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South Africa sought to implement an ecologically representative Marine Protected Area (MPA) network to achieve biodiversity and fisheries management goals with least impact on offshore stakeholders. The result was the declaration of a spatially efficient network representing 131 of 150 marine ecosystem types (87%) in 5.4% of ocean area. We outline the 15‐year process from planning to implementation of 20 new MPAs, including contentious areas recognized as important for conservation decades ago. Systematic Conservation Planning (SCP) supported by 532 data layers and an inclusive stakeholder process identified priority areas, reduced conflict and guided complex trade‐offs. Multiple scenarios and iterative improvements increased transparency, supported ocean zonation and achieved balanced compromises while maintaining conservation objectives. Key challenges, enabling factors and lessons are shared. We demonstrate that flexible, evidence‐based SCP together with adaptive social processes that are alert to opportunities can support implementation of representative MPA networks aligned to ocean economy goals. South Africa used systematic planning and inclusive stakeholder engagement to protect 87% of its 150 marine ecosystem types in just 5% ocean area [ABSTRACT FROM AUTHOR]

Abstract Recreational vessels are important contributors to the spread of marine alien species, particularly in relation to secondary spread within novel regions. As such, these vessels should be considered a monitoring priority. The aim of this study was to identify a preferred method for monitoring recreational vessels for alien species, while simultaneously developing a framework that enables managers to objectively choose the most effective sampling approach given their financial constraints. Divers and a remotely operated vehicle (ROV) were considered in relation to four sampling approaches i.e. meanders, transects, inspection of niche areas and the collection of quadrats. Each was applied to the same 53 vessels which represented a spectrum of hull fouling cover. The most effective methods were diver scrape quadrats (Range of alien species numbers per quadrat: 0–9, Total alien species: 20) and inspections of niche areas (Range of alien species numbers: 0–5, Total alien species: 9). All methods employed using an ROV had low efficacy and incurred high costs. While scrape samples were one of the most expensive methods, this was offset by the lowest cost per species detected. Thus, it is recommended that monitoring programmes utilize scrape samples and niche area inspections, but when faced with financial constraints, diver meanders and niche inspections offer sound alternatives for detecting alien species. Graphical abstract Image 1 Highlights • Recreational yacht fouling is an important regional vector for marine alien species. • There is a need to effectively and efficiently monitor yachts for alien species. • Most yachts (79%) supported fouling covering 1–40% of hull surfaces. • Scrape quadrats and niche area inspections by divers detected most alien species. • Scrape sampling incurred the least cost per species detected. [ABSTRACT FROM AUTHOR]

Ecology and biodiversity research are underpinned by species richness patterns and their environmental drivers. However, a key topic in this discussion is the accuracy of these patterns which are greatly dependent on species detection probabilities. Due to variations in detection of species, true ecological patterns may be distorted. This is particularly true for subtidal macro‐infaunal communities. We tested three hypothesized relationships between marine benthic macrofaunal diversity and depth using species richness per site estimated with a capture–recapture heterogeneity model that accounts for variable detection probabilities. These metrics were based on data from 42 replicated sites across the continental shelf of the Southern Benguela. Average detection probability decreased with greater depth but species richness increased along the same depth gradient. The conflation of these trends in observed diversity data resulted in a positively near‐linear depth–diversity relationship, while accounting for variable species detection revealed a much stronger relationship. Ignoring species detection in ecosystems with imperfect detection could therefore distort species richness patterns, which has implications for ecological theory, management and conservation. [ABSTRACT FROM AUTHOR]

Harbours are known introduction foci of marine alien species. They act as recipients of new introductions and as sources for regional spread. We report on subtidal surveys of fouling communities from 14 harbours along the coastline of South Africa that were used to identify predictors of high alien species numbers in support of prioritisation of monitoring actions by authorities. The harbours varied in nature from large, international shipping hubs to small, regional fishing harbours and recreational marinas. Fouling assemblages were assessed using visual and scrape sampling to ensure the detection of large, mobile and small inconspicuous species. In total, 29 alien species were recorded, 15 of which were detected outside of their previously known ranges. The number of species recorded per harbour varied from five to. Results revealed that high numbers of alien species were associated with the presence of yachts and low primary productivity. Harbours which had yachts and occurred in areas with mean Chl a minimum levels lower than 0.21 mg.m-3 had the highest number of alien species, while harbours without yachts that were larger than 0.1km2 supported the fewest alien species. These findings suggest that the presence of yachts can be used to identify harbours with high numbers of alien species, particularly in regions with low productivity. While the applicability of these findings to other regions remains to be tested, this work suggests that harbours that fall within this category could be prioritised for monitoring of marine alien species. [ABSTRACT FROM AUTHOR]

