Marine Environmental Assessment Research Articles

A path to make well-informed decisions when considering the decommissioning of subsea pipelines

Australia’s law mandates the removal of infrastructure once not in use unless the Titleholder can demonstrate an equal or superior safety and environmental outcome. Around 100 infield and export pipelines in Australian waters, with an approximate total length of 5000 km, are nearing their end-of-life period. Three common decommissioning options are considered for subsea pipelines: complete removal, partial removal, or in-situ abandonment. Decommissioning these pipelines will cost an estimated US$13 billion, ~33% of the cumulative Australian offshore decommissioning liability, should the full removal option be selected. When decommissioning subsea pipelines, it is essential to consider that they have been exposed to hazardous fluids and aggressive environments. Careful assessments should determine the recyclability of recovered materials, decontamination, and the environmental risks associated with each decommissioning option. A holistic approach is needed to identify and quantify contaminants in subsea pipelines. In the early stages of decommissioning, planning, sampling, and laboratory testing are necessary to identify plastic coating types, degradation mechanisms, constituents released to the environment, types and mechanisms related to mercury/naturally occurring radioactive materials, and chemical stability. This paper aims to identify and present effective methods for addressing the impact of pipeline constituents on the Marine Environment Assessment while assessing potential decommissioning options and explains how tools can support decision-making. In summary, decommissioning subsea pipelines requires careful assessment and planning to ensure environmental and safety compliance. The paper provides a guide to understanding the process, highlighting the importance of quality assurance, risk assessment, and the selection of appropriate decommissioning options.

The acute neurotoxicity of inorganic mercury in Mactra chinensis philippi

Inorganic mercury (IHg) is hazardous to marine organisms especially resulting in neurotoxicity, bivalves are sensitive to pollutants as “ocean sentinel”, but data on the neurotoxicity of IHg in bivalves are sparse. So we chosed M. chinensis philippi with typical neural structures in bivalves to investigate the neurotoxicity of IHg, which could be helpful to understand the specificity of neural regulation and the response characteristics of bivalves. After acute exposed to IHg (HgCl2) for 24 h, the metabolites of ganglion tissues in M. chinensis philippi were evaluated using 1H-nuclear magnetic resonance based metabolomics; Ca2+, neurotransmitters (nitric oxide, glutamate, acetylcholine) and related enzymes (calcineurin, nitric oxide synthase and acetylcholinesterase) were measured using biochemical detection. Compared to the control group, the levels of the nitric oxide (81.04 ± 12.84 μmol/g prot) and acetylcholine (30.93 ± 12.57 μg/mg prot) in M. chinensis philippi of IHg-treated were decreased, while glutamate (2.11 ± 0.61 mmol/L) increased significantly; the activity of nitric oxide synthase (679.34 ± 135.33 U/mg prot) was increased, while acetylcholinesterase (1.39 ± 0.44 U/mg prot) decreased significantly, and the activity of calcineurin (0.52 ± 0.02 U/mg prot) had a statistically insignificant increasing tendency. The concentration of Ca2+ (0.92 ± 0.46 mmol/g prot) in the IHg-treated group was significantly higher than that in the control group. OPLS-DA was performed to reveal the difference in metabolites between the control and IHg-challenged groups, the metabolites of glucose, glutamine, inosine, succinate, glutamate, homarine, and alanine were sensitive to IHg, subsequently metabolic pathways that were affected including glucose metabolism, glutamine metabolism, nucleotide metabolism, Krebs cycle, amino acid metabolism and osmotic regulation. In our study, IHg interfered with metabolites in M. chinensis philippi, thus the corresponding metabolic pathways were changed, which influenced the neurotransmitters subsequently. Furthermore, Ca2+overload affected the synthesis or degradation of the neurotransmitters, and then the altered neurotransmitters involved in changes in metabolic pathways again. Overall, we hypothesized that the neurotoxic effects of IHg on bivalve were in close contact with metabolism, neurotransmitters, related enzymes and Ca2+, which could be effective neurotoxic biomarkers for marine environmental quality assessment, and also provide effective data for the study of the regulatory mechanism of the nervous system in response to IHg in bivalves.

