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Area-based fisheries management measures (ABFMs) are commonly related to the sustainable use of resources but are increasingly considered broader conservation measures. This Scoping Review (ScR) identified and mapped the evidence base regarding the contribution of ABFMs to fisheries sustainability and marine conservation. The ScR was conducted following the JBI methodology and the PRISMA statement. A total of 2,391 documents were identified, and following a two-stage screening process, 151 documents were eventually included in the ScR for full review and data extraction. Most of the documents were published during the last 12 years. Studies had a wide geographical distribution (mainly located in Europe and North America), were primarily conducted at the subnational level, concerned fishing restrictions of towed gears, and assessed ABFMs from a single stock’s perspective. ABFMs identified were of various types, and the use of terminology was not consistent in the literature. Multiple combinations of data collection (primarily experimental surveys/sampling and open data sources) and analysis methods (most commonly, fisheries and ecological analyses and modelling) were applied (often in combination), using a variety of different metrics. Various knowledge gaps emerged, mainly related to the study of ABFMs networks and the application of an interdisciplinary and ecosystem-based approach for assessing ABFMs. The social, economic, and environmental impact of ABFMs was positive in most cases (56%) and in less cases negative (22%) or mixed (14%). This ScR is a valuable source of information for the contribution of ABFMs to rebuilding marine ecosystems and attaining CBD conservation targets through the lens of the OECM concept.

This study examined trends along a gradient of fishing intensity in an artisanal coral reef fishery over a 10-year period along 75 km of Kenya's most populated coastline. As predicted by Malthusian scenarios, catch per unit effort (CPUE), mean trophic level, the functional diversity of fished taxa, and the diversity of gear declined, while total annual catch and catch variability increased along the fishing pressure gradient. The fishery was able to sustain high (~16 Mg·km⁻²·yr⁻¹) but variable yields at high fishing pressure due to the dominance of a few productive herbivorous fish species in the catch. The effect of two separate management strategies to overcome this Malthusian pattern was investigated: fisheries area closure and elimination of the dominant and most \"competitive\" gear. We found that sites within 5 km of the enforced closure showed significantly lower total catch and CPUE, but increased yield stability and trophic level of catch than predicted by regression models normalized for fishing effort. Sites that had excluded illegal beach seine use through active gear management exhibited increased total catch and CPUE. There was a strong interaction between closure and gear management, which indicates that, for closures to be effective at increasing catch, there must be simultaneous efforts at gear management around the periphery of the closures. We propose that Malthusian effects are responsible for the variation in gear and catch and that active management through reduced effort and reductions in the most competitive gear have the greatest potential to increase the functional and trophic diversity and per-person productivity.

This study investigated spillover (biomass export) around 6 marine protected areas (MPAs) in the western Mediterranean based on catch and effort data from artisanal fisheries. The selected MPAs were Cerbère-Banyuls and Carry-le-Rouet in France, and Medes, Cabrera, Tabarca, and Cabo de Palos in Spain. These MPAs had been functional for more than 8 yr and incorporate areas of fisheries closure and restricted use where fishing is limited. We based our study on the hypotheses that, in the presence of biomass export, (1) fishing effort would concentrate close to MPA boundaries, and (2) fishery production, expressed as catch per unit area (CPUA), would be highest near MPA boundaries and decrease with distance. We selected data from 14 ‘fishing tactics’ using gill nets, trammel nets and bottom long-lines targeting sparids, mullids, serranids, scorpaenids and palinurids. We analyzed the spatial distribution of effort, fishery production and revenues per unit area, using generalized additive models (GAMs), and we tested regression slopes of effort density and CPUA with distance to closure boundaries, using generalized linear models (GLMs). GAMs allowed us to recognize habitat discontinuities or ‘hot spots’ of high production in the vicinity of the MPAs, and to identify the extent of potential spillover effects in order to implement GLMs. We found evidence of effort concentration and high fishery production near fisheries closures for all fishing tactics analyzed and significant negative slopes for most. Revenues generally followed trends similar to CPUA. Significant negative slopes from GLM of effort density and CPUA with distance from fisheries closures were indicative of biomass export where habitats across closure boundaries had some degree of continuity. The spatial extent of spillover was consistent with species mobility and fisheries efficiency and extended 700 to 2500 m from fishery closure boundaries. Our results suggest that coastal MPAs can be an effective management tool for artisanal fisheries in the region and can be extended to the rest of the western Mediterranean, as the fishing tactics studied are typical of the region.