The article examines the implications of the Marine Protected Areas (MPAs) debate for the proposed Phakisa MPA Network in South Africa. Topics discussed include an overview of Phakisa MPA Network, the economic potential of the coastal and marine environment of the region, the threat post to oceans, the necessity for healthy oceans, and the significant role of MPAs in healthy ocean management.

Marine unconsolidated sediment habitats, the largest benthic ecosystem, are considered physically controlled ecosystems driven by a number of local physical processes. Depth and sediment type are recognised key drivers of these ecosystems. Seascape (i.e., marine landscape) habitat classifications are based solely on consistent geophysical features and provide an opportunity to define unconsolidated sediment habitats based on processes which may vary in distribution through space and time. This paper aimed to classify unconsolidated sediment seascapes and explore their diversity in an eastern boundary upwelling region at the macro-scale, using the South African west coast as a case study. Physical variables such as sediment grain size, depth and upwelling-related variables (i.e., maximum chlorophyll concentration, austral summer bottom oxygen concentration and sediment organic carbon content) were included in the analyses. These variables were directly measured through sampling, or collated from existing databases and the literature. These data were analysed using multivariate Cluster, Principal Components Ordination and SIMPER analyses (in PRIMER 6 + with PERMANOVA add-in package). There were four main findings; (i) eight seascapes were identified for the South African west coast based on depth, slope, sediment grain size and upwelling-related variables, (ii) three depth zones were distinguished (inner, middle and outer shelf), (iii) seascape diversity in the inner and middle shelves was greater than the outer shelf, and (iv) upwelling-related variables were responsible for the habitat diversity in both inner and middle shelves. This research demonstrates that the inclusion of productivity and its related variables, such as hypoxia and sedimentary organic carbon, in seascape classifications will enhance the ability to distinguish seascapes on continental shelves, where productivity is most variable. [ABSTRACT FROM AUTHOR]

Using the first high-resolution geophysical data set collected from the uThukela Banks Marine Protected Area (MPA), we reveal a plethora of hitherto unknown or poorly resolved seabed features. In tandem with several remotely operated vehicle dives, we improve on the previous National Biodiversity Assessment map for the area and reveal a more complex picture of the seabed geology and geomorphology on which the MPA is predicated. The upper slope (-120 m and deeper) is dominated by small canyons, gullies and rills that occasionally extend to the shelf edge and form a series of slumps. Suspected cold-water corals were imaged on the interfluves of the Thukela Canyon. The mid to outer shelf (-60 to -100 m) is mostly rocky, and is composed of Pliocene-age siltstones for the most part. Aeolianite shorelines are found at depths of 60 m and 100 m, in which palaeo-lagoons and parabolic aeolian dune systems are also preserved. These features provide habitat for mesophotic corals and demersal fishes. Overlying and abutting hard rock substrates are unconsolidated sandy sediments that are mobilised by the inshore movement of the Agulhas Current. An inshore mud belt characterised by pockmarks associated with free gas expulsion is mapped for the first time. A well-developed palaeo-drainage pattern is also revealed, posing exciting new opportunities for the study of benthic communities associated with palaeo-estuaries and lagoons now exposed at the seabed. Several new habitats, both inside and out of the MPA boundaries, should form the basis for future research within the MPA, in addition to informing expansions of the MPA. Significance: • Using a newly collected geophysical data set, we provide an unprecedented glimpse into the newly proclaimed uThukela Banks Marine Protected Area. • We reveal a complexity of marine habitats hitherto unknown from previous biodiversity surveys. These habitats include areas of possible expansion given the recognition of keystone species that occur just outside the MPA limits. [ABSTRACT FROM AUTHOR]

