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Climate change can affect reef fish both directly (e.g., mortality, growth, fecundity) and indirectly (e.g., habitat degradation). The extent to which the effects of rising water temperature could drive changes in fish populations and if and how these effects may interact with potential management interventions remain unclear. The objective of this study was to test various hypothesized mechanisms by which sea surface temperature (SST) could affect reef fish population dynamics and explore these effects in combination with fishing effort restrictions and spatial closures. To do this, we modeled hypothesized relationships between SST and two governing parameters of the fish populations: intrinsic growth rate (r) and carrying capacity (K). We coupled these temperature-dependent fish population models with a fisheries harvest model and explored interactions between thermal effects, fishing effort level, and spatial closures. Under small closure scenarios, we found that the thermal effects models predicted substantially lower fish population biomass and harvest compared to the baseline (constant r and K) model. Under large closure scenarios, the thermal effects models more closely resembled the baseline. Generally, incorporating spatial closures mitigated some of the detrimental thermal effects on fish biomass and allowed for increased harvest under certain fishing effort levels. Whether intrinsic growth or carrying capacity most affected fish population levels also depended on the fishing effort and the spatial closure area. Overall, we described how fishing effort and spatial closures can influence the relative importance of key processes and the extent to which rising water temperatures affect fish populations and harvest. [ABSTRACT FROM AUTHOR]

Temporal patterns in spawning and juvenile recruitment can have major effects on population size and the demographic structure of coral reef fishes. For harvested species, these patterns are crucial in determining stock size and optimizing management strategies such as seasonal closures. For the commercially important coral grouper (Plectropomus spp.) on the Great Barrier Reef, histological studies indicate peak spawning around the summer new moons. Here we examine the timing of spawning activity for P. maculatus in the southern Great Barrier Reef by deriving age in days for 761 juvenile fish collected between 2007 and 2022, and back-calculating settlement and spawning dates. Age-length relationships were used to estimate spawning and settlement times for a further 1002 juveniles collected over this period. Unexpectedly, our findings indicate year-round spawning activity generates distinct recruitment cohorts that span several weeks to months. Peak spawning varied between years with no clear association with environmental cues, and little to no alignment with existing seasonal fisheries closures around the new moon. Given the variability and uncertainty in peak spawning times, this fishery may benefit from additional and longer seasonal closures, or alternative fisheries management strategies, to maximize the recruitment contribution from periods of greatest reproductive success. [ABSTRACT FROM AUTHOR]

Coral reef fish assemblages are threatened globally, underscoring the need for data‐driven management to reduce threats and restore populations. Comparing fishery management approaches is aided by a detailed understanding of the key factors controlling species' abundances.The aims of this study were to assess the importance of biophysical factors compared with fishing impacts on the biomass of reef fishes on Florida's Coral Reef and to evaluate the potential effects of common management interventions on fish biomass.Fishing impact was estimated using a fishery‐independent modelling approach and the biomass of the snapper–grouper complex as a proxy for the effects of fishing. Using a separate subset of data from underwater fish surveys, estimated fishing impact was then combined with 18 biophysical variables to model the current biomass of all reef fish species, the snapper–grouper complex, grazing species and species collected for aquaria.Models explained between 51 and 64% of the variance in fish biomass for the fish groups. The strongest predictor of biomass in the snapper–grouper complex was fishing impact (accounting for 25.2% of the explained variance), whereas reef complexity was the strongest predictor for all other groups.High‐resolution maps were produced from the statistical models, including maps of current fish biomass and maps of potential biomass under several management scenarios: a no‐take marine reserve, moderate and extensive coral restoration and the addition of artificial benthic structure. Adding structure had the largest single impact on predicted fish biomass (23–72% increase from current estimated levels). However, beneficial synergies emerged when combining habitat‐based management and fishing closures, with some combinations resulting in a reef‐wide averaged 89% increase in biomass relative to current estimated levels.The results suggest that conservation strategies aimed at protecting and increasing structural reef complexity should be an important part of fishery management discussions. [ABSTRACT FROM AUTHOR]

Coral reef fishes often exhibit specific or restricted depth distributions, but the factors (biotic or abiotic) that influence patterns of depth use are largely unknown. Given inherent biological gradients with depth (i.e. light, nutrients, habitat, temperature), it is expected that fishes may exploit certain depths within their environment to seek out more favourable conditions. This study used baited remote underwater video (BRUV) systems to document variation in the taxonomic and functional (trophic and size) structure of a fish assemblage along a shallow to upper-mesophotic depth gradient (13–71 m) at a submerged, offshore shoal in the northern Great Barrier Reef. BRUVs were deployed during two separate time periods (February and August 2017), to separately examine patterns of depth use. Both the relative abundance and diversity of reef fishes declined with depth, and there were pronounced differences in the taxonomic and functional structure of the fish assemblage across the depth gradient. In shallow habitats (< 30 m), the fish assemblage was dominated by herbivores, detritivores, planktivores and sessile invertivores, whereas the fish assemblage in deeper habitats (> 30 m) was dominated by piscivores and mobile invertivores. Depth and habitat type were also strong predictors for important fisheries species such as coral trout (Plectropomus spp.), emperors (Lethrinus spp.) and trevallies (Carangid spp.). We found limited evidence of temporal changes in depth and habitat use by fishes (including fisheries target species), although recorded temperatures were 4 °C higher in February 2017 compared to August 2017. [ABSTRACT FROM AUTHOR]

Healthy parrotfish (family Scaridae) communities fulfill the essential ecosystem process of herbivory in coral reefs, but artisanal fisheries that target parrotfish have degraded their populations. Outright bans and gear restrictions that do not allow parrotfish capture can effectively protect and restore parrotfish populations. As these management actions would be unfeasible in many places, options that allow some fishing but still encourage population rebuilding need to be considered. The life history of parrotfish complicates management decisions because they transition from a mostly female “initial phase” to an all-male “terminal phase.” Size-selective fishing on the largest fish can lead to unnaturally low proportions of males in a population, potentially leading to losses in reproduction. At the same time, these visually distinct life phases could present an opportunity to employ a type of catch restriction that would be easy to understand and monitor. We built an agent-based model of the stoplight parrotfish, Sparisoma viride, which included three possible mechanisms of life-phase transitioning, to predict how this species and others like it might react to catch restrictions based on life phase. We found that restricting catch to only terminal-phase (male) fish typically led to populations of greater abundance and biomass and less-disturbed life-phase ratio, compared to a similar fishing mortality applied to the whole population. This model result highlights a potentially important lesson for all exploited protogynous hermaphrodites: a robust population of initial-phase fish may be key to maximizing reproductive potential when the size at life-phase transition compensates for changes in population structure.

