Multispecies spatial assessment models for the British Columbia groundfish trawl fishery

1999 ◽  
Vol 56 (4) ◽  
pp. 601-628 ◽  
Author(s):  
Carl J Walters ◽  
Ramón Bonfil
Keyword(s):  
British Columbia ◽  
Protected Areas ◽  
Gravity Model ◽  
Marine Protected Areas ◽  
Management Strategies ◽  
Fishing Effort ◽  
Catch Per Unit Effort ◽  
Trawl Fishery ◽  
Spatial Redistribution ◽  
Quota Management

A multispecies spatial model is proposed for evaluation of trawl management strategies and tested with data from British Columbia groundfish. Minimum stock sizes are estimated for 16 species using spatial catch per unit effort data; these data indicate that only small proportions of most stocks are exposed to fishing at any time and that exchange rates of fish between the grounds and other habitats are rapid. A gravity model for spatial effort allocation predicts substantial side effects of marine protected areas or discarding of particular species on nontarget species/grounds due to redistribution of fishing effort. Multispecies, multiground delay-difference models are used in conjunction with the gravity model for spatial effort distribution to predict long-term population responses to various regulatory strategies. This simulation suggests that species composition and spatial structure of the fishery are changing slowly due to reduction in abundance of long-lived species, but rapid collapses of target stocks are unlikely due to spatial redistribution of effort in response to local declines. We question whether quota management (individual vessel quotas) can be safely implemented due to extreme uncertainty about current stock sizes and suggest that a better strategy may be to simply denominate fishing rights as individual effort quotas while providing protection for sensitive stocks through carefully placed marine protected areas.

scholarly journals Lack of recreational fishing compliance may compromise effectiveness of Rockfish Conservation Areas in British Columbia

2018 ◽  
Author(s):  
Dana Haggarty ◽  
Steve J.D. Martell ◽  
Jonathan B. Shurin
Keyword(s):  
British Columbia ◽  
Protected Areas ◽  
Marine Protected Areas ◽  
Fishing Effort ◽  
Area Ratio ◽  
Recreational Fishing ◽  
Conservation Areas ◽  
Fish Stocks ◽  
Ecological Recovery ◽  
Recovery Education

Compliance with spatial fishing regulations (e.g., marine protected areas, fishing closures) is one of the most important, yet rarely measured, determinants of ecological recovery. We used aerial observations of recreational fishing events from creel surveys before, during, and after 77 Rockfish Conservation Areas (RCAs) were established in British Columbia, Canada. There was no evidence of a change in fishing effort in 83% of the RCAs, and effort in five RCAs increased after establishment. Fishing effort in open areas adjacent to the RCAs declined with time and was higher than effort in the RCAs in all 3 years. Next, we used compliance data for 105 RCAs around Vancouver Island to model the drivers of compliance. Compliance was related to the level of fishing effort around the RCA, the size and perimeter-to-area ratio of RCAs, proximity to fishing lodges, and the level of enforcement. Noncompliance in RCAs may be hampering their effectiveness and impeding rockfish recovery. Education and enforcement efforts to reduce fishing effort inside protected areas are critical to the recovery of depleted fish stocks.

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

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hunter S. Lenihan ◽  
Jordan P. Gallagher ◽  
Joseph R. Peters ◽  
Adrian C. Stier ◽  
Jennifer K. K. Hofmeister ◽  
...  
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Spiny Lobster ◽  
Fishing Effort ◽  
Fishing Ground ◽  
Catch Per Unit Effort ◽  
Panulirus Interruptus ◽  
The Status ◽  
Larval Production ◽  
And Behavior

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.

scholarly journals Lack of recreational fishing compliance may compromise effectiveness of Rockfish Conservation Areas in British Columbia

2016 ◽  
Vol 73 (10) ◽  
pp. 1587-1598 ◽  
Author(s):  
Dana R. Haggarty ◽  
Steve J.D. Martell ◽  
Jonathan B. Shurin
Keyword(s):  
British Columbia ◽  
Protected Areas ◽  
Marine Protected Areas ◽  
Fishing Effort ◽  
Area Ratio ◽  
Recreational Fishing ◽  
Conservation Areas ◽  
Fish Stocks ◽  
Ecological Recovery ◽  
Recovery Education