The high-latitude coral communities of southern Africa suffered minimal impacts during past mass bleaching events. Recent reports indicate an increase in bleaching frequency during the last decade, yet the actual levels of thermal stress and contributing factors in these bleaching events, and the degree of acclimatisation or adaptation on these reefs are poorly understood. During the 2005 warm-water anomaly in the southern Indian Ocean we conducted bleaching surveys and collected samples for genotyping of the algal symbiont communities at 21 sites in southern Mozambique and South Africa. Coral bleaching reached unprecedented levels and was negatively correlated with both latitude and water depths. Stylophora pistillata and Montipora were the most susceptible taxa, whereas three common branching corals had significantly different bleaching responses ( Stylophora > Acropora > Pocillopora). Temperature records indicated that localised strong upwelling events coupled with persistent above-average seawater temperatures may result in accumulated thermal stress leading to bleaching. Symbiodinium in 139 scleractinian corals belonged almost exclusively to clade C, with clade D symbionts present in only 3% of the colonies. Two atypical C subclades were present in Stylophora and Pocillopora colonies and these were more abundant in shallow than deeper sites. Taxon-specific differences in bleaching responses were unrelated to different clades of algal symbionts and suggest that Symbiodinium C subtypes with diverse thermal tolerance, coupled with acclimatisation and morphology of the host colony influence the bleaching response. Additionally, the predominance of putatively thermal-sensitive Symbiodinium in southern African corals may reflect a limited experience of bleaching and emphasises the vulnerability of these reefs to moderate levels of thermal stress. [ABSTRACT FROM AUTHOR]

Coral reefs reach their southernmost limits in the southwestern Indian Ocean in Maputaland, South Africa. Here, we investigate the recent global coral bleaching event of 2016, the thermal dynamics of these marginal high-latitude reefs and the potential environmental factors regulating the responses of coral communities. Pre-, peak- and post-bleaching surveys of over 9850 coral colonies from 29 genera were undertaken over 3 years across 14 sites spanning 120 km of coastline using point-intercept and visual bleaching index survey methodologies. Bleaching data were related to several environmental variables including temperature, degree heating weeks (DHW), depth, latitude, and upwelling intensity. These reefs have experienced a history of relatively low thermal stress based on DHW. Long-term in situ temperature records nevertheless showed no obvious trend of increase. In situ temperatures also displayed poor relationships, with temperatures predicted by the Representative Concentration Pathway models. Mild coral bleaching with no significant mortality was recorded across sites with taxon-specific bleaching responses evident. Latitude and cumulative daily DHW were significantly related to the bleaching index whereas depth and interactions of depth with latitude and DHW were not. While upwelling of cooler water may offer some refuge to coral communities, especially in the Central and Southern Reef Complexes where it is more pronounced, this may only be transient as the upwelled water may also experience some degree of warming in future, thereby limiting such protection from global warming. [ABSTRACT FROM AUTHOR]

• Responsive indicators need to be identified to define good ecological condition. • Fish metrics responded better to pressure gradients than benthic community metrics. • Size-based metrics were more suitable than compositional metrics of reef condition. • Higher biomass, length & proportion of mature target fish represent good condition. • Identification of possible indicators for Essential Biodiversity Variables (EBVs) Baseline data for reference conditions are needed to determine the impacts of human pressures on the structure and functioning of marine ecosystems. However, baseline data are seldom available, and a comprehensive understanding of what good ecological condition is or how to measure it is often lacking. In the absence of true baselines, well established and effective marine protected areas (MPAs) can be used to approximate reference conditions. Thus, the aim of this study was to use effective no-take MPAs to identify suitable indicators that can be used for condition assessments of rocky reefs in South Africa. To achieve this, we tested the response of two types of metrics (compositional and size-based), using in situ fish and benthic community data, to three levels of human pressures in two ecoregions in South Africa. Results showed that traditionally-used structural metrics, such as total abundance or species richness, were less responsive than size-based metrics, including total biomass, average length and proportion of mature fish. Rocky reef ecosystems exposed to low anthropogenic pressure were characterised by a higher biomass, average length and proportion of mature and large (>30 cm) fish than reefs with moderate and high pressures. Benthic communities appeared more resilient than fish communities to the typical human pressures in the study region. Overall, the greatest effect of pressure was observed in the heavily impacted sub-tropical Natal Shelf Ecoregion, while rocky reefs in the warm-temperate Agulhas Shelf Ecoregion appeared to be in better condition than expected. This study identified assemblage patterns and indicators that appeared responsive and sensitive to different levels of human pressure, which can be used to infer good and poor ecological condition of rocky reef ecosystems. These results indicate which species (e.g., target species) and traits (e.g., size) are most vulnerable to local human pressures and will be suitable for condition assessments. [ABSTRACT FROM AUTHOR]

