Cumulative impact assessment for ecosystem-based marine spatial planning

An enhanced Cumulative Impact Assessment framework supporting Ecosystem-based Coastal Spatial Planning and Blue Growth in a data-poor region

Ecosystem-based Coastal Spatial Planning (EB-CSP) addresses the substantial need for assessing the cumulative impacts of coastal human footprint on ecosystem services. This study proposes a holistic Cumulative Impact Assessment (CIA) methodology, leveraging open-source and modelled geospatial data, exemplified in the data-limited coastal zone of Heraklion Prefecture. The methodology assesses the impacts of land- and sea-based anthropogenic activities on Final Ecosystem Services (FES) as assessment endpoints and explores the spatial variations in CIA results engaging spatial autocorrelation and hotspot analysis. Thus, Geodetector analysis was conducted to investigate the spatial differentiation and driving mechanisms of CIA distribution, still unknown in marine regions. Results revealed that shipping and fishing activities contributed to the higher CIA values, with P. oceanica meadows being the most impacted FES. Impact hotspots were concentrated near urban centres, reflecting regional differentiation. Factor detection identified land-based activities as driving forces impacting the study area and in the northern part separately, while bathing waters dominated in the south. Among ecological influencing factors, Photosynthetically Active Radiation (PAR) was highlighted at the study area level, whereas P. oceanica was predominant regionally. Synergistic interactions prevailed between land-based activities and PAR in the study area overall, between spawning areas with urbanization and tourism in the north and bathing waters with agriculture and urbanization in the south. The proposed methodology facilitates the identification of priority conservation zones and informs decision-making for managing driving human activities in the EB-CSP context while offering actionable recommendations for future impact mitigation and sustainable ecosystem services utilization in data-limited coastal regions.

Marine spatial planning and marine protected area planning are not the same and both are key for sustainability in a changing ocean

Marine spatial planning (MSP) and marine protected area (MPA) planning are two distinct area-based management processes that are often conflated. While engaging in MPA planning is crucially important for biodiversity conservation and localized sustainable use, it cannot bring the benefits that larger scale MSP can deliver. Confusing the two can lead not only to missed opportunities to support ocean sustainability, but also to inefficiencies and even conflict. Here, we clearly define and distinguish each approach, then discuss opportunities to optimise synergies, especially under rapidly changing climate. MSP can support conservation efforts by taking the broader context into account, while integrating conservation and MPA planning into MSP allows for the maintenance of ocean health-always a core goal of marine management.

Incorporating ecosystem component interactions and indirect effects in cumulative impact assessment models

The cumulative impact of anthropogenic pressures on coastal seas is important to consider for a strategic and sustainable management of marine ecosystems. We aim to demonstrate how, and to what extent, incorporating interactions among ecosystem components (species and habitats) and indirect effects of pressures through other ecosystem components can develop existing cumulative impact assessment (CIA) models. A Swedish case study area was selected to test a simplified version of the extended regional Symphony CIA model. Five pollution- and climate-driven pressures acting on three trophically connected ecosystem components, i.e. cod, herring and plankton species/organism groups, were used. In addition, we conducted a systematic review of the scientific literature to determine the impact weight scores for an advancement of the method. The results from the development of CIA models clearly indicate the importance of introducing ecosystem component interactions and indirect effects into CIA models. The total cumulative impact increased by 117 % in the test area, but even more importantly, the development of the model resulted in a spatially more detailed outcome with a greater spatial variability in the magnitude of the total cumulative impact. New areas were highlighted that are under pressure compared to the original model. Thus, the development of the model captures cumulative impacts that would otherwise be overlooked if ecosystem component interactions and indirect effects were ignored. These types of changes to CIA models are required to increase the predictive power and ecological relevance to accommodate solid holistic and ecosystem-based marine management.

