Literature Library

Currently indexing 10059 titles

Approval and Promulgation of Implementation Plans; State of Oregon; Regional Haze State Implementation Plan

40 CFR Part 52

EPA–R10–OAR–2012–0344, FRL–9676–1

Agency: Environmental Protection Agency (EPA)

Action: Proposed rule

Summary: EPA is proposing to approve portions of a State Implementation Plan (SIP) revision submitted by the State of Oregon on December 10, 2010 and supplemented on February 1, 2011, as meeting the requirements of Clean Air Act (CAA or the Act) section 169A and B and Federal Regulations in 40 CFR 51.308. In a previous action on July 5, 2011, EPA approved portions of the December 10, 2010, SIP submittal as meeting the requirements for interstate transport for visibility of CAA section 110(a)(2)(D)(II) and certain requirements of the regional haze program including the requirements for best available retrofit technology (BART). 76 FR 38997. The action in this Federal Register notice addresses the remaining requirements of the CAA and EPA’s rules that require states to prevent any future and remedy any existing anthropogenic impairment of visibility in mandatory Class I areas caused by emissions of air pollutants from numerous sources located over a wide geographic area (also referred to as the ‘‘regional haze program’’). In this action, EPA proposes to approve the remaining regional haze SIP elements for which EPA previously took no action in the July 5, 2011 notice.

Dates: Written comments must be received at the address below on or before June 22, 2012.

Development of an Interpretive Exhibit on Marine Reserves and Marine Protected Areas in Oregon

Citation Information: Project Report submitted to Marine Resource Management Program, College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR; 2012

Author: Amy Vandehey

Abstract: Oregon is currently in the process of establishing Marine Reserves (MRs) and Marine Protected Areas (MPAs) within Oregon’s Territorial Sea. To assure that residents are aware of impending policy and the science behind it, science educators must formulate education tools that define terms and identify issues, but do not alienate sectors of the public that have alternative viewpoints. Because general ocean literacy is low, there is a need to raise awareness and interest about MRs and MPAs and their current status in Oregon.

The goals of this project were to design an effective museum exhibit, and raise the public’s awareness about MRs and MPAs in Oregon. The specific learning outcomes were to: 1) Recognize that a) Oregon has Marine Reserves, b) Marine Reserves are different from Marine Protected Areas, and c) Marine Reserves are in different locations along the Oregon coast; 2) Describe the Oregon process of establishing Marine Reserves by acknowledging that there are many people involved with a variety of backgrounds, and the visitor can get involved; and 3) Articulate the scientific and potential ecological benefits of Marine Protected Areas and Marine Reserves.

The exhibit was displayed at Hatfield Marine Science Center (HMSC) Visitor Center in Newport, OR. The center is a key site for public education on marine issues important to Oregonians, and supports free-choice learning. A survey was administered at SeaFest 2008 held on the HMSC campus to assess the current baseline knowledge and needs of the HMSC audience. This led to the development of two main prototypes which were evaluated for attractiveness, clarity and messaging. Results from exhibit Prototype II indicated that the messages were clear, but that the text and stakeholder videos were too long, and more interactive elements needed to be added. I conclude with some specific suggestions for the next iteration of the exhibit, and future directions to broaden the impact of the materials developed.

Predicting stakeholder support for fishery policies

Citation Information: Coastal Management; Volume 40, Issue 1, 2012; pages 20-32

DOI: 10.1080/08920753.2011.637484

Authors: Arren Mendezona Allegretti, Jerry J. Vaske & Stuart Cottrell

Abstract: Fisheries management has been used to address declining fisheries and threats to livelihood and food security. Past research suggests that public support for fishery policies is a necessary component for sustaining the long-term success of fisheries management. This study predicted public support by examining fishers’ perspectives on co-management and fish catch since the establishment of marine protected areas (MPAs), a commonly employed fisheries management tool. Data were obtained from onsite surveys (n = 505) with fishers from three municipalities in Cebu, Philippines: Oslob, Santander, and Samboan. Structural path analyses revealed that beliefs about co-management and fish catch predicted support for fishery policies (R2 = 59%). Separate path analyses for each municipality showed that co-management had greater influence in predicting public support for fishery policies in Oslob and Santander. Fish catch was a better predictor for public support for fishery policies in Samboan. Results can help local governments, non-governmental organizations, and fishery managers to prioritize, plan, and improve fisheries management in municipal waters.

