Equivalence in yield from marine reserves and traditional fisheries management

Chapter 19 - Yet Another Review of Marine Reserves as Reef Fishery Management Tools

Many traditions of coastal peoples may be viewed as traditional forms of marine conservation because, like modern fisheries management, they restrict fishing gear, fishing times, and places, but their effects are little studied in practice. A study was undertaken of human culture and fisheries resources in an area of southern Kenya, designated as a national marine reserve, to determine the effect of the existing 'traditional management' on fisheries yields and on the ecological condition of the fished reefs. This area has one of the oldest and most elaborate cultural traditions concerning sacred sites and rituals of sacrifice along the Kenyan coast. The purpose of the customs is, however, to appease spirits rather than to regulate fish stocks which are traditionally seen to fluctuate independently of fishing effort. Many of these traditions have decayed in recent times as Islamization of the culture has occurred, and authority has shifted towards national organizations, weakening the effectiveness of the traditional leaders. Coincidentally, fishers have adopted new or foreign gear, colleagues, and traditions. Two adjacent landing sites (Mvuleni and Mwanyaza) have, however, successfully stopped pull seiners from landing their catch at their sites for over 20 years through passive means. Other landing sites have adopted pull seining. Both landing areas use arguments based on tradition to justify their use of gear. The two landings that restrict pull seining have higher per capita fish catches than those that do not. Nonetheless, there were no obvious differences in the ecological condition of the reefs at these two management areas; both areas were amongst the most degraded reefs reported in East Africa. Biological diversity and coral cover were reduced greatly in all these areas compared to other fished or fully-protected marine park or reserve sites established by the national government. Presently, traditional management is not effective in protecting species diversity or ecological functions, which was probably never the intention of the customs. The conflict between national organizations and local fishers arises because some resource users are concerned that the management proposed by the national organizations will eventually lead to the total loss of access to, and control of the resource by local fishers. There is, therefore, a need to resolve conflicts concerning gear use and regulation, and a need to increase awareness of the expectations and management programmes among the national and local organizations. Many of the traditional forms of management are compatible with the policies of national organizations, but confusion and conflict occur concerning enforcement and its benefits. To solve these conflicts discussions are required between traditional and national fisheries leaders to develop mutually-acceptable policies that augment and share the power of management.

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 309:11-24 (2006) - doi:10.3354/meps309011 Alongshore advection and marine reserves: consequences for modeling and management David M. Kaplan* Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, California 95616, USA *Email: dmkaplan@ucdavis.edu ABSTRACT: The appropriate configuration of marine reserves for maximizing harvests or ensuring species persistence when there is uncertainty or variability in larval dispersal patterns is not completely understood. This is particularly true in environments with large alongshore advection rates, as the success of a system of marine reserves depends on connectivity through larval and/or adult dispersal between adjacent marine reserves. In this paper, the consequences of alongshore advection in the presence of marine reserves for a fish species with sedentary adults and widely dispersing larvae are examined. First, a uniform configuration of reserves with constant alongshore advection rate is considered. The highest overall catch and recruitment rates occur when the spacing between reserves is precisely tuned to the advection distance. When the alongshore advection distance is allowed to vary in time, catch and recruitment are considerably less sensitive to alongshore advection. At small diffusion distances, catch values differ from what would be predicted from the time-averaged larval dispersal pattern due to density-dependent post-settlement effects. It is important to include short time scale settlement variability in marine reserve models under these conditions. When the spacing between reserves is allowed to vary, the tuning of the system to particular advection distances is less precise. Configurations of marine reserves with a variety of spacings between reserves exhibited more uniform catch levels as a function of advection distance. This suggests that variability in the spacing between reserves is desirable for protecting a diverse group of species with different dispersal patterns. KEY WORDS: Marine protected areas · Fisheries management · Population dynamics · Variable reserve-spacing · Advection variability Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 309. Online publication date: March 15, 2006 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2006 Inter-Research.