Challenges in expert ratings of marine habitat and species sensitivity to anthropogenic pressures

Expert knowledge can help fill gaps in quantitative empirical information about complex ecological phenomena. We examined the level of agreement between 21 studies that collected expert ratings of the sensitivity of species and habitats to human activities and their pressures as input data for mapping the human impact on marine ecosystems. Our analyses revealed broad agreement about which human activities and pressures many species and habitats are sensitive to. These agreements reflect a common view of the main threats to ocean ecosystems. In contrast, scores provided by individual experts varied both within and across studies. Sensitivity scores collected with the same method for different regions were often more similar than scores collected for the same region but with different methods. These results highlight how inconsistencies in the design of many expert surveys can lead to variable outcomes. It is important to employ more consistent and theoretically grounded methods and protocols when eliciting expert ratings of species' sensitivity to pressures, to ensure compatibility across studies and maintain rigour in analyses supporting effective ocean management.

Stability and reliability of regional cumulative impact mapping: A Canadian Pacific case study

Cumulative impact mapping is a commonly applied spatial representation of the impacts of human activities on the ocean. This spatial model has been applied at varying scales around the world, in part due to its ability to visually communicate complicated information in a simple way. The application of the model to decision-making processes requires an understanding of the reliability and stability of its outputs. This paper represents both an updated regional application in Pacific Canada and an evaluation of the tool over two iterations, 2015 and 2023. The regional application utilised higher model resolution and new and improved data inputs including 38 habitats and 46 activities across five sectors. High impact hotspots were found around major population centres and ports, as well as in fishing and shipping areas along the continental shelf. Commercial fishing, shipping, and climate change (sea surface temperature change) remained the major drivers of cumulative impacts in the region, and cumulative impacts per unit area continued to be highest in kelp and seagrass. Results suggest evidence of decreased impacts where improved protection for sponge reefs were implemented but show an overall increase in cumulative impacts for the region. Results showed consistency and reliability in the location of cumulative impact hotspots. Refinements in data quality and resolution of spatial data inputs contributed towards increasing the spatial precision of hot spot areas identified. Confidence in the cumulative impact mapping outputs and applications for marine spatial planning, marine protected area designation and management, research, and decision support are discussed.

Cumulative human impacts on global marine fauna highlight risk to biological and functional diversity

Anthropogenic stressors to marine ecosystems from climate change and human activities increase extinction risk of species, disrupt ecosystem integrity, and threaten important ecosystem services. Addressing these stressors requires understanding where and to what extent they are impacting marine biological and functional diversity. We model cumulative risk of human impact upon 21,159 marine animal species by combining information on species-level vulnerability and spatial exposure to a range of anthropogenic stressors. We apply this species-level assessment of human impacts to examine patterns of species-stressor interactions within taxonomic groups. We then spatially map impacts across the global ocean, identifying locations where climate-driven impacts overlap with fishing, shipping, and land-based stressors to help inform conservation needs and opportunities. Comparing species-level modeled impacts to those based on marine habitats that represent important marine ecosystems, we find that even relatively untouched habitats may still be home to species at elevated risk, and that many species-rich coastal regions may be at greater risk than indicated from habitat-based methods alone. Finally, we incorporate a trait-based metric of functional diversity to identify where impacts to functionally unique species might pose greater risk to community structure and ecosystem integrity. These complementary lenses of species, function, and habitat provide a richer understanding of threats to marine biodiversity to help inform efforts to meet conservation targets and ensure sustainability of nature's contributions to people.

A Novel Joint Denoising Method for Hydrophone Signal Based on Improved SGMD and WT

Underwater acoustic technology as an important means of exploring the oceans is receiving more attention. Denoising for underwater acoustic information in complex marine environments has become a hot research topic. In order to realize the hydrophone signal denoising, this paper proposes a joint denoising method based on improved symplectic geometry modal decomposition (ISGMD) and wavelet threshold (WT). Firstly, the energy contribution (EC) is introduced into the SGMD as an iterative termination condition, which efficiently improves the denoising capability of SGMD and generates a reasonable number of symplectic geometry components (SGCs). Then spectral clustering (SC) is used to accurately aggregate SGCs into information clusters mixed-clusters, and noise clusters. Spectrum entropy (SE) is used to distinguish clusters quickly. Finally, the mixed clusters achieve the signal denoising by wavelet threshold. The useful information is reconstructed to achieve the original signal denoising. In the simulation experiment, the denoising effect of different denoising algorithms in the time domain and frequency domain is compared, and SNR and RMSE are used as evaluation indexes. The results show that the proposed algorithm has better performance. In the experiment of hydrophone, the denoising ability of the proposed algorithm is also verified.