Identifying the rates of recovery of fish in no-take areas is fundamental to designing protected area networks, managing fisheries, estimating yields, identifying ecological interactions, and informing stakeholders about the outcomes of this management. Here we study the recovery of coral reef fishes through 37 years of protection using a space-for-time chronosequence of four marine national parks in Kenya. Using AIC model selection techniques, we assessed recovery trends using five ecologically meaningful production models: asymptotic, Ricker, logistic, linear, and exponential. There were clear recovery trends with time for species richness, total and size class density, and wet masses at the level of the taxonomic family. Species richness recovered rapidly to an asymptote at 10 years. The two main herbivorous families displayed differing responses to protection, scarids recovering rapidly, but then exhibiting some decline while acanthurids recovered more slowly and steadily throughout the study. Recovery of the two invertebrate-eating groups suggested competitive interactions over resources, with the labrids recovering more rapidly before a decline and the balistids demonstrating a slower logistic recovery. Remaining families displayed differing trends with time, with a general pattern of decline in smaller size classes or small-bodied species after an initial recovery, which suggests that some species-and size-related competitive and predatory control occurs in older closures. There appears to be an ecological succession of dominance with an initial rapid rise in labrids and scarids, followed by a slower rise in balistids and acanthurids, an associated decline in sea urchins, and an ultimate dominance in calcifying algae. Our results indicate that the unfished \"equilibrium\" biomass of the fish assemblage >10 cm is 1100-1200 kg/ha, but these small parks (<10 Km²) are likely to underestimate prehuman influence values due to edge effects and the rarity of taxa with large area requirement, such as apex predators, including sharks.

Identifying spatiotemporal hotspots is important for understanding basic ecological processes, but is particularly important for species at risk. A number of terrestrial and aquatic species are indirectly affected by anthropogenic impacts, simply because they tend to be associated with species that are targeted for removals. Using newly developed statistical models that allow for the inclusion of time-varying spatial effects, we examine how the co-occurrence of a targeted and nontargeted species can be modeled as a function of environmental covariates (temperature, depth) and interannual variability. The nontarget species in our case study (eulachon) is listed under the U.S. Endangered Species Act, and is encountered by fisheries off the U.S. West Coast that target pink shrimp. Results from our spatiotemporal model indicated that eulachon bycatch risk decreases with depth and has a convex relationship with sea surface temperature. Additionally, we found that over the 2007-2012 period, there was support for an increase in eulachon density from both a fishery data set (+40%) and a fishery-independent data set (+55%). Eulachon bycatch has increased in recent years, but the agreement between these two data sets implies that increases in bycatch are not due to an increase in incidental targeting of eulachon by fishing vessels, but because of an increasing population size of eulachon. Based on our results, the application of spatiotemporal models to species that are of conservation concern appears promising in identifying the spatial distribution of environmental and anthropogenic risks to the population.

