Marine Reserve Networks Research Articles

Effects of protection and temperature variation on temporal stability in a marine reserve network.

Understanding the drivers of ecosystem stability has been a key focus of modern ecology as the impacts of the Anthropocene become more prevalent and extreme. Marine protected areas (MPAs) are tools used globally to promote biodiversity and mediate anthropogenic impacts. However, assessing the stability of natural ecosystems and responses to management actions is inherently challenging due to the complex dynamics of communities with many interdependent taxa. Using a 12-year time series of subtidal community structure in an MPA network in the Channel Islands (United States), we estimated species interaction strength (competition and predation), prey species synchrony, and temporal stability in trophic networks, as well as temporal variation in sea surface temperature to explore the causal drivers of temporal stability at community and metacommunity scales. At the community scale, only trophic networks in MPAs at Santa Rosa Island showed greater temporal stability than reference sites, likely driven by reduced prey synchrony. Across islands, competition was sometimes greater and predation always greater in MPAs compared with reference sites. Increases in interaction strength resulted in lower temporal stability of trophic networks. Although MPAs reduced prey synchrony at the metacommunity scale, reductions were insufficient to stabilize trophic networks. In contrast, temporal variation in sea surface temperature had strong positive direct effects on stability at the regional scale and indirect effects at the local scale through reductions in species interaction strength. Although MPAs can be effective management strategies for protecting certain species or locations, our findings for this MPA network suggest that temperature variation has a stronger influence on metacommunity temporal stability by mediating species interactions and promoting a mosaic of spatiotemporal variation in community structure of trophic networks. By capturing the full spectrum of environmental variation in network planning, MPAs will have the greatest capacity to promote ecosystem stability in response to climate change.

Regional differences in fishing behavior determine whether a marine reserve network enhances fishery yield

A network of marine reserves can enhance yield in depleted fisheries by protecting populations, particularly large, old spawners that supply larvae for interspersed fishing grounds. The ability of marine reserves to enhance sustainable fisheries is much less evident. We report empirical evidence of a marine reserve network improving yield regionally for a sustainable spiny lobster fishery, apparently through the spillover of adult lobsters and behavioral adaptation by the fishing fleet. Results of a Before-After, Control-Impact analysis found catch, effort, and Catch-Per-Unit Effort increased after the establishment of marine reserves in the northern region of the fishery where fishers responded by fishing intensively at reserve borders, but declined in the southern region where they vacated once productive fishing grounds. The adaptation of the northern region of the fishery may have been aided by a history of collaboration between fishers, scientists, and managers, highlighting the value of collaborative research and education programs for preparing fisheries to operate productively within a seascape that includes a large marine reserve network.

Biophysical modelling and graph theory identify key connectivity hubs in the Mediterranean marine reserve network

Connectivity plays a key role in the effectiveness of MPA networks ensuring metapopulation resilience through gene flow and recruitment effect. Yet, despite its recognized importance for proper MPA network functioning, connectivity is not often assessed and is very seldomly used in marine spatial planning. Here, we combined biophysical modelling with graph theory to identify Mediterranean marine reserves that support connectivity between different ecoregions through stepping-stone processes, thus preventing network fragmentation, and those that have an important role as propagule source areas contributing to the recruitment and rescue effects. We identified 19 reserves that play a key role towards the functioning of the network, serving either as stepping-stones or as propagule sources, yet with distinct patterns between ecological groups with contrasting propagule duration (PD). The Côte D’Azur marine reserves are important both as stepping-stones and propagule sources for several ecological groups. Also, key is the Capo Rizzuto and Plemmirio marine reserves due to their role as stepping stones between different marine ecoregions, particularly for species with longer PD (Pisces, Crustacea and Echinodermata). These results provide stakeholders and managers with crucial information for the implementation and management of an efficient marine reserve network in the Mediterranean.

Integrating larval connectivity into the marine conservation decision-making process across spatial scales.

