Community-based conservation results in the recovery of reef fish spawning aggregations in the Coral Triangle

In the Coral Triangle community-based marine protected areas (MPAs) are being established at a prolific rate. Their establishment can benefit both fisheries and biodiversity, and they provide both a socially and economically acceptable means of managing coral reefs in developing nations. However, because such MPAs are typically small (usually <0.5 km²), they will rarely provide protection to large mobile fishes. An exception to this limitation may exist when community-based MPAs are established to protect small sites where vital processes occur, such as fish spawning aggregations (FSAs). To test the effectiveness of small (0.1–0.2 km²) MPAs for protecting FSAs, we monitored three FSA sites where brown-marbled grouper (Epinephelus fuscoguttatus), camouflage grouper (Epinephelus polyphekadion) and squaretail coralgrouper (Plectropomus areolatus) aggregate to spawn. Sites were monitored during peak reproductive periods (several days prior to each new moon) between January 2005 and November 2009. All three sites are located in New Ireland Province, Papua New Guinea, and had been exploited for decades, but in 2004 two sites were protected by the establishment of community-based MPAs. The third site continued to be exploited. Over the monitoring period densities of E. fuscoguttatus and E. polyphekadion increased at both MPAs, but not at the site that remained open to fishing. At one MPA the densities of E. polyphekadion increased tenfold. Our findings demonstrate that community-based MPAs that are appropriately designed and adequately enforced can lead to the recovery of populations of vulnerable species that aggregate to spawn.     

Italian marine reserve effectiveness: Does enforcement matter?

Marine protected areas (MPAs) have become popular tools worldwide for ecosystem conservation and fishery management. Fish assemblages can benefit from protection provided by MPAs, especially those that include fully no-take reserves. Fish response to protection can thus be used to evaluate the effectiveness of marine reserves. Most target fish are high-level predators and their overfishing may affect entire communities through trophic cascades. In the Mediterranean rocky sublittoral, marine reserves may allow fish predators of sea urchins to recover and thus whole communities to be restored from coralline barrens to macroalgae. Such direct and indirect reserve effects, however, are likely to be related to the enforcement implemented. In Italy, many MPAs that include no-take reserves have been declared, but little effort has been spent to enforce them. This is a worldwide phenomenon (although more common in some regions than others) that may cause MPAs and reserves to fail to meet their targets. We found that 3 of 15 Italian marine reserves investigated had adequate enforcement, and that patterns of recovery of target fish were related to enforcement. No responses were detected when all reserves were analyzed as a whole, suggesting enforcement as an important factor to be considered in future studies particularly to avoid that positive ecological responses in properly managed reserves can be masked by neutral/negative results in paper parks. Positive responses were observed for large piscivores (e.g. dusky groupers) and sea urchin predators at reserves where enforcement was effective. Those reserves with low or null enforcement did not differ from fished areas.     

The effects of marine protected areas on the population dynamics of a South African limpet, Cymbula oculus, relative to the influence of wave action

Populations of a protandric limpet, Cymbula oculus, were compared between two South African Marine Protected Areas (MPAs), Dwesa and Tsitsikamma, and four exploited sites, and between sites exposed to or sheltered from strong wave action. Harvesting is decimating populations of this limpet. Compared with harvested sites, limpets in MPAs were 30-50% larger, adult densities 75% greater and biomass 30-90% greater. The female:male ratio was 0.58:1 inside the MPAs, but 0.11:1 at harvested sites. Growth rate and age-at-maturity were unaffected by harvesting, but survivorship was 10-fold higher inside MPAs, and reproductive output a staggering 80-fold higher. Conversely, recruitment was three times higher in harvested than protected areas, and inversely correlated with adult density. Wave action had negative effects of similar magnitude to harvesting. Limpets at sheltered sites were 65% larger, biomass 80% greater, female proportions 40% higher, survivorship 25% greater and growth 33% greater. Recruitment was, however, 45% greater at wave-exposed sites. All these effects were detected only inside the MPAs, being masked by harvesting elsewhere. The impacts of harvesting and wave action could never have been detected without the existence of MPAs, emphasizing their importance for base-line studies as well as protection. Dwesa MPA is under threat from poaching and demands for access to resources, but a strong case exists for retaining at least a core fully protected area. Our results clearly illustrate the need for MPAs among the tools used for coastal management.     