Wave environment analysis at Norwegian harbours for land-based aquaculture facilities using a combined phase-averaging and phase-resolving numerical modelling approach

Numerical wave modelling of Norwegian coastal areas is challenging due to the drastically varying bathymetry, irregular coastline, and large domains of interest. The widely used phase-averaging models are limited by such bathymetric and topographic conditions. Phase-resolving models provide higher accuracy regarding strong nonlinear wave transformations with the trade-off of a higher computational cost. This study provides a combined phase-averaging and phase-resolving modelling approach to analyse the wave conditions for on-shore aquaculture facilities at the site candidates Fiskenes and Breivik, Andøya, Norway. The phase-averaging spectral model SWAN is used for the offshore sea state analysis based on the offshore hind-cast data. The analysis is performed on cascade nested grids, with increasing accuracy closer to the proposed harbour locations. A novel interpolation algorithm is proposed to provide comprehensive sea state information with every offshore wave directions without requiring additional simulations. The critical wave conditions are identified from SWAN and used as input to the open-source phase-resolving fully nonlinear potential flow model REEF3D::FNPF. Four scenarios are investigated and densely spaced wave gauges in the entire computational domain provide the distribution of significant wave height. The combined and cascade simulation approach helps to achieve a balance between computational efficiency and accuracy for large-scale marine environment assessment. The results show detailed wave statistics in the entire area of relevance near both harbours and provide a quantitative reference for both the site choice and the harbour design.

Marine spatial planning identifies solutions for offshore wind farms at fishery and environment in Taiwan territorial waters

Some fishery and environmental organizations criticize offshore wind farms affecting fishery livelihood and marine ecological biological environment. The problems offshore wind farm directly affect the fishing ground due to ocean currents, marine ecology, and the marine environment being changed. In addition, fishing operations may carelessly damage undersea offshore wind farm cables disrupting energy operations, many fishing activities are restricted within the offshore wind farm areas and marine ecological biological environment has been damaged by offshore wind farm. However, marine spatial planning could coordinate offshore wind farm stakeholders and conducts marine environmental impact assessments to identify suitable offshore wind farms. The purpose finds solutions for offshore wind farm in the fishery and marine ecological biological environment. The research questions are how to reduce offshore wind farm impact on fishery livelihood and marine ecological biological environment through marine spatial planning and marine environmental impact assessment in the Taiwan territorial waters. In online questionnaires of 404 respondents, 64.36% supported marine spatial planning site selection and marine environmental impact assessment could reduce offshore wind farm impact; 66.83% agreed offshore wind farm coexistence with multiple uses, increasing fishery and biodiversity; 58.17% agreed on public financial participation in offshore wind farm to increase social acceptance. The findings are consistent with previous research. However, interviewees challenged that multiple uses coexistence might affect some populations in the ecosystem and further investigations are required. Another, 50.50% agreed on updated regulations of marine spatial planning, marine environmental impact assessment, insurance, specific fund, feedback, and compensation of offshore wind farm that could improve fishery livelihood and marine ecological biological environment. Finally, based on the study results, the paper suggests that energy policy could open public financial participation in offshore wind farm increasing social acceptance, skill training influenced groups for employment, enhancing fishery livelihood, and protecting marine ecological biological environment.

A new simulation framework to evaluate the suitability of eDNA for marine and aquatic Environmental Impact Assessments

AbstractA model was developed to forecast and compare changes in species presence assessed with either eDNA or traditional observations. We use it to explore how ecosystem conditions could affect the suitability of eDNA for Environmental Impact Assessment. First, a deterministic model simulated the dynamics of the impacted population (called “receptor” in EIA) and their shed DNA fragment concentrations. Second, random distributions of receptor organisms and eDNA fragment quantities at steady state were simulated within the impacted spatial domain (called “project area”). Then, simple random samplings were performed for both the receptor and eDNA. Third, post‐sampling processes (eDNA extraction, amplification, and analysis) were simulated to estimate the taxon detection probability. Fourth, we simulated an impact by modifying the growth, mortality, and mobility (null, passive, and active) parameters of the receptor taxon. eDNA detection probability curves were then estimated for a range of environmental sample volumes by fitting a Weibull cumulative distribution function. A F‐like statistic compared detection curves before and after impact. Statistically significant differences were detected with eDNA in impact scenarios where receptor taxon growth rate decreased and receptor mobility was null or passive. In scenarios where the project area accumulates DNA shed from multiple categories of the same taxon (e.g., from dead organisms if mortality increased or when individuals can cross project area boundaries), it is difficult to assess impact. Our study shows that results obtained from eDNA sampling will not always agree with an impact classically assessed on a receptor population. One reason is that sources of the total eDNA pool are not identified. The modeling highlights the need: to do preliminary testing of sample sizes, to develop new approaches that will identify sources from the pool of extracted DNA, and to improve descriptions of the ecogeochemical processes required to forecast shed DNA reactivity.