Larval dispersal connectivity is typically integrated into spatial conservation decisions at regional or national scales, but implementing agencies struggle with translating these methods to local scales. We used larval dispersal connectivity at regional (hundreds of kilometers) and local (tens of kilometers) scales to aid in design of networks of no-take reserves in Southeast Sulawesi, Indonesia. We used Marxan with Connectivity informed by biophysical larval dispersal models and remotely sensed coral reef habitat data to design marine reserve networks for 4 commercially important reef species across the region. We complemented regional spatial prioritization with decision trees that combined network-based connectivity metrics and habitat quality to design reserve boundaries locally. Decision trees were used in consensus-based workshops with stakeholders to qualitatively assess site desirability, and Marxan was used to identify areas for subsequent network expansion. Priority areas for protection and expected benefits differed among species, with little overlap in reserve network solutions. Because reef quality varied considerably across reefs, we suggest reef degradation must inform the interpretation of larval dispersal patterns and the conservation benefits achievable from protecting reefs. Our methods can be readily applied by conservation practitioners, in this region and elsewhere, to integrate connectivity data across multiple spatial scales.

The legacies of land clearance and trophic downgrading accumulate to affect structure and function of kelp forests

AbstractAotearoa New Zealand is the last major landmass settled by people, and therefore provides a recent record of ecological legacy effects in the coastal zone. Large‐scale land clearances of forests accelerated over the last century, affecting the concentration of suspended sediments, light environment, and nutrient composition on rocky reefs, and consequently the distribution, abundance, and composition of algal forests. The environmental effects were compounded in many places by overfishing and long‐term declines of large predatory species, often leading to proliferation and extensive grazing by sea urchins. In this study, we examine these processes in three biogeographic regions that have been differentially affected by ecological legacy effects. The study was based on the depth‐specific associations between sea urchins (Evechinus chloroticus) and the common kelp (Ecklonia radiata) from multiple sites within each region, some of which were sampled over two decades within no‐take marine reserves and in actively fished areas. Satellite‐derived estimates of water‐column properties were used as proxies for the relative effects of coastal sedimentation on kelp forest habitats. We then used an information‐theoretic framework to assess the relative factor weightings of marine reserve effects on urchin density, total suspended solids (TSS), and regional urchin density on the depth‐specific density of Ecklonia radiata. The fishing effects were significant within and outside of reserves in the northern and central regions, but the effect sizes were by far strongest in the northern region. In the central region characterized by extensive land clearance and forestry combined with high coastal retention of water, the concentration of TSS had a major influence on the depth distribution of kelp, confining it to shallow water (<10‐m depth) in small patches where urchins did not overgraze. These patterns are in sharp contrast to the small marine reserve effects and deep distribution of Ecklonia radiata in the southern region, which has intact native forested catchments, comparatively low fishing pressure, and a large regional network of marine reserves. The results highlight important differences in how centuries‐old legacies of land clearance and exploitation affect regional‐scale dynamics of sea urchins and kelp and define the appropriate spatial scale of ecosystem‐based management of critical kelp forest habitats.

Distribution Patterns of Reef Fish Larvae in the Dipolog Srait, Philippines

The composition, abundance and distribution of reef fish were strongly influenced by the trends in salinity, temperature and mixing regimes of the water during the three oceanographic cruises conducted in the vicinity of the marine reserve networks of Dipolog Strait. Forty-seven families of reef fish larvae were identified. Carangidae, Labridae, Scaridae, Gobiidae and Apogonidae were the top five most abundant larvae comprising 64.7 % of the total number of reef fish larvae collected. Shifts in the dominance of the top five most abundant reef fish families occurred primarily between the northeast and southwest monsoons coinciding with the changes in the temperature profiles of the water column. Abundance of reef fish larvae showed variability across the three sampling periods due to the succession of the dominant species of reef fish larvae. Fluctuations in salinity brought about by the transition from Northeast to Southwest monsoon period could explain the variation. Density distribution of reef fish larvae significantly increased with the increasing depth of the mixed layer during northeast monsoon period. The downwelling off the coast of southern Negros in February and April cruises contributed to the high abundance of reef fish larvae in this part of the strait, while the uniform mixing of the water column in June 2010 at southwest monsoon resulted in the weakening of density gradient of reef fish larvae.The study demonstrated the variable responses of the reef fish larvae to the gradients of chlorophyll in the Dipolog Strait. A better understanding on the retention mechanism of reef fish larvae along the coast of southern Negros, where the main marine reserve networks exist, is provided by the present study.