Environmental DNA (eDNA) metabarcoding is an evolving tool that can provide broader assessments of marine biodiversity than conventional visual census methods. The outputs of this approach are, therefore, crucial to provide data for conservation priorities and to support fisheries management. We conducted a study using eDNA metabarcoding to understand the distribution of marine biodiversity across Indonesia and to investigate the abundance of three major phyla that comprise a majority of marine biodiversity. In this study, a total of 13,819,634 reads corresponding to 23,252 unique sequences belonging to the phyla Chordata, Mollusca, and Echinodermata were generated from COI amplicons obtained from 92 seawater eDNA samples collected from nine locations and 17 sites. Beta diversity differed significantly across locations (PERMANOVA: p < 0.05) based on Bray–Curtis and Jaccard indices. Taxa of interest were not distributed equally and there were no discernible patterns detected across the sampling area. This might be due to the highly variable percentage of sequenced species between families, preventing robust estimation of species richness. Overall, 45% of reads were identified to species level while 55% were classified as unidentified taxa. Interestingly, the percentage of unidentified taxa was similar between two locations with distinct characteristics representing eastern and western extremities of the sampling region. Despite a relatively poor rate of assignment to species level, our results highlight unprecedented levels of marine biodiversity and strong differences in species composition. This further supports the contention that the eDNA approach is a sensitive method that can provide useful data, in particular to detect changes in species composition. Importantly, this method is clearly advantageous to evaluate marine biodiversity on a large scale and can provide data to support region-wide coral reef management strategies. Knowing species diversity and the degree to which various taxa are distributed is a fundamental for advancing our knowledge of marine ecology and can play an important role in forecasting population dynamics and evolution as well as in refining conservation practices. [ABSTRACT FROM AUTHOR]

Marine food webs are structured through a combination of top‐down and bottom‐up processes. In coral reef ecosystems, fish size is related to life‐history characteristics and size‐based indicators can represent the distribution and flow of energy through the food web. Thus, size spectra can be a useful tool for investigating the impacts of both fishing and habitat condition on the health and productivity of coral reef fisheries. In addition, coral reef fisheries are often data‐limited and size spectra analysis can be a relatively cost‐effective and simple method for assessing fish populations. Abundance size spectra are widely used and quantify the relationship between organism size and relative abundance. Previous studies that have investigated the impacts of fishing and habitat condition together on the size distribution of coral reef fishes, however, have aggregated all fishes regardless of taxonomic identity. This leads to a poor understanding of how fishes with different feeding strategies, body size‐abundance relationships, or catchability might be influenced by top‐down and bottom‐up drivers. To address this gap, we quantified size spectra slopes of carnivorous and herbivorous coral reef fishes across three regions of Indonesia representing a gradient in fishing pressure and habitat conditions. We show that fishing pressure was the dominant driver of size spectra slopes such that they became steeper as fishing pressure increased, which was due to the removal of large‐bodied fishes. When considering fish functional groups separately, however, carnivore size spectra slopes were more heavily impacted by fishing than herbivores. Also, structural complexity, which can mediate predator‐prey interactions and provisioning of resources, was a relatively important driver of herbivore size spectra slopes such that slopes were shallower in more complex habitats. Our results show that size spectra slopes can be used as indicators of fishing pressure on coral reef fishes, but aggregating fish regardless of trophic identity or functional role overlooks differential impacts of fishing pressure and habitat condition on carnivore and herbivore size distributions. [ABSTRACT FROM AUTHOR]

Multiuse marine protected areas (MPAs) that utilize a mosaic of no-take and sustainable use zones are an increasingly common tool for promoting fish population recovery while minimizing socioeconomic conflict. However, significant gaps remain in our understanding of the effects of multiuse MPAs on reef-fish populations, and how protection from fishing may interact with biophysical gradients to drive ecological outcomes. Here, we examine changes in fish assemblages inside and outside of two multiuse MPAs in Raja Ampat, Indonesia, over the first four to five years after their implementation. We use linear models to assess the impact of protection status, anthropogenic pressure, and biophysical gradients on changes in four biological metrics: abundance, biomass, mean size, and size-spectra. In addition, we use multivariate analyses to assess whether fish assemblages in protected and unprotected reefs diverged after MPA establishment. We find that both fish abundance and biomass were driven equally or more by benthic characteristics than protection status and that these environmental impacts were decoupled from the effects of MPAs. Contrary to expectations, increases in abundance were more pronounced in unprotected reefs, where fish assemblages diverged from protected reefs through an increase of herbivorous parrotfishes (Subfamily Scarinae) likely driven by increased algal production on hard-bottom reef areas. However, mean size and size-spectra improved in sustainable use zones compared to unprotected reefs, demonstrating that non-exclusionary management can provide ecological benefits, especially when combined with nearby no-take areas. Increased mean size was also associated with lower human population sizes, suggesting a strong influence of fishing pressure, which is mediated by MPAs. Our findings suggest that multiuse MPAs can quickly achieve some fisheries management objectives and that these effects are likely to increase over longer timescales. However, biophysical context can have significant impacts on reef-fish assemblages that are distinct from the effects of overlying fisheries management. [ABSTRACT FROM AUTHOR]

Fisheries management relies on various catch and effort controls to preserve spawning stock biomass and maximize sustainable yields while limiting fishery impacts on marine ecosystems. These include species-specific minimum or maximum size limits to protect either small non-reproductive subadults, a portion of reproductively mature adults, or large highly fecund individuals. Protecting size classes of mature fish is expected to yield a viable source of larvae for replenishing populations and reduce the risk of recruitment overfishing, yet size-specific recruitment contributions have rarely been assessed empirically. Here, we apply genetic parentage analysis to measure the reproductive success of a size-structured population of a commercially important species of coral grouper (Plectropomus maculatus—Serranidae) in no-take marine reserves (NTMRs) in the Great Barrier Reef Marine Park, Australia. Although the per capita reproductive success of individual fish increases rapidly with body length, the numerous young mature female fish, below the minimum size limit (MSL) (38 cm total length), were responsible for generating disproportionately large contributions (36%) towards larval replenishment of both fished and reserve reefs. Our findings indicate that MSLs are an effective harvest control measure to safeguard a portion of the spawning stock biomass for coral grouper and supplement recruitment subsidies assured from NTMRs. [ABSTRACT FROM AUTHOR]

Drawing from ethnographic fieldwork, this paper attends to the persistent use of Destructive Fishing Gear (DFG) in a Marine Protected Area (MPA) in southeastern Tanzania. Based on participant observation, document analysis, in-depth interviews and focus group discussions conducted with villagers, I argue that the MPA has failed to eliminate the use of DFG because of its inability to address the historically-embedded political, economic, and sociocultural dimensions of DFG use in the inshore fishery. I contend that pre-existing and conservation-induced conditions of poverty drive the continued use of DFG inside the MPA. Such circumstances are framed by colonial and post-independence state-level development policies. They are also textured by breakdowns in customary marine tenure practices, changing beliefs about which types of fishing gear villagers consider to be traditional, and community-defined moral rights to fish for the fulfilment of basic material needs. I maintain that MPAs must take into account the anthropological complexities of poverty if they are to be effective.

Catastrophic overfishing of small‐scale coastal fisheries through the Pacific poses a major threat to regional food security and biodiversity. Globally, approaches to fisheries assessment and management that were developed for industrial fisheries, are failing small‐scale data‐poor fisheries. The Pacific Community has called for a complete rethink of fisheries methodologies for the region; a "new song" of change for small‐scale coastal fisheries. This article describes the application in Fiji of a new approach to facilitating coastal fisheries management reform. Spawning Potential Surveys (SPS) is a pragmatic multi‐disciplinary blend of sciences, that combines a new form of length‐based assessment and communication strategies informed by theories of behavior change, nudge and diffusion, that is initiated with programs of citizen science to inform policy development and catalyze broader societal change. Our project successfully coordinated Fiji‐based NGOs to work with the Ministry of Fisheries, communities, provincial government and supply chains, to collect the data needed to assess ~90% of the Fijian reef fish catch, conduct the analyses needed to develop new management policies, and build a broad consensus in society to support the ongoing reform process that has now been initiated by the Ministry. This project demonstrates the feasibility and effectiveness of the SPS methodology for informing and motivating coastal fisheries reform in the Pacific, as well as the necessity of a long term and multi‐disciplinary approach to achieve the societal change needed. [ABSTRACT FROM AUTHOR]

