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Marine heat waves (MHWs), extended periods of unusually high ocean temperatures that significantly impact marine ecosystems, are prevalent in the Southern California Bight (SCB), increased thermal stratification has intensified these events over recent decades, affecting California sea lions by disrupting prey availability, leading to malnutrition and higher mortality rates. Rising atmospheric CO2 levels have exacerbated this issue, contributing to the warming of surface waters. Climate models predict that MHWs will continue to increase in frequency, severity, and duration, posing further risks to marine life. Despite the presence of a significant sea lion colony off the coast of San Diego, little research has been conducted on MHWs in the SCB impact on the local sea lion population. This research examines various aspects of MHWs at San Diego, including defining MHWs, historical occurrences, current trends, and their implications for California sea lions, while exploring potential policy and mitigation strategies to protect Southern California's marine ecosystems. Daily sea Surface Temperature (SST) measurements from La Jolla Scripps Pier (1916-2023) are used to quantify local MHWs relative to a shifting baseline (i.e., one that adjusts for the long-term warming trend), and to a fixed baseline (i.e., the warming trend alone increases MHW occurrences). We investigate critical questions about MHW evolution and duration, considering the continuous warming of the oceans. We consider what the two definitions of MHWs imply for upwelling and nutrient supply to the ocean surface, and the implications for California sea lion prey availability. We identify future research priorities, particularly improved measures of sea lion population counts, and the need for better indicators of MHW impacts beyond SST.

Marine Ecosystem Models (MEMs) are increasingly driven by Earth System Models (ESMs) to better understand marine ecosystem dynamics, and to analyze the effects of alternative management efforts for marine ecosystems under potential scenarios of climate change. However, policy and commercial activities typically occur on seasonal-to-decadal time scales, a time span widely used in the global climate modeling community but where the skill level assessments of MEMs are in their infancy. This is mostly due to technical hurdles that prevent the global MEM community from performing large ensemble simulations with which to undergo systematic skill assessments. Here, we developed a novel distributed execution framework constructed of low-tech and freely available technologies to enable the systematic execution and analysis of linked ESM/MEM prediction ensembles. We apply this framework on the seasonal-to-decadal time scale, and assess how retrospective forecast uncertainty in an ensemble of initialized decadal ESM predictions affects a mechanistic and spatiotemporal explicit global trophodynamic MEM. Our results indicate that ESM internal variability has a relatively low impact on the MEM variability in comparison to the broad assumptions related to reconstructed fisheries. We also observe that the results are also sensitive to the ESM specificities. Our case study warrants further systematic explorations to disentangle the impacts of climate change, fisheries scenarios, MEM internal ecological hypotheses, and ESM variability. Most importantly, our case study demonstrates that a simple and free distributed execution framework has the potential to empower any modeling group with the fundamental capabilities to operationalize marine ecosystem modeling., JS acknowledges institutional support from the Polytechnic University of Catalunya (UPC), Barcelona, Spain. RB, VC, MC, EE, NK, PO, DR and JS acknowledge the European Union's Horizon 2020 research and innovation programme under Grant 817578 (TRIATLAS). VC and JS acknowledge the European Commission's Horizon 2020 Research and Innovation programme under Grant 101000302 (EcoScope). JS and MC acknowledge the European Commission's Horizon 2020 Research and Innovation programme under Grant 101060072 (ACTNOW) and the Spanish Ministry of Science and Innovation Grant PID2020-118097RB-I00 (ProOceans). MC acknowledges institutional support of the “Severo Ochoa Centre of Excellence” accreditation CEX2019-000928-S. JS, MC and NK conceived the study. NK and DR provided and described the NorESM1 data; RB, EE and PO provided and described EC-Earth3-CC data. MC, JS and VC contributed with EcoOcean. JS developed the MEM run framework and made the ESM data operative with the infinite patience of PO. JS wrote the MS and executed the EcoOcean simulations. VC, LJM, RH, MP and AF analyzed the data. All authors contributed to crafting the final paper., Peer Reviewed, "Article signat per 12 autors/es: Jeroen Steenbeek, Pablo Ortega, Raffaele Bernardello, Villy Christensen, Marta Coll, Eleftheria Exarchou, Alba Fuster-Alonso, Ryan Heneghan, Laura Julià Melis, Maria Grazia Pennino, David Rivas, Noel Keenlyside ", Postprint (published version)