Towards climate-smart, three-dimensional protected areas for biodiversity conservation in the high seas

Marine species are moving rapidly in response to warming, often in different directions and with variations dependent on location and depth. Given the current impetus to increase the area of protected ocean to 30%, conservation planning must include the 64% of the ocean beyond national jurisdictions, which in turn requires associated design challenges for conventional conservation to be addressed. Here we present a planning approach for the high seas that conserves biodiversity, minimizes exposure to climate change, retains species within reserve boundaries and reduces conflict with fishing. This is developed using data from across four depth domains, considering 12,932 vertebrate, invertebrate and algal species and three climate scenarios. The resultant climate-smart conservation areas cover 6% of the high seas and represent a low-regret option that provides a nucleus for developing a full network of high-seas marine reserves. Protecting the ocean from increasing threats requires the development of high-seas marine reserve networks. An approach that optimizes biodiversity, minimizes climate change exposure and reduces fisheries conflict enables low-regret climate-smart conservation areas to be identified.

Prevalence and severity of sublethal injuries in crown‐of‐thorns starfish relative to marine reserves in the Great Barrier Reef

Abstract Spatial and temporal stochasticity in the abundance and population dynamics of crown‐of‐thorns starfish (COTS; Acanthaster spp.) highlight the critical need for improved knowledge of demographic variability within and among populations. This study compared the prevalence (proportion of individuals) and severity (extent of damage) of injuries in adult COTS between contrasting fisheries management zones in Australia's Great Barrier Reef, explicitly testing whether injuries are more prevalent or severe on reefs where fishing is not permitted. Prevalence of sublethal injuries was significantly higher for COTS collected from reefs within Marine National Park Zones, where fishing is effectively prohibited, versus Conservation Park Zones or Habitat Protection Zones, where fishing is permitted, but regulated. This finding is consistent with the notion that predation rates on COTS are higher within reef habitats where fishing is prohibited, presumably due to the bigger size or higher abundance of predatory fishes. Severity was predominantly low among the injured starfish and there was no significant difference between management zones. Nevertheless, there was a higher frequency of individuals with between one and three injured arms in no‐take reefs compared to those from reefs that were open to fishing. Prevalence and severity of sublethal injuries was higher in medium‐sized COTS (11–30 cm diameter) compared to larger COTS (>30 cm diameter). This study adds to existing evidence that established networks of marine reserves can have benefits beyond conservation and fisheries management, including potential reductions in the likelihood of devastating population irruptions of COTS and mitigation of further coral loss.

Best‐practice fisheries management associated with reduced stocks and changes in life histories

AbstractCurrent best‐practice policy recommendations for managing fish stocks are achieved by a mixture of maintaining modest fishing mortality (restricting effort, times and gear), marine reserve networks and not subsidizing unprofitable fisheries. A seldom evaluated question is how effective these proposed approaches are for maintaining all fish stocks and biodiversity elements in marine seascapes? Both recommended and unrecommended fishing practices fragment habitats and reduce metapopulation connectivity with potentially unexpected seascape‐level consequences. To better understand these outcomes, we pooled and evaluated fish community data into two seascape groupings for comparisons of biomass and life‐history characteristics. These were remote baseline reefs (>9 hr from regional cities and >4 hr from human habitation, n = 584 locations) and those emulating best‐practice seascapes (BPS, n = 140). BPS were a mix of high‐compliance marine reserves (fishable biomass = 892 ± 696 (±SD) kg/ha, n = 95; >5 km2 and >15 years of closure) and fished seascapes (478 ± 395 kg/ha, n = 45) that had biomass near the maximum sustained yield (MSY) estimates for coral reefs. The fish communities in the BPS locations differed considerably from the remote baseline by having 49% of the median and 32% of the mean biomass, smaller community‐weighted body sizes, and faster growth and mortality rates. Most of the declines were associated with high biomass taxa that included carnivorous jacks (Carangidae), snappers (Lutjanidae), groupers (Serranidae) and triggerfish (Balistidae), which were reduced to between 11% and 28% of the mean baseline. Surgeonfish (Acanthuridae) and parrotfish (Scarinae) were an exception in being reduced to only 48 and 53% of the baseline's mean biomass, respectively. As expected, community‐level body sizes and age values were larger and trophic level higher, while growth and mortality were lower in baselines than BPS seascapes. After evaluating the different environmental responses between seascapes and accounting for the largest geographic factor, longitude, we evaluated the community responses to 4 possible BPS planning scenarios. Biomass responses to age and trophic level and length at maturity were similar and predictable for the two seascapes. In contrast, growth and generation time responses differed between seascapes. Baselines had peak biomass patterns at intermediate values, whereas BPS displayed a declining influence of growth and a saturating response for generation time. Consequently, deviations between BPS and baselines indicate that current BPS proposals do not fully emulate the ecology of remote or wilderness locations. Therefore, wilderness will be a required management designation if the global fish communities are to be fully conserved.