Background: Coral reefs are rapidly changing in response to local and global stressors. Research to better understand and inform the management of these stressors is burgeoning. However, in situ studies of coral reef ecology are constrained by complex logistics and limited resources. Many reef studies are also hampered by the scale-dependent nature of ecological patterns, and inferences made on causal relationships within coral reef systems are limited by the scales of observation. This is because most socio-ecological studies are conducted at scales relevant to the phenomenon of interest. However, management often occurs across a significantly broader, often geopolitical, range of scales. While there is a critical need for incisive coral reef management actions at relevant spatial and temporal scales, it remains unclear to what extent the scales of empirical study overlap with the scales at which management inferences and recommendations are made. This systematic map protocol will evaluate this potential scale mismatch with the goal of raising awareness about the significance of effectively addressing and reporting the scales at which researchers collect data and make assumptions. Methods: We will use the Collaboration for Environmental Evidence (CEE) systematic mapping guidelines to identify relevant studies using a framework-based synthesis to summarise the spatial and temporal scales of coral reef fish ecology research and the scales at which management inferences or recommendations are made. Using tested predefined terms, we will search for relevant published academic and grey literature, including bibliographic databases, web-based search engines, and organisational websites. Inclusion criteria for the evidence map are empirical studies that focus on coral reef fish ecological organisation and processes, those informing management interventions and policy decisions, and management documents that cite coral reef research for management decision-making. Study results will be displayed graphically using data matrices and heat maps. This is the first attempt to systematically assess and compare the scales of socio-ecological research conducted on coral reef systems with their management. [ABSTRACT FROM AUTHOR]

Rapid degradation of the world's coral reefs jeopardizes their ecological functioning and ultimately imperils the wellbeing of the millions of people with reef-dependent livelihoods. Ecosystem accessibility is the main driver of their conditions, with the most accessible ecosystems being most at risk of resource depletion. People's socioeconomic conditions can change as they get further from urban centers and can profoundly influence people's relationship with the environment. However, the mechanisms through which increasing accessibility from human societies affects natural resources are still unclear. A plausible mechanism through which markets influence the environment is through the socioeconomic changes that tend to accompany accessibility. We used social and ecological data from 10 coastal communities and 31 reefs in northwest Madagascar to (i) unravel the respective influences of the local fish market and coastal communities on reef fish biomass and (ii) investigate how communities' socioeconomic and resource use characteristics change with increasing proximity to markets. We used generalized additive models to reveal that reef fish biomass is strongly related to the accessibility of both markets and local communities. We also highlight that the ways coastal communities use marine resources changes predictably with market proximity. More precisely, market proximity affects fishing gear (technique effect), wealth, and selling strategies (scale effect) of coastal communities. Our findings emphasize the need to better quantify links between markets and fishing communities through household-level surveys to implement market-based actions that could help to regulate the effect of markets on both fish stocks and fishing communities. [ABSTRACT FROM AUTHOR]

Social networks have been and remain important in Oceania for building and maintaining social-ecological resilience. However, there is little quantitative information on the role of fish and fishing in resource sharing networks and how networks may be impacted by socioeconomic and environmental changes, which is critical information for developing culturally appropriate fisheries management strategies. To better understand this gap, we conducted social network analysis of sharing networks in 18 villages in Fiji across a socioeconomic gradient. Villages formed two clusters based on network characteristics: villages on the main island had less cohesive networks with more cash and purchased good sharing, while villages located on other islands had more cohesive networks with a greater proportion of natural resource sharing. Metrics of network cohesion were positively correlated with mean household fishing frequency and negatively correlated with measures of material wealth. Fishers reported sharing the largest estimated catch from gillnets and night spearfishing. Given concerns about the sustainability of these fishing practices, we suggest methods for regulating these gears while maintaining fish sharing customs. This study shows how social network analysis can be conducted to better understand sharing networks to support natural resource management. [ABSTRACT FROM AUTHOR]

Coral reef fisheries support the livelihoods of millions of people in tropical countries, despite large‐scale depletion of fish biomass. While human adaptability can help to explain the resistance of fisheries to biomass depletion, compensatory ecological mechanisms may also be involved. If this is the case, high productivity should coexist with low biomass under relatively high exploitation. Here we integrate large spatial scale empirical data analysis and a theory‐driven modelling approach to unveil the effects of human exploitation on reef fish productivity–biomass relationships. We show that differences in how productivity and biomass respond to overexploitation can decouple their relationship. As size‐selective exploitation depletes fish biomass, it triggers increased production per unit biomass, averting immediate productivity collapse in both the modelling and the empirical systems. This 'buffering productivity' exposes the danger of assuming resource production–biomass equivalence, but may help to explain why some biomass‐depleted fish assemblages still provide ecosystem goods under continued global fishing exploitation. [ABSTRACT FROM AUTHOR]

Bahaman coral reefs have been on a steady decline since the 1900s, following the arrival of Europeans to the islands. Conditions have only worsened since, with the primary cause being overfishing. Overfishing depletes fish stocks and denies corals the interaction with functional groups that are necessary for their health. Without a strong herbivorous contingent of fish, reefs have slid into a macro algal trophic level that is difficult to reverse. This study focuses on the extent of overfishing of reef species by foreign boats in the Bahamas. It also considers contribution foreign boaters make to the local economy and their willingness to pay for conservation measures. With estimates of the amount of seafood recreational boaters and local commercial fishermen catch, a comparison is made about their relative contribution to the overfishing problem. A determination of boater’s spending provides an estimate of their contribution to the local economy. The willingness to pay for reef conservation and moorings indicates whether more money can be extracted for marine conservation projects. The study was conducted in the Exumas, a group of out islands southeast of Nassau that are representative of the reef degradation and development found throughout the Bahamas.

The exotic coral reefs of the Abrolhos Bank are a valuable source of goods and services for many Brazilians. The Abrolhos coral reefs are home to the most productive reef fisheries on the entire Brazilian coast and attract tourists each year with their natural beauty. Yet in the last fifty years, commercial fishing has replaced artisanal fishing, the Atlantic forest cover has vanished, and oil and gas exploration has begun. A network of marine protected areas (MPAs) is an achievable and effective solution to protect this coral reef ecosystem before the sustainability of the local fisheries and tourism industry are compromised. This study identifies gaps in knowledge about Abrolhos coral reef ecosystem and provides a much needed framework for the collection and analysis of data essential for MPA network design including identifying threats, understanding the factors that maintain coral reef resilience, determining methods for monitoring MPA success, and identifying obstacles to establishing MPAs.

