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

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alessandro Cau ◽  
Andrea Bellodi ◽  
Rita Cannas ◽  
Maurizio Fois ◽  
Paolo Guidetti ◽  
...  

Abstract 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.

2011 ◽  
Vol 21 (6) ◽  
pp. 564-572 ◽  
Author(s):  
Maria Cristina Follesa ◽  
Rita Cannas ◽  
Alessandro Cau ◽  
Danila Cuccu ◽  
Alice Gastoni ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hunter S. Lenihan ◽  
Jordan P. Gallagher ◽  
Joseph R. Peters ◽  
Adrian C. Stier ◽  
Jennifer K. K. Hofmeister ◽  
...  

AbstractMarine 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.


2014 ◽  
Vol 72 (suppl_1) ◽  
pp. i232-i243 ◽  
Author(s):  
Elizabeth A. Babcock ◽  
William J. Harford ◽  
Robin Coleman ◽  
Janet Gibson ◽  
Julio Maaz ◽  
...  

Abstract In Belize, beginning in 2011 at Glover's Reef Marine Reserve, and in 2012 at Port Honduras Marine Reserve, fishers have been required to keep logbooks to document their catch and effort. A Bayesian depletion model including in-season recruitment was applied to the standardized catch per unit effort (cpue) of Caribbean spiny lobster (Panulirus argus) from the logbooks to estimate the abundance and fishing mortality of lobsters at both sites. Two alternative subsets of the cpue data were used to account for changes in targeting caused by the opening and closing of the queen conch (Strombus gigas) season. At Glover's Reef, a typical model estimated abundance ∼66–79 000 lobsters. Of these, ∼60–85% were present at the beginning of the season and the rest recruited into the fished population later in the season. The depletion model applied to data from the 2012 season at Port Honduras found an abundance of ∼12 000 lobsters, and in-season recruitment was not supported by the data. That in-season recruitment was present at Glover's Reef and not at Port Honduras may be explained by the fact that Glover's Reef has more unfished areas that could serve as a source of adult lobsters during the season. Glover's Reef has a larger no-take zone (20% of the reserve area, compared with 5% at Port Honduras), and it is surrounded by a deep wall reef where lobsters are found below the depth accessible to fishers. The models estimated a harvest fraction of ∼70% in both reserves.


2012 ◽  
Vol 39 (3) ◽  
pp. 295-304 ◽  
Author(s):  
DEBBIE J. FREEMAN ◽  
ALISON B. MACDIARMID ◽  
RICHARD B. TAYLOR ◽  
ROBERT J. DAVIDSON ◽  
ROGER V. GRACE ◽  
...  

SUMMARYMonitoring species’ response in marine protected areas is important for informing both the management of those areas and the establishment of additional protected areas. Populations of spiny lobsters Jasus edwardsii were monitored in eight New Zealand marine reserves for up to 34 years. The populations displayed highly variable responses to protection. While a few showed rapid (within 1–2 years of protection) increases in abundance, others showed little response even after a decade of protection. Some reserves displayed little initial recovery, then a sudden increase following several years of protection, while others displayed significant declines in abundance following initial recovery. Marine reserves located in areas with initially high densities of juveniles tended to have rapid recovery, but aspects of reserve design had no significant influence on the recovery rate. Variability among recovery trajectories also suggests that supply-side dynamics may be a key driver of lobster recovery. Densities of legal-sized lobsters were positively correlated with reserve age, but the abundance of juvenile lobsters increased in all but one reserve, indicating enhanced recruitment, survival and/or movement of juvenile lobsters into reserves. It is important to consider the placement of reserves, with respect to potential levels of larval supply, when establishing marine reserves for either conservation or fisheries management purposes and for evaluating their effectiveness.


2002 ◽  
Vol 29 (4) ◽  
pp. 484-492 ◽  
Author(s):  
Mark Tupper ◽  
Murray A. Rudd

Marine reserves are widely considered to potentially benefit reef fisheries through emigration, yet the empirical basis for predicting the extent of this for small reserves is weak. The effects of fishing pressure and habitat on biomass and catch per unit effort (CPUE) of three species of exploited reef fish were studied at South Caicos, Turks and Caicos Islands. Distribution and abundance of hogfish (Lachnolaimus maximus) and white margate (Haemulon album) were inversely correlated with cover of fleshy macroalgae. Nassau grouper (Epinephelus striatus) were positively associated with vertical relief, but were unaffected by algal cover. Mean size, density, and biomass of hogfish were higher in a small (4 km2) marine reserve than on fished reefs, as was biomass of white margate. CPUE of hogfish was inversely related to distance from the centre of the reserve, suggesting that spillover of this species from the reserve to adjacent reefs may enhance local yields, possibly providing economic incentives for fishers to comply with reserve regulations. Fishing pressure, however, had no apparent effect on Nassau grouper. Larger fishes and those that migrate to spawn, such as economically valuable Nassau grouper, may move over too large a range to be effectively protected by small marine reserves. Small reserves may not protect all fish, but they can increase the biomass of smaller or more sedentary reef fishes and may be a useful tool for the conservation or management of species such as hogfish. Other policy options, such as seasonal spawning closures or total allowable catches, need to be considered for larger, more mobile fishes in the Turks and Caicos Islands.