Persistence of depleted abalones in marine reserves of central California

We evaluated the persistence and possible recovery of two depleted marine mollusks, the red (Haliotis rufescens) and black abalone (H. cracherodii), in central California, USA. Monitoring over 32-years did not reveal increasing or decreasing trends in red abalone abundances and sizes over the past three decades, in the absence of harvesting. Comparisons between marine reserves protected for at least 25 years and sites with open public access showed significant difference in size structure for black abalone, with individuals greater than 8 cm in shell length comprising 14–37% of animals in reserves and 2–11% at open-access sites, and a trend for greater abundances of red abalone within reserves. Despite no increasing trends, protection in one of the no-take reserves, the Hopkins marine life refuge (HMLR), has led to persistence of red abalone populations over multiple generations, at average densities of 0.2 individuals/m². At other locations, both within the HMLR and elsewhere, red abalone densities are lower than at the location where long-term studies were conducted (av. 0.03 animals/m²), and an order of magnitude lower than for black abalone (av. 0.4 animals/m²). These results suggest that continued fishery closure and protection in no-take reserves are effective tools for allowing persistence of abalone populations, though there are no signs of recovery to levels comparable to those preceding fisheries collapse. Such failure to recover is most likely associated with high natural mortality and possibly continued illegal take, but not with processes underlying low abalone population levels elsewhere, including food or habitat limitation, recruitment failure, or disease. Linking current structure and trends to specific processes is a crucial first step towards devising focused strategies for conserving and re-building depleted marine populations.     

Assessing the effects of marine protected area (MPA) on a reef fish assemblage in a northwestern Mediterranean marine reserve: Identifying community-based indicators

Marine protected areas (MPAs) are increasingly envisaged as a tool to manage coastal ecosystems and fisheries. Assessment of their performance with respect to management objectives is therefore important. A number of MPAs provided conservation benefits for fished species. Observed benefits do not apply to all species at all times, and responses to protection are also highly variable among fish taxa. Among the many empirical studies on marine reserves, only a few designs considered ‘before and after data’ and spatial variation. In this paper, we are interested in assessing the effect of a no-take reserve on the reef fish assemblage in a northwestern Mediterranean example. Data were obtained from a three-year survey using underwater visual censuses (UVC), before and after MPA establishment. Permutational multivariate analysis of variance (PERMANOVA) and multivariate regression trees (MRT) were used to evaluate the effects of reserve protection on the reef fish assemblage, while accounting for habitat. Modelled biological responses were abundances and diversity indices calculated at different levels of the assemblage. Significant effects were found for many of these metrics. In addition to PERMANOVA, univariate models provided more insight into the magnitude and direction of effects. The most sensitive metrics were related to large species and species targeted by fishing. These results may be used to choose the metrics that are more suitable as community-based indicators of MPA impact in the perspective of monitoring programs.     

Gradients of abundance and biomass across reserve boundaries in six Mediterranean marine protected areas: Evidence of fish spillover?

Marine protected areas (MPAs) are considered as an effective tool in marine coastal management, and considered able to enhance local fisheries through adult fish spillover. Indirect evidence of fish spillover could be obtained by horizontal gradients in fish abundance. To address this question, the existence of gradients of fish abundance and biomass across marine reserve boundaries was assessed in six Mediterranean MPAs using underwater visual censuses performed at various distances from the core of the MPA, in integral reserve (IR), to buffer zone (BZ) and fished areas. A reserve effect was evidenced with higher values of fish species richness (×1.1), abundance (×1.3), and biomass (×4.7) recorded inside MPAs compared to adjacent fished areas. Linear correlations revealed significant negative gradients in mean fish biomass in all the reserves studied after the effect of habitat had been removed, whereas negative gradients in abundance were less conspicuous. Generalized additive models suggested two main patterns of biomass gradients, with a sharp decrease at the IR-BZ boundary or at the BZ-fished area boundary. It was estimated that fish spillover beneficial to local fisheries occurred mostly at a small spatial scale (100s of metres). The existence of regular patterns of negative fish biomass gradients from within MPAs to fished areas was consistent with the hypothesis of adult fish biomass spillover processes from marine reserves and could be considered as a general pattern in this Mediterranean region.     