The orange-spotted grouper Epinephelus coioides is one of the most important commercially exploited fish species in the Arabian Gulf. Studies to establish the basic biological knowledge necessary for sustainable exploitation are few and of limited spatial extent. We carry out a comparative analysis of life history traits of this sequential hermaphrodite and of trends of abundance in coral reefs, northern vs. southern Gulf. We found remarkable differences in sex proportion by length and age, rates of somatic growth, size at maturity and production of gonadic biomass, and no differences in the age composition, mode of growth, timing and duration of spawning, natural mortality rate, and trends of abundance. In the northern Gulf, the reproductive tactics could be diandric protogyny or protandric because males disappear at higher size and later age. In the southern Gulf, the strategy is protogyny, with full predominance of females in early life and full predominance of males in late life. In the northern Gulf, the orange-spotted grouper could exhibit bidirectional sex change. We suggest that fisheries policies should be versatile, consisting of regional-wide as well as local management measures, to account for local differences and regional-wide commonalities in life history traits and trends of abundance. [ABSTRACT FROM AUTHOR]

Drawing from ethnographic fieldwork, this paper attends to the persistent use of Destructive Fishing Gear (DFG) in a Marine Protected Area (MPA) in southeastern Tanzania. Based on participant observation, document analysis, in-depth interviews and focus group discussions conducted with villagers, I argue that the MPA has failed to eliminate the use of DFG because of its inability to address the historically-embedded political, economic, and sociocultural dimensions of DFG use in the inshore fishery. I contend that pre-existing and conservation-induced conditions of poverty drive the continued use of DFG inside the MPA. Such circumstances are framed by colonial and post-independence state-level development policies. They are also textured by breakdowns in customary marine tenure practices, changing beliefs about which types of fishing gear villagers consider to be traditional, and community-defined moral rights to fish for the fulfilment of basic material needs. I maintain that MPAs must take into account the anthropological complexities of poverty if they are to be effective. [ABSTRACT FROM AUTHOR]

Spatial expansions can provide a false sense of sustainability to fish markets and their consumers who perceive stable landings through time despite localized depletions. This study examined attributes of monthly landings and changes in size structures within a commercial coral-reef fishery that had stable landings for 11 years. Regression models revealed a significant rise in the ratio of landings between calm and windy months, depicting that stable landings were driven by increased fishing effort or success during the calmer months when less exploited reefs became accessible. Within the calmer months, "race-to-fish" dynamics also evolved for some target species, such as parrotfishes, whose landings became increasingly concentrated towards the onset of calm favorable conditions. During this same time, the size structure for 15 out of 19 target species that comprised 60% of annual landings decreased. The cumulative results suggested that (1) spatial management units can be improved by taking environmental gradients that define fishing access into consideration, and (2) thresholds for size-and-age-based policies should be established with respect to life-history parameters that maximize cohort production and protect against declining size structures. Both recommendations resonate with traditional forms of management across the Pacific that were based on reef tenure and knowledge of how species respond to fishing pressure. [ABSTRACT FROM AUTHOR]

There is a critical need to understand patterns and causes of intraspecific variation in physiological performance in order to predict the distribution and dynamics of wild populations under natural and human‐induced environmental change. However, the usual explanation for trait differences, local adaptation, fails to account for the small‐scale phenotypic and genetic divergence observed in fishes and other species with dispersive early life stages. We tested the hypothesis that local‐scale variation in the strength of selective mortality in early life mediates the trait composition in later life stages. Through in situ experiments, we manipulated exposure to predators in the coral reef damselfish Dascyllus aruanus and examined consequences for subsequent growth performance under common garden conditions. Groups of 20 recently settled D. aruanus were outplanted to experimental coral colonies in Moorea lagoon and either exposed to natural predation mortality (52% mortality in three days) or protected from predators with cages for three days. After postsettlement mortality, predator‐exposed groups were shorter than predator‐protected ones, while groups with lower survival were in better condition, suggesting that predators removed the longer, thinner individuals. Growth of both treatment groups was subsequently compared under common conditions. We did not detect consequences of predator exposure for subsequent growth performance: Growth over the following 37 days was not affected by the prior predator treatment or survival. Genotyping at 10 microsatellite loci did indicate, however, that predator exposure significantly influenced the genetic composition of groups. We conclude that postsettlement mortality did not have carryover effects on the subsequent growth performance of cohorts in this instance, despite evidence for directional selection during the initial mortality phase. We tested whether post‐settlement mortality can modify the trait composition of adult populations at a local scale by experimentally manipulating exposure to predators in coral reef damselfish. Predator exposure did not have carryover effects on subsequent growth performance of cohorts in this instance, despite indications that mortality was selective for phenotypic traits and genetic markers. [ABSTRACT FROM AUTHOR]

Healthy parrotfish (family Scaridae) communities fulfill the essential ecosystem process of herbivory in coral reefs, but artisanal fisheries that target parrotfish have degraded their populations. Outright bans and gear restrictions that do not allow parrotfish capture can effectively protect and restore parrotfish populations. As these management actions would be unfeasible in many places, options that allow some fishing but still encourage population rebuilding need to be considered. The life history of parrotfish complicates management decisions because they transition from a mostly female “initial phase” to an all-male “terminal phase.” Size-selective fishing on the largest fish can lead to unnaturally low proportions of males in a population, potentially leading to losses in reproduction. At the same time, these visually distinct life phases could present an opportunity to employ a type of catch restriction that would be easy to understand and monitor. We built an agent-based model of the stoplight parrotfish, Sparisoma viride, which included three possible mechanisms of life-phase transitioning, to predict how this species and others like it might react to catch restrictions based on life phase. We found that restricting catch to only terminal-phase (male) fish typically led to populations of greater abundance and biomass and less-disturbed life-phase ratio, compared to a similar fishing mortality applied to the whole population. This model result highlights a potentially important lesson for all exploited protogynous hermaphrodites: a robust population of initial-phase fish may be key to maximizing reproductive potential when the size at life-phase transition compensates for changes in population structure.

The importance of top‐down effects in structuring ecological communities has been widely debated by ecologists. One way in which to examine these processes is to study the secondary effects of predator removal on communities. This study examined the role of predatory fishes in structuring communities of coral reef fishes, by using a network of marine reserves (the Great Barrier Reef Marine Park) as a natural experiment. We hypothesized that reefs with high densities of piscivores (marine reserves) would have distinct fish communities from those where piscivores have been depleted through fishing, due to variation in predation pressure. We predicted that predator depletion would result in “prey release”, and a corresponding increase in prey densities along a gradient of fishing intensity, causing a change in the community composition of reef fishes. To address this, fish counts and habitat surveys were conducted at four locations on the Great Barrier Reef. At each location, comparisons were made amongst three marine park zones that varied in their exposure to fishing practices; no‐ take marine reserves, limited fishing areas, and open fishing areas. The density and biomass of predators varied consistently among zones at each location. Furthermore, we found strong evidence for prey release at all four locations, resulting in distinct fish assemblages amongst zones. Reefs open to fishing had much lower densities of piscivores, and higher densities of prey and herbivorous fishes compared to marine reserves. This broad pattern was consistent amongst locations, and persisted at the level of species, trophic groups, families and communities. Habitat characteristics did not vary significantly amongst zones in a consistent manner amongst locations. Although habitat relationships were strong for specialist species such as butterflyfishes, densities of predators were stronger predictors of prey density for most species, and the trophic composition of reef fish communities differed significantly amongst zones at all locations. Results from this study support the concept that top‐down effects can be strong divers of prey populations and influence community structure in highly diverse systems. These data emphasize the vital role of predators, and reinforce the importance of preserving and restoring top‐down trophic interactions in ecological systems.