Understanding the functional relationship between marine predators and their prey is vital to inform ecosystem‐based management. However, collecting concurrent data on predator behaviour and their prey at relevant scales is challenging. Moreover, opportunities to study these relationships in the absence of industrial fishing are extremely rare. We took advantage of an experimental fisheries closure to study how local prey abundance influences foraging success and chick condition of Endangered African penguins Spheniscus demersus in the Benguela ecosystem. We tracked 75 chick‐provisioning penguins with GPS–time–depth devices, measured body condition of 569 chicks, quantified the diet of 83 breeding penguins and conducted 12 forage fish hydro‐acoustic surveys within a 20 km radius of Robben Island, South Africa, over three years (2011–2013). Commercial fishing for the penguins' main prey, sardine Sardinops sagax and anchovy Engraulis encrasicolus, was prohibited within this 20 km radius during the study period. Local forage fish abundance explained 60% of the variation in time spent diving for 14 penguins at sea within 2 days of a hydro‐acoustic survey. Penguin foraging effort (time spent diving, number of wiggles per trip, number of foraging dives and the maximum distance travelled) increased and offspring body condition decreased as forage fish abundance declined. In addition, quantile regression revealed that variation in foraging effort increased as prey abundance around the colony declined. Policy implications. Our results demonstrate that local forage fish abundance influences seabird foraging and offspring fitness. They also highlight the potential for offspring condition and the mean–variance relationship in foraging behaviour to act as leading indicators of poor prey abundance. By rapidly indicating periods where forage resources are scarce, these metrics could help limit seabird fisheries competition and aid the implementation of dynamic ocean management.

Predatory release has long been considered a potential contributor to population outbreaks of crown-of-thorns starfish (CoTS; Acanthaster spp.). This has initiated extensive searches for potentially important predators that can consume large numbers of CoTS at high rates, which are also vulnerable to over-fishing or reef degradation. Herein, we review reported predators of CoTS and assess the potential for these organisms to exert significant mortality, and thereby prevent and/or moderate CoTS outbreaks. In all, 80 species of coral reef organisms (including fishes, and motile and sessile invertebrates) are reported to predate on CoTS gametes (three species), larvae (17 species), juveniles (15 species), adults (18 species) and/or opportunistically feed on injured (10 species) or moribund (42 species) individuals within reef habitats. It is clear however, that predation on early life-history stages has been understudied, and there are likely to be many more species of reef fishes and/or sessile invertebrates that readily consume CoTS gametes and/or larvae. Given the number and diversity of coral reef species that consume Acanthaster spp., most of which (e.g., Arothron pufferfishes) are not explicitly targeted by reef-based fisheries, links between overfishing and CoTS outbreaks remain equivocal. There is also no single species that appears to have a disproportionate role in regulating CoTS populations. Rather, the collective consumption of CoTS by multiple different species and at different life-history stages is likely to suppress the local abundance of CoTS, and thereby mediate the severity of outbreaks. It is possible therefore, that general degradation of reef ecosystems and corresponding declines in biodiversity and productivity, may contribute to increasing incidence or severity of outbreaks of Acanthaster spp. However, it seems unlikely that predatory release in and of itself could account for initial onset of CoTS outbreaks. In conclusion, reducing anthropogenic stressors that reduce the abundance and/or diversity of potential predatory species represents a “no regrets” management strategy, but will need to be used in conjunction with other management strategies to prevent, or reduce the occurrence, of CoTS outbreaks.

Many pelagic marine ecosystems have a wasp-waist trophic structure characterised by low diversity of mid-trophic species, typically small, shoaling forage fish that are eaten by a wide range of top predators. In the North Sea, this mid-trophic position is occupied by the lesser sandeel Ammodytes marinus. Over the last 30–40 yr, the abundance and length-at-age of sandeels have declined, but information on concurrent changes in the diets of seabird communities is scarce. We used data on chick diet composition, sandeel length-at-age and energy density collected at a colony in the western North Sea from 1973–2015, to test for dietary shifts in this seabird community during a period when a local sandeel fishery opened, operated and was closed. We found a long-term decline in the overall importance (measured as the frequency of occurrence and proportion of biomass in diet samples) of sandeels, particularly 1+ group fish. However, there were species-specific differences such that the overall decline in sandeels was strongest in common guillemots Uria aalge, while the shift from 1+ group to 0 group sandeels was apparent in all species except European shags Phalacrocorax aristotelis. Community-level differences were also apparent in the alternative prey to sandeels, with with common guillemot, razorbill Alca torda, Atlantic puffin Fratercula arctica, and black-legged kittiwake Rissa tridactyla chicks being fed clupeids, predominantly sprat Sprattus sprattus, while shag chicks received a wide range of benthic fish species. There was also evidence for a decline in the quality of sandeels fed to chicks with significant decreases in length-at-age of 0 group and 1+ group. However, there was no significant annual variation in the energy density of sandeels except for 2004, when values were exceptionally low. Neither the opening nor the closing of the sandeel fishery had any detectable effect on chick diet composition, sandeel length or sandeel energy density. Overall, our results suggest marked community-level changes in seabird diet composition over the last 3 decades that may reflect long-term declines in the abundance and quality of their principal prey.