Links between sex change and fish densities in marine protected areas

Sex change is widespread among marine fishes, including many species that are fished heavily, and is thought to be of conservation concern under some circumstances. As such, an important question in conservation is whether the implementation of marine protected areas (MPAs), which is a commonly used marine conservation tool, works as effectively for sex-changers as for non-sex-changers. To address this issue, we used meta-analyses of the ratio of fish abundances inside vs. outside MPAs to determine whether sex change affects the extent to which fish densities respond to protection. When all data were considered, there were similar responses to protection irrespective of reproductive mode. However, when analyses were restricted to older reserves (at least 10 years’ protection), female-first sex-changers consistently benefited from protection. Non-sex-changers and male-first sex-changers showed more variable responses to protection and, as a result, there were no significant differences between fish with different reproductive modes in their overall response to protection. The same results were observed when the effects of fisheries status (targeted vs. not targeted) were controlled. Our results support the use of MPAs as important components of conservation and demonstrate that old reserves are most consistently beneficial to female-first sex-changing species. Finally, our results highlight the fact that some effects of protection are only detectable after several generations.     

Inter-annual variability in the home range of breeding turtles: Implications for current and future conservation management

We assessed home range size for breeding loggerhead turtles (Caretta caretta) near the limit of the species range at the Greek island of Zakynthos in the Mediterranean. Thirteen adult females and seven adult males were tracked using GPS units (loggers and transmitters) during May and June of 2006, 2007 and 2008. Kernel analysis indicated that core home range sizes (50% estimator; range: 2.9-19.7 km²) for both males and females were restricted to a 7.5 km tract of coastline. 15% of GPS locations fell outside of the national park protection zones, while within the protected breeding area 88% of GPS locations occurred in zones of minimal protection. Female home ranges were 64% larger in 2008 than in 2006 and 2007, indicating that several years monitoring may be required for the most effective designation of marine protected areas (MPAs). Ten of the tracked females departed the core breeding area on 15 occasions for periods of 1-15 days travelling distances of 10-100 km, although none nested at alternative breeding sites. The inter-annual variability of breeding area home range size and likelihood of incidence of forays appeared be correlated with barometric pressure. The movement responses of loggerheads to environmental conditions implicates an ability to switch nesting areas over small scales in response to climate change. However, such behaviour suggests the protection of existing core breeding sites may be inadequate, with policy makers being required to consider the protection of broader areas to encompass potential changes in the habitat needs of this species.     

Connectivity between island Marine Protected Areas and the mainland

In addition to protecting important species or ecosystems, ideally Marine Protected Areas (MPAs) should also act as propagule sources and be located where they can receive larval influxes so as to buffer species against local extinctions and allow genetic mixing. There are many examples of island MPAs across the world because of their advantages compared to mainland sites, and although evidence suggests they effectively protect biodiversity and may have localized fisheries benefits, their contribution to larval export and connectivity to mainland areas remains largely unknown; these are important aspects of MPA sustainability and functioning. Here I examined the genetic differentiation between four island MPAs in northern Europe and their respective mainlands, relative to differentiation of populations along the coast at similar spatial scales for two marine invertebrates (Semibalanus balanoides, planktonic larvae; Nucella lapillus, direct development). These data were used to infer past patterns of larval exchange between populations. Gene flow was restricted at all four locations between the islands and the mainland, compared to gene flow along the coast (for both species) and more distant islands had greater differentiation than those closer to the mainland for S. balanoides, but not for N. lapillus. My results of genetic analysis suggest that island MPAs may not provide as much larval export or receive as much buffering against local extinctions, compared with mainland populations (for a similar sized protected area). My findings are especially relevant to the creation of MPA networks and in understanding the importance of connectivity in achieving the greatest fisheries benefits and in ensuring inter-MPA linkages. Low levels of larval exchange may limit the success of any protected area and may prevent multiple conservation objectives from being achieved.     

Establishing baselines for recovery in a marine reserve (Poor Knights Islands, New Zealand) using local ecological knowledge

Local ecological knowledge is a potentially valuable, but mostly untapped, resource for evaluating decadal-scale shifts in abundances of organisms. In this study, recollections of long-term divers were quantified to assess changes in underwater life at the Poor Knights Islands in temperate northeastern New Zealand from the 1960s to 2000s, in order to establish baselines for recovery since the islands were protected within a no-take marine reserve in late 1998. Data were validated against quantitative data from contemporary monitoring programmes (established in the late 1990s), with the divers conservative in that their reported changes were smaller than those from the scientific monitoring. The divers reported large (60–88%) and steady long-term declines in abundances of black corals (Lillipathes lilliei), tube sponges (Calyx imperialis), packhorse lobster (Sagmariasus verreauxi), and several large predatory fishes. There was little or no suggestion of recent recovery in these species following no-take protection. Only the sparid fish Pagrus auratus and sharks were considered to have substantially increased in numbers following no-take protection. Multivariate analysis of data derived from the divers’ recollections detected no signs of recovery at the community-level, although full no-take protection appeared to have stopped further change along the major axis of variation. Our results highlight the value of local ecological knowledge for investigating decadal-scale changes in reef biota and for providing a longer-term context for evaluating the efficacy of marine reserves.     