Highlights • Alternative methods to estimate fishing mortality rates from length-frequencies are consistent. • Methods to estimate overfished status are less consistent due to different selectivity assumptions. • The fishery at Glover's Reef Marine Reserve, Belize, is experiencing overfishing. • Both spear and hook and line gear contribute to overfishing, but for different species. Abstract Using information on the species composition and length-frequencies of fish caught in the spear and hook and line fisheries of Glover's Reef Marine Reserve, Belize, we evaluated changes between 2004–2010 and 2011–2017 in single-species and ecosystem sustainability indicators. The two gears differed in species caught, and both changed species composition between time periods, with the line fishers targeting smaller species, and the spear fishers responding to a parrotfish ban by catching more snappers and small groupers, as well as grey angels. Both gears caught smaller fish in 2011–2017 compared to 2004–2010, indicating overfishing. Species often caught immature were black grouper, Nassau grouper and mutton snapper with spears, and black snapper with lines. Most fish of other species were mature, but many were smaller than the optimal size for harvest. Fishing mortality rates were higher than natural mortality rates for most species in both gears in both time periods, whether calculated from average length or by length-based spawning potential ratio (LBSPR), implying that most populations were experiencing overfishing. Many species also had a low spawning potential ratio, implying a high probability that they were overfished. In general, many species were subject to unsustainable levels of fishing, and, according to the Froese indicators, some would benefit from size limits to protect immature individuals. These results are supported despite uncertainty in life history parameters for fishes in Belize, and differences between data poor assessment methods. [ABSTRACT FROM AUTHOR]

Abstract Tropical coral reef ecosystems in the Pacific region are degrading rapidly as ocean temperatures rise and local anthropogenic stressors increase. In this context of rapid change, effective site-based management of coral reef fisheries necessitates flexible environmental governance that is closely attuned to the needs of multiple stakeholders who depend on the fishery for income, food, and cultural identity. As such, many practitioners and scholars call for adaptive co-management of coral reef fisheries where local resource users play a primary role in environmental governance with the support of flexible institutions that operate across organizational scales. This article describes the history and evaluates the current status of marine governance in Moorea, French Polynesia. Established in 2004, the management framework is under revision because it has failed to meet its ecological objectives and has generated discontent among many stakeholders. Drawing on household surveys, interviews, and archival information, the challenges to as well as the factors that may enable a more successful transition of the current governance arrangement towards co-management are detailed. It is argued that recent social mobilization, subsistence and cultural links to the fishery, the presence of geographically and socially relevant traditional governance boundaries, and the implementation of co-management in other parts of French Polynesia are positive factors. However, lack of trust between stakeholders, social heterogeneity, disruption of traditional cultural institutions and practices, minimal institutional support, and an uncertain legal framework suggest that there are significant headwinds for maneuvering towards successful co-management in Moorea. Highlights • Conflicts led to social mobilization and demands for environmental governance changes. • Some Mooreans have organized around rahui , a traditional management arrangement. • Appropriate and established inter-island governance boundaries enable co-management. • Lack of trust between stakeholders is a major hindrance. • Presence of coral reef research centers present challenges and opportunities. [ABSTRACT FROM AUTHOR]

Abstract: A holistic basis for achieving ecosystem‐based management is needed to counter the continuing degradation of coral reefs. The high variation in recovery rates of fish, corresponding to fisheries yields, and the ecological complexity of coral reefs have challenged efforts to estimate fisheries sustainability. Yet, estimating stable yields can be determined when biomass, recovery, changes in per area yields and ecological change are evaluated together. Long‐term rates of change in yields and fishable biomass‐yield ratios have been the key missing variables for most coral reef assessments. Calibrating a fishery yield model using independently collected fishable biomass and recovery data produced large confidence intervals driven by high variability in biomass recovery rates that precluded accurate or universal yields for coral reefs. To test the model's predictions, I present changes in Kenyan reef fisheries for >20 years. Here, exceeding yields above 6 tonnes km−2 year−1 when fishable biomass was ~20 tonnes/km2 (~20% of unfished biomass) resulted in a >2.4% annual decline. Therefore, rates of decline fit the mean settings well and model predictions may therefore be used as a benchmark in reefs with mean recovery rates (i.e. r = 0.20–0.25). The mean model settings indicate a maximum sustained yield (MSY) of ~6 tonnes km−2 year−1 when fishable biomass was ~50 tonnes/km2. Variable reported recovery rates indicate that high sustainable yields will depend greatly on maintaining these rates, which can be reduced if productivity declines and management of stocks and functional diversity are ineffective. A number of ecological state‐yield trade‐off occurs as abrupt ecological changes prior to biomass levels that produce MSY. [ABSTRACT FROM AUTHOR]

Abstract: Leslie matrix models are an important analysis tool in conservation biology that are applied to a diversity of taxa. The standard approach estimates the finite rate of population growth (λ) from a set of vital rates. In some instances, an estimate of λ is available, but the vital rates are poorly understood and can be solved for using an inverse matrix approach. However, these approaches are rarely attempted due to prerequisites of information on the structure of age or stage classes. This study addressed this issue by using a combination of Monte Carlo simulations and the sample‐importance‐resampling (SIR) algorithm to solve the inverse matrix problem without data on population structure. This approach was applied to the grey reef shark (Carcharhinus amblyrhynchos) from the Great Barrier Reef (GBR) in Australia to determine the demography of this population. Additionally, these outputs were applied to another heavily fished population from Papua New Guinea (PNG) that requires estimates of λ for fisheries management. The SIR analysis determined that natural mortality (M) and total mortality (Z) based on indirect methods have previously been overestimated for C. amblyrhynchos, leading to an underestimated λ. Updated distributions of Z and λ were produced for the GBR population and corrected obvious error in the demographic parameters for the PNG population. This approach provides opportunity for the inverse matrix approach to be applied more broadly to situations where information on population structure is lacking. [ABSTRACT FROM AUTHOR]

Coral reefs around the world are changing rapidly, with overfishing of herbivorous fishes and increased sediment inputs being two of the major local-scale stressors. We therefore assessed the effects of sediment loads and overfishing on the nutritional quality and yield to grazing fishes of algal turfs, within the epilithic algal matrix, on a coral reef at Lizard Island, Australia. Low, ambient and high sediment loads were maintained on turf-covered coral tiles, with and without grazer exclusion cages, for 1 month. Subsequently, algal turfs were removed and analysed for organic carbon and nitrogen content. Under grazer exclusion, sediment additions decreased algal turf biomass by approximately 63%, while algal turf biomass was the highest on tiles with sediments removed. In the presence of grazing fishes, algal turfs in all treatments were cropped by grazers to similar low biomass levels. Nitrogen content of algal turfs followed a similar trend. Effectively, added sediments decreased the potential yield of algal turf biomass and nitrogen to grazing fishes by an average of 2000 and 3300%, respectively. Sediments profoundly affect algal turf yield to grazing herbivorous fishes and, therefore, the productivity of algal turf-based food chains, potentially diminishing reef-based fisheries. [ABSTRACT FROM AUTHOR]

We conduct a framed field experiment in Indonesian fishing communities, with an eye toward evaluating alternative decision-making processes for setting extraction restrictions to preserve coral reef fisheries in the absence of stringent monitoring and enforcement. We explore whether the individual extraction decision varies according to three non-binding recommended extraction levels originating from (1) a democratic process, (2) a group leader or (3) an external source. For the sample as a whole, we find a strong effect of the external treatment, with a weaker effect of the democratic treatment and no effect of the leadership treatment. Closer inspection reveals that the results are driven by one of the three sites where the experiment was conducted – that having the highest levels of ethnic and religious diversity. There we find that democratic decision-making as well as information originating from outside the community reduces the extraction level, a result that is robust to regressions controlling for individual and community attributes. The absence of effects in two of the three sites suggests that a non-binding recommendation may often be insufficient in promoting the cooperative behavior that underpins contemporary approaches to managing coral reefs. [ABSTRACT FROM AUTHOR]

