Search

Accurate assessments of ecosystem condition are needed to inform management processes such as systematic conservation planning and protected area expansion, marine spatial planning and other effective area‐based conservation measures. Yet measuring the condition of dynamic and often largely inaccessible marine ecosystems is extremely difficult and presents a global challenge.Broad‐scale cumulative impact assessments have been used in South Africa as a proxy for marine ecosystem condition in national assessments and reporting because the data are more readily available, and knowledge exists on the impacts of various human activities (or pressures) on marine ecosystems. While useful for national reporting, assessments based on in situ ecological data are also needed at finer scales relevant to management.Applying the HELCOM BEAT approach, this study used in situ ecological data to identify potential methods and indicators that can be applied in South Africa to conduct integrated ecosystem assessments and to assess the suitability of current cumulative impact assessments as a proxy for condition.Aggregated fish indicators demonstrated greater sensitivity to varying human pressures compared with benthic community indicators, with responsiveness differing by location. Notably, site‐level differences in empirical condition emerged that broad‐scale cumulative assessments often missed. The study thus highlighted the varying suitability of cumulative impact scores as proxies for condition, indicating their reliability for fish communities. However, this is also dependent on the pressure types included, the biotic indicators used and the area of focus.Conservation decisions based solely on cumulative impact scores could misrepresent the actual condition of the environment, which makes it difficult to make management decisions, especially at finer scales. As such, conservation initiatives need to be regionally adapted to effectively address the unique pressures and conditions of each area and should be tailored to account for fine‐scale variability, instead of adopting a one‐size‐fits‐all approach. [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]

• Ecological Infrastructure (EI) is a promising framework to map ecosystem services. • EI was defined in the context of place-based conservation and management. • EI performance evaluation should include information on demand, flow and capacity. • EI should be prioritised through a systematic spatial prioritisation process. • 16 recommendations were made for mapping EI. Ecosystem services are an important nexus between people and nature. Nevertheless, their inclusion in place-based conservation and management is limited also because they are often intangible. The Ecological Infrastructure (EI) concept is a promising framework to address this, but a clear definition and mapping approach is still missing. We aim to analyse the uses of EI and to distil a definition and recommendations for using EI as a framework for mapping ecosystem services. A semi-systematic review of peer-reviewed and grey literature was conducted to examine: (1) perceptions of what constitutes EI (n = 117), and (2) EI mapping approaches (n = 51). The main interpretations of EI indicated that it should be natural or naturally functioning (56%); deliver multiple services (75%); and benefit humans (64%) and biodiversity (36%). EI was thus defined as 'natural and naturally functioning ecological systems or networks of ecological systems that deliver multiple services to humans and enable biodiversity persistence'. Studies have used simple proxies, e.g., land cover, to identify EI, sometimes combined with service-specific variables. To evaluate EI performance (26% of studies), modelling all three ecosystem service aspects (capacity, flow, and demand) was considered appropriate. EI prioritisation (50% of studies) as part of a systematic spatial prioritisation process was recommended. Sixteen recommendations for mapping EI for inclusion in place-based conservation and management were developed. We illustrate how EI can be used to integrate ecosystem services into conservation and management in three real-world applications. The EI-based framework is a promising approach and supports the new 'people and nature' era in conservation. [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]

• 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]