Marine protected areas (MPAs) are portions of the marine environment which are protected from some or all human activity. Where extraction of living resources is forbidden, these MPAs are best referred to as marine reserves. Often these are proposed as a safeguard against collapse of fish stocks, although reserves may have numerous other beneficial purposes. However, as a tool for fisheries management, where optimal and/or maximum sustainable yield is the objective, I submit that reserves are generally not as effective as traditional management measures, and are not appropriate for the vast majority of marine species. This is because most marine species are far too mobile to remain within a reserve and/or are not overfished. However, in the United States, of those marine fishes that are experiencing overfishing or are overfished, most have come under management within the last decade, employing more traditional fishery management measures, and are experiencing recovery. For those few species whic...

Spillover of adult fish biomass is an expected benefit from no-take marine reserves to adjacent fisheries. Here, we show fisher-naïve behaviour in reef fishes also spills over from marine reserves, potentially increasing access to fishery benefits by making fishes more susceptible to spearguns. The distance at which two targeted families of fishes began to flee a potential fisher [flight initiation distance (FID)] was lower inside reserves than in fished areas, and this reduction extended outside reserve boundaries. Reduced FID persisted further outside reserves than increases in fish biomass. This finding could help increase stakeholder support for marine reserves and improve current models of spillover by informing estimates for spatial changes in catchability. Behavioural changes of fish could help explain differences between underwater visual census and catch data in quantifying the spatial extent of spillover from marine reserves, and should be considered in the management of adjacent fisheries.

Sustaining fishery resources is crucial to the survival and wealth of artisanal fishers in Ghana. The artisanal fisheries sector ofGhana provides food, employment, livelihood support and socio-economic benefits to the Ghanaian economy. Fishery resourcesof Ghana are under stress from population pressure, increasing demand of fish and fishery products and open-access regime.Formal fisheries management practices have not yielded the desired results. There is an increasing need for traditional fisheriespractices to be incorporated into formal fisheries management practices. The aim of this paper is to conduct an in-depth studyon traditional marine fisheries management systems in Ghana in order to provide information to enhance the management of theartisanal fisheries.Data was collected through document analysis (between May 2014 and January 2015), field observation andquestionnaire-based interview (between 26th and 30th of July 2014). Results show that the Chief Fisherman and CommunityBased Fisheries Management Committee are important structures in the fisheries management system of Ghana. The ChiefFisherman is the person that leads resolution of disputes and gives access to fishing in the communities. There are a number ofmeasures such as non-fishing days, ban on landing certain fish species during festival periods to prevent overfishing. Taboos andcultural practices such as performing of rituals to ‘sea gods’ and consulting of oracles during certain periods of the year help tomanage the fish stocks. With respect to the performance of the fishing communities, Elmina performed better with combinationof various traditional practices to prevent overfishing. Fishers in Elmina also had adequate knowledge of current fishing rulesand regulations than fishers in Adina, Chorkor and Dixcove. Fishers and fishing communities must be educated on the need toavoid unapproved fishing practices to help keep the fishery resources healthy for sustainable exploitation. Fishers should also beequipped with alternative livelihood jobs in order to reduce the pressure on the fishery resources. A national policy to integratetraditional management practices into formal fisheries management plans should be established.

Quantitative assessments of the capacity of marine reserves to restore historical fish body-size distributions require extensive repeated sampling to map the phenotypic responses of target populations to protection. However, the “no take” status of marine reserves oftentimes precludes repeated sampling within their borders and, as a result, our current understanding of the capacity of marine reserves to restore historical body-size distributions remains almost entirely reliant on independent, static visual surveys. To overcome this challenge, we promote the application of a traditional fisheries tool known as a “back-calculation”, which allows for the estimation of fish body lengths from otolith annuli distances. This practical application was pursued in this study, using data collected in five marine reserves and adjacent fished reefs in the Philippines, to investigate spatiotemporal disparities in length-at-age of the brown surgeonfish, Acanthurus nigrofuscus. The spatial component of our analyses revealed that 1) A. nigrofuscus were phenotypically similar between marine reserves and fished reefs during their early life history; 2) marine reserve and fished reef populations diverged into significantly different length-at-age morphs between ages three and six, in which protected fish were predominantly larger than conspecifics in fished reefs; and 3) A. nigrofuscus returned to a state of general phenotypic similarity during later life. The temporal component of our analyses revealed that younger generations of A. nigrofuscus exhibited significant, positive year effects that were maintained until age eight, indicating that, within the significant age cohorts, younger generations were significantly larger than older generations.