Effects of fishing and protection on Brazilian reef fishes

The vast Brazilian coast harbors unique and diverse reef fish communities. Unfortunately, relatively little is known about the impact of fishing on these fish species, and few management or conservation efforts are being made to protect them. Here, we examine the effect of different levels of protection on the composition, abundance, and size structure of reef fish species along a 2500 km portion of the Brazilian coastline, noting in particular the relative abundance of endemics and the effect of protection on these species. Pairwise comparisons of sites with different protection status (more versus less protected) were used to determine the potential responses of reef fishes to the establishment of marine protected areas. Highly targeted species (top predators and large herbivores) were significantly more abundant and larger in size within sites with a higher degree of protection, indicating that they benefit from protection, while lightly fished and unfished species were not. These results are consistent with past work documenting the responses of species to protection. Here, we use our results in particular to suggest strategies and provide expectations for managing and protecting Brazilian reef fisheries. Because this biogeographic province lies entirely within the jurisdiction of a single nation, there may be unique and significant opportunities to effectively manage and conserve these fish species.     

Do partial marine reserves protect reef fish assemblages?

Fish assemblages in the Mimiwhangata Marine Park, an area closed to commercial fishing but open to most forms of recreational fishing, were compared with adjacent fished areas. Two survey methodologies were used; baited underwater video and underwater visual census. Snapper (Pagrus auratus), the most heavily targeted fish species in the region, showed no difference in abundance or size between the Marine Park and adjacent control areas. When compared to the fully no-take Poor Knights Island Marine Reserve and two other reference areas open to all kinds of fishing (Cape Brett and the Mokohinau Islands), the abundance and size of snapper at the Marine Park were most similar to fished reference areas. In fact, the Marine Park had the lowest mean numbers and sizes of snapper of all areas, no-take or open to fishing. Baited underwater video found that pigfish (Bodianus unimaculatus), leatherjackets (Parika scaber) and trevally (Pseudocaranx dentex) were significantly more common in the Marine Park, than in the adjacent control areas. However, none of these species are heavily targeted by fishers. Underwater visual census found similar results with five species significantly more abundant in the Marine Park and five species more abundant outside the Marine Park. The lack of any recovery by snapper within the Marine Park, despite the exclusion of commercial fishers and restrictions on recreational fishing, indicates that partial closures are ineffective as conservation tools. The data suggest fishing pressure within the Marine Park is at least as high as at other ‘fished’ sites.     

Hindsight in marine protected area selection: A comparison of ecological representation arising from opportunistic and systematic approaches

Systematic approaches to site selection for marine protected areas (MPAs) are often favored over opportunistic approaches as a means to meet conservation objectives efficiently. In this study, we compared analytically the conservation value of these two approaches. We locate this study in Danajon Bank, central Philippines, where many MPAs were established opportunistically based on community preference, with few if any contributions from biophysical data. We began by identifying the biophysical data that would have been available when the first MPA was created in Danajon Bank (1995). We next used these data with the reserve selection software Marxan to identify MPAs that covered the same area as is protected under the current set of MPAs (0.32% of the total study area) and that would protect the greatest number of conservation targets at the lowest cost. We finally compared the conservation value of the current MPAs to the value of those selected by Marxan. Because of the dearth of biophysical data available in 1995 and the small area currently under protection, Marxan identified multiple configurations of MPAs that would protect the same percentage of conservation targets, with little differentiation among sites. Further, we discovered that the costs of obtaining and analyzing these data to be used for conservation planning would have been large relative to resources typically available to conservation planners in developing countries. Finally, we found that the current set of MPAs protected more ecological features than would be expected by chance, although not as many as could be protected using a systematic approach. Our results suggest that an opportunistic approach can be a valuable component of conservation planning, especially when biophysical data are sparse and community acceptance is a critical factor affecting the success of an MPA.     