In Pohnpei, Micronesia, a 10-year (2006–2015) follow-up market survey was conducted to provide the basis for a comparative assessment of the status of the commercial inshore fishery, to inform management and to identify the most relevant management options. Within this timeframe, marketed coral reef fish volumes declined by 50 mt ( ca. 20%), the use of unsustainable fishing methods (nighttime spearfishing and small-mesh gillnets) increased from 75.5% to 81.9%, and catch-per-unit-effort decreased from 3.4 ± 0.1 to 3.2 ± 0.4 kg h −1  fisher 1 . Simultaneously, the economic return as price per unit effort was nearly halved for all gear types. Trip volumes increased, however, this was paralleled by a rise in the average number of fishers per trip, particularly for nighttime spearfishing. Effort shifted from inner to outer reef areas and further away from high fisher density communities. At the family level, increases in the percentage of lower tropic level catch were observed, with herbivores and planktivores increasing in frequency in catch more than other trophic level fishes. The only weight increase among top carnivores was for epinephelids, however this was accompanied by a greater contribution by juveniles for the most commonly targeted grouper, Camouflage grouper, Epinephelus polyphekadion . Among fish families, eight epinephelids were absent in catch in 2015 compared to 2006, with additional species observed in speared catch in 2015 that were absent in 2006. To reverse continuing declines and prevent the potential for fisheries collapse, government needs to institute rights-based management, ban the use of nighttime spearfishing and small-mesh gillnets, and improve existing enforcement within marine protected areas and markets. [ABSTRACT FROM AUTHOR]

The role of speciation processes in shaping current biodiversity patterns represents a major scientific question for ecologists and biogeographers. Hence, numerous methods have been developed to determine the geography of speciation based on co‐occurrence between sister‐species. Most of these methods rely on the correlation between divergence time and several metrics based on the geographic ranges of sister‐taxa (i.e. overlap, asymmetry). The relationship between divergence time and these metrics has scarcely been examined in a spatial context beyond regression curves. Mapping this relationship across spatial grids, however, may unravel how speciation processes have shaped current biodiversity patterns through space and time. This can be particularly relevant for coral reef fishes of the Indo‐Pacific since the origin of the exceptional concentration of biodiversity in the Indo‐Australian Archipelago (IAA) has been actively debated, with several alternative hypotheses involving species diversification and dispersal. We reconstructed the phylogenetic relationships between three species‐rich families of coral reef fish (Chaetodontidae, Labridae, Pomacentridae) and calculated co‐occurrence metrics between closely related lineages of those families. We demonstrated that repeated biogeographic processes can be identified in present‐day species distribution by projecting co‐occurrence metrics between related lineages in a geographical context. Our study also evidence that sister‐species do not co‐occur randomly across the Indo‐Pacific, but tend to overlap their range within the IAA. We identified the imprint of two important biogeographic processes that caused this pattern in 48% of the sister‐taxa considered: speciation events within the IAA and repeated divergence between the Indian and Pacific Ocean, with subsequent secondary contact in the IAA. [ABSTRACT FROM AUTHOR]

Determining whether many functionally complementary species or only a subset of key species are necessary to maintain ecosystem functioning and services is a critical question in community ecology and biodiversity conservation. Identifying such key species remains challenging, especially in the tropics where many species co-occur and can potentially support the same or different processes. Here, we developed a new community-wide scan (CWS) approach, analogous to the genome-wide scan, to identify fish species that significantly contribute, beyond the socio-environmental and species richness effects, to the biomass and coral cover on Indo-Pacific reefs. We found that only a limited set of species (51 out of approx. 400, approx. 13%), belonging to various functional groups and evolutionary lineages, are strongly and positively associated with fish biomass and live coral cover. Many of these species have not previously been identified as functionally important, and thus may be involved in unknown, yet important, biological mechanisms that help sustain healthy and productive coral reefs. CWS has the potential to reveal species that are key to ecosystem functioning and services and to guide management strategies as well as new experiments to decipher underlying causal ecological processes. [ABSTRACT FROM AUTHOR]

Rights-based management approaches are being increasingly applied to global fisheries as an alternative to deficiencies associated with centralized or top-down management. In fisheries, these approaches may include a diversity of methods such as catch shares, territorial user rights for fishing, individual transferable quotas, fisheries concessions, cooperatives, and comanagement. Many of these approaches are being implemented in small-scale fisheries contexts, without full consideration of how the legacy of previous governing institutions or tenure arrangements may affect implementation. Likewise, few case studies examine whether rights-based management approaches are appropriate for given contexts, examine how they fit within a nested administrative hierarchy, or describe their shared property rights components in practice. These knowledge gaps may obscure key stewardship incentives, veil existing power relations, and constrain opportunities for different management models while also prolonging or preventing governance transformations. We illustrate the importance of these factors through a case study of institutional change in coral reef fisheries in Hawai'i. We use institutional analysis to examine coral reef fisheries management across two time periods: historical marine tenure in the Hawaiian Kingdom (1810-1893) and under contemporary centralized management (1982-2018). We then compared these management regimes to emerging comanagement in Hawai'i (1994-2018). Our analysis reveals that few rights are actually devolved to communities seeking to implement comanagement. We also highlight considerable administrative complexity and variability within historical marine tenure regimes. We conclude by considering several issues relevant to the performance of rights-based approaches such as comanagement, including devolution of property rights to the local level, matching administrative and social-ecological complexity, the importance of historical context and narratives in shaping solutions, and the perceived legitimacy of governance arrangements. [ABSTRACT FROM AUTHOR]

Abstract: To design effective marine reserves and support fisheries, more information on fishing patterns and impacts for targeted species is needed, as well as better understanding of their key habitats. However, fishing impacts vary geographically and are difficult to disentangle from other factors that influence targeted fish distributions. We developed a set of fishing effort and habitat layers at high resolution and employed machine learning techniques to create regional‐scale seascape models and predictive maps of biomass and body length of targeted reef fishes for the main Hawaiian Islands. Spatial patterns of fishing effort were shown to be highly variable and seascape models indicated a low threshold beyond which targeted fish assemblages were severely impacted. Topographic complexity, exposure, depth, and wave power were identified as key habitat variables that influenced targeted fish distributions and defined productive habitats for reef fisheries. High targeted reef fish biomass and body length were found in areas not easily accessed by humans, while model predictions when fishing effort was set to zero showed these high values to be more widely dispersed among suitable habitats. By comparing current targeted fish distributions with those predicted when fishing effort was removed, areas with high recovery potential on each island were revealed, with average biomass recovery of 517% and mean body length increases of 59% on Oahu, the most heavily fished island. Spatial protection of these areas would aid recovery of nearshore coral reef fisheries. [ABSTRACT FROM AUTHOR]

Abstract: The status of fisheries requires establishing and evaluating benchmarks derived from unfished ecosystems. Habitats, environmental conditions, properties of the fish communities and management systems could potentially influence the variability surrounding benchmarks. Consequently, eighteen variables including habitat, number of species, life histories, thermal and productivity environments were tested for influences on reef fish biomass in 62 reefs within old high compliance closures along the east African coastline. Biomass and weighted life history characteristics were classified and described for total, fishable, target and non‐target groups. Benchmark biomass fell within a 95% confidence interval of ~1,030–1,250 kg/ha and equally distributed among target and non‐target groups. While some relationships were statistically significant, most were weak, poorly sampled (ocean exposed reefs), had uncertain relationships with biomass (number of species), or the explained variation was bounded within the above confidence intervals (habitat and environment). Therefore, a regional unfished biomass benchmark (B0) of 1,150 and 560 kg/ha is recommended for total and target biomasses, respectively. Weighted life history metrics indicate that the target had slower life histories than the non‐target fish communities. Consequently, they will be fished unsustainably if yield recommendations are derived from the total, resilient or non‐target fish life history metrics. The intrinsic rates of increase (r) and target categorization of biomass were the most influential metrics in estimating yields. [ABSTRACT FROM AUTHOR]