Participatory GIS mapping highlights indirect use and existence values of coastal resources and marine conservation areas

Consideration of social and cultural dimensions in coastal and marine planning has increased and ecosystem services provide important framing to investigate values and priorities associated with these systems. Research efforts in coastal communities offer insights on social dimensions of ocean and coastal management decisions, but questions remain about how demographics and geographic residence affect perceptions of marine resources and management. We conducted and analyzed a public participation geographic information system (PPGIS) mapping survey of Oregon residents to capture uses and perceived values of coastal and marine areas. We measured coastal values, explored regional differences in those values, and identified a suite of coastal and marine ecosystem services that Oregonians prioritize from the recently established marine reserve network. Examining respondent demographics, conservation values, and coastal geographic features, we discovered values varied by region in Oregon, with regions demonstrating distinct value orientations. Regional differences in value orientation highlight the importance of incorporating multiple interpretations of value into coastal resource communication strategies, and the consequence of coastal proximity on attitudes and values about coastal resources. Incorporating use (indirect and direct) and non-use (existence) values into a Total Economic Value framework revealed that participants prioritized indirect use (scenic, recreation) over direct use and existence values coastwide. Spatial variation of participant’s use and value locations demonstrates the utility of participatory mapping in marine spatial planning efforts, both in documenting spatially explicit non-market values of coastal areas and identifying potential areas of conflict among coastal stakeholder groups. Within Oregon’s marine reserve network, which was not delineated in the mapping exercise, value preferences diverged from coastwide averages, wherein existence values (biodiversity/wildlife, wilderness, etc.) were elevated above other categories.

Restricted dispersal in a sea of gene flow.

How far do marine larvae disperse in the ocean? Decades of population genetic studies have revealed generally low levels of genetic structure at large spatial scales (hundreds of kilometres). Yet this result, typically based on discrete sampling designs, does not necessarily imply extensive dispersal. Here, we adopt a continuous sampling strategy along 950 km of coast in the northwestern Mediterranean Sea to address this question in four species. In line with expectations, we observe weak genetic structure at a large spatial scale. Nevertheless, our continuous sampling strategy uncovers a pattern of isolation by distance at small spatial scales (few tens of kilometres) in two species. Individual-based simulations indicate that this signal is an expected signature of restricted dispersal. At the other extreme of the connectivity spectrum, two pairs of individuals that are closely related genetically were found more than 290 km apart, indicating long-distance dispersal. Such a combination of restricted dispersal with rare long-distance dispersal events is supported by a high-resolution biophysical model of larval dispersal in the study area, and we posit that it may be common in marine species. Our results bridge population genetic studies with direct dispersal studies and have implications for the design of marine reserve networks.

The benefits of heterogeneity in spatial prioritisation within coral reef environments

Coral reefs are highly vulnerable habitats, threatened by climate change and local anthropogenic impacts. Management is imperative, and spatial prioritisation apportions the area of interest to inform investments of scarce conservation resources. Spatially delineated planning units used to make management decisions are typically large enough to contain significant natural variabilities, but the ecological significance of such variance is seldom considered in planning decisions. On coral reefs, the patchiness of habitat quality within planning units matters both ecologically and functionally. Here, we show that considering within-planning unit variance in spatial prioritisation influences the location and design of reserve networks. Studying Timor-Leste, we statistically model the average and variance in coral cover. We compare conservation priority areas for scenarios informed by coral cover and variance to a baseline scenario with the spatial prioritisation software Marxan. To further explain these differences, and to show the value of including coral variance as a metric in spatial prioritisation, we created a reserve quality score. We show that the similarity between reserve networks was only 57% for protection, and 44% for restoration objectives. For both objectives, the inclusion of cover variance improves the conservation benefit of management. This project has shown a novel way to target areas for restoration. These results demonstrate that not only is mean coral cover (and, by extension, reef condition) a key criterion in selecting marine conservation actions, but its variance must be considered in spatial conservation prioritisation to improve both the efficiency and benefit of management actions within marine reserve networks.