Compliance with spatial fishing regulations (e.g., marine protected areas, fishing closures) is one of the most important, yet rarely measured, determinants of ecological recovery. We used aerial observations of recreational fishing events from creel surveys before, during, and after 77 Rockfish Conservation Areas (RCAs) were established in British Columbia, Canada. There was no evidence of a change in fishing effort in 83% of the RCAs, and effort in five RCAs increased after establishment. Fishing effort in open areas adjacent to the RCAs declined with time and was higher than effort in the RCAs in all 3 years. Next, we used compliance data for 105 RCAs around Vancouver Island to model the drivers of compliance. Compliance was related to the level of fishing effort around the RCA, the size and perimeter-to-area ratio of RCAs, proximity to fishing lodges, and the level of enforcement. Noncompliance in RCAs may be hampering their effectiveness and impeding rockfish recovery. Education and enforcement efforts to reduce fishing effort inside protected areas are critical to the recovery of depleted fish stocks.

scholarly journals Effectiveness of a feedback management procedure based on controlling the size of marine protected areas through catch per unit effort

2008 ◽  
Vol 65 (7) ◽  
pp. 1216-1226 ◽  
Author(s):  
Mikihiko Kai ◽  
Kunio Shirakihara
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Fishing Effort ◽  
Alternative Procedure ◽  
Target Level ◽  
Catch Per Unit Effort ◽  
Short Term ◽  
Unit Effort ◽  
Management Procedure ◽  
Population Dynamics Model

Abstract Kai, M., and Shirakihara, K. 2008. Effectiveness of a feedback management procedure based on controlling the size of marine protected areas through catch per unit effort. – ICES Journal of Marine Science, 65: 1216–1226. The effectiveness of a feedback management procedure using marine protected areas (MPAs) was investigated. This procedure does not control fishing effort, but it does increase the size of the MPA when the catch per unit effort (cpue) is below a predetermined target level and reduces the size when the cpue is above this level. Stability analyses of the approach, which consisted of a population dynamics model and a model to control MPA size, suggest that this procedure can lead to recovery of a depleted population and sustain that population at a predetermined target level, even when there is hyperstability (a non-linear relationship between population size and cpue). An alternative procedure using fishing effort instead of MPA size may also function well, although both procedures may need a long time for a depleted population to approach the target level. Performance of both procedures was examined using numerical simulations focused on system dynamics in the short term after management implementation. The procedure using MPA size was more effective at preventing population collapse. Simulations suggest that if this procedure starts from a desirable level of initial MPA size, it has advantages over the alternative procedure through creating speedier population recovery and a higher level of short-term catch.

Oceanographic connectivity among marine protected areas on the north coast of British Columbia, Canada

2005 ◽  
Vol 62 (6) ◽  
pp. 1350-1362 ◽  
Author(s):  
Clifford LK Robinson ◽  
John Morrison ◽  
Michael GG Foreman
Keyword(s):  
British Columbia ◽  
Protected Areas ◽  
Marine Protected Areas ◽  
Particle Dispersion ◽  
Marine Conservation ◽  
Ocean Current ◽  
North Coast ◽  
Late Winter ◽  
Conservation Area ◽  
The North

The main objective of our study was to use a three-dimensional oceanographic simulation model to understand connectivity among the proposed Gwaii Haanas National Marine Conservation Area (GHNMCA) and 10 other proposed or existing marine protected areas (MPAs) on the north Pacific coast of Canada. The simulations were conducted using passive particles placed at three depths and vertically migrating particles for 30 or 90 days in late winter. Simulated surface particle dispersion was found to be consistent with winter ocean current observations made from analysis of satellite imagery, current mooring, and drifter data. The GHNMCA would contribute to a network of MPAs because it supplies and receives particles from other MPAs in northern British Columbia. Model simulations also indicate that the greatest source of particles to GHNMCA originate from 30-m and not 2-m flows. Finally, the simulated mean daily dispersal rate of 2.0 km·day–1 would allow fish and invertebrates to self-seed northern portions of the GHNMCA in winter. Together, the GHNMCA and other MPAs appear to contribute a large percentage of particles to non-MPA regions in northern Hecate Strait, which may be considered a particle sink in winter.

Heterogeneity in fishers' and managers' preferences towards management restrictions and benefits in Kenya

2012 ◽  
Vol 39 (4) ◽  
pp. 357-369 ◽  
Author(s):  
TIMOTHY R. MCCLANAHAN ◽  
CAROLINE A. ABUNGE ◽  
JOSHUA E. CINNER
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Management Strategies ◽  
National Level ◽  
Minimum Size ◽  
Management Tools ◽  
Management Actions ◽  
Key Stakeholders ◽  
Landing Sites ◽  
The Government