Although debates exist, marine reserves play an important role in fisheries management. Based on stable equilibrium state, theoretical frameworks of various systems suggest that fisheries management with the implementation of marine reserves has obvious advantage in achieving multiple goals such as improving the target fisheries yields as well as maintaining species persistence in comparison with strategy of traditional fishing effort control. More recently, ecologists pay attention to the transient dynamics of fisheries yields when marine reserves are established. Simulation results suggest that the relative advantages between different fisheries management strategies (the implementation of marine reserves vs. traditional fishing effort control) depend on not only life histories but also the measurement metrics of fisheries yields (measured by number vs. measured by weight). Further research on transient dynamic pattern of fisheries yields can help fishery managers adjust relevant policies at an appropriate ecological time scale to achieve both conservation and economic goals, which provide a theoretical foundation for adaptive marine reserve management.

<p>Marine reserves (MRs) have been established in many parts of the globe for a variety of reasons and there is an increasing body of evidence that indicates they provide a wide range of benefits that can extend beyond their boundaries. In the present study, the biological effects of protection provided by MRs in New Zealand were evaluated, particularly focusing on the potential impacts of reserves on non-protected areas in terms of export of biomass. First, the biological response of two exploited species to MR protection in New Zealand was quantified by comparing meta-analysis results based on response ratio (RR) analysis and Hedges’ g statistics. Then, effect of MR size and age on those biological responses was determined. Most MRs supported a greater density of larger individuals than unprotected areas. Results indicated that the benefits provided by MRs scale with reserve size. Also, MR age explained a significant amount of the variation in the density and length of both species. Comparison of the performance of RRs with Hedges’ g revealed that RR analysis is an appropriate alternative to Hedges’ g statistic for meta-analyses of MR effectiveness because of its ease of use and interpretation. Then, a 14-year time series of fish density data was analyzed to determine early changes in a multi-species fish assemblage inside the Taputeranga Marine Reserve (TMR) compared to adjacent fishing grounds using a Before and After Control-Impact Paired Series (BACIPS) design. This analysis was performed in order to detect changes in fish density due to protection. Commercial, recreational and traditional fisheries are important in this region and the biomasses of several exploited species have been substantially depleted as a result of fishing. The exclusion of fishing from the area should enable at least some species to recover inside the reserve, as has happened in other reserves in New Zealand. The faster growing, more productive species, and those that have been heavily exploited are expected to recover within a few years. Early changes in density were evident in the area protected by the TMR for most of the species surveyed in terms of the effect size analysis. However, most of the changes were too small to be detected with the statistical analyses that were performed. To determine the most appropriate methodology to be used in a later survey in the study area, two Baited Underwater Video (BUV) methodologies (Horizontal versus Vertical set-up) were compared in terms of their ability to record the density and size of reef fish. Results indicated that both the horizontal and vertical BUV techniques are able to detect both conspicuous and cryptic species and both techniques were effective in the detection of carnivorous species, especially large predatory species such as blue cod, but also effective in the detection of fish species that have been overestimated in terms of abundance by other methodologies. The horizontal BUV technique seems to be a better technique for evaluating reef fish size, especially when measuring large fish that exhibit highly aggressive behaviour. The horizontal BUV technique was later used in conjunction with the Underwater Visual Census (UVC) technique to assess the effects of the protection provided by the TMR. A multispecies analysis was carried out to detect any differences in density and length of fish between reserve and fished areas and to detect gradients of fish density across reserve boundaries that could be related to the occurrence of spillover from the reserve to adjacent fished areas. Density gradients provide indirect evidence of spillover, defined as the movement of adult individuals from reserve to adjacent non-protected areas. Little evidence consistent with a positive effect of reserve protection in the TMR was found. Also, little evidence of spillover was found, with theexception of two target species (blue cod and blue moki). In contrast with the findings of previous studies, density gradients were found for both sedentary and vagile species. These results are consistent with the occurrence of density independent spillover that is expected to occur as soon as the density inside reserve areas is higher compared to fished areas. To further understand the patterns of fish movement relative to the effect of protection provided by MRs, spatial differences in density, length and survival of blue cod inside the TMR and adjacent fishing grounds and the movement patterns of the species across the boundaries of the reserve through a capture-mark-recapture (CMR) analysis were examined. CMR studies can provide direct evidence of spillover. Evidence of a positive effect of reserve protection in the TMR for blue cod in terms of increased density, length and survival in reserve areas was found. Also, evidence of high site fidelity of blue cod in both reserve and fished areas, with the majority of individual moving only short distances was found. However, the potential for this species to also travel long distances (>100 km) was confirmed, suggesting the possibility for spillover of the species from reserved to fished areas. Overall, the results of my thesis indicate that New Zealand MRs, consistent with a large body of earlier evidence, are having positive effects on the abundance and size of the species that afford protection to. These results also highlight that both MR age and area are important factors determining the response to protection both in terms of the effects within reserves and on adjacent non-protected areas. Finally, my results highlight the fact that the greater benefits in terms of increased abundance and size, and also movement across reserve boundaries, are obtained for highly exploited species that can potentially move between areas.</p>