Declining natural resources have led to a cultural renaissance across the Pacific that seeks to revive customary ridge-to-reef management approaches to protect freshwater and restore abundant coral reef fisheries. Effective ridge-to-reef management requires improved understanding of land-sea linkages and decision-support tools to simultaneously evaluate the effects of terrestrial and marine drivers on coral reefs, mediated by anthropogenic activities. Although a few applications have linked the effects of land cover to coral reefs, these are too coarse in resolution to inform watershed-scale management for Pacific Islands. To address this gap, we developed a novel linked land-sea modeling framework based on local data, which coupled groundwater and coral reef models at fine spatial resolution, to determine the effects of terrestrial drivers (groundwater and nutrients), mediated by human activities (land cover/use), and marine drivers (waves, geography, and habitat) on coral reefs. We applied this framework in two ‘ridge-to-reef’ systems (Hā‘ena and Ka‘ūpūlehu) subject to different natural disturbance regimes, located in the Hawaiian Archipelago. Our results indicated that coral reefs in Ka‘ūpūlehu are coral-dominated with many grazers and scrapers due to low rainfall and wave power. While coral reefs in Hā‘ena are dominated by crustose coralline algae with many grazers and less scrapers due to high rainfall and wave power. In general, Ka‘ūpūlehu is more vulnerable to land-based nutrients and coral bleaching than Hā‘ena due to high coral cover and limited dilution and mixing from low rainfall and wave power. However, the shallow and wave sheltered back-reef areas of Hā‘ena, which support high coral cover and act as nursery habitat for fishes, are also vulnerable to land-based nutrients and coral bleaching. Anthropogenic sources of nutrients located upstream from these vulnerable areas are relevant locations for nutrient mitigation, such as cesspool upgrades. In this study, we located coral reefs vulnerable to land-based nutrients and linked them to priority areas to manage sources of human-derived nutrients, thereby demonstrating how this framework can inform place-based ridge-to-reef management. [ABSTRACT FROM AUTHOR]

Islands offer unique model systems for studying fisheries development in relation to the growing global seafood trade. This study examines how export-driven fisheries in India's oceanic islands (Andaman and Nicobar Islands and Lakshadweep Islands) differ significantly as a result of their varied history, culture, available infrastructure and market access. Despite being geographically closer to export centres on the Indian mainland, processing and transport infrastructure in the Lakshadweep Islands are limited. This only allows for the trade of non-perishable commodities like dried tuna that are caught using traditional pole-and-line fishing techniques, restricting reef exploitation to local preference-based consumption and opportunistic export. The Andaman Islands, on the other hand, with multiple daily flight connections and large private and government processing facilities, are better connected to export markets. The relatively recent and multicultural fisheries of these islands supply marine commodity chains for reef fishery goods such as dried shark fins, frozen snapper fillets and chilled groupers. The Nicobar Islands are furthest away from mainland export centres and are mostly populated by indigenous communities – fishing here is mostly for subsistence and local sale. Revised estimates of travel times to export market centres are counterintuitive in terms of geographical distances and are significantly different from travel times to local markets. [ABSTRACT FROM PUBLISHER]

Coral reefs sustain millions of people worldwide, yet in recent years, social, environmental, and climate change have caused major declines in coral reef fisheries. Small-scale coral reef fisheries research has largely focused on community-level drivers of fishing, ignoring the heterogeneities that exist within communities. We used social-ecological indicators from 20 coastal villages in Fiji to identify potential fine-scale, context-appropriate drivers of estimated household fish catch. Indicators were developed based on a review of the literature, discussions with local experts, and a pilot study. Using structural equation models, we found that importance of fishing to income, household fish consumption, livelihood diversity, travel time to market, and coral reef area all positively affect estimated household-level fish catch. Our results contrast with findings from other larger scale studies by identifying that households further from markets had higher fishing frequency. We highlight the role of middlemen in these small-scale fisheries, who have been largely overlooked as drivers of fisheries catch. Our findings emphasize the need for household-level analyses to better understand the complexities in coral reef social-ecological systems to more effectively manage small-scale fisheries in communities. [ABSTRACT FROM AUTHOR]

The Spermonde Archipelago holds one of the largest artisanal fisheries in Indonesia, providing livelihoods for local communities and many other people involved in international trade networks of seafood. High demand and a lack of enforcement of existing fisheries regulations turn into high pressure for the coral reef ecosystem, contributing to its overall degradation. Estimations on the ecological impacts of different levels of fishing pressure, as well as fisheries stock assessments and marine resource management require precise information of the spatial distribution of fishing effort, which involves great uncertainty when only anecdotal information is considered. We explored the feasibility of applying participatory boat tracking to complement fisheries data during the NW monsoon season 2014–2015. We conducted interviews, measured catch landings, and distributed GPS data loggers among hook and line fishermen to identify fishing grounds by gear-dependent patterns of boat movement. Most of the fishing activities involved two gears (octopus bait and trolling line for live groupers) and three fishing grounds. The mass of catch landings was dominated by Octopoda (CPUE = 10.1 kg boatday−1) while the most diverse group was the fish family Serranidae, with Plectropomus leopardus being the main target species. In conclusion, boat tracking combined with interviews and catch surveys has proven a useful tool to reduce uncertainty in information on spatial resource use, while allowing a high level of participation by fishermen.

Sustainable fisheries management is key to restoring and maintaining ecological function and benefits to people, but it requires accurate information about patterns of resource use, particularly fishing pressure. In most coral reef fisheries and other data-poor contexts, obtaining such information is challenging and remains an impediment to effective management. We developed the most comprehensive regional view of shore-based fishing effort and catch published to date, to show detailed fishing patterns from across the main Hawaiian Islands (MHI). We reveal these regional patterns through fisher “creel” surveys conducted by local communities, state agencies, academics, and/or environmental organizations, at 18 sites, comprising >10,000 h of monitoring across a range of habitats and human influences throughout the MHI. All creel surveys included in this study except for one were previously published in some form (peer-reviewed articles or gray literature reports). Here, we synthesize these studies to document spatial patterns in nearshore fisheries catch, effort, catch rates (i.e., catch-per-unit-effort (CPUE)), and catch disposition (i.e., use of fish after catch is landed). This effort provides for a description of general regional patterns based on these location-specific studies. Line fishing was by far the dominant gear type employed. The most efficient gear (i.e., highest CPUE) was spear (0.64 kg h−1), followed closely by net (0.61 kg h−1), with CPUE for line (0.16 kg h−1) substantially lower than the other two methods. Creel surveys also documented illegal fishing activity across the studied locations, although these activities were not consistent across sites. Overall, most of the catch was not sold, but rather retained for home consumption or given away to extended family, which suggests that cultural practices and food security may be stronger drivers of fishing effort than commercial exploitation for coral reef fisheries in Hawai‘i. Increased monitoring of spatial patterns in nearshore fisheries can inform targeted management, and can help communities develop a more informed understanding of the drivers of marine resource harvest and the state of the resources, in order to maintain these fisheries for food security, cultural practices, and ecological value.