Effects of marine reef National Parks on fishery CPUE in coastal Kenya

The role of marine protected areas in conserving fish stocks and their potential influence on adjacent fisheries was studied at Malindi and Watamu Marine National Parks, Kenya (established in 1968). For most species catch per unit effort (CPUE) in traditional Dema traps fished across park boundaries was higher within the parks (up to an order of magnitude). However, a few species (e.g., the seagrass parrotfish, Leptoscarus vaigensis and the whitespotted rabbitfish, Siganus sutor, WSR) had higher seasonal CPUE outside the parks. Potential spillover of fishes from the parks to adjacent fished areas was tested with a logistic “decay” model of density gradients (CPUE) across park borders from fringing and patch reefs. A steep decay in CPUE off the Malindi patch reef suggested little spillover of most species. However, greater spillover was suggested off fringing reefs. Species differences were evident. The two most important commercial species showed different density gradients. Species diversity declined more abruptly off the fringing reefs. We conclude that although spillover of most species from the parks is limited, the most important commercial species exhibits significant spillover to adjacent fisheries and the Parks likely comprise important nursery and growth areas for other species.     

Improving social acceptability of marine protected area networks: A method for estimating opportunity costs to multiple gear types in both fished and currently unfished areas

We present a novel method for calculating the opportunity costs to fishers from their displacement by the establishment of marine protected areas (MPAs). We used a fishing community in Kubulau District, Fiji to demonstrate this method. We modelled opportunity costs as a function of food fish abundance and probability of catch, based on gear type and market value of species. Count models (including Poisson, negative binomial and two zero-inflated models) were used to predict spatial abundance of preferred target fish species and were validated against field surveys. A profit model was used to investigate the effect of restricted access to transport on costs to fishers. Spatial distributions of fish within the three most frequently sighted food fish families (Acanthuridae, Lutjanidae, Scaridae) varied, with greatest densities of Lutjanidae and Acanthuridae on barrier forereefs and greatest densities of Scaridae on submerged reefs. Modelled opportunity cost indicated that highest costs to fishers arise from restricting access to the barrier forereefs. We included our opportunity cost model in Marxan, a decision support tool used for MPA design, to examine potential MPA configurations for Kubulau District, Fiji Islands. We identified optimum areas for protection in Kubulau with: (a) the current MPA network locked in place; and (b) a clean-slate approach. Our method of modelling opportunity cost gives an unbiased estimate for multiple gear types in a marine environment and can be applied to other regions using existing species data.     

Evaluating marine protected areas for the conservation of tropical coastal sharks

Global declines in shark populations have created uncertainty in the future status of many species and conservation efforts are urgently needed. Marine protected areas (MPAs) are used increasingly as conservation tools around the world, but how they benefit mobile and wide ranging species like sharks remains unclear. To evaluate the degree of protection MPAs may provide for sharks, we used an array of acoustic receivers to examine the movements and spatial use of two tropical coastal species within two MPAs in the Great Barrier Reef Marine Park, Australia. Juvenile pigeye (Carcharhinus amboinensis) and adult spottail (Carcharhinus sorrah) sharks were fitted with acoustic transmitters from 2009 to 2010. Both species displayed long-term use of MPAs, with some individuals detected for longer than 600 days. The mean percentage of time C. amboinensis and C. sorrah spent inside MPAs was 22% and 32%, respectively. MPA use varied seasonally, with C. amboinensis spending a higher percentage of time inside MPAs in summer (mean = 28%) and C. sorrah spending a higher percentage of time inside MPAs in winter (mean = 40%). Although sharks used large areas inside MPAs, most individuals tended to use only half of the available protected space. In addition, all sharks made excursions from MPAs and individuals exited and re-entered at consistent locations along the MPA boundaries. These results demonstrate that MPAs have conservation benefits for shark populations by providing protection across different species and life stages, and tracking studies can be used to help tailor MPA design to maximize effectiveness.     