Elasmobranch population declines due to human impacts have been documented at a global scale, having impacts on the functioning and structure of marine ecosystems. This situation leads to an international focus on the conservation of their populations and a key step in the management and conservation of elasmobranch populations is to understand their trophic ecology. Here, by using stable isotopes analysis, we investigated the trophic relationships, trophic niche breadth, and trophic redundancy among 21 batoids and 12 sharks inhabiting the Persian Gulf and Gulf of Oman, two productive areas of the Arabian Sea considered global elasmobranch hotspots. Isotopic results revealed differences in the trophic niche and trophic position among the elasmobranch sampled at species and at family level. For example, the batoids of the family Torpedinidae and the sharks of the family Triakidae occupied higher trophic positions and the family Glaucostegidae showed a lower trophic niche width, whereas the batoids of the family Myliobatidae or Gymnuridae, in overall, showed lower higher trophic niche width, reflecting the trophic habits described for most of the sampled species. We also provided some insights into the ecology of poorly known species, especially relevant for those that are endangered at a global or regional scale. In conclusion, we provide new information about the trophic ecology among batoids and sharks inhabiting the Persian Gulf and Gulf of Oman. This information is highly useful to study the consequences of future changes on their feeding preferences due to natural or human-related factors

This study aims at characterizing the hydrodynamic context and transport patterns that prevailed during the MERITE-HIPPOCAMPE cruise to assist in the interpretation of in-situ observations. The main physical attributes and structures (mesoscale eddies as well as fine-scale fronts and filaments) are analyzed based on various physical diagnostics. They were computed from satellite data and data-assimilative model outputs to describe ocean dynamics. The Northern and Algerian Currents were prominent features during the cruise while the western basin is divided by the vertically-tilted Balearic front. Temperature and salinity were used to distinguish different water masses at both surface and sub-surface. Sea-level anomalies, relative vorticity, and Okubo-Weiss parameter distributions have shown the presence of marked eddies around stations St10 and St11. Furthermore, Finite-Size Lyaponuv Exponents revealed that the former was rather located on a fine-scale filament near the edge of a cyclonic eddy while the latter was closer to the core of an anticyclone. Nearshore thermal fronts were detected with the Belkin and O'Reilly Algorithm (BOA), especially around stations St17 and St19. The potential coastal sources of contaminants were tested using Lagrangian Origin Maps (LOM), suggesting that stations St1, St2, St4, St11, and St15 were most likely influenced by coastal waters. Additionally, an atmospheric reanalysis combined with a Lagrangian dispersal model allowed for estimating wet deposition events of contaminants while tracking the fate of water masses where rainfall took place. Finally, we provide a set of explanatory quantitative and qualitative variables for future statistical analyses that aim at explaining the distribution of both chemical and biological samples collected during the cruise.

Two prominent factors posing a major threat to biodiversity in marine ecosystems are climate change and the establishment of invasive species, and the interaction between these two. Because of the upwelling of cold, nutrient-rich water, the coast of Portugal is a thermal refuge and distribution edge for cold-adapted species, making it a particularly important study area from a biodiversity point of view. In this study I investigated the physiological tolerance to heat stress of six different native and co-occurring non-native marine species, red algae; C. crispus and G. turuturu, brown algae; S.polyschides and U. pinnatifida, and mussels ; X.securis and M.galloprovincialis, in the intertidal rocky coast of Portugal. Dynamic ramping assays with four different durations and intensity of thermal stress was conducted for each specie to determine a so-called thermal death time (TDT) curve and the thermal tolerance parameters CTmax (the temperature that will cause death within one min) and z (the decrease in thermal decay over time) for each specie. To compare the thermal tolerance between the native vs non-native species a linear mixed effects model was applied. This study found a significantly higher thermal tolerance to extreme temperatures expressed as the upper critical temperature CTmax in the invasive red algae G. turuturu and mussel X.securis compared to its native counterparts C.crispus and M.galloprovincialis. The study found no significant difference in the thermal tolerance expressed for the kelp species S. polyschides and U.pinnatifida which had a similar response to the heat challenge. The implication from these the findings for the coast of Portugal, could be that the invasive algae and mussel might better survive an extreme event such as a heatwave then the co-occurring native, while the invasive kelp species would respond in a similar way to the heat challenge. Hence the invasive capacity might depend more on the invasion window after a stressful even