Sources, bioaccumulation, and toxicity mechanisms of cadmium in Chlamys farreri

The Potentially toxic elements (PTEs) cadmium (Cd) is one of the most serious stressors polluting the marine environment. Marine bivalves have specific high enrichment capacity for Cd. Previous studies have investigated the tissue distribution changes and toxic effects of Cd in bivalves, but the sources of Cd enrichment, migration regulation during growth, and toxicity mechanisms in bivalves have not been fully explained. Here, we used stable-isotope labeling to investigate the contributions of Cd from different sources to scallop tissues. We sampled the entire growth cycle of Chlamys farreri, which is widely cultured in northern China, from juveniles to adult scallops. We found tissue variability in the bioconcentration–metabolism pattern of Cd in different bound states, with Cd in the aqueous accounting for a significant contribution. The accumulation pattern of Cd in all tissues during growth was more significant in the viscera and gills. Additionally, we combined a multi-omics approach to reveal a network of oxidative stress-induced toxicity mechanisms of Cd in scallops, identifying differentially expressed genes and proteins involved in metal ion binding, oxidative stress, energy metabolism, and apoptosis. Our findings have important implications for both ecotoxicology and aquaculture. They also provide new insights into marine environmental assessment and mariculture development.

Cumulative environmental risk assessment of metals and polycyclic aromatic hydrocarbons from ship activities in ports

Marine environmental risk assessments rarely consider the cumulative risk from multiple contaminants and sources. Ships give rise to a range of contaminants, originating from different onboard sources, resulting in contaminant loads to the marine environment. Here, the Ship Traffic Emission Assessment Model (STEAM), in combination with the hydrodynamic and chemical fate model MAMPEC, was used to calculate loads and predicted environmental concentrations (PECs) of metals and polycyclic aromatic hydrocarbons, in four ports. PECs were compared to the predicted no effect concentrations (PNEC) to assess environmental risk from the different onboard sources, both separately and cumulatively. The results show that three out of four ports were subject to unacceptable risk. This study highlights the importance of accounting for multiple contaminant sources when assessing the marine environmental risks of shipping and challenges the suitability of the proposed new international guidelines on how to assess risk of scrubber water discharge.

Editorial: Coastal and marine environmental quality assessments

Editorial: Coastal and marine environmental quality assessments

Marine environment and maritime safety assessment using Port State Control database.

Port State Control (PSC) is the inspection of foreign ships in national ports assists in the removal of substandard ship commerce from the global sea and ensures that no ship poses a threat to maritime safety and the marine environment. When a clear ground is discovered during an inspection, the inspector has the authority to detain the ship until the flaws are corrected in order to assure safety and reduce pollution hazards. This paper adopted a traditional literature review method using the selected six (6) years data from the inspections conducted by maritime authorities from 2016 to 2021 and incorporate with qualitative and quantitative analysis to ascertain the influence of each risk factor on the number of arrests, including the relationship between risk factors and the type of detain deficiency, which is a critical part of the study. This study's findings provide important insights into how to facilitate an effective way in selecting the ship to be inspected, followed by identifying the ship's risk profile and designing the inspection area, which plays a critical role in assisting the inspector in terms of time efficient and effective inspection (especially for the ships, which have a short duration at berth) during inspection to further strengthen maritime safety, ship's safety, seafarers' health and marine environmental protection.