Cumulative effects of multiple stressors impact an endangered seagrass population and fish communities

Coastal ecosystems are becoming increasingly threatened by human activities and there is growing appreciation that management must consider the impacts of multiple stressors. Cumulative effects assessments (CEAs) have become a popular tool for identifying the distribution and intensity of multiple human stressors in coastal ecosystems. Few studies, however, have demonstrated strong correlations between CEAs and change in ecosystem condition, questioning its management use. Here, we apply a CEA to the endangered seagrass Posidonia australis in Pittwater, NSW, Australia, using spatial data on known stressors to seagrass related to foreshore development, water quality, vessel traffic and fishing. We tested how well cumulative effects scores explained changes in P. australis extent measured between 2005 and 2019 using high-resolution aerial imagery. A negative correlation between P. australis and estimated cumulative effects scores was observed (R2 = 22 %), and we identified a threshold of cumulative effects above which losses of P. australis became more likely. Using baited remote underwater video, we surveyed fishes over P. australis and non-vegetated sediments to infer and quantify how impacts of cumulative effects to P. australis extent would flow on to fish assemblages. P. australis contained a distinct assemblage of fish, and on non-vegetated sediments the abundance of sparids, which are of importance to fisheries, increased with closer proximity to P. australis. Our results demonstrate the negative impact of multiple stressors on P. australis and the consequences for fish biodiversity and fisheries production across much of the estuary. Management actions aimed at reducing or limiting cumulative effects to low and moderate levels will help conserve P. australis and its associated fish biodiversity and productivity.

Advancing the initiatives of sustainable coastal and marine areas development in Pakistan through marine spatial planning

Coastal states are currently transitioning their traditional socio-economic activities into a single platform to address the emerging issues of the coast and marine environment. For countries like Pakistan, managing multiple coastal and marine activities is a significant challenge. The lack of proper management policies and an inefficient decision-making process put various types of pressure on the ecological functions of Pakistan's coastal and marine areas. The Government of Pakistan has not yet prioritized coastal and marine affairs in its policy agenda, resulting in a halt to the process of sustainable development. Moreover, a lack of financial allocation for large-scale coastal and marine projects, a shortage of trained human resources, insufficient coordination among organizations, and unstable political decisions and governance impede the sustainable delivery of the projects. This paper discusses Pakistan's coastal and marine policy targets and highlights various issues through PESTLE analysis, which encompasses political (P), economic (E), social (S), technological (T), legal (L), and environmental (E) factors that limit the advancement of sustainable coastal and marine development. This paper aims to determine the advantages of adopting marine spatial planning (MSP) in Pakistan and how its implementation can bring social, ecological, and economic prosperity. The study provides a baseline for the country's coastal and marine policymakers regarding the advancement of a blue economy through MSP.

A risk-based approach to cumulative effects assessment for large marine ecosystems to support transboundary marine spatial planning: A case study of the yellow sea

Cumulative effects assessment (CEA) should be conducted at ecologically meaningful scales such as large marine ecosystems to halt further ocean degradation caused by anthropogenic pressures and facilitate ecosystem-based management such as transboundary marine spatial planning (MSP). However, few studies exist at large marine ecosystems scale, especially in the West Pacific seas, where countries have different MSP processes yet transboundary cooperation is paramount. Thus, a step-wise CEA would be informative to help bordering countries set a common goal. Building on the risk-based CEA framework, we decomposed CEA into risk identification and spatially-explicit risk analysis and applied it to the Yellow Sea Large Marine Ecosystem (YSLME), aiming to understand the most influential cause-effect pathways and risk distribution pattern. The results showed that (1) seven human activities including port, mariculture, fishing, industry and urban development, shipping, energy, and coastal defence, and three pressures including physical loss of seabed, input of hazardous substances, nitrogen, and phosphorus enrichment were the leading causes of environmental problems in the YSLME; (2) benthic organisms, fishes, algae, tidal flats, seabirds, and marine mammals were the most vulnerable ecosystem components on which cumulative effects acted; (3) areas with relatively high risk mainly concentrated on nearshore zones, especially Shandong, Liaoning, and northern Jiangsu, while coastal bays of South Korea also witnessed high risk; (4) certain risks could be observed in the transboundary area, of which the causes were the pervasive fishing, shipping, and sinking of pollutants in this area due to the cyclonic circulation and fine-grained sediments. In future transboundary cooperation on MSP, risk criteria and evaluation of existing management measures should be incorporated to determine whether the identified risk has exceeded the acceptable level and identify the next step of cooperation. Our study presents an example of CEA at large marine ecosystems scale and provides a reference to other large marine ecosystems in the West Pacific and elsewhere.