In the context of accelerating climate change and socioeconomic development in the Arctic and Subarctic, the Sentinel North research program at Université Laval helps generate the knowledge needed to improve our understanding of the changing northern environment and its impact on humans and their health. Addressing the complex issues brought on by these changes requires a research approach that transcends traditional disciplinary boundaries. Sentinel North fosters the convergence of expertise in the engineering, natural, social and health sciences to catalyze scientific discovery and innovation in support of sustainable health and development in the North. This compendium gathers a selection of research results from the Sentinel North program from 2017 to 2022. Results have been integrated into five interdisciplinary chapters addressing major northern issues.

Climate change scenarios suggest that large-scale carbon dioxide removal (CDR) will be required to maintain global warming below 2°C, leading to renewed attention on ocean iron fertilization (OIF). Previous OIF modelling has found that while carbon export increases, nutrient transport to lower latitude ecosystems declines, resulting in a modest impact on atmospheric CO2. However, the interaction of these CDR responses with ongoing climate change is unknown. Here, we combine global ocean biogeochemistry and ecosystem models to show that, while stimulating carbon sequestration, OIF may amplify climate-induced declines in tropical ocean productivity and ecosystem biomass under a high-emission scenario, with very limited potential atmospheric CO2 drawdown. The ‘biogeochemical fingerprint’ of climate change, that leads to depletion of upper ocean major nutrients due to upper ocean stratification, is reinforced by OIF due to greater major nutrient consumption. Our simulations show that reductions in upper trophic level animal biomass in tropical regions due to climate change would be exacerbated by OIF within ~20 years, especially in coastal exclusive economic zones (EEZs), with potential implications for fisheries that underpin the livelihoods and economies of coastal communities. Any fertilization-based CDR should therefore consider its interaction with ongoing climate-driven changes and the ensuing ecosystem impacts in national EEZs.

Humans, as all members of the animal kingdom, have always interacted with the natural environment. However, as populations grew exponentially due to agricultural and technological advances, their impact on ecosystems has become disproportionate. Anthropogenic influence on coastal marine environments has detrimental effects on ecosystem balance and function. Negative impacts of human activity can be referred to collectively as pollution. Sources of pollution include, but are not limited to, chemical waste, human effluent, plastic, and heavy metals. In this text, I explore the impacts of effluent and microplastic on the marine environment, within the context of annual and diel biogeochemical cycles. I investigated bottom-up control on phytoplankton growth over two seasonal cycles in the Southern California Bight off the coast of Orange County. I measured nutrient concentrations, in addition to a suite of biogeochemical variables, to assess the dynamics of primary production. I observed moderate Spring nutrient pulses and corresponding high chlorophyll concentrations. Higher nutrient concentrations were attributed to weak coastal upwelling and a strong Pineapple Express event that contributed a significant pulse of nutrients from shore. Through this I demonstrate that isolated heavy rain events carry the capacity to cause punctuated algal blooms in low-nutrient environments. During Summer, I found strong nutrient drawdown, rendering the upper layer nutrient-deplete. The water column was highly stratified, indicated by both high temperature and salinity signatures. During Fall and Winter, the water column was less thermally stratified, and we observed lower salinity in the upper layer. I found that wastewater effluent can impact already anthropogenically altered coastal environments, by providing a constant influx of nutrients. Throughout the year, there is a constant influx of wastewater input from the Orange County Sanitation District outflow pipe. Though the pipe has

The development of biobased and circular value chains entails multiple opportunities and challenges and involves multiple actors across the value chain with different interests and available knowledge. The PHA value chain based on mixed microbial culture systems could be depicted as a sort of puzzle, whose different pieces are assembled in this thesis by integrating the available knowledge, tools, and methodologies. This thesis assisted the decision-making during the development of this innovative value chain at multiple levels: from solving the local bottlenecks (zoom in) within the anaerobic fermentation and the PHA downstream processing to forecast the development of waste-to-PHA biorefineries and developing a framework (zoom out) that connects stakeholders across the value chain.