A coherent, representative, and bioregional marine reserve network shows consistent change in rocky reef fish assemblages

AbstractWorldwide, several countries have established coherent, representative, and large‐scale networks of marine reserves to conserve biodiversity. Very few have, however, published systematic assessments of the ecological responses to this network protection, hindering broad understanding of their generality, utility, and efficacy. We present data collected from systematic sampling of rocky reef fish assemblages at sites across a network of 27 no‐take marine reserve areas (NTMR) and 27 partially protected areas (PPA) nested within multiple marine parks (regional networks) across three Australian bioregions spanning >1000 km of coastline (7° latitude) to test the generality of ecological change across this network. We also sampled 18 reference areas (outside of the marine parks) to provide an independent assessment of potential NTMR effects and also to assess whole marine park effects. Baited remote underwater video (BRUV) was used to sample fishes between depths of 20–40 m over austral winters in four years (2010, 2011, 2015, and 2016). Despite substantial bioregional differences in fish assemblages, large and consistent effects of NTMR protection were detected across all bioregions for a key commercially and recreationally harvested species, Chrysophrys auratus (pink snapper). There were substantial increases in relative abundance of C. auratus in NTMR compared with fished zones through time (effect sizes >150%). The wider assemblage of targeted fish (excluding C. auratus) only showed relatively small effects of protection (~11%) with trends observed for site‐attached wrasses (labrids) and planktivores (e.g., commercially fished Scorpis lineolata) that are recreationally and commercially harvested. Furthermore, the relative abundance of non‐target or by‐catch species generally did not differ among management zones across the bioregional network. These results highlight how NTMR can be used to assess the ecological effects of fishing and wider environmental management, and can be incorporated into ecosystem‐based management for reef species more generally. Importantly, the provision of robust evidence of the performance and generality of NTMR over large‐spatial scales (e.g., bioregions) provides greater confidence in the expected outcomes from marine reserve networks as a conservation management approach.

Estimating discount rates for environmental goods: Are People’s responses inadequate to frequency of payments?

Most stated preference studies estimate discount rates using a split-sample approach. Each sample faces a different payment frequency (for instance, 1, 5, 10) together with a randomly assigned bid vector; both the frequency of payments and the bid are fixed for a specific individual. This paper evaluates whether allowing respondents to choose their preferred payment frequency affects the estimated discount rate. We use data from a contingent valuation survey of a network of marine reserves and estimate discount rates using both an exogenous and endogenous approach. The former calculates the mean of the willingness to pay (WTP) for each sample and then finds the discount rate that makes the present value of each payment frequency equivalent. The latter estimates the WTP and the discount rate jointly. Results show that allowing people to choose the payment schedule significantly reduces the implicit discount rate. We observed the highest reductions in discount rates when we used all the information available from the valuation questions to bound the WTP distribution. Our analysis suggests that the exogenous approach would not be recommended for testing the adequacy of people’s responses to the frequency of payments.

Distribution of demersal fish assemblages along the west coast of St Lucia: Implications for planning no‐take marine reserves

Abstract Evidence‐based decisions relating to effective marine protected areas as a means of conserving biodiversity require a detailed understanding of the species present. The Caribbean island nation of St Lucia is expanding its current marine protected area network by designating additional no‐take marine reserves on the west coast. However, information on the distribution of fish species is currently limited. This study used baited remote underwater stereo‐video to address this shortcoming by investigating the effects of depth and seabed habitat structure on demersal fish assemblages and comparing these assemblages between regions currently afforded different protection measures. From the 87 stations visited a total of 5,921 fish were observed comprising 120 fish taxa across 22 families. Species richness and total abundance were higher within the highly managed region, which included no‐take reserves. Redundancy analysis explained 17% of the total variance in fish distribution, driven predominantly by the seabed habitats. The redundancy analysis identified four main groups of demersal fishes each associated with specific seabed habitats. The current no‐take marine reserves protected two of these groups (i.e. fishes associated with the ‘soft corals, hard corals or gorgonians’ and ‘seagrass’ groups). Importantly, habitats dominated by sponges, bacterial mats, algal turfs or macroalgae, which also supported unique fish assemblages, are not currently afforded protection via the marine reserve network (based on the five reserves studied). These results imply that incorporation of the full breadth of benthic habitat types present would improve the efficacy of the marine reserve network by ensuring all fish assemblages are protected.