Fostering sustainable local social–ecological interactions playing out against a backdrop of larger-scale dynamics are ubiquitous challenges to natural resource management and biodiversity conservation. Social-ecological vulnerability assessments are highly relevant for place-based management and can help target and prioritize management actions. However, an understanding of how linked social-ecological vulnerabilities respond to external drivers is still lacking. This paper presents an approach that integrates the spatial and temporal dimensions into social-ecological vulnerability assessments, where social and ecological vulnerabilities are linked by a feedback loop. The approach is applied to the Moorea coral reef social-ecological system, which has been significantly influenced by major environmental and social drivers over the last decade. Temporal changes in linked social-ecological vulnerabilities are mapped before and after exposure to the multiple drivers. Nearly 23% of households and 13% of the reef area show low and decreasing vulnerability despite exposure. However, high and increasing levels of vulnerability were detected in 6% of households and associated reefs after exposure to the drivers, providing early warnings of potentially unsustainable situations. Importantly, changes in ecological vulnerability did not propagate linearly to changes in social vulnerability. Similarly, hot spots of social vulnerability were not necessarily associated with hot spots of ecological vulnerability, highlighting the need to specifically adapt management interventions to local social-ecological settings. Mapping social-ecological dependencies in space and time provides communities and decision-makers with the information required to identify and prioritize management interventions while accounting for the effects of large-scale or external drivers. [ABSTRACT FROM AUTHOR]

Abstract: Recreational diving is a concern regarding its effects on benthic assemblages, especially on heavily dived coral reefs. However, spearfisher behaviour and the scale of damage they cause to corals remains unknown. The behaviour of recreational spearfishers was observed to determine their rate of physical contacts with corals. The experience level and fishes captured by spearfishers were assessed to establish their relationship with the number of contacts with corals. All spearfishers made contact with corals, at an average rate of 1.25 ± 0.1 SE touches per minute and caused physical damage at a rate 0.51 ± 0.04 per minute. Massive corals were most frequently touched and branching corals were most frequently damaged. Touches and damage occurred mainly through fin kicks, spearfisher bodies and spearguns. Contact rates varied according to spearfisher experience level and the fish they were targeting. Novice spearfishers showed no preference for specific targets while experienced spearfishers target mesopredator fishes. Spearfishing caused the highest known rates of touches and damage to corals among all the activities involving recreational diving. The activity may add to local stressors on corals, especially at sites with high visitation rates. Understanding how the factors that affect spearfisher behaviour and their effects on corals may help managers to develop strategies to mitigate the incidence of damaging behaviour. [ABSTRACT FROM AUTHOR]

Almost all environmental management comes at an economic cost that may not be borne equitably by all stakeholders. Here, we investigate how heterogeneity in catch and profits among fishers influences the trade-off among the triple-bottom-line objectives of recovering a fish population, maximizing its economic value and distributing restrictions equitably across fishers. As a case-study, we examine management reform of an ecologically and economically important coral reef fishery operating within the Great Barrier Reef Marine Park. Using a simulation model, we find that total profitability of the fishing industry is 40% lower if recovery plans are equitable when compared to the most economically efficient plan. However, efficient recovery plans were typically highly inequitable because they required some fishers to cease fishing. Equity was defined according to different norms, and the efficiency loss was greatest when catch losses were shared equally across fishers rather than in proportion to their historical catch. We then varied key social, economic and biological parameters to identify cases when equity and efficient recovery would trade-off most strongly. Recovery plans could be both efficient and equitable when heterogeneity in fisher's catches and individual catch efficiencies was lower. If fishers were homogenous then equitable plans could have maximal economic efficiency. These results emphasize the importance of considering heterogeneity in individual fishers when designing recovery plans. Recovery plans that are inequitable may often fail to gain stakeholder support, so in fisheries with high heterogeneity we should temper our expectations for marked increases in profits. [ABSTRACT FROM AUTHOR]

Sustainable fisheries management is key to restoring and maintaining ecological function and benefits to people, but it requires accurate information about patterns of resource use, particularly fishing pressure. In most coral reef fisheries and other data-poor contexts, obtaining such information is challenging and remains an impediment to effective management. We developed the most comprehensive regional view of shore-based fishing effort and catch published to date, to show detailed fishing patterns from across the main Hawaiian Islands (MHI). We reveal these regional patterns through fisher “creel” surveys conducted by local communities, state agencies, academics, and/or environmental organizations, at 18 sites, comprising >10,000 h of monitoring across a range of habitats and human influences throughout the MHI. All creel surveys included in this study except for one were previously published in some form (peer-reviewed articles or gray literature reports). Here, we synthesize these studies to document spatial patterns in nearshore fisheries catch, effort, catch rates (i.e., catch-per-unit-effort (CPUE)), and catch disposition (i.e., use of fish after catch is landed). This effort provides for a description of general regional patterns based on these location-specific studies. Line fishing was by far the dominant gear type employed. The most efficient gear (i.e., highest CPUE) was spear (0.64 kg h−1), followed closely by net (0.61 kg h−1), with CPUE for line (0.16 kg h−1) substantially lower than the other two methods. Creel surveys also documented illegal fishing activity across the studied locations, although these activities were not consistent across sites. Overall, most of the catch was not sold, but rather retained for home consumption or given away to extended family, which suggests that cultural practices and food security may be stronger drivers of fishing effort than commercial exploitation for coral reef fisheries in Hawai‘i. Increased monitoring of spatial patterns in nearshore fisheries can inform targeted management, and can help communities develop a more informed understanding of the drivers of marine resource harvest and the state of the resources, in order to maintain these fisheries for food security, cultural practices, and ecological value. [ABSTRACT FROM AUTHOR]

Despite their importance for human well-being, nearshore fisheries are often data poor, undervalued, and underappreciated in policy and development programs. We assess the value chain for nearshore Hawaiian coral reef fisheries, mapping post-catch distribution and disposition, and quantifying associated monetary, food security, and cultural values. We estimate that the total annual value of the nearshore fishery in Hawaiʻi is $10.3-$16.4 million, composed of non-commercial ($7.2-$12.9 million) and commercial ($2.97 million licensed + $148,500-$445,500 unlicensed) catch. Hawaii’s nearshore fisheries provide >7 million meals annually, with most (>5 million) from the non-commercial sector. Over a third (36%) of meals were planktivores, 26% piscivores, 21% primary consumers, and 18% secondary consumers. Only 62% of licensed commercial catch is accounted for in purchase reports, leaving 38% of landings unreported in sales. Value chains are complex, with major buyers for the commercial fishery including grocery stores (66%), retailers (19%), wholesalers (14%), and restaurants (<1%), who also trade and sell amongst themselves. The bulk of total nearshore catch (72–74%) follows a short value chain, with non-commercial fishers keeping catch for household consumption or community sharing. A small amount (~37,000kg) of reef fish—the equivalent of 1.8% of local catch—is imported annually into Hawaiʻi, 23,000kg of which arrives as passenger luggage on commercial flights from Micronesia. Evidence of exports to the US mainland exists, but is unquantifiable given existing data. Hawaiian nearshore fisheries support fundamental cultural values including subsistence, activity, traditional knowledge, and social cohesion. These small-scale coral reef fisheries provide large-scale benefits to the economy, food security, and cultural practices of Hawaiʻi, underscoring the need for sustainable management. This research highlights the value of information on the value chain for small-scale production systems, making the hidden economy of these fisheries visible and illuminating a range of conservation interventions applicable to Hawaiʻi and beyond. [ABSTRACT FROM AUTHOR]