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Nonreef habitats such as mangroves, seagrass, and macroalgal beds are important for foraging, spawning, and as nursery habitat for some coral reef fishes. The spatial configuration of nonreef habitats adjacent to coral reefs can therefore have a substantial influence on the distribution and composition of reef fish. We investigate how different habitats in a tropical seascape in the Philippines influence the presence, density, and biomass of coral reef fishes to understand the relative importance of different habitats across various spatial scales. A detailed seascape map generated from satellite imagery was combined with field surveys of fish and benthic habitat on coral reefs. We then compared the relative importance of local reef (within coral reef) and adjacent habitat (habitats in the surrounding seascape) variables for coral reef fishes. Overall, adjacent habitat variables were as important as local reef variables in explaining reef fish density and biomass, despite being fewer in number in final models. For adult and juvenile wrasses (Labridae), and juveniles of some parrotfish taxa (Chlorurus), adjacent habitat was more important in explaining fish density and biomass. Notably, wrasses were positively influenced by the amount of sand and macroalgae in the adjacent seascape. Adjacent habitat metrics with the highest relative importance were sand (positive), macroalgae (positive), and mangrove habitats (negative), and fish responses to these metrics were consistent across fish groups evaluated. The 500‐m spatial scale was selected most often in models for seascape variables. Local coral reef variables with the greatest importance were percent cover of live coral (positive), sand (negative), and macroalgae (mixed). Incorporating spatial metrics that describe the surrounding seascape will capture more holistic patterns of fish–habitat relationships on reefs. This is important in regions where protection of reef fish habitat is an integral part of fisheries management but where protection of nonreef habitats is often overlooked. [ABSTRACT FROM AUTHOR]

Baseline ecological studies of mesophotic coral ecosystems are lacking in the equatorial Indo-West Pacific region where coral reefs are highly threatened by anthropogenic and climate-induced disturbances. Here, we used baited remote underwater video to describe benthic habitat and fish assemblage structure from 10 to 80 m depth at Apo Island, a well-managed marine protected area in the Philippines. We conducted surveys 2 yr after two storms (in 2011 and 2012) caused severe damage to shallow coral communities within the no-take marine reserve (NTMR) of Apo Island, which led to declines in fish populations that had built up over three decades. We found that hard coral cover was restricted to < 40 m deep in the storm-impacted NTMR and a nearby fished area not impacted by storms. Benthic cover at mesophotic depths (> 30 m) was dominated by sand/rubble and rock (dead coral) with low cover of soft corals, sponges and macroalgae. Storm damage appeared to have reached the deepest limit of the fringing reef (40 m) and reduced variability in benthic structure within the NTMR. Species richness and/or abundance of most trophic groups of fish declined with increasing depth regardless of storm damage. There were differences in taxonomic and trophic structure and degree of targeting by fisheries between shallow and mesophotic fish assemblages. Threatened shark species and a fish species previously unreported in the Philippines were recorded at mesophotic depths. Our findings provide a first glimpse of the benthic and fish assemblage structure of Philippine coral reef ecosystems across a wide depth gradient. This work also underscores how a combination of limited coral reef development at mesophotic depths close to shallow reefs and severe habitat loss caused by storms would result in minimal depth refuge for reef fish populations. [ABSTRACT FROM AUTHOR]