SUMMARYIncreasing the chances that resource users engage in and comply with management regulations is a continual problem for many conservation initiatives globally. This is particularly common when resource users perceive more personal costs than benefits from specific management actions. Analysis of interviews with managers and fishers from 22 landing sites along the coast of Kenya indicated how key stakeholders perceived the scale of benefits and costs from different management strategies. Potential underlying causes of divergent perceptions towards different management tools were evaluated, including marine protected areas, no-take fisheries closures, gear use, minimum size of fish caught and species restrictions. The analysis identified three distinct opinion groups: (1) a group of nine landing sites that scaled their preference for most management restrictions neutral to low, with exceptions for minimum sizes of captured fish and gear restrictions; (2) a group of eight landing sites that scaled their preference for the above and species restrictions and closed season higher, and were more neutral about closures and marine protected areas; and (3) a group containing four landing sites and the managers’ offices that rated their preference for the above and closed areas and marine protected areas as high. Logistic regression was used to examine whether these groups differed in wealth, education, age, perceptions of disparity in benefits, dependence on fishing and distance to government marine protected areas. The most frequent significant factor was the resource users’ perceived disparity between the benefits of the management to themselves and their communities, with the benefits to the government. Consequently, efforts to reduce this real or perceived disparity are likely to increase adoption and compliance rates. Most widespread positively-viewed restrictions, such as gear use and minimum size of fish, should be promoted at the national level while other restrictions may be more appropriately implemented at the community level.

Interactions of productivity, predation risk, and fishing effort in the efficacy of marine protected areas for the central Pacific

2005 ◽  
Vol 62 (6) ◽  
pp. 1320-1336 ◽  
Author(s):  
Steven J.D. Martell ◽  
Timothy E Essington ◽  
Bob Lessard ◽  
James F Kitchell ◽  
Carl J Walters ◽  
...  
Keyword(s):  
Protected Areas ◽  
Predation Risk ◽  
Ocean Circulation ◽  
Marine Protected Areas ◽  
Fishing Effort ◽  
Management Tool ◽  
Central Pacific ◽  
Positive Effects ◽  
Negative Effect ◽  
Catch Statistics

Ecospace biomass-dynamics models for the central North Pacific predict strong space-time variation in abundances of various trophic groups in relation to nutrient-driven patterns in primary production and circulation-driven concentration of production in convergence areas. The model predicts simple patterns in ecosystem organization and abundances along productivity gradients. Predicted patterns are robust to alternative assumptions about how mobile organisms may alter dispersal behavior in relation to local fitness (per capita gain from net food intake minus predation mortality). Large marine protected areas (MPAs) would be needed to rebuild endangered populations and counter impacts of growing fishing effort. We expected that increases in dispersal rate in response to lower food availability and higher predation risk would reduce efficacy of MPAs as a management tool. Instead, simulations indicated that this negative effect may generally be eliminated or even reversed by positive effects of fitness-maximizing behaviors. Interannual variability in ocean circulation can further reduce the efficacy of MPAs; therefore, the dynamic nature of pelagic environments should also be considered in MPA design. Anomalies in ocean circulation may shift productive areas relative to MPA location, resulting in increased fishing mortality and (or) misinterpretation of catch statistics.

scholarly journals Functionality and Effectiveness of Marine Protected Areas in Southeastern Brazilian Waters for Demersal Elasmobranchs

2021 ◽  
Vol 8 ◽  
Author(s):  
Thamíris C. Karlovic ◽  
Renata R. Gomes ◽  
Paulo C. Paiva ◽  
Elizabeth A. Babcock ◽  
June F. Dias
Keyword(s):  
Protected Areas ◽  
Functional Groups ◽  
Relative Abundance ◽  
Marine Protected Areas ◽  
Community Dynamics ◽  
Action Plan ◽  
Management Strategies ◽  
Species Conservation ◽  
Northern Coast ◽  
Anthropogenic Pressures