Ecological risk assessment of metallic nanoparticles on the marine environments: Species sensitivity distributions analysis

Metallic nanoparticles (NPs) are increasingly being used and inevitably entering the marine environment. Therefore, the adverse effects of NPs on individual marine species have attracted increasing attentions. However, to date, the ecological risks of NPs on the marine ecosystem remain poorly understood. In this study, species sensitivity distributions (SSDs) were constructed for Ag, ZnO, CuO, and TiO2 NPs to understand their ecotoxicity to the marine ecosystem and the contribution of size effect and ion effect to the nanotoxicity. Furthermore, a case study on the assessment of marine ecological risk and marine environment carrying capacity of metallic NPs was performed in Jiaozhou Bay, China. The results showed the toxicity of metallic NPs to marine species following the order of Ag > ZnO > CuO > TiO2. Both size effect and ion effect contributed to the toxicity of NPs. Environmental concentrations of Ag, ZnO, CuO, and TiO2 NPs are much lower than the predicted no-effect concentrations, indicating that these metallic NPs have not yet posed risks to the marine ecosystem based on currently limited measured environmental concentrations of metallic NPs in seawater. And the marine environment carrying capacity of Ag, ZnO, CuO, and TiO2 NPs in Jiaozhou Bay seawater were determined to be 5.03, 8.72, 93.06, and 629.79 t, respectively. The results help us understand the ecological risk of NPs in marine environments and provide a scientific basis for the sustainable development of nanotechnology.

Introduction to the special series, "The future of marine environmental monitoring and assessment".

Traditional marine monitoring can be a resource‐intensive process that often covers a network of sampling stations where data are collected manually by divers, or discretely using in situ water samples at different depths at fixed positions followed by laboratory analysis. As such, environmental status is often reported after a delay of months or years. However, things are set to change for the better. Recent advances in technologies, such as remote sensing, machine learning techniques, modeling for non‐experts, acoustic monitoring, and intelligent integration of modeling and sensor measurements will revolutionize the future of marine environmental monitoring and monitoring systems. This special series touches upon some of the new technologies and models that may be an integrated part of ecosystem assessment and management in the future. Although technologies are being developed and integrated for marine monitoring around the world, the integration with ecosystem models is still in the early days. Still, this series highlights inspirational examples of the time ahead of us. Integr Environ Assess Manag 2022;18:888–891. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Study of dissolve oxygen, salinity and temperature around western Offshore: A case study around ONGC’S offshore Filed (HRA & NLM platform), Arabian Sea, India

Marine ecosystems cover approximately 71% of the Earth's surface and contain approximately 97% of the planet's water. Dissolve oxygen, which is a vital parameter in Ocean’s primary production, is having a sensitive integrating property reflecting physical and biogeochemical changes in the marine environment. The dissolve oxygen in the sea water is affected by parameters such as high organic load, high temperature and high salinity level. The higher the oil pollution load, less will be the dissolved oxygen concentration level. The solubility of oxygen decrease as temperature increases. Dissolved oxygen decreases exponentially as salt levels increase. Thus temperature and salinity have a great impact upon biological productivity and are important to understand the dynamics of water column. Nearly all living organisms need oxygen in order to carry out their biological processes. By analyzing the variation of dissolve oxygen, temperature and salinity, environmental status of that particular study area can be assessed. As a preventive measure to protect water bodies, Oil and Natural Gas Corporation Limited, India is regularly conducting Offshore Environment Monitoring around western continental shelf of Arabian Sea, where ONGC’s Platforms and Installations are located. An attempt has been made for assessment of marine environment around ONGC’s offshore Filed (HRA & NLM platform), Arabian Sea by the study of dissolve oxygen, salinity and Temperature etc. The paper includes the output of monitoring activities of ONGC considering three parameters i.e. temperature, salinity and dissolved oxygen for assessing the environmental health of the study area. The study of the three parameters ONGC’s offshore Filed (HRA & NLM platform) has been done considering the monitoring data for the year 2020-21 and their variation has been studied with the values of Reference location (situated at 10 km from the installation). It has been observed from the study that there is no significant changes in the mean values of three parameters compared to the reference mean values. This clearly establishes that the oil production activities at HRA & NLM platform is not affecting the dissolve oxygen level around the installation.

Diurnal variation of cloud cover over the Baltic Sea

Instantaneous cloud cover over the Baltic Sea, estimated from satellite information, may differ by as much as several dozen percent between the day and night. This difference may result from both weather conditions and different algorithms used for the day and night. The diurnal differences in cloudiness measured by proprietary and operational systems were analysed as part of research on marine environmental assessment and monitoring. An optimised algorithm for 2017 was presented and supplemented with information from radiation modelling. The study showed that, in general, the average values of daily changes in cloud cover over the sea depend on the season, which generally corresponds to the length of the day and contrasts with the amount of cloudiness. The results were compared with available online data that met the night and day detection criteria, the climate model, and the climate index. The averaged analysis of seasonal changes showed that similar values of the satellite estimates are higher than those obtained from the climate model and the lidar estimation. The satellite estimates from SatBaltic showed the lowest uncertainty. The diurnal cycle was confirmed by all analysed systems. These results may indicate common physical mechanisms and a methodological reason for the uncertainty of satellite-based data. The results clearly showed the existing diurnal difference in the amount of cloud cover over the Baltic Sea and indicated that this difference is not always explained by the physical properties of the atmosphere. The probable causes for these uncertainties were identified and diagnosed.