An exploration of Hul’qumi’num Coast Salish peoples’ attitudes towards the establishment of no-take zones within marine protected areas in the Salish Sea, Canada

Citation Information: The Canadian Geographer / Le Géographe canadien; Volume 56, Issue 2, pages 260–274, Summer / ete 2012

Authors: Cheri A. Ayers, Phil Dearden, and Rick Rollins

Abstract: The Canadian Government has committed to establishing a national network of Marine Protected Areas. Progress in the Salish Sea (Strait of Georgia) of British Columbia has been slow. Opposition by First Nations is a factor as these protected areas have the potential to impact on Aboriginal rights. This case study with the Hul’qumi’num First Nations examines their approaches to marine conservation and their perspectives on “no-take zones” as a component of marine conservation. The study used a variety of community engagement procedures including relationship building, hiring of a Hul’qumi’num research assistant, conducting individual interviews, focus groups, and field surveys. Interviews were conducted with 41 participants contacted because of their knowledge and interest in marine resource use. The views reported provide a rich understanding of Hul’qumi’num attitudes, but cannot be generalised to the whole population. There was widespread support for efforts to involve local First Nations communities in the development of management plans for marine resources, and also for recognition of First Nation reliance on marine resources for food, social, and ceremonial needs and for economic development opportunities. The establishment of permanent no-take zones was met with both opposition and support. The most highly endorsed statement about no-take zones is one of principle—that they are a violation of Aboriginal rights. However, there was also strong agreement that permanent no-take zones would help reduce over-fishing. The National Marine Conservation Area program is in its infancy and it remains to be seen how the “strictly protected” zone of the legislation will be interpreted in relationship to Aboriginal harvesting practices. However it is clear that successful conservation will only occur with Aboriginal consent in many areas and there needs to be greater investment in understanding Aboriginal perspectives on marine conservation.

Multi-scale marine biodiversity patterns inferred efficiently from habitat image processing

Citation Information: Ecol Appl. 2012 Apr; 22(3):792-803

Authors: Mellin C, Parrott L, Andréfouët S, Bradshaw CJ, MacNeil MA, Caley MJ.

Abstract: Cost-effective proxies of biodiversity and species abundance, applicable across a range of spatial scales, are needed for setting conservation priorities and planning action. We outline a rapid, efficient, and low-cost measure of spectral signal from digital habitat images that, being an effective proxy for habitat complexity, correlates with species diversity and requires little image processing or interpretation. We validated this method for coral reefs of the Great Barrier Reef (GBR), Australia, across a range of spatial scales (1 m to 10 km), using digital photographs of benthic communities at the transect scale and high-resolution Landsat satellite images at the reef scale. We calculated an index of image-derived spatial heterogeneity, the mean information gain (MIG), for each scale and related it to univariate (species richness and total abundance summed across species) and multivariate (species abundance matrix) measures of fish community structure, using two techniques that account for the hierarchical structure of the data: hierarchical (mixed-effect) linear models and distance-based partial redundancy analysis. Over the length and breadth of the GBR, MIG alone explained up to 29% of deviance in fish species richness, 33% in total fish abundance, and 25% in fish community structure at multiple scales, thus demonstrating the possibility of easily and rapidly exploiting spatial information contained in digital images to complement existing methods for inferring diversity and abundance patterns among fish communities. Thus, the spectral signal of unprocessed remotely sensed images provides an efficient and low-cost way to optimize the design of surveys used in conservation planning. In data-sparse situations, this simple approach also offers a viable method for rapid assessment of potential local biodiversity, particularly where there is little local capacity in terms of skills or resources for mounting in-depth biodiversity surveys.