Well-designed and effectively managed networks of marine reserves can be effective tools for both fisheries management and biodiversity conservation. Connectivity, the demographic linking of local populations through the dispersal of individuals as larvae, juveniles or adults, is a key ecological factor to consider in marine reserve design, since it has important implications for the persistence of metapopulations and their recovery from disturbance. For marine reserves to protect biodiversity and enhance populations of species in fished areas, they must be able to sustain focal species (particularly fishery species) within their boundaries, and be spaced such that they can function as mutually replenishing networks whilst providing recruitment subsidies to fished areas. Thus the configuration (size, spacing and location) of individual reserves within a network should be informed by larval dispersal and movement patterns of the species for which protection is required. In the past, empirical data regarding larval dispersal and movement patterns of adults and juveniles of many tropical marine species have been unavailable or inaccessible to practitioners responsible for marine reserve design. Recent empirical studies using new technologies have also provided fresh insights into movement patterns of many species and redefined our understanding of connectivity among populations through larval dispersal. Our review of movement patterns of 34 families (210 species) of coral reef fishes demonstrates that movement patterns (home ranges, ontogenetic shifts and spawning migrations) vary among and within species, and are influenced by a range of factors (e.g. size, sex, behaviour, density, habitat characteristics, season, tide and time of day). Some species move <0.1-0.5 km (e.g. damselfishes, butterflyfishes and angelfishes), <0.5-3 km (e.g. most parrotfishes, goatfishes and surgeonfishes) or 3-10 km (e.g. large parrotfishes and wrasses), while others move tens to hundreds (e.g. some groupers, emperors, snappers and jacks) or thousands of kilometres (e.g. some sharks and tuna). Larval dispersal distances tend to be <5-15 km, and self-recruitment is common. Synthesising this information allows us, for the first time, to provide species, specific advice on the size, spacing and location of marine reserves in tropical marine ecosystems to maximise benefits for conservation and fisheries management for a range of taxa. We recommend that: (i) marine reserves should be more than twice the size of the home range of focal species (in all directions), thus marine reserves of various sizes will be required depending on which species require protection, how far they move, and if other effective protection is in place outside reserves; (ii) reserve spacing should be <15 km, with smaller reserves spaced more closely; and (iii) marine reserves should include habitats that are critical to the life history of focal species (e.g. home ranges, nursery grounds, migration corridors and spawning aggregations), and be located to accommodate movement patterns among these. We also provide practical advice for practitioners on how to use this information to design, evaluate and monitor the effectiveness of marine reserve networks within broader ecological, socioeconomic and management contexts.