Behavioural responses of non-breeding waterbirds to marine traffic in the near-shore environment

ABSTRACT Capsule Recording of behavioural responses to ferry traffic for 11 target species showed that Red-throated Diver Gavia stellata, Slavonian Grebe Podiceps auratus, and Black-throated Diver Gavia arctica were most likely to react to passing vessels. Aim To provide information on how responses to marine traffic vary between waterbird species to inform marine spatial planning and environmental impact assessments in the near-shore environment. Methods We recorded behavioural responses to ferry traffic for 11 target species in near-shore waters: Common Eider Somateria mollissima, Goldeneye Bucephala clangula, Long-tailed Duck Clangula hyemalis, Velvet Scoter Melanitta fusca, Red-breasted Merganser Mergus serrator, Black-throated Diver, Great Northern Diver Gavia immer, Red-throated Diver, European Shag Gulosus aristotelis, Slavonian Grebe and Black Guillemot Cepphus grylle. Responses were analysed using generalized linear models and mixed models. Results Red-throated Diver, Black-throated Diver and Slavonian Grebe were the most likely species to exhibit a response to passing vessels. While Red-throated Divers and Slavonian Grebes were highly likely to flush, Black-throated Divers and Great Northern Divers rarely took flight, instead favouring swim or dive responses. In rougher sea conditions birds were more likely to take flight, and the propensity to respond declined across the wintering period. Conclusions This research provides comparative evidence on the behavioural responses of waterbirds to marine traffic. The results support previous studies which highlighted the high sensitivity of diver species to disturbance and provide new evidence that Slavonian Grebe may also be a high sensitivity species.

Assessment of marine environment by ABC (abundance biomass comparison) analysis—A case study on western offshore area of Arabian Sea

Assessment of the variations in marine ecosystem can be effectively monitored using benthic fauna because pollutants from any source will ultimately end in the seabed. The benthic communities play an important role in the transfer of materials from primary production through detrital pool into higher tropic levels, including commercially exploitable fish. Majority of the benthic fauna are sedentary and sessile in nature and cannot avoid any environmental perturbation, hence are considered sensitive indicator of change in the environment caused by natural and anthropogenic disturbances. Based on the analysis of abundance and biomass of benthic communities, one very important and effective study in analyzing marine environment i.e. ABC (Abundance-Biomass Comparison) has been adopted in this paper.

Plastic debris ingestion by seabirds on the Korean Peninsula

Plastic ingestion studies in seabirds that analyse the frequency of occurrence and the characteristics of the plastics ingested by each species provide valuable information for marine environmental assessments by quantifying the impacts of marine debris on seabirds. We investigated the frequency of plastic ingestion from a sample of 387 individuals of 11 seabird species on the Korean Peninsula. We found evidence of plastic ingestion in red-breasted mergansers (Mergus serrator) (33.3%), Pacific loons (Gavia pacifica) (10.0%), Swinhoe's storm petrels (Hydrobates monorhis) (93.7%), black-tailed gulls (Larus crassirostris) (12.9%) and ancient murrelets (Synthliboramphus antiquus) (0.9%). In particular, it was observed that Swinhoe's storm petrels had the highest frequency of plastic ingestion, both in terms of the number of affected individuals, and the accumulated mass of plastic debris ingested. The majority of seabirds examined in our study had ingested microplastics, comprised predominantly of user plastics. This is the first report quantifying plastic ingestion in seabirds on the Korean Peninsula and in the broader area of the East Asian Seas.

