la posible conexión AS-clima-océano con la variabilidad pesquera del crustáceo. Teniendo en cuenta los volúmenes de captura de langosta y la importancia económica que ello constituye para la región, se considera un aspecto importante para su posible aplicación práctica y explotación de este conocimiento en el marco de la tendencia en los ecosistemas debido a la variabilidad climática.
 Palabras claves: Clima Espacial, Clima, Producción Pesquera.

A model-based approach to standardizing American lobster (Homarus americanus) ventless trap abundance indices

Fishery-independent ventless trap surveys are an integral component to assessing American lobster (Homarus americanus) population trends, as they can sample complex, heavily fished habitats where most survey gear has difficulty accessing. U.S. American lobster stocks have been assessed within state waters using a standardized ventless trap survey since 2006. However, confounding survey attributes that may contribute to catch variability have not been investigated and some discontinuity in sampling has resulted in missing estimates of abundance. We constructed sex- and stock-specific generalized linear mixed models to discern the dynamics between lobster catch and individual survey factors and removed these sources of variability when producing continuous abundance indices. Soak time, day of year, and unique site had measurable contributions to the variability in lobster catch per ventless trap. Generally, sex- and stock-specific abundance indices from this model-based approach and a traditional design-based approach exhibited similar trends. The two approaches’ magnitudes and trends for the Gulf of Maine were nearly identical. For Southern New England, model-based index trends were smoother and lower in magnitude than the design-based estimates. The greatest difference in the two approaches’ trends for the Southern New England indices were in the early and terminal years. This work serves as an example of how variability associated with fixed and random effects of a survey can be accounted for when producing abundance indices used in stock assessments.

Evidence that spillover from Marine Protected Areas benefits the spiny lobster (Panulirus interruptus) fishery in southern California

Marine Protected Areas (MPAs) are designed to enhance biodiversity and ecosystem services. Some MPAs are also established to benefit fisheries through increased egg and larval production, or the spillover of mobile juveniles and adults. Whether spillover influences fishery landings depend on the population status and movement patterns of target species both inside and outside of MPAs, as well as the status of the fishery and behavior of the fleet. We tested whether an increase in the lobster population inside two newly established MPAs influenced local catch, fishing effort, and catch-per-unit-effort (CPUE) within the sustainable California spiny lobster fishery. We found greater build-up of lobsters within MPAs relative to unprotected areas, and greater increases in fishing effort and total lobster catch, but not CPUE, in fishing zones containing MPAs vs. those without MPAs. Our results show that a 35% reduction in fishing area resulting from MPA designation was compensated for by a 225% increase in total catch after 6-years, thus indicating at a local scale that the trade-off of fishing ground for no-fishing zones benefitted the fishery.