Abstract Climate change and fishery impacts modify the spatial distribution of marine species. Understanding and predicting changes in distribution is important for adaptation by fishers and the management of fishery resources and biodiversity. However, identifying such trends is challenging given the variability inherent in trawl survey data. We apply a novel two-step approach to identify fish distribution trends from trawl surveys. First, species-specific average locations (mean latitude and longitude centre of gravity) and extent (effective area occupied) were estimated within a spatio-temporal delta modelling framework. The resulting time series and associated variance estimates were then passed to a multivariate Bayesian state-space model to estimate average trends over the study period. We applied this two-stage approach to three decades (1986–2016) of demersal trawl research survey data from the Agulhas Bank of South Africa to quantify distributional changes in 44 commonly caught fishes (chondrichthyans and teleosts). Across the entire assemblage, average trends showed a westward (alongshore) shift in location and a reduction in the extent of populations. At the species level, six taxa showed a location trend towards the west or south-west, and three shifted towards the east or north-east. The area occupied by species showed two taxa that had a decreasing trend in spatial extent and one species that was expanding. The mean westward and contracting trends of the assemblage were interpreted as likely signals of climate forcing, whereas the eastward shift of three species may be linked to fishing impacts. A lack of knowledge of subsurface oceanographic changes in the region challenges interpretation of the distribution changes and is identified as a research priority. We recommend additional research regarding causal drivers of distribution shifts, specifically to attribute observed changes to climate, fishing, and inter-annual environmental variability. [ABSTRACT FROM AUTHOR]

Abiotic determinants of community composition on shallow reefs are seldom examined at a scale transcending biogeographic regions, and knowledge for the western Indian Ocean is sparse. To address this deficit, turnover in reef community composition was quantified, using gradient forest analyses, along gradients of nine abiotic variables collected in situ or via remote sensing at 54 sites across and within three bioregions: Tropical Western Indian Ocean (Tropical WIO), Delagoa and Natal, spanning 4800 km of east African coastline (5.2-31.1°S). All oceanographic variables differed significantly among bioregions. At a scale across bioregions, wave height declined northwards, while temperature increased. Values for suspended inorganic sediments, chlorophyll- a concentration [chl- a], turbidity and nutrients were all lowest in Delagoa, in association with the scarcity of rivers there. The most novel and unexpected finding was that the northwards decline in wave action was more strongly associated with changes in community composition across bioregions than any other variable. Temperature was the second-most important variable at that scale. Within bioregions, temperature and [chl- a] had strongest relationships with community composition in the Tropical WIO. By contrast, in Delagoa, reef profile, susceptibility to sand inundation and reef heterogeneity were most strongly associated with community composition; and in Natal, depth, turbidity and suspended sediment were foremost. Variables of greatest importance within bioregions distilled to (1) those influencing food/energy supply ([chl- a], turbidity, depth and suspended sediments), which were of particular importance in the Tropical WIO and Natal bioregions, and (2) those altering sand inundation and small-scale current dynamics of reefs (profile, heterogeneity and depth), which were leading factors in the Delagoa Bioregion. [ABSTRACT FROM AUTHOR]