Ensuring the efficacy of Marine Protected Areas (MPAs) requires that adequate management strategies be implemented according to the MPA’s objectives. Within the scope of species conservation, achieving MPA objectives demands understanding of the role played by MPAs for the target species. In 2014, Brazilian stakeholders and experts set the action plan for elasmobranchs’ conservation, which intended to create new protected areas and expand the existing ones. Nevertheless, more than 65% of Brazilian elasmobranch species are threatened by anthropogenic pressures such as fisheries and habitat loss. In addition, their ecological aspects are not well studied, which might jeopardize the success of the proposed actions. To assess the functionality and effectiveness of two no-take MPAs for sixteen demersal species, the Wildlife Refuge of Alcatrazes (WRA) and the Tupinambás Ecological Station (TES), we evaluated the community structure, space-time variations in functional diversity and changes in fishery indicators. Community dynamics were driven by inshore intrusion and time persistent effects of a cold and nutrient-rich water mass, the South Atlantic Central Water, which increased the relative abundance of species, functional groups, and overall diversity. Spatially, the heterogeneity of benthic habitats, due to the action of stronger waves in specific parts of the MPAs, reflects a diverse community of benthic invertebrates, explaining differences in relative abundance and similarities in space use by the functional groups. Regarding effectiveness, the MPAs make up a key network with the surrounding protection areas to support the ecosystem maintenance on the central and northern coast of the São Paulo state. The establishment of the TES has positively influenced the community throughout the years while the recent creation of the WRA may have promoted some improvements in fisheries indicators for a threatened guitarfish. We propose different functions of the Alcatrazes archipelago for each species and suggest some measures to enhance not only elasmobranch conservation but also the MPAs’ effectiveness.

scholarly journals Causes of Mortality for Endangered Antillean Manatees in Cuba

2021 ◽  
Vol 8 ◽  
Author(s):  
Anmari Alvarez-Alemán ◽  
Eddy García Alfonso ◽  
James A. Powell ◽  
Charles A. Jacoby ◽  
James D. Austin ◽  
...  
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Fishing Effort ◽  
Commercial Fishing ◽  
Fishing Gear ◽  
Illegal Hunting ◽  
Lack Of Information ◽  
Causes Of Mortality ◽  
Antillean Manatees ◽  
Causes Of Deaths

The Antillean manatee is categorized as endangered by the International Union for the Conservation of Nature primarily due to its low abundance. Further declines in abundance are expected due to a group of human related threats that include illegal hunting, fatal interactions with fishing gear, increasing watercraft traffic, and pollution. The nature of current threats is not well described for every critical population of manatees. In particular, threats to manatees have not been documented or evaluated in a systematic manner in coastal waters surrounding Cuba, which is a major reason why plans specifically addressing conservation of manatees in Cuba have not been implemented. To address this lack of information, we assessed patterns in various threats by reviewing reports of stranded (alive or dead) and captured manatees, with some reports being historical and others consistently available since 2001. For 94% of the contemporary cases, carcasses of dead animals were reported; the remainder (6%) involved live manatees and subsequent efforts to rescue and rehabilitate them. Documented causes of mortality included poaching (38%), entanglement in fishing gear (10%), deaths of dependent calves (2.5%), and boat collisions (2.5%). The cause of death for the remaining 47% of reports could not be determined. Mortalities were highest in areas with intensive commercial fishing effort, and mortalities in marine protected areas indicated a need for improved management. These initial findings provide the first estimates of the magnitude of mortality of manatees in Cuba and yield valuable insights into the causes of deaths. The existence of intense and poorly regulated fishing in certain areas, including protected areas, represents a potentially significant threat to manatees. The effects and management of this activity, especially in habitats that are critical for manatees, merit further attention.

scholarly journals MARINE CAPTURE FISHERIES POLICY FORMULATION AND THE ROLE OF MARINE PROTECTED AREAS AS TOOL FOR FISHERIES MANAGEMENT IN INDONESIA

2018 ◽  
Vol 30 ◽  
pp. 33-45
Author(s):  
D. G.R. Wiadnya ◽  
P. J. Mous ◽  
R. Djohani ◽  
M. V. Erdmann ◽  
A. Halim ◽  
...  
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Scientific Evidence ◽  
Code Of Conduct ◽  
Fishing Effort ◽  
Policy Formulation ◽  
Maximum Sustainable Yield ◽  
Fish Stocks ◽  
Fisheries Policy

The FAO Code of Conduct for Responsible Fisheries states that conservation and management decisions for fisheries should be based on the best scientific evidence available. Studies show that most of Indonesia's capture fisheries are either full or over-exploited. However, the fishery sector is still expected to contribute to the increase of Indonesia's GNP through an increase in total catches. Furthermore, the current practice of using catch-effort data and Maximum Sustainable Yield models to inform Indonesia’s fisheries policies is flawed, putting sustainability and long-term profitability of Indonesia's fisheries at risk. In this paper, the authors argue that to ensure the survival of Indonesia's fish stocks and fisheries: fisheries policy must shift from development-oriented management towards management for sustainability. Furthermore, fisheries managers must accept that 'untapped resources' may not exist or cannot be exploited profitably, and that any transfer of fishing effort between fishing grounds may contribute to collapse of local fisheries. Also, fisheries managers should change the management paradigm from MSY models to eco-system based management, wherein Marine Protected Areas should play an important role.

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