Evaluation of marine spatial planning

Citation Information: Marine Policy; Volume 37, January 2013, Pages 214–229; Social and cultural impacts of marine fisheries

Author: Gonçalo Carneiro

Abstract: Evaluation is generally recognised as an essential step for learning and improvement in marine spatial planning (MSP). Practical guidance and experience relative to evaluation in MSP is, however, very limited. To address this gap, this paper addresses a set of issues relevant for evaluation design and performance: the object of evaluation is discussed in relation to the functions of planning, the choice of objectives and the timing of evaluation; factors affecting causality attribution are analysed, namely multi-causality of observed effects, counterfactual design, time lags and uncertainty; and possibilities and requirements regarding stakeholder involvement in evaluation are considered.

Six models of planning evaluation are reviewed, based on which a step-wise framework for MSP evaluation is developed. Future research should pilot test and assess this framework and broaden the evidence base relative to impacts of marine management initiatives.

Application Of Ecological Criteria In Selecting Marine Reserves And Developing Reserve Networks

Citation Information: Ecological Applications 13:215–228; 2003

Authors: Callum M. Roberts, George Branch, Rodrigo H. Bustamante, Juan Carlos Castilla, Jenifer Dugan, Benjamin S. Halpern, Kevin D. Lafferty, Heather Leslie, Jane Lubchenco, Deborah McArdle, Mary Ruckelshaus, and Robert R. Warner

Ecological Criteria For Evaluating Candidate Sites For Marine Reserves

Citation Information: Ecological Applications 13:199–214; 2003

Authors: Callum M. Roberts, Sandy Andelman, George Branch, Rodrigo H. Bustamante, Juan Carlos Castilla, Jenifer Dugan, Benjamin S. Halpern, Kevin D. Lafferty, Heather Leslie, Jane Lubchenco, Deborah McArdle, Hugh P. Possingham, Mary Ruckelshaus, and Robert R. Warner

Using Siting Algorithms In The Design Of Marine Reserve Networks

Citation Information: Ecological Applications 13:185–198; 2003

Authors: Heather Leslie, Mary Ruckelshaus, Ian R. Ball, Sandy Andelman, and Hugh P. Possingham

Abstract: Using benthic habitat data from the Florida Keys (USA), we demonstrate how siting algorithms can help identify potential networks of marine reserves that comprehensively represent target habitat types. We applied a flexible optimization tool—simulated annealing—to represent a fixed proportion of different marine habitat types within a geographic area. We investigated the relative influence of spatial information, planning-unit size, detail of habitat classification, and magnitude of the overall conservation goal on the resulting network scenarios. With this method, we were able to identify many adequate reserve systems that met the conservation goals, e.g., representing at least 20% of each conservation target (i.e., habitat type) while fulfilling the overall aim of minimizing the system area and perimeter. One of the most useful types of information provided by this siting algorithm comes from an “irreplaceability analysis,” which is a count of the number of times unique planning units were included in reserve system scenarios. This analysis indicated that many different combinations of sites produced networks that met the conservation goals. While individual 1-km2 areas were fairly interchangeable, the irreplaceability analysis highlighted larger areas within the planning region that were chosen consistently to meet the goals incorporated into the algorithm. Additionally, we found that reserve systems designed with a high degree of spatial clustering tended to have considerably less perimeter and larger overall areas in reserve—a configuration that may be preferable particularly for sociopolitical reasons. This exercise illustrates the value of using the simulated annealing algorithm to help site marine reserves: the approach makes efficient use of available resources, can be used interactively by conservation decision makers, and offers biologically suitable alternative networks from which an effective system of marine reserves can be crafted.