Globally, South Africa ranks in the top five countries regarding marine species richness per unit area. Given the high diversity, it is not surprising that many invertebrate taxa in the region are poorly characterised. The South African azooxanthellate Scleractinia (Anthozoa) is one such taxonomic group, and was last reviewed by Boshoff in 1980. Although more recent regional publications have reported on some species, there has not been a faunistic review that accounts for the country's species diversity since then. Moreover, numerous unidentified specimens representing more than three decades of sampling effort have accumulated. In this study the authors update the state of knowledge of South African azooxanthellate coral species. Specimens, particularly those within the extensive collections of the Iziko South African and Smithsonian museums, were morphologically examined and identified. Other data considered included historic data represented as imagery data, associated species data from recent research surveys, and the scientific literature. To date, the study has increased the total number of known species from 77 to 108 across eleven families, 28 new South African records, and three are new species with one new genus. [ABSTRACT FROM AUTHOR]

Understanding how fish associate with habitats across marine landscapes is crucial to developing effective marine spatial planning (MSP) in an expanding and diversifying ocean economy. Globally, anthropogenic pressures impact the barely understood temperate mesophotic ecosystems and South Africa's remote Amathole shelf is no exception. The Kei and East London region encompass three coastal marine protected areas (MPAs), two of which were recently extended to the shelf-edge. The strong Agulhas current (exceeding 3 m/s), which runs along the narrow shelf exacerbates sampling challenges. For the first time, a remotely operated vehicle (ROV) surveyed fish and their associated habitats across the shelf. Results indicated fish assemblages differed between the two principle sampling areas, and across the shelf. The number of distinct fish assemblages was higher inshore and on the shelf-edge, relative to the mid-shelf. However, the mid-shelf had the highest species richness. Unique visuals of rare Rhinobatos ocellatus (Speckled guitarfish) and shoaling Polyprion americanus (wreckfish) were collected. Visual evidence of rhodolith beds, deep-water lace corals and critically endangered endemic seabreams were ecologically important observations. The ROV enabled in situ sampling without damaging sensitive habitats or extracting fish. This study provided information that supported the Amathole MPA expansions, which extended protection from the coast to beyond the shelf-edge and will guide their management. The data gathered provides baseline information for future benthopelagic fish and habitat monitoring in these new MPAs. [ABSTRACT FROM AUTHOR]

Temperate mesophotic ecosystems are generally poorly understood and in South Africa, few studies have analysed imagery from benthic assemblages in this depth range. This study used a remotely operated vehicle (ROV) to survey and describe benthic communities off the Kei River in the Amathole Region of South Africa's Indian Ocean. The CATAMI classification scheme was used to annotate 215 images from 14 sites in the 30–100 m depth range. Multivariate analyses (Cluster and MDS) produced eight benthic communities and nine corresponding environmental variables were investigated as potential drivers of observed patterns in epifauna. LINKTREE analysis identified depth and substratum as the best distinguishing environmental variables and generated three groups that represent rhodolith beds, macroalgal reefs and animal forests. A major depth break was evident at 74 m that separated rhodolith beds and macroalgal reefs into the upper mesophotic and animal forests into the lower mesophotic zones. Information from this study is important for marine spatial planning and management and contributed directly to the delineation and zonation of the Amathole Offshore Marine Protected Area. [Display omitted] • Upper mesophotic zone (<74 m) had macroalgae, lower mesophotic zone (>74 m) was sponge-dominated. • The Amathole shelf has 8 invertebrate communities in 3 groups: rhodolith beds, macroalgal reefs and animal forests. • Depth and substratum type were important factors structuring macrobenthic community patterns. [ABSTRACT FROM AUTHOR]

Systematic conservation planning is intended to inform spatially explicit decision making. Doing so requires that it be integrated into complex regulatory and governance processes, and there are limited instances where this has been achieved effectively. South Africa is a global leader in the application of conservation plans, the outputs of which are widely used for spatial planning and decision making in many spheres of government. We aimed to determine how conservation planning in the country progressed from theory to implementation, and to identify practical actions that enabled this transition, by assessing temporal trends in the characteristics of conservation plans (1990–2017, n = 94). Since 2010 conservation planning has entered an operational period characterized by government leadership of plans, administrative rather than ecological planning domains, decreasing size of planning units, increasing emphasis on end‐user products, and scheduled revision of plans. Key actions that enabled this progression include transitioning leadership of plans from scientists to practitioners, building capacity within implementing agencies, creating opportunities to integrate plans in legislative processes, establishing a strong community of practice, adopting implementation‐focused methods, and balancing standardization with innovation. Learning from this model will allow other countries, particularly those with a similar megadiverse, developing context, to operationalize conservation planning into spatial planning and decision making. Article impact statement: Systematic conservation planning can be operationalized into government policy and regulatory processes. [ABSTRACT FROM AUTHOR]