&lt;p&gt;A critical question for ecologists and fisheries managers is what drives the demographic processes that dictate the abundance and size structure of ecologically and commercially important species. Marine Reserves (MRs) provide an opportunity to examine species in the absence of human disturbance (i.e. no fishing) and to investigate how habitat type, quantity and condition contribute to yield large individuals and dense aggregations that are typical of a more natural state. However, an improved understanding of the efficacy of marine reserves requires a robust examination of habitats inside and outside reserves to distinguish any reserve effect from a potential confounding habitat effect. Abalone are a valuable nearshore fishery in many parts of the world and many stocks have been overexploited to the point of collapse. Countries striving to rebuild their abalone stocks are utilizing MRs to support viable populations and focusing on habitat requirements that produce large aggregations and individuals. The abalone commonly referred to as the blackfoot paua (Haliotis iris) is a culturally and ecologically important New Zealand (NZ) species and is the focus of customary, recreational and commercial fisheries. However, the demography and growth rates of paua populations are highly variable, with pockets of “stunted” populations occurring throughout NZ. Density-dependent processes, differential juvenile success, variable habitat quality and fishing pressure have all been suggested to influence the fitness of individuals and the demography of paua populations. My research utilizes MRs to control for fishing activity and thereby to investigate ecological patterns and the effects of habitat on paua abundance and size variability. The main objectives of this thesis were to quantify the response of paua to MR status, distinguish habitat effect from a reserve effect and understand the contribution of habitat variables on demography and growth. Research was conducted within and surrounding five MRs in central NZ. The habitats in and outside MRs were not significantly different in physical and biogenic characteristics, but paua occurred in significantly greater densities and were significantly larger within four MRs compared with outside, illustrating that marine reserves do afford protection for paua. Paua within MRs were significantly more dense and larger in areas of relatively higher wave exposure and dense macroalgal cover. Despite protection, paua were found to be undersized or “stunted” at Long Island and Horoirangi MRs. I conducted surveys to evaluate the effect of density and the contribution of habitat variables on paua size at two spatial scales across environmental gradients. To further test the hypothesis that habitat effects growth a 12 month translocation experiment was conducted at Long Island MR. The surveys revealed that environmental gradients exist at small and large scales and explained how paua size varied along these gradients. The habitat variables which supported larger size individuals were consistent across both locations, where paua were significantly larger in areas that were exposed with high algal cover than those at sheltered areas with low algal cover. This result was further confirmed by the translocation experiment which revealed that paua translocated from a stunted environment to a normal environment grew significantly more than conspecifics placed at the stunted environment. To further explore the response of paua to protection and see if patterns were consistent across bioregions in areas with “normal” size paua I conducted research at the Taputeranga MR on the Wellington South Coast to evaluate juvenile and adult population densities and examine stage-specific habitat requirements. Juvenile paua were found in higher densities at fished sites in areas that were sheltered from wave exposure and dominated by cobbles and boulder fields. Adult paua were found in greater densities and were larger in size within the reserve than outside, which was the opposite finding to the baseline survey illustrating reserve effectiveness. Although within the reserve there were large aggregations and individual adults which may support population reproductive success, juvenile and adult population densities were not correlated. Results from this study indicate that marine reserve implementation does have an impact on adult populations but that habitat is more important for juvenile success. Although this thesis focused on paua within the scope of protection, MRs are placed in NZ to protect a suite of species. To thoroughly investigate habitats I conducted a rigorous inside-outside habitat analysis utilizing multibeam bathymetric data and video footage from drop camera surveys at Taputeranga MR. Habitat maps produced by NIWA were utilized to plan drop camera sampling locations and 278 drops were conducted across 8 sites associated with TMR. Analysis revealed that habitats within fished and reserve sites were comparable in physical and biogenic habitat quantities, although the reserve had greater topographic relief. However, when examining only a subsample of fished sites there were pronounced habitat differences between in and outside the reserve, where the western fished sites have significantly more rocky reef with greater algal cover than the reserve and eastern sites. These results illustrate the need for quantification of habitat when siting fished (control) areas and conducting inside versus outside reserve comparisons. This research has determined that MRs do afford protection for paua in central NZ. The differentiation between habitat and reserve effects that I have identified has direct relevance to current and future MRs in NZ and highlights the need for studies to examine habitat effect in MR spatial planning at a global level. Furthermore, this research highlights the importance of considering stage-specific habitat requirements when designing the spatial arrangement of MRs by protecting juvenile habitat as well as adults to increase chances of recovery. These abalone-habitat associations, showing the importance of exposure and macroalgal cover for growth, can be used to assist in management decisions within NZ such as considerations for siting management areas and potential translocations and are directly applicable to abalone conservation, management concerns and recovery efforts across the world.&lt;/p&gt;