Applying Ecological Criteria To Marine Reserve Design: A Case Study From The California Channel Islands

Citation Information: Ecological Applications 13:170–184; 2003

Authors: Satie Airamé, Jenifer E. Dugan, Kevin D. Lafferty, Heather Leslie, Deborah A. McArdle, and Robert R. Warner

Abstract: Using ecological criteria as a theoretical framework, we describe the steps involved in designing a network of marine reserves for conservation and fisheries management. Although we describe the case study of the Channel Islands, the approach to marine reserve design may be effective in other regions where traditional management alone does not sustain marine resources. A group of agencies, organizations, and individuals established clear goals for marine reserves in the Channel Islands, including conservation of ecosystem biodiversity, sustainable fisheries, economic viability, natural and cultural heritage, and education. Given the constraints of risk management, experimental design, monitoring, and enforcement, scientists recommended at least one, but no more than four, reserves in each biogeographic region. In general, the percentage of an area to be included in a reserve network depends on the goals. In the Channel Islands, after consideration of both conservation goals and the risk from human threats and natural catastrophes, scientists recommended reserving an area of 30–50% of all representative habitats in each biogeographic region. For most species of concern, except pinnipeds and seabirds, information about distributions, dispersal, and population growth was limited. As an alternative to species distribution information, suitable habitats for species of concern were used to locate potential reserve sites. We used a simulated annealing algorithm to identify potential reserve network scenarios that would represent all habitats within the smallest area possible. The analysis produced an array of potential reserve network scenarios that all met the established goals.

Propagule Dispersal Distance And The Size And Spacing Of Marine Reserves

Citation Information: Ecological Applications 13:159–169; 2003

Authors: Alan L. Shanks, Brian A. Grantham, and Mark H. Carr

Abstract: This study compiled available information on the dispersal distance of the propagules of benthic marine organisms and used this information in the development of criteria for the design of marine reserves. Many benthic marine organisms release propagules that spend time in the water column before settlement. During this period, ocean currents transport or disperse the propagules. When considering the size of a marine reserve and the spacing between reserves, one must consider the distance which propagules disperse. We could find estimates of dispersal distance for 32 taxa; for 25 of these, we were also able to find data on the time the propagules spent dispersing. Dispersal distance ranged from meters to thousands of kilometers, and time in the plankton ranged from minutes to months. A significant positive correlation was found between the log-transformed duration in the plankton and the log-transformed dispersal distance (r = 0.7776, r2 = 0.60, df = 1, 25, P = 0.000); the more time propagules spend in the water column the further they tend to be dispersed. The frequency distribution of the log-transformed dispersal distance is bimodal (kurtosis = −1.29, t = −4.062, P < 0.001) with a gap between 1 and 20 km. Propagules that dispersed <1 km spent less time in the plankton (<100 h), or if they remained in the plankton for a longer period, they tended to remain in the waters near the bottom. Propagules that dispersed >20 km spent more than 300 h in the plankton. The bimodal nature of the distribution suggests that evolutionary constraints may reduce the likelihood of evolving mid-range dispersal strategies (i.e., dispersal between 1 and 20 km) resulting in two evolutionarily stable dispersal strategies: dispersal <1 km or >20 km. We suggest that reserves be designed large enough to contain the short-distance dispersing propagules and be spaced far enough apart that long-distance dispersing propagules released from one reserve can settle in adjacent reserves. A reserve 4–6 km in diameter should be large enough to contain the larvae of short-distance dispersers, and reserves spaced 10–20 km apart should be close enough to capture propagules released from adjacent reserves.

Species–Area Relationships And Marine Conservation

Citation Information: Ecological Applications 13:138–145; 2003

Author: Joseph E. Neigel

Abstract: The species–area relationship (SPAR) was the central paradigm for the emerging science of reserve design in the 1970s and early 1980s. The apparent consistency of the SPAR for natural areas suggested that it could be used to predict the number of species that would be maintained within the isolated confines of a nature reserve. This proposed use of the SPAR led to heated debates about how best to partition space among reserves. However, by the end of the 1980s, the SPAR was no longer a central issue in reserve design. There was too much uncertainty about the underlying causes of the SPAR to trust that it would hold for reserves. The SPAR was also inappropriate for the design of single-species reserves and thus did not answer the traditional needs of wildlife managers. Ecologists subsequently focused their reserve-design efforts on the management of individual populations to reduce the probability of extinction and the loss of genetic variation. Nevertheless, because the SPAR does not require detailed knowledge of the requirements of individual species, it is still used to estimate local species richness and to predict the effects of habitat loss and fragmentation on biodiversity. These applications of the SPAR may be especially useful in the design of marine reserves, which often differ in purpose from conventional terrestrial reserves and may require fundamentally different approaches.