Aim The species-area relationship-based method of setting habitat-specific conservation targets assumes that detectability of species is perfect. However, this assumption is often violated. This paper aimed to combine species-area relationship ( SAR)-based target setting with multispecies occupancy models to better represent communities with a large proportion of rare species, such as marine invertebrate macrofauna, include variable species detection and quantify uncertainty around conservation targets. Location South African West Coast continental shelf. Methods The macro-infaunal dataset used in these analyses consisted of 427 species from 42 sites and 220 samples. To examine the effect of variable species detection and include uncertainty around conservation targets, we compared asymptotic estimator-based targets with those based on multispecies site occupancy models ( MSOMs) in a Bayesian framework, which allowed us to account for the observation process and quantify uncertainty more comprehensively. Results Targets based on MSOM were generally higher than those based on asymptotic estimators, with wider credible intervals. Between 10% and 15% (95% credible interval) of the area should be protected to represent 80% of the species, with the exception of one habitat with many common species that had a conservation target of 2%. Main conclusions Detection error-corrected targets based on MSOM are higher than uncorrected targets based on asymptotic estimators for habitats with lower detection and higher proportions of rare species. Our estimated conservation targets are close to the 10% target for marine habitats set by the Convention of Biological Diversity and in line with international studies but should be considered minimum targets as they do not take into account species persistence. Our results affirm the value of the modified SAR approach, which is applicable to any marine or terrestrial ecosystem. Unlike earlier methods, our modification naturally quantifies uncertainty in estimated conservation targets providing a measure of target robustness for decision-makers. [ABSTRACT FROM AUTHOR]

Representative and adequate reserve networks are key to conserving biodiversity. This begs the question, how much of which features need to be placed in protected areas? Setting specifically-derived conservation targets for most ecosystems is common practice; however, this has never been done for sandy beaches. The aims of this paper, therefore, are to propose a methodology for setting conservation targets for sandy beach ecosystems; and to pilot the proposed method using data describing biodiversity patterns and processes from microtidal beaches in South Africa. First, a classification scheme of valued features of beaches is constructed, including: biodiversity features; unique features; and important processes. Second, methodologies for setting targets for each feature under different data-availability scenarios are described. From this framework, targets are set for features characteristic of microtidal beaches in South Africa, as follows. 1) Targets for dune vegetation types were adopted from a previous assessment, and ranged 19–100%. 2) Targets for beach morphodynamic types (habitats) were set using species–area relationships (SARs). These SARs were derived from species richness data from 142 sampling events around the South African coast (extrapolated to total theoretical species richness estimates using previously-established species–accumulation curve relationships), plotted against the area of the beach (calculated from Google Earth imagery). The species-accumulation factor ( z ) was 0.22, suggesting a baseline habitat target of 27% is required to protect 75% of the species. This baseline target was modified by heuristic principles, based on habitat rarity and threat status, with final values ranging 27–40%. 3) Species targets were fixed at 20%, modified using heuristic principles based on endemism, threat status, and whether or not beaches play an important role in the species' life history, with targets ranging 20–100%. 4) Targets for processes and 5) important assemblages were set at 50%, following other studies. 6) Finally, a target for an outstanding feature (the Alexandria dunefield) was set at 80% because of its national, international and ecological importance. The greatest shortfall in the current target-setting process is in the lack of empirical models describing the key beach processes, from which robust ecological thresholds can be derived. As for many other studies, our results illustrate that the conservation target of 10% for coastal and marine systems proposed by the Convention on Biological Diversity is too low to conserve sandy beaches and their biota. [ABSTRACT FROM AUTHOR]