2020 ◽  
Vol 655 ◽  
pp. 139-155
Author(s):  
DC Yates ◽  
SI Lonhart ◽  
SL Hamilton

Marine reserves are often designed to increase density, biomass, size structure, and biodiversity by prohibiting extractive activities. However, the recovery of predators following the establishment of marine reserves and the consequent cessation of fishing may have indirect negative effects on prey populations by increasing prey mortality. We coupled field surveys with empirical predation assays (i.e. tethering experiments) inside and outside of 3 no-take marine reserves in kelp forests along the central California coast to quantify the strength of interactions between predatory fishes and their crustacean prey. Results indicated elevated densities and biomass of invertebrate predators inside marine reserves compared to nearby fished sites, but no significant differences in prey densities. The increased abundance of predators inside marine reserves translated to a significant increase in mortality of 2 species of decapod crustaceans, the dock shrimp Pandalus danae and the cryptic kelp crab Pugettia richii, in tethering experiments. Shrimp mortality rates were 4.6 times greater, while crab mortality rates were 7 times greater inside reserves. For both prey species, the time to 50% mortality was negatively associated with the density and biomass of invertebrate predators (i.e. higher mortality rates where predators were more abundant). Video analyses indicated that macro-invertivore fishes arrived 2 times faster to tethering arrays at sites inside marine reserves and began attacking tethered prey more rapidly. The results indicate that marine reserves can have direct and indirect effects on predators and their prey, respectively, and highlight the importance of considering species interactions in making management decisions.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7278 ◽  
Author(s):  
Juan Carlos Murillo-Posada ◽  
Silvia Salas ◽  
Iván Velázquez-Abunader

Management of low-mobility or benthic fisheries is a difficult task because variation in the spatial distribution and population dynamics of the resources make the monitoring and assessment of these fisheries challenging. We assumed that environmental, spatial, and temporal factors can contribute to the variability of the relative abundance of such species; we used Generalized Additive Models for Location Scale and Shape (GAMLSS) to test this hypothesis using as a case study the lobster fishery (targeting two species) in the Galapagos Marine Reserve, Ecuador. We gathered data on each of the two species of lobster on a monthly basis over seven years, including: (a) onboard observers’ records of catch data, fishing effort, and ground location by trip, and (b) data from interviews undertaken with fishers at their arrival to port, recording the same type of information as obtained from onboard observers. We use this information to analyze the effect of the measured variables and to standardize the Catch per Unit Effort (CPUE) in each case, using the GAMLSS. For both species, the temperature, region, fishing schedule, month, distance, and the monitoring system were significant variables of the selected models associated with the variability of the catch rate. ForPanulirus penicillatus, CPUE was higher at night than during the day, and forPanulirus gracilisit was higher during the day. Increased temperature resulted in a decrease of CPUE values. It was evident that temporal, spatial scales and monitoring system can influence the variability of this indicator. We contend that the identification of drivers of change of relative abundance in low-mobility species can help to support the development of monitoring and assessment programs for this type of fisheries.


Oryx ◽  
2010 ◽  
Vol 44 (2) ◽  
pp. 213-218 ◽  
Author(s):  
Martin Dallimer ◽  
Martim Melo

AbstractTerrestrial and freshwater molluscs are amongst the most threatened of all taxa, yet data exist on the distribution and status of only a small proportion of the species. Here we present the results of the first systematic survey of a terrestrial mollusc on the island of Príncipe in the Gulf of Guinea. Archachatina bicarinata has never been previously surveyed, despite being categorized as Vulnerable on the IUCN Red List and suffering from unregulated harvesting for food. We found that A. bicarinata is restricted to primary rainforest and its abundance and probability of occurrence increased as surveyed sites became less accessible. Additional anecdotal evidence from the observations of previous scientific expeditions, local guides and snail harvesters suggested that the species has suffered a dramatic decline in population size and distribution in recent years. We therefore recommend that immediate action be taken to prevent its imminent extinction on Príncipe. The collection of A. bicarinata from protected areas should be banned, as should commercial harvesting and sales. Subsistence collecting should be limited to larger individuals. Our data have been used to inform the management plans for the protected areas on Príncipe and São Tomé, and this should help to ensure the future of A. bicarinata on both islands.


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