Weak biodiversity connectivity in the European network of no-take marine protected areas

The need for international cooperation in marine resource management and conservation has been reflected in the increasing number of agreements aiming for effective and well-connected networks of Marine Protected Areas (MPAs). However, the extent to which individual MPAs are connected remains mostly unknown. Here, we use a biophysical model tuned with empirical data on species dispersal ecology to predict connectivity of a vast spectrum of biodiversity in the European network of marine reserves (i.e., no-take MPAs). Our results highlight the correlation between empirical propagule duration data and connectivity potential and show weak network connectivity and strong isolation for major ecological groups, resulting from the lack of direct connectivity corridors between reserves over vast regions. The particularly high isolation predicted for ecosystem structuring species (e.g., corals, sponges, macroalgae and seagrass) might potentially undermine biodiversity conservation efforts if local retention is insufficient and unmanaged populations are at risk. Isolation might also be problematic for populations' persistence in the light of climate change and expected species range shifts. Our findings provide novel insights for management directives, highlighting the location of regions requiring additional marine reserves to function as stepping-stone connectivity corridors.

Catastrophes, connectivity and Allee effects in the design of marine reserve networks

Catastrophic events, like oil spills and hurricanes, occur in many marine systems. One potential role of marine reserves is buffering populations against disturbances, including the potential for disturbance‐driven population collapses under Allee effects. This buffering capacity depends on reserves in a network providing rescue effects, setting up a tradeoff where reserves need to be connected to facilitate rescue, but also distributed in space to prevent simultaneous extinction. We use a set of population models to examine how dispersal ability and the disturbance regime interact to determine the optimal reserve spacing. We incorporate fishing in a spatially‐explicit model to understand the effect of objective choice (e.g. conservation versus fisheries yield) on the optimal reserve spacing. We show that the optimal spacing between reserves increases when accounting for catastrophes with larger spacing needed when Allee effects interact with catastrophes to increase the probability of extinction. We also show that classic tradeoffs between conservation and fishing objectives disappear in the presence of catastrophes. Specifically, we found that at intermediate levels of disturbance, it is optimal to spread out reserves in order to increase both population persistence and to maximize spillover into non‐reserve areas.

How did a network of marine protected areas impact adjacent fisheries? Evidence from Australia

Marine‐protected areas (MPAs) are an effective means of improving habitat quality and biodiversity in the world’s oceans. While the advantages of MPAs as a mechanism for conservation and biodiversity are well established, the potential improvements to fishery performance resulting from a network of MPAs are still being established. Countries around the world have committed to establishing networks of MPAs within their waters by 2020, in response to the United Nations Convention on Biological Diversity. This, coupled with the increasing global demand for seafood and heavy reliance on fishery resources as a source of economic development for many coastal communities, means that an understanding of how these networks can be expected to impact fishery performance is extremely important. We use a difference‐in‐difference modelling approach to isolate the change in the fishery performance associated with the south‐east marine reserve network in Australia. We find no evidence that the economic performance of adjacent fisheries was negatively impacted by the network. This lack of impact is likely due to a network design explicitly intended to avoid effort displacement in key fisheries, along with fishery management changes intended to remove excess fishing capacity.

A network of grassroots reserves protects tropical river fish diversity.

Intensive fisheries have reduced fish biodiversity and abundance in aquatic ecosystems worldwide1-3. 'No-take' marine reserves have become a cornerstone of marine ecosystem-based fisheries management4-6, and their benefits for adjacent fisheries are maximized when reserve design fosters synergies among nearby reserves7,8. The applicability of this marine reserve network paradigm to riverine biodiversity and inland fisheries remains largely untested. Here we show that reserves created by 23 separate communities in Thailand's Salween basin have markedly increased fish richness, density, and biomass relative to adjacent areas. Moreover, key correlates of the success of protected areas in marine ecosystems-particularly reserve size and enforcement-predict differences in ecological benefits among riverine reserves. Occupying a central position in the network confers additional gains, underscoring the importance of connectivity within dendritic river systems. The emergence of network-based benefits is remarkable given that these reserves are young (less than 25 years old) and arose without formal coordination. Freshwater ecosystems are under-represented among the world's protected areas9, and our findings suggest that networks of small, community-based reserves offer a generalizable model for protecting biodiversity and augmenting fisheries as the world's rivers face unprecedented pressures10,11.

Disentangling the Core–periphery Structure in Marine Reserve Networks Based on a Genetic Algorithm

Disentangling the Core–periphery Structure in Marine Reserve Networks Based on a Genetic Algorithm