Problems and Perspectives Regarding Recruitment of Spiny Lobsters, Panulirus argus, to the South Florida Fishery

1986 ◽  
Vol 43 (11) ◽  
pp. 2099-2106 ◽  
Author(s):  
William G. Lyons

Inappropriate minimum size, illegal harvest, fishery-induced juvenile growth retardation and mortality, and excessive effort have reduced reproductive contributions and depressed yield-per-recruit in the overcapitalized south Florida spiny lobster (Panulirus argus) fishery. Measures recommended to improve yield-per-recruit are as follows: increase minimum legal size to 85–90 mm carapace length; require escape gaps in traps; eliminate possession of sublegal lobsters aboard vessels; prohibit harvest in nurseries; reduce fishing effort; improve enforcement of fishery regulations; and initiate programs to educate fishermen regarding impacts of fishery practices. International management is recommended to assure larval recruitment among Pan-Caribbean stocks.

1986 ◽  
Vol 43 (11) ◽  
pp. 2221-2227 ◽  
Author(s):  
J. M. Marx

Settlement of spiny lobster, Panulirus argus, pueruli occurs year-round in south Florida, but seasonal trends are not consistent. Recruitment peaks are common in spring but sometimes occur in other seasons. Postsettlement dynamics of seasonal settlement classes must be determined to establish a relationship between puerulus abundance and subsequent fishery yield. Pueruli settle in various shallow-water habitats, including masses of the red alga Laurencia, algal-covered mangrove roots, and colonies of the bryozoan, Bugula. Settlement habitats of 0.04–2 ha can produce 1906–3913 juveniles (20 mm carapace length) annually. Management must protect these critical habitats to assure productivity of the spiny lobster fishery.


Crustaceana ◽  
1996 ◽  
Vol 69 (8) ◽  
pp. 958-973 ◽  
Author(s):  
Enrique Lozano-Alvarez

AbstractThe spiny lobster catch from Bahia de la Ascensión, a large bay on the central coast of the Mexican Caribbean, is composed mainly of young adults and large juveniles of Panulirus argus. The fishery in this bay is based on artificial shelters called "casitas". A substantial part of the lobsters found beneath the casitas is of sublegal size (minimum size limit ~ 74 mm carapace length, CL). The possibility of ongrowing sublegal juveniles in portable sea enclosures to maximize the harvestable biomass was explored. The enclosures (3 x 3 x 1 m) were installed in shallow depths in the bay. Juveniles taken from nearby casitas were introduced in the enclosures and kept for different periods. Lobsters were fed with live molluscs and fish remains and were provided with suitable shelters. Experiments were conducted in two stages, in 1992 and 1993. Growth in size (CL) and in harvestable biomass (weight of legal-size lobsters) was examined. Maximum growth rates, lower percentages of mortality, and higher increases in harvestable biomass of lobsters were obtained after about 45 days. Confinement periods longer than 45 days resulted in reduced growth and higher mortality. Observations on lobster behaviour showed an increase in aggressive encounters and dominance displays from the third week of captivity onwards, which could be the main cause for the increase in mortality. The alternative of ongrowing sublegal juveniles for short periods (45 days), in conjuction with the casita system, could help increase the unit value of the catch.


2001 ◽  
Vol 52 (8) ◽  
pp. 1559 ◽  
Author(s):  
Rodney D. Bertelsen ◽  
Thomas R. Matthews

Using diver surveys, we compared the size structure, fecundity, and reproductive season of spiny lobsters (Panulirus argus) in the Dry Tortugas National Park lobster sanctuary with those of spiny lobsters in the south Florida fishery. The number of lobsters of both sexes larger than the legal size limit declined sharply in the fishery but not in the sanctuary. Clutch sizes were larger in the Dry Tortugas sanctuary, averaging 0.8 million, than in the fishery, averaging 0.3 million. The reproductive season was shorter and more intense in the sanctuary than in the fishery. In addition, lobsters in the sanctuary begin producing eggs at a larger size and produce more eggs per gram of body mass than lobsters in the fishery. Peak egg production occurs earlier in larger lobsters than in small ones. Establishing a fundamental reason for the differences between lobster reproduction in the sanctuary and that in the fishery is not possible until the chronological age of lobsters can be determined, but one hypothesis consistent with these differences is that, if lobsters reproduce at a certain chronological age, then sublethal fishery practices may account for slower growth for some lobsters resulting in some smaller but older reproductively active lobsters.