Recent reports have raised serious concerns about the rapid declines of historically productive marine fishery resources and the degradation of essential fish habitats. This global crisis has spurred development of innovative management strategies to rebuild depleted fisheries and marine ecosystems. One highly touted strategy involves the design and creation of marine reserves (areas off limits to extractive uses) to rebuild fisheries and conserve marine biodiversity. In this paper, we propose an integrated sequence of methodologies that provides an objective, quantitative framework for the design of marine reserves in spatially heterogeneous coastal ocean environments. The marine reserve designs proposed here satisfy the multiple, often-conflicting criteria of disparate resource user groups. This research is the first attempt to explicitly explore the trade-off between the conservation goals of fishery management and coral reef protection and the consumptive interests of commercial and recreational fishing fleets. The spatial distribution and size abundance of reef fish stocks throughout the Florida Keys coral reef ecosystem were estimated from a database consisting of more than 18,000 visual samples taken from 1979 to 2002. These distributions of multispecies abundance and biomass, in conjunction with a geographic database of coral reef habitats, are used to demonstrate an integer goal programming methodology for the design of networks of marine reserves, called plans. Once multiple plans are proposed, a simulation model is used to assess the effects of reserve size and shape on select Florida Keys reef fish populations under dynamic spatial and temporal conditions.

Massive differential site-specific and species-specific responses of temperate reef fishes to marine reserve protection

When can marine reserves improve fisheries management?

Summary Marine reserves are simple management tools that exclude extractive and destructive human activities from areas of the ocean. Given that fishing is one of the greatest impacts in most coastal ecosystems, networks of marine reserves are recognised as a core part of implementing ecosystem-based management in marine systems. Research in New Zealand marine reserves has contributed disproportionately to the global understanding of how species and ecosystems respond to marine reserve protection. We use examples from New Zealand to demonstrate the unequivocal role that marine reserves play in protecting exploited species within their boundaries, and how the recovery of exploited species can have wider conservation and fisheries value through indirect mechanisms and the movement of individuals from reserves. Progress towards developing a comprehensive and representative network of marine reserves in New Zealand has been slow because of a lack of political will, marine protected area legislation, and clear scientific guidance on marine reserve network design. Based on progress in designing networks of marine reserves internationally, and their demonstrated role in protecting biodiversity, we recommend a set of scientific guidelines to aid future development of marine reserves networks in New Zealand, and recommend that such networks be at the core of future marine spatial planning processes. Introduction Marine reserves are areas of the ocean that are protected from all extractive and destructive human activities (Lubchenco et al . 2003). They are often referred to as ‘no-take’ marine reserves as fishing is the main activity that is typically eliminated from a particular stretch of coast when a marine reserve is established. Given that fishing is the most widespread and historic human impact in coastal environments worldwide (Jackson et al . 2001) marine reserves provide a simple management tool to protect defined areas of the ocean from the impacts of fishing. While management of many fisheries is improving (Worm et al . 2009), there have been widespread calls to increase the level of protection for marine species through the implementation of networks of marine reserves worldwide (Wood et al . 2008). Fishing has a myriad of impacts on species as well as ecosystems through habitat disturbance and changes to food webs (Dayton et al . 2003). While marine reserves are not a panacea, as humans have a wide variety of impacts on marine ecosystems, they can protect the species and ecosystems within their boundaries from the effects of fishing.