The impact of marine reserves: do reserves work and does reserve size matter?

Citation Information: Ecological Applications 13:117–137; 2003

Author: Benjamin S. Halpern

Abstract: Marine reserves are quickly gaining popularity as a management option for marine conservation, fisheries, and other human uses of the oceans. Despite the popularity of marine reserves as a management tool, few reserves appear to have been created or designed with an understanding of how reserves affect biological factors or how reserves can be designed to meet biological goals more effectively (e.g., attaining sustainable fish populations). This shortcoming occurs in part because the many studies that have examined the impacts of reserves on marine organisms remain isolated examples or anecdotes; the results of these many studies have not yet been synthesized. Here, I review the empirical work and discuss the theoretical literature to assess the impacts of marine reserves on several biological measures (density, biomass, size of organisms, and diversity), paying particular attention to the role reserve size has in determining those impacts. The results of 89 separate studies show that, on average, with the exception of invertebrate biomass and size, values for all four biological measures are significantly higher inside reserves compared to outside (or after reserve establishment vs. before) when evaluated for both the overall communities and by each functional group within these communities (carnivorous fishes, herbivorous fishes, planktivorous fishes/invertebrate eaters, and invertebrates). Surprisingly, results also show that the relative impacts of reserves, such as the proportional differences in density or biomass, are independent of reserve size, suggesting that the effects of marine reserves increase directly rather than proportionally with the size of a reserve. However, equal relative differences in biological measures between small and large reserves nearly always translate into greater absolute differences for larger reserves, and so larger reserves may be necessary to meet the goals set for marine reserves.

Dispersal Potential of Marine Invertebrates in Diverse Habitats

Citation Information: Ecological Applications 13:108–116; 2003

Authors: Grantham, Brian A., Ginny L. Eckert, and Alan L. Shanks

Abstract: Life-history parameters were used to estimate the dispersal potential of 1021 marine macroinvertebrates recorded in species lists from 91 sites comprising rocky intertidal, subtidal, kelp forest, sandy beach, and soft-bottom habitats in Washington, Oregon, and California. Mean species richness was significantly greater in the California rocky subtidal habitat. Data on development mode, planktonic larval duration, rafting potential, and adult mobility were compiled, and summaries of the dispersal potentials of taxa within each habitat type were generated and compared. In summary, development mode was known or estimated for 76% of species; larval planktonic duration for 49%; adult mobility for 76%; and rafting potential for 46%. In comparisons of species' life-history traits among habitats, sand-dominated habitats were distinct from rocky habitats. In rocky habitats, 42% of species had planktonic feeding larvae, 43% had planktonic nonfeeding larvae, and 15% had nonplanktonic larvae. Sandy intertidal habitats had higher proportions of taxa with nondispersing, nonplanktonic larvae and lower proportions of planktonic feeding and nonfeeding larvae than all other sites. Soft-bottom subtidal communities had the highest proportion of taxa with planktonic feeding development and larvae with planktonic lifespans >30 d. Species in soft-bottom subtidal sites, therefore, have the greatest potential for extensive larval dispersal, whereas species in soft-bottom intertidal sites have the least potential for larval dispersal. In these sites with limited larval dispersal potential, there is greater potential for adult dispersal through adult movement and rafting. These differences in the dispersal potential of larvae and adults suggest that the effect of environmental changes and the effectiveness of reserves may differ between habitats. Conservation methods, including the use of marine reserves, must therefore be tailored to the habitat of interest if effective protection of community resources is to be achieved.