No-take marine reserves are increasingly popular tools for conservation and fisheries management. While much attention has been paid to evaluating the effects of design aspects (size, location, etc.) in achieving reserve objectives, less emphasis has been placed on the role of stakeholder compliance. Therefore, the first aim of this study was to evaluate the state of compliance literature and examine the methods used to measure compliance in reserves. The state of compliance literature is limited, although publications with compliance information have increased sixfold in the last decade. However, most studies containing compliance information (63%) fail to provide quantitative estimates. Furthermore, most (95%) quantitative estimates of compliance were reported using a single method, which is problematic because each method has biases and limited applicability. Methods used to indicate compliance include (i) direct observation; (ii) indirect observation; (iii) law enforcement records; (iv) direct questioning; (v) expert opinion; and (vi) modelling. Our second aim was to empirically demonstrate the critical role of compliance in reserve outcomes by comparing a mixed-effects model on compliance data synthesized from 63 marine reserves to that of a null model. The model of best fit demonstrated a negative relationship between non-compliance and target species biomass response ratios. Thus, without incorporating any aspects of reserve design, compliance data predicted reserve response ratios of fish biomass. Accordingly, researchers should explore ways to better understand and measure non-compliance. Therefore, future research should triangulate multiple sources of quantitative compliance data collected using standardized techniques and conduct baseline surveys before reserve implementation. [ABSTRACT FROM AUTHOR]

The article presents a study which aims to determine the capability of no-take marine reserves (NTMRs) in enhancing community complexity and species richness. The underwater visual census (UVC) technique was used in estimating coral reef fishes' density and special richness. Analyses were conducted at two islands in the Philippines. Results indicate the ability of no-take reserves in exporting complex communities outside their boundaries.

This article studies density-dependent spillover from a marine reserve. A large proportion of fish stocks are currently over-exploited by marine capture fisheries. No-take marine reserves are one potential solution to enhance the long-term sustainability of many of these fisheries. The use of marine reserves as fisheries management tools remains controversial, since clear demonstrations of such export functions are technically and logistically difficult. To date, some of the best evidence for spillover comes from studies that have demonstrated increased abundance of targeted fish inside reserves and in adjacent fished areas over time. Mechanisms of spillover can be either density dependent or density independent. Density-dependent movements may occur due to space limitation and territorial interactions. It implies a gradual development of a net export process driven by density-dependent interactions inside a reserve. Density-dependent movement occurs when the rate and directionality of individual movements change with population density.

Marine protected areas are increasingly being implemented to attain a variety of conservation and fisheries management objectives. Although rarely considered, protection of targeted species within these areas may also conserve behaviours (e.g. boldness) that are often the first removed by human exploitation. Here we examine fish behaviour in fished, no-take, and no-entry management zones for a highly targeted reef fish species (coral trout; Plectropomus leopardus ) on coral reefs in two regions of the Great Barrier Reef Marine Park, Australia. Using three behavioural metrics (flight-initiation distance, pre-flight behaviour, and escape trajectories), we demonstrate how protected areas, particularly no-entry zones, can effectively conserve naïve or bold behavioural traits in fish populations. Flight-initiation distance was consistently highest in fished zones, but the effects of protection afforded by no-take and no-entry zones varied by study region. Flight-initiation distance was consistently higher for fish above the minimum legal retention size limit, except in no-entry zones of the southern region. This indicates that no-entry zones may be maintaining near-natural, pre-exploitation behaviour, which could have considerable implications for the genetic and social structures of a highly valuable commercial species. Conservation and fisheries management would therefore benefit from an increased understanding of how fish behaviour can influence population structures, and how these populations may be influenced by fishing and other human interactions. [ABSTRACT FROM AUTHOR]

Fishing is altering aquatic ecosystems through changes in the abundance, species composition and behavior of target species. Changes in fish behavior have received relatively little attention, despite significant evidence of behavioral change driven by human impacts mediating function and processes in terrestrial ecosystems, and emerging evidence that the same is true in marine systems even within marine reserves. Here, we measured the wariness of two families of coral reef fishes in both fished areas and marine reserves embedded within a fished seascape along an exploitation gradient ranging from wilderness sites (Chagos) to heavily fished areas (the Philippines). We used linear mixed effect models to identify relationships between fish flight initiation distance (FID) and fishing pressure, fish size, habitat complexity and life-history stage. Critically, fish FID increased with fishing pressure both in fished areas and inside marine reserves. These results imply that as fishing pressure increases in adjacent areas, progressively greater fish wariness may reduce the magnitude of some ecosystem functions within small marine reserves. [ABSTRACT FROM AUTHOR]