1986 ◽  
Vol 43 (11) ◽  
pp. 2228-2234 ◽  
Author(s):  
Douglas R. Gregory Jr. ◽  
Ronald F. Labisky

Long-distance movements of the spiny lobster Panulirus argus were studied in two Gulf of Mexico habitats (Shallows, Mid-depth) and three Atlantic Ocean habitats (Shallows, Patch Reef, and Deep Reef) in the lower Florida Keys during the mid-1970's. Of 6062 spiny lobsters tagged and released at the five sites between June 1975 and August 1976, 465 of the 771 (13%) lobsters recovered yielded usable movement data. Eighty percent of the tags were recovered within the first 3 mo of the 8 mo commercial fishing season (July 26 – March 31). Directions and rates of movements differed significantly (P < 0.05) among sites. Movements from Gulf sites were generally oriented to the west and southwest, toward the Atlantic offshore reefs, at mean displacement velocities of 0.57 km/d (Mid-depth) and 0.24 km/d (Shallows). Movements of lobsters from the Atlantic sites were principally eastward and westward, parallel to the reef line and island chain, at mean displacement velocities of 0.02 km/d (Deep Reef) and 0.05 km/d (Shallows, Patch Reef). The more directed movements of spiny lobsters from Gulf sites may reflect a migration from nursery grounds to the Atlantic reefs, which not only constitute the primary spawning habitat but also exhibit a more stable winter environment than the shallow Gulf. Movements of spiny lobsters within Atlantic waters reflect localized random onshore–offshore dispersal patterns typical within reef environments.


2012 ◽  
Vol 3 ◽  
pp. 131
Author(s):  
Romina Alzugaray Martínez ◽  
Rafael Puga Millán

La langosta común, Panulirus argus, es una de las especies con mayor valor comercial en el Atlántico Centro Occidental. En Cuba se han realizado numerosos estudios para conocer y actualizar su estado de explotación y recomendar medidas de manejo. A pesar de estas medidas, las capturas continúan disminuyendo, por lo que el objetivo del presente estudio consistió en evaluar la dinámica de la población de langosta en la región suroriental de Cuba, a través de dos estrategias analíticas diferentes. A partir de datos de captura y esfuerzo pesquero de 1979-2010, se aplicaron un análisis de población virtual (VPA) y un análisis estadístico de captura por edades (SCA). Se examinó la relación lineal entre los datos primarios y las variables estimadas por los modelos. El ajuste de los modelos lineales de los datos se evaluó mediante el Criterio de Información de Akaike corregido (AICc). Según ambos métodos de captura por edades, el tamaño poblacional y el reclutamiento de langostas con un año de edad han disminuido en la región en el período estudiado, aunque el SCA muestra estabilización en la última década. Mientras, la biomasa poblacional disminuyó hasta estabilizarse en la última década, lo cual puede relacionarse con el comportamiento histórico de la captura por unidad de esfuerzo. Existen asociaciones lineales significativas entre los datos primarios y las variables estimadas. Según los valores de Δi, el modelo VPA garantiza el mejor ajuste de las variables a las relaciones lineales estimadas. Abstract Spiny lobster, Panulirus argus, is one of the most commercially valuable species in the Western Central Atlantic. Although numerous studies have been conducted in Cuba to learn and update its exploitation status and to recommend management measures, catches continue to decline. Consequently, the objective of this study was to evaluate the dynamics of the lobster population in Cuba’s southeastern region, through two different analytical strategies. Using catch and fishing effort data from 1979-2010, a Virtual Population Analysis (VPA) and a Statistical Catch-at-age Analysis (SCA) were applied. We examined the linear relationship between raw data and the variables estimated by the models. The fit of the linear models to data was assessed using the corrected Akaike Information Criterion (AICc). According to both age-structured methods, population size and recruitment of one year old lobster have declined in the region during the study period, although the SCA shows stabilization in the last decade. Population biomass decreased to stabilize in the last decade, this may relate to the historical behavior of the catch per unit effort. There are significant linear associations between raw data and estimated variables. According to Δi values, the VPA model ensures the best fit for the variables of estimated linear relationships.


Crustaceana ◽  
2016 ◽  
Vol 89 (9) ◽  
pp. 1057-1081 ◽  
Author(s):  
Juan C. Jaimes ◽  
Carlos A. Trujillo ◽  
Raúl Cruz ◽  
Carlos E. P. Teixeira ◽  
María O. B. Menezes

This study examines the settlement patterns of the Caribbean lobsterPanulirus argus(Latreille, 1804) on the continental shelf of Caribbean Colombia during a period of 16 months (December 2002-March 2004). Field studies of the puerulus settlement were performed using 20 submerged collectors between 10 and 11 m depth, at three locations (Taganga Bay, Pelícano Island and Pozos Colorados Bay) and five stations. Our goal was to collect information comparable among stations, to analyse the spatio-temporal variability of puerulus settlement, and to verify possible associations with the discharge of the Orinoco River and the regional oceanic circulation. The peak time of larval recruitment occurred in March and April, in July the influx of settlement was minimal, and a second peak occurred between August and November. We propose a hypothesis that the Panama-Colombia gyre (quasi-permanent) located in the southern Colombia Basin, could provide the mechanism that ensures self-recruitment of the stock in this region.