Comparing Marine And Terrestrial Ecosystems: Implications For The Design Of Coastal Marine Reserves

Citation Information: Ecological Applications 13:90–107; 2003

Authors: Mark H. Carr, Joseph E. Neigel, James A. Estes, Sandy Andelman, Robert R. Warner, and John L. Largier

Abstract: Concepts and theory for the design and application of terrestrial reserves is based on our understanding of environmental, ecological, and evolutionary processes responsible for biological diversity and sustainability of terrestrial ecosystems and how humans have influenced these processes. How well this terrestrial-based theory can be applied toward the design and application of reserves in the coastal marine environment depends, in part, on the degree of similarity between these systems. Several marked differences in ecological and evolutionary processes exist between marine and terrestrial ecosystems as ramifications of fundamental differences in their physical environments (i.e., the relative prevalence of air and water) and contemporary patterns of human impacts. Most notably, the great extent and rate of dispersal of nutrients, materials, holoplanktonic organisms, and reproductive propagules of benthic organisms expand scales of connectivity among nearshore communities and ecosystems. Consequently, the “openness” of marine populations, communities, and ecosystems probably has marked influences on their spatial, genetic, and trophic structures and dynamics in ways experienced by only some terrestrial species. Such differences appear to be particularly significant for the kinds of organisms most exploited and targeted for protection in coastal marine ecosystems (fishes and macroinvertebrates). These and other differences imply some unique design criteria and application of reserves in the marine environment. In explaining the implications of these differences for marine reserve design and application, we identify many of the environmental and ecological processes and design criteria necessary for consideration in the development of the analytical approaches developed elsewhere in this Special Issue.

Considerations In Estimating Larval Dispersal Distances From Oceanographic Data

Citation Information: Ecological Applications 13:71–89; 2003

Author: John L. Largier

Abstract: Determination of larval dispersal distances and larval origins is a central challenge in contemporary marine ecology. In this work, the larval dispersal problem is discussed from the perspective of oceanography. Following formulation of the advection–diffusion model, the importance of scale is argued. When considering dispersion parameters at the appropriate population scales, advection is usually weaker than initially anticipated (and often used), and diffusion is stronger than typically used in model studies. Focusing attention on coastal populations, the importance of retention zones is described, and the more general existence of a coastal boundary layer is discussed. The coupling of cross-shore and alongshore dispersion results in a nonlinear relation between alongshore dispersal distance and larval planktonic period for dispersion in a sheared flow. Thus, small changes in cross-shore dispersal, whether due to environmental differences or larval behavior result in significant differences in alongshore dispersal. Finally, the interplay between advection and diffusion is explored, showing the importance of adequately representing the diffusive effects that mitigate alongshore advection. In most cases, diffusion acts to prevent “washout” of a population and allows for more flexibility in the size and spacing of effective marine reserves. Future challenges must bring oceanographers and ecologists together around specific dispersal problems if there is to be a significant improvement in the notable absence of hard data in this field of enquiry.

Comparing Designs Of Marine Reserves For Fisheries And For Biodiversity

Citation Information: Ecological Applications 13:65–70; 2003

Authors: Alan Hastings and Louis W. Botsford

Abstract: We compare and contrast the design of networks of marine reserves for two different, commonly stated goals: (1) maintaining high yield in fisheries and (2) conserving biodiversity, in an idealized setting using simple models. The models describe larval dispersal over a system of evenly spaced reserves of equal size, assuming sedentary adults. We initially demonstrate that, since populations in reserve systems can be sustained either by covering a minimal fraction of the coast with small reserves or by covering a smaller fraction of the coast with few large reserves, cost considerations dictate that the conservation goal would be best met by reserves as large as practically possible. In contrast, the fisheries goal of maximizing yield requires maximizing larval export outside of reserves, which we show means that reserves should be as small as practically possible. Meeting the fisheries goal is ultimately more costly because it suggests a larger area of the coastline should be in reserves, but it also improves on conservation goals by enhancing sustainability for species dispersing longer distances.