Evaluating the combined effect of climate and anthropogenic stressors on marine coastal ecosystems: Insights from a systematic review of cumulative impact assessment approaches

Cumulative impacts increasingly threaten marine and coastal ecosystems. To address this issue, the research community has invested efforts on designing and testing different methodological approaches and tools that apply cumulative impact appraisal schemes for a sound evaluation of the complex interactions and dynamics among multiple pressures affecting marine and coastal ecosystems. Through an iterative scientometric and systematic literature review, this paper provides the state of the art of cumulative impact assessment approaches and applications. It gives a specific attention to cutting-edge approaches that explore and model inter-relations among climatic and anthropogenic pressures, vulnerability and resilience of marine and coastal ecosystems to these pressures, and the resulting changes in ecosystem services flow. Despite recent advances in computer sciences and the rising availability of big data for environmental monitoring and management, this literature review evidenced that the implementation of advanced complex system methods for cumulative risk assessment remains limited. Moreover, experts have only recently started integrating ecosystem services flow into cumulative impact appraisal frameworks, but more as a general assessment endpoint within the overall evaluation process (e.g. changes in the bundle of ecosystem services against cumulative impacts). The review also highlights a lack of integrated approaches and complex tools able to frame, explain, and model spatio-temporal dynamics of marine and coastal ecosystems' response to multiple pressures, as required under relevant EU legislation (e.g., Water Framework and Marine Strategy Framework Directives). Progress in understanding cumulative impacts, exploiting the functionalities of more sophisticated machine learning-based approaches (e.g., big data integration), will support decision-makers in the achievement of environmental and sustainability objectives.

A Bayesian Network model to identify suitable areas for offshore wave energy farms, in the framework of ecosystem approach to marine spatial planning

The production of energy from waves is gaining attention. In its expansion strategy, technical, environmental and socioeconomic aspects should be taken into account to identify suitable areas for development of wave energy projects. In this research we provide a novel approach for suitable site identification for wave energy farms. To achieve this objective, we (i) developed a conceptual framework, considering technical, environmental and conflicts for space aspects that play a role on the development of those projects, and (ii) it was operationalized in a Bayesian Network, by building a spatially explicit model adopting the Spanish and Portuguese Economic Exclusive Zones as case study. The model results indicate that 1723 km² and 17,409 km² are highly suitable or suitable for the development of wave energy projects (i.e. low potential conflicts with other activities and low ecological risk). Suitable areas account for a total of 2.5 TWh∙m^-1 energy resource. These areas are placed between 82 and 111 m water depth, 18-30 km to the nearest port, 21-29 km to the nearest electrical substation onshore, with 143-170 MWh m^-1 mean annual energy resource and having 124-150 of good weather windows per year for construction and maintenance work. The approach proposed supports scientists, managers and industry, reducing uncertainties during the consenting process, by identifying the most relevant technical, environmental and socioeconomic factors when authorising wave energy projects. The model and the suitability maps produced can be used during site identification processes, informing Strategic Environmental Assessment and ecosystem approach to marine spatial planning.

Projected climate change impact on a coastal sea-As significant as all current pressures combined

Climate change influences the ocean's physical and biogeochemical conditions, causing additional pressures on marine environments and ecosystems, now and in the future. Such changes occur in environments that already today suffer under pressures from, for example, eutrophication, pollution, shipping, and more. We demonstrate how to implement climate change into regional marine spatial planning by introducing data of future temperature, salinity, and sea ice cover from regional ocean climate model projections to an existing cumulative impact model. This makes it possible to assess climate change impact in relation to pre-existing cumulative impact from current human activities. Results indicate that end-of-century projected climate change alone is a threat of the same magnitude as the combination of all current pressures to the marine environment. These findings give marine planners and policymakers forewarning on how future climate change may impact marine ecosystems, across space, emission scenarios, and in relation to other pressures.