2012 ◽  
Vol 63 (5) ◽  
pp. 387
Author(s):  
Ashley J. Frisch ◽  
Jean-Paul A. Hobbs

Quantification of demographic parameters is important for understanding how populations interact with their environment and for developing sustainable harvest strategies. Our aims were to quantify demographic parameters and yield of painted spiny lobster (Panulirus versicolor) at Northwest Island, Great Barrier Reef and review fishery management regulations in view of the findings. Using catch-curve analysis and an intensive mark–recapture program, the local lobster population was found to be sparsely distributed (~1.3 ha–1), with low rates of natural mortality (0.25–0.28 year–1) and immigration (0.05 ha–1 year–1). Under current management regulations (no minimum size limit; MSL), yield-per-recruit peaked at 0.38 kg when fishing mortality was 0.4 year–1. Implementation of a 100-mm (carapace length) MSL is recommended because it provides the best compromise between yield and stock size and has minimal impact on existing fishing practices. Revocation of the prohibition on possessing egg-bearing females is also recommended because it would reduce wastage of lobsters that are inadvertently killed by spear-fishers and because there appears to be little chance of localised recruitment overfishing. This study provides the first estimate of mortality rate for P. versicolor and highlights the importance of this parameter for understanding demographic processes and optimising management regulations.


1986 ◽  
Vol 43 (11) ◽  
pp. 2353-2359 ◽  
Author(s):  
R. C. A. Bannister ◽  
J. T. Addison

Stock assessment of the European lobster (Homarus gammarus) has involved yield per recruit analysis based on the established length cohort methodology of Jones (1974. ICES C.M. 1974/F:33; 1981. FAO Fish. Circ. 734) which assumes that recruitment to the fishery is independent of spawning stock. The Shepherd (1982. J. Cons. Int. Explor. Mer 40: 67–75) model has been used to simulate a range of assumed stock–recruitment relationships, and the resulting sensitivity analysis describes how these affect the relation between yield or biomass and four management variables, namely fishing mortality, minimum carapace length, maximum carapace length, and the capture or noncapture of egg-bearing females. Yield curves show a clear maximum with a marked tendency to stock collapse when fishing effort is high. For the range of simulations considered, the probability of an early recruit failure is greatest for asymptotic stock–recruitment curves, which generate yield curves with maxima at an effort substantially lower than the present level. Only with a highly overcompensatory stock–recruitment curve is there a case for increasing effort to maximise yield, but such a relationship tends to reduce the benefit of increasing minimum carapace length or of setting a maximum carapace length. The model predicts that the assumption made about the stock–recruitment relationship also has a marked effect on the results expected from a ban on the landing of egg-bearing females. Overall the results confirm the unsatisfactory prognosis of the yield per recruit model and emphasise the need to gain an understanding of the biological factors determining the shape of the lobster stock–recruitment curve.


2001 ◽  
Vol 52 (8) ◽  
pp. 1623 ◽  
Author(s):  
K. L. Cochrane ◽  
K. L. Cochrane ◽  
B. Chakalall ◽  
B. Chakalall

The Caribbean spiny lobster Panulirus argus is widely distributed in the western central Atlantic and supports important fisheries in many of the countries within this area. Total reported landings have been between 27000 and 30000 tonnes per annum over the last decade. However, recent assessments undertaken under the auspices of the Western Central Atlantic Fisheries Commission (WECAFC) have indicated that the resource is being fully or over-exploited over much of its range. The results also revealed widespread deficiencies in the data available, which create problems in undertaking reliable assessments and in the subsequent provision of management advice. The studies, undertaken with full regional participation, suggested that in most countries the need is urgent to control and frequently to reduce fishing effort for the species and that in some countries both spawner biomass and potential yield would benefit from increases in the minimum size of the lobsters caught. This paper describes the fisheries for Caribbean spiny lobster, including their socio-economic importance in the region. It provides an over-view of the results of the 1997 and 1998 WECAFC workshops on the species and of the implications of those results for management for sustainable use. Finally, the need for regional, or, at least, subregional, management of the fisheries is discussed, with reference to the conclusions of the WECAFC 2000 workshop.


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