Population Models For Marine Reserve Design: A Retrospective And Prospective Synthesis

Citation Information: Ecological Applications 13:47–64; 2003

Authors: Leah R. Gerber, Louis W. Botsford, Alan Hastings, Hugh P. Possingham, Steven D. Gaines, Stephen R. Palumbi, and Sandy Andelman

Abstract: We synthesize results from existing models of marine reserves to identify key theoretical issues that appear to be well understood, as well as issues in need of further exploration. Models of marine reserves are relatively new in the scientific literature; 32 of the 34 theoretical papers we reviewed were published after 1990. These models have focused primarily on questions concerning fishery management at the expense of other objectives such as conservation, scientific understanding, recreation, education, and tourism. Roughly one-third of the models analyze effects on cohorts while the remaining models have some form of complete population dynamics. Few models explicitly include larval dispersal. In a fisheries context, the primary conclusion drawn by many of the complete population models is that reserves increase yield when populations would otherwise be overfished. A second conclusion, resulting primarily from single-cohort models, is that reserves will provide fewer benefits for species with greater adult rates of movement. Although some models are beginning to yield information on the spatial configurations of reserves required for populations with specific dispersal distances to persist, it remains an aspect of reserve design in need of further analysis. Other outstanding issues include the effects of (1) particular forms of density dependence, (2) multispecies interactions, (3) fisher behavior, and (4) effects of concentrated fishing on habitat. Model results indicate that marine reserves could play a beneficial role in the protection of marine systems against overfishing. Additional modeling and analysis will greatly improve prospects for a better understanding of the potential of marine reserves for conserving biodiversity.

Avoiding Current Oversights In Marine Reserve Design

Citation Information: Ecological Applications 13:32–46; 2003

Authors: Steven D. Gaines, Brian Gaylord, and John L. Largier

Abstract: The pun in the above title reflects two points. First, marine life cycles commonly include a dispersive juvenile stage that is moved about by ocean currents. This stage often is the predominant, or only, means of dispersal that connects spatially disjunct populations. As a consequence, details of dispersal likely play a critical role in determining the effectiveness of marine reserves as a management and conservation tool. Curiously, however (and this is the second point of the title), although dozens of models for marine reserves now exist, few actually account explicitly for larval dispersal. Moreover, those that do include dispersal, do so almost exclusively by considering it to be a nondirectional spreading process (diffusion), ignoring the effects of directional transport by currents (advection). Here we develop a population dynamical model for marine organisms with relatively sedentary adults whose larvae are transported in a simple flow field with both diffusive spreading and directional characteristics. We find that advection can play a dominant role in determining the effectiveness of different reserve configurations. Two of the most important consequences are: (1) with strong currents, multiple reserves can be markedly more effective than single reserves of equivalent total size; and (2) in the presence of strong currents, reserves can significantly outperform traditional, effort-based management strategies in terms of fisheries yield, and do so with less risk. These results suggest that successful reserve design may require considerable new efforts to examine explicitly the role of dispersal of young.

Principles for the Design of Marine Reserves

Citation Information: Ecological Applications 13:25–31; 2003

Authors: Louis W. Botsford, Fiorenza Micheli, and Alan Hastings

Abstract: The theory underlying the design of marine reserves, whether the goal is to preserve biodiversity or to manage fisheries, is still in its infancy. For both of these goals, there is a need for general principles on which to base marine reserve design, and because of the paucity of empirical experience, these principles must be based on models. However, most of the theoretical studies to date have been specific to a single situation, with few attempts to deduce general principles. Here we attempt to distill existing results into general principles useful to designers of marine reserves. To answer the question of how fishery management using reserves compares to conventional management, we provide two principles: (1) the effect of reserves on yield per recruit is similar to increasing the age of first capture, and (2) the effect of reserves on yield is similar to reducing effort. Another two principles answer the question of how to design reserve configurations so that species with movement in various stages will be sustainable: (3) higher juvenile and adult movement lowers sustainability of reserves for biodiversity, but an intermediate level of adult movement is required for reserves for fishery management, and (4) longer larval dispersal distance requires larger reserves for sustainability. These principles provide general guidelines for design, and attention to them will allow more rapid progress in future modeling studies. Whether populations or communities will persist under any specific reserve design is uncertain, and we suggest ways of dealing with that uncertainty.

Pages

Subscribe to OpenChannels Literature Library