The role of the cadmium-binding protein response of the digestive gland of the Yesso scallop Mizuhopecten yessoensis (Jay, 1857) for marine environmental assessments

The ability of Pectinidae to accumulate heavy metals and store them in their tissues allows the use of scallops for biomonitoring marine pollution. High molecular weight metallothionein (MT)-like proteins (MTlps) play a central role in this process. Two major MTlps (72 and 43 kDa) have been identified in the digestive glands of Mizuhopecten yessoensis (Yesso scallop). These proteins have a very high affinity for the heavy metals cadmium, cobalt, and caesium. Additionally, these proteins can be deposited in large quantities in the digestive glands of this mollusc. It has been shown that 72 kDa MTlp is the main stress-response protein in areas polluted with cadmium or radioactive metals. Monitoring the amounts of MTlps in the digestive glands of the scallop M. yessoensis in areas with different anthropogenic pollutants has shown that these proteins are reliable biological markers of heavy-metal pollution in the marine environment.

Spatial Heterogeneity of Marine Environment Changes: A Case Study in Laizhou Bay and Its Adjacent Waters, China

Temporal and spatial heterogeneity identifications of marine environment and its changes have great significances in marine spatial planning and offshore pollution control. In this study, considering the integration of marine ecological environment and sea-land interaction, we built a spatialized evaluation model named Marine Environment Change Spatial Assessment (MECSA) to quantify the marine environment status and changes. In MECSA, we applied the geospatial model and the pressure-state-response (PSR) model for processing and integrating evaluation indicators. A case study in the Laizhou Bay showed that the marine environment quality was generally in a declining state from 2009 to 2015. In 2015, the Marine Environment Index (MEI) had decreased by 0.1 compared with 2009, although the two years all reached a ‘Good’ level. The spatial MEI layers of the two years showed a same distribution: the southwestern part was in poorer status, with a fan ring shape gradually getting better to the northeast. The Marine Organisms Response Index (MORI) contributed the most to the MEI. Therefore, future marine environmental assessment and spatial planning should focus on the identification the marine environment with its changes from the perspective of spatial heterogeneity and systemicity. Based on single indicators and comprehensive evaluation results, we can propose spatially targeted policies and recommendations scientifically.

New record of Phrikoceros inca (Polycladida, Cotylea) from the central coast of Peru, with a review of polyclads known from Peruvian waters

ABSTRACT Polyclads are marine free-living Platyhelminthes, generally disregarded in marine environmental assessments. Here, Phrikoceros inca (Cotylea, Pseudocerotidae), identified on the basis of external features such as its ear-like, held-erected pseudotentacles, number and position of pseudotentacular eyes, circular-like cerebral eyespot, ruffled-shaped body and coloration patterns, was recorded for Peru for the first time. This finding, which occurred in Pucusana beach, near Lima, on the central coast of Peru, extends the distribution of P. inca ~1700 km north, thus becoming the northernmost record of this polyclad species. Also, the formally described species of polyclads from Peru are reviewed and listed.

Marine ecological and environmental health assessment using the pressure-state-response framework at different spatial scales, China

Coastal seas are sensitive marine ecosystems, subject to stress from human activities and climate change. Understanding their health is therefore essential. In this study, we developed a comprehensive marine health assessment index (MHI) system using the pressure-state-response framework, and used it to explore the temporal and spatial differences in marine health for 4 Chinese seas and 11 coastal regions of these seas. The South China Sea was relatively healthy, with an average MHI score of 0.72; the other coastal regions were moderately healthy, with MHI of 0.60 for the Yellow Sea, 0.59 for the Bohai Sea, and 0.56 for the East China Sea. At a provincial scale, Hainan’s coastal sea was relatively healthy. Guangdong, Shanghai, Tianjin, Liaoning, and Shandong had relatively healthy coastal seas; the others were moderately healthy. The overall health of most seas and provincial coasts decreased from 2003 to 2018. However, MHI increased by 10.6% in the East China Sea, versus 16.4 and 6.7% (respectively) for the Shanghai and Zhejiang coastal seas in the East China Sea, and a decrease of 4.9% for the Fujian coastal sea. The Bohai Sea MHI decreased by 1.6%, but Tianjin’s MHI increased by 1.7%. Therefore, the MHI trends were inconsistent between the regional and provincial scales. Marine disasters and environmental factors caused large MHI changes at a regional scale, whereas human factors were more important at the provincial scale. Our results show that an assessment’s spatial scale strongly affects the key factors that will be identified. Our results will help marine managers assess marine health at different spatial scales to support marine protection planning.