Fishery closures are widely used to promote the sustainability of fish stocks. Fishery agencies typically have very little data relevant to planning closure enforcement actions and evaluating the effectiveness of closures, due in part to the vast expanse and remote nature of many closures. In some cases the effectiveness of closures can be evaluated using data from GPS based beacons, such as Automatic Identification System (AIS) or Vessel Monitoring Systems (VMS) installed on fishing boats. In fisheries where few boats are equipped with AIS or VMS, the rating of closures relies on other data sources capable of detecting or inferring fishing activity. One such source comes from low light imaging data collected by the NASA/NOAA Visible Infrared Imaging Radiometer Suite (VIIRS), which can detect fishing boats using lights to attract catch. This is a widely used practice in Asia and several other regions. NOAA has developed an automatic system for reporting the locations of VIIRS boat detections with a nominal four hour temporal latency. VIIRS boat detection alerts are running for more than 900 fishery closures in the Philippines, with email and SMS transmission modes. These alerts are being actively used in the Philippines to plan enforcement actions and there is a growing list of apprehensions that occurred based on tip-offs from VIIRS. The VIIRS boat detection archive extends back to April 2012. A VIIRS closure index (VCI) has been developed to rate the effectiveness of closures on monthly increments in terms of a percentage. The VCI analysis was performed on three types of closures: an ad hoc fishery closure associated with a toxic industrial discharge, a seasonal fishery closure and a permanent closure in restricted coastal waters. The VCI results indicate that it is possible to rank the effectiveness of different closure, year-to-year differences in compliance levels, and to identify closure encroachments which may warrant additional enforcement effort.

AIM: Numbers of coral reef species are broadly influenced by historical, physical and geographical factors that are often the basis for prioritizing conservation and management investments. In contrast, the number of species at a site is often influenced by site‐specific factors, including abundance, benthic cover and other habitat features (depth and exposure), fishing pressure and resource management. Conservation policies and programmes often prioritize geographies or specific management systems within specific geographies. I evaluate the variance in number of species at the site scale and estimate the contributions of fishing pressure, local habitat factors and regional geography to local diversity. LOCATION: Coral reefs of the south‐western Indian Ocean (SWIO). METHODS: Site‐level species richness data from an extensive field sample of common coral reef fish at 266 sites in seven SWIO countries were analysed to create four species richness metrics to evaluate the effects of local site, geography and management. RESULTS: The local number of species was strongly predicted by an asymptotic relationship with fish biomass, followed by habitat variables, and lastly by the geographical positions of latitude and longitude. A species richness centre or ‘hotspot’ was found between Madagascar and the African coastline, but the variance attributable to geography when biomass and habitat effects were removed was small. Evaluation of the number of species in five existing fisheries management categories indicated that differences were chiefly influenced by biomass rather than habitat factors. MAIN CONCLUSIONS: Although the centre of species richness may indicate a climate refugium that should be considered in conservation prioritization, this diversity‐centre effect can weaken if habitat and biomass features are reduced by climate disturbances and fishing. Consequently, the highest priority for conserving local numbers of reef fish species is to maintain biomass above the c. 600 kg ha⁻¹ threshold found in this study.