The deep demersal fish fauna at depths of 100–400 m in canyons off the St Lucia Marine Protected Area along the north coast of KwaZulu-Natal is compared with similar fish communities at the Comoro Islands and in the Indo-Pacific region. Fifty-four fish species were seen or photographed from the submersible Jago or by the discovery team of scuba divers in the coelacanth, Latimeria chalumnae, habitat of the canyons off Sodwana Bay. An additional 94 fish species known from depths of 100–200 m along the coast of northern KwaZulu-Natal are likely to occur in the canyon habitat. The fish fauna of the Sodwana canyons shares at least 18 species with the deep demersal fish community off tropical coral reefs of the Indo-Pacific region. Thirty-seven of the Sodwana canyon fishes are also known from the coelacanth habitat in the Comoros. [ABSTRACT FROM AUTHOR]

Using the manned submersible Jago, the habits, distribution and number of coelacanths within all main submarine canyons of the Greater St Lucia Wetland Park were studied during 47 survey dives, with a total bottom time of 166 hours at depths ranging from 46 to 359 m, between 2002 and 2004. Twenty-four individuals were positively identified from three of the canyons, primarily from inside caves at or close to the canyon edges at depths of 96–133 m with water temperatures between 16 and 22.5°C. The population size of coelacanths within the canyons is assumed to be relatively small; coelacanths are resident but not widespread nor abundant within the park. [ABSTRACT FROM AUTHOR]

• Condition is still seldom or poorly defined in marine ecological studies. • A critical review of methods and indicators for condition assessments is provided. • Five Indicator categories, which vary in terms of data requirements and inference. • This review supports indicator selection & framework development for assessments. This review provides a broad conceptual overview of different approaches to measuring marine ecosystem condition and guidance for framework development (particularly relevant for developing countries). The objectives were to review definitions of ecosystem condition and identify the core approaches and key challenges within the research area. Furthermore, we reviewed the advantages and disadvantages of different indicators that can be used for condition assessments. A semi-systematic approach drawing from more than 300 studies covering a broad range of methods was followed. Generally, definitions of ecosystem condition are based on known changes to the ecosystem, but ultimately, they should align with the definition of an ecosystem and consider ecosystem structure and functioning. As far as possible, the definition should relate an observed state to a reference condition or ecological target. Importantly, definitions of condition should be practical, scalable and always provided when conducting condition assessments. Five indicator categories were identified including pressures, physical parameters, biological structure, functional structure and ecological models. Indicators mostly focus on drivers of change (i.e. ex situ pressures) or the structure of the ecosystem, as these data are easier to obtain. While valuable, these classes of indicators can only provide an indirect appraisal of ecosystem functioning in instances where the relationship between pressure, structure and functioning are known. Indicators that measure structure and functioning of an ecosystem can be used to directly report on condition; however, the data (and monitoring) requirements make them impractical in most instances. Ideally, integrated assessments, that measure indicators from all indicator categories, should be prioritised to provide a comprehensive overview of condition. However, this often requires transdisciplinary collaboration, substantial research capacity (and associated funding) and time to collect the necessary data. An alternative is to select a few strategic indicators that can provide data to address the definition of ecosystem condition and at the same time provide a feasible approach to address the project specific research objectives. Where possible, a data-derived approach should be followed as in situ measurements have potential to improve the understanding of impacts of anthropogenic pressures on ecosystem functioning, and in turn facilitate better management of human activities and enhance ecosystem functioning. [ABSTRACT FROM AUTHOR]

One of the stated applications of the IUCN Red List of Ecosystems (RLE) is to influence government policy and decision-making. We share 15 years' experience in integrating an independently developed indicator of ecosystem threat status into government policies and practice. South Africa's ecosystem threat status indicator was conceptualised in the early 2000s and progressed from a project-based indicator to listing of threatened ecosystems in terms of national legislation in 2011. We show the range of applications of the indicator, from its use as a headline indicator in the National Biodiversity Assessment to its role as a direct trigger for Environmental Impact Assessment. The strong link between threatened ecosystems and systematic conservation planning in South Africa also enabled ecosystem threat status to inform multi-sectoral development planning and decision-making. We show how bridging products, data availability, persistent mainstreaming and stakeholder engagement have encouraged the use of the indicator in government policy. The advantages and disadvantages of legislative listing are shared. Sound scientific foundations, combined with pragmatism, have provided a policy-relevant tool for focussing management on threatened ecosystems. We make active recommendations that will facilitate the policy uptake of the IUCN RLE in other countries. [ABSTRACT FROM AUTHOR]