An improved method of assessing marine utilization impact to describe the man-land relationship for coastal management: a case study of the Laizhou Bay, China

Understanding the level of human impact on the marine environment requires integrated and ecosystem-based assessment. This research proposes a method based on geospatial modeling at the activity level to assess the potential impact of marine utilization on coastal management and conservation. Laizhou Bay in China was selected as a case study. The research identified the spatial distribution of economic sectors and the potential impact of that distribution on important marine ecological management zones. The findings reveal that, from high to low, threats exist in the bay-head, and to the east and west, and that marine ecological zones are over-used for open mariculture because the environmental impact of this activity is believed to be low. This paper reveals the spatial distribution of threats from a variety of marine-area uses on the ecology of Laizhou Bay. The findings provide support for policymakers in the implementation of marine ecological red-line policy and in the management of the utilization of the marine environment.

Combined effects of human pressures on Europe's marine ecosystems

Marine ecosystems are under high demand for human use, giving concerns about how pressures from human activities may affect their structure, function, and status. In Europe, recent developments in mapping of marine habitats and human activities now enable a coherent spatial evaluation of potential combined effects of human activities. Results indicate that combined effects from multiple human pressures are spread to 96% of the European marine area, and more specifically that combined effects from physical disturbance are spread to 86% of the coastal area and 46% of the shelf area. We compare our approach with corresponding assessments at other spatial scales and validate our results with European-scale status assessments for coastal waters. Uncertainties and development points are identified. Still, the results suggest that Europe's seas are widely disturbed, indicating potential discrepancy between ambitions for Blue Growth and the objective of achieving good environmental status within the Marine Strategy Framework Directive.

Spatial and temporal analysis of cumulative environmental effects of offshore wind farms in the North Sea basin

The North Sea basin is one of the busiest maritime areas globally with a considerable number of anthropogenic pressures impacting the functioning of the marine ecosystem. Due to growing EU ambitions for the deployment of large offshore wind farm projects (OWF), as part of the 2050 renewable energy roadmap, there is a key need for a holistic understanding of OWF potential impacts on the marine ecosystem. We propose a holistic Cumulative Effect Assessment methodology, applied using a geo-spatial open-source software, to assess impacts of OWF related pressures on selected seabed habitats, fish, seabird and mammal species. We take into account pressures specific to the three OWF development phases, spanning 1999-2050, for the entire North Sea basin. Our results underline 2022 as the peak year of cumulative impacts for the approved OWFs, followed by a considerable increase in potential impacts of the planned 212GWs, by 2050. The spatio-temporal analysis of the OWF environmental impacts presents the shift between highly impacted areas over the studied timeline and distinguishes between concentrated areas of high impacts (S-E of UK) and dispersed areas of high impacts (Germany). Our results can inform decision-makers and the OWF industry in a joint effort to mitigate the environmental impacts of future large OWF developments.

Spatial-Planning-Based Ecosystem Adaptation (SPBEA): A Concept and Modeling of Prone Shoreline Retreat Areas

Ecosystem-based adaptation to climate change impacts, such as shoreline retreat, has been promoted at the international, national, and even local levels. However, among scientists, opinions about how to implement it in spatial-planning practices are varied. Science-based environmental factors, human wellbeing, and sustainable development can be strengthened by developing spatial-planning-based ecosystem adaptations (SPBEAs). Therefore, this article aims to assess how the SPBEA model can be developed within an area prone to shoreline retreat. A coastal area of the Sayung subdistrict in Central Java, Indonesia, was selected as a study area because it has experienced a massive shoreline retreat. A multicriteria analysis (MCA) method was employed for developing the model by using the geographic information system (GIS) technique of analysis, divided into three steps: the fishpond zone determination, which involved the analytical hierarchy process (AHP) method in the process of model development; the fishpond site determination; SPBEA fishpond site development. The results show that the SPBEA model is the best practice solution for combatting shoreline retreat because of tidal waves and/or sea-level rise. The spatial site management should empower the coastal protection zone and the sustainable fishpond zone by implementing a silvofishery approach.