Restoration of threatened red gorgonian populations: An experimental and modelling approach

The increasing disturbances affecting marine communities highlight the need to examine restoration measures that can be added to other conservation efforts for threatened populations. The main goal of this study was to examine the usefulness of ecological restoration in the management of gorgonian populations damaged by diving activity in intensively visited marine protected areas (MPAs). We used field experiments as well as simulations from size-structured matrices to assess the utility of transplantation of living fragments from damaged colonies to increase the viability of threatened populations. Despite results showing that technique failure caused the loss of 40% of transplants, well-attached transplants achieved survival rates (80%) similar to those of natural colonies. Surprisingly, environmental conditions (light level and presence of algae) did not have a significant effect on the mortality of the transplants, but did affect methodological failure rates (37% of transplants were lost in the photophilous treatments in contrast to the 25% lost in sciaphilous treatment). The simulations showed a substantial increase in the annual population growth rate (λ) only when transplantation was performed every two years and under the most demanding conditions (recovering 75% of the detached colonies and obtaining 3 fragments from each one). Predictions from the size-structured matrix model suggest severe limitations of this technique at larger spatial scales. However, our study confirms the feasibility of this restoration measure to contribute to the recovery of populations in MPAs affected by local disturbances. The experimental and modelling approaches developed here may provide useful guidelines for future studies on the restoration of marine populations.     

Food-web traits of protected and exploited areas of the Adriatic Sea

This study presents a comparative analysis of protected and exploited Mediterranean Sea food webs using standardized ecological models of two ecosystems: the Central-North Adriatic Sea (highly exploited) and the Miramare Natural Marine Reserve (Northern Adriatic Sea, protected since 1986). Food webs are analysed in terms of structural and functional traits including trophic levels, transfer efficiency, trophic role of species and keystoneness, trophic spectra and other synthetic ecological indicators. Our results highlight similarities between food webs of the Adriatic Sea, differences that are likely due to the impact of fishing and differences that should be related to other factors. Analysis of biomass distribution along functional groups and of trophic spectra indicates that protected area presents higher mean trophic level of the community, higher biomasses, lower production and generally lower transfer efficiency than fished area. Our results indicate that measures of food web complexity (system omnivory index and ascendency), as well as pelagic/demersal and fish/invertebrates biomass ratios are higher in the protected area than in exploited ecosystem due to fishing-induced changes. Thus, this study highlights that marine protected areas can efficiently contribute to maintain structural and functional traits of marine ecosystems.     

Responses to marine reserves: Decreased dispersion of the sparid Pagrus auratus (snapper)

Quantifying the movement of exploited species inside marine reserves is a popular research topic, yet few studies have quantified movement inside and outside of reserves. If individuals inside reserves behave differently to those outside, this information should be incorporated into reserve design and in management efforts to avoid the selective removal of certain behaviors. We used acoustic telemetry to monitor the movements of the sparid Pagrus auratus (snapper) inside and outside a marine reserve (the Leigh Marine Reserve, north-eastern New Zealand). We tagged 39 snapper within an array of acoustic receivers that encompassed reserve and fished areas. Nineteen snapper were resident over a 5-month period; the remainder either left the array or died. Residential fish expressed two home range types. One group had uni-modal home ranges that on average encompassed c.900 m linear distance. All nine residential snapper from the reserve displayed this behavior, as well as five of ten residential fish from the non-reserve area. The second group (five fish, all from the non-reserve area) had home ranges with two separate modes (bi-modal home ranges), which on average encompassed c.2 100 m linear distance. We suggest that some aspect of the marine reserve environment encourages extreme residency by either the modification of individual behaviors or through the removal of selective exploitation. If true this suggests that reserves and populations of exploited animals may become dependent on the life history characteristics of the individuals they encourage or select for.     

Designing marine reserves for interacting species: Insights from theory

The primary goals of marine reserves include protecting biodiversity and ecosystem structure. Therefore, a multispecies approach to designing and monitoring reserve networks is necessary. To gain insight into how the interactions between species in marine communities may affect reserve design, we synthesize marine reserve community models and community models with habitat destruction and fragmentation, and we develop new extensions of existing models. This synthesis highlights the potential for species interactions to alter reserve design criteria; in particular, accounting for species interactions often leads to an increase in reserve size necessary to protect populations. Accounting for species interactions also indicates the need to base reserve design and monitoring on a variety of species, especially long-distance dispersers, inferior colonizers, and specialists. Finally, the new model extensions highlight how, given dispersal, source populations outside reserves as well as increases in fished populations after reserve establishment may negatively affect reserve populations of competitors or prey. Therefore, multispecies harvest dynamics outside reserves and before reserve establishment are critical to determining the appropriate reserve size, spacing, and expectations after establishment. These models highlight the importance of species interactions to reserve design and provide guidelines for how this complexity can begin to be incorporated into conservation planning.