Large-scale offshore wind energy developments represent a major player in the energy transition but are likely to have (negative or positive) impacts on marine biodiversity. Wind turbine foundations and sour protection often replace soft sediment with hard substrates, creating artificial reefs for sessile dwellers. Offshore wind farm (OWF) furthermore leads to a decrease in (and even a cessation of) bottom trawling, as this activity is prohibited in many OWFs. The long-term cumulative impacts of these changes on marine biodiversity remain largely unknown. This study integrates such impacts into characterization factors for life cycle assessment based on the North Sea and illustrates its application. Our results suggest that there are no net adverse impacts during OWF operation on benthic communities inhabiting the original sand bottom within OWFs. Artificial reefs could lead to a doubling of species richness and a two-order-of-magnitude increase of species abundance. Seabed occupation will also incur in minor biodiversity losses in the soft sediment. Our results were not conclusive concerning the trawling avoidance benefits. The developed characterization factors quantifying biodiversity-related impacts from OWF operation provide a stepping stone toward a better representation of biodiversity in life cycle assessment.

Ichthyoplankton represent the first life stages of fish. The study of ichthyoplankton is crucial to understanding marine ecosystems and plays an important role in the management and durability of fisheries resources. During March and October of 2019, two oceanographic ichthyoplankton surveys were conducted in the Mediterranean Sea of Morocco from Tanger to Saadia by studying the horizontal structure of the ichthyoplankton species assemblage and its relation to environmental parameters. The average surface water temperature was (15.8°C in spring and 16.4°C in autumn). The fish eggs and larvae were more abundant in March than in October (21268 eggs/10m² and 14084 larvae/10m² in spring and 10094 eggs/10m² and 13796 larvae/10m²). In both seasons, fish eggs from the families Sternoptychidae and Sparidae were dominant (10101 eggs/10m² and 7527 eggs/10m² in spring and 4422 eggs/10m² and 3928 eggs/10m² in fall, respectively). However, Myctophidae larvae were the most abundant in the study area, reaching 7601 larvae/10m² in spring and 11021 larvae/10m² in autumn. The environmental parameters: temperature, salinity and chlorophyll-a (surface) seem to directly influence the spatial distribution of ichtyoplancton. On the other hand, it seems that predation by jellyfish (Pelagia noctiluca)was a very important factor that added to the factors that influenced the distribution of the species of fish eggs and larvae. This work represents the first survey conducted in the southwestern Alboran Sea, which studies the horizontal structure of the ichthyoplankton species assemblage and its relation to environmental factors in the spring and autumn of 2019.

An increasing number of studies using marine environmental DNA (eDNA) approaches are showing its potential application in marine fisheries management by helping and simplifying some of the labor-intensive traditional surveys required to assess exploited populations and ecosystem status. eDNA approaches (i.e. metabarcoding and targeted) can support to ecosystem-based fisheries management by providing information on species composition; surveillance of invasive, rare and/or endangered species; and providing estimates of species abundance. Due to these potential uses in fisheries and conservation sciences, the number of studies applying eDNA approaches in marine habitats has expanded in the very last few years. However, a lack of consistency across studies when applying pipelines for data analyses, makes results difficult to compare among them. Such lack of consistency is partially caused by poor knowledge in the management of raw sequences data, and analytical methods allowing comparative results. Hence, we review here the essential steps of eDNA data processing and analyses to get sound, reproducible, and comparable results, providing a set of bioinformatics tools useful for each step. Altogether this review presents the state of the art of eDNA data analyses towards a comprehensive application in fisheries management promoting sustainability

The use of functional traits of a community as a method to measure its functional dynamics in response to environmental change has gained attention because trait-based approaches offer systematic opportunities to understand the interactions between species diversity and ecosystem function. However, the relationship between functional traits of periphytic protozoa and contamination of aquatic habitats with antibiotics is poorly understood. In this study, we investigated the influence of the antibiotic nitrofurazone on functional traits of marine periphytic protozoan fauna. For this purpose, the protozoan assemblages were collected from coastal waters of the Yellow Sea at Qingdao, northern China, during four seasons of a one-year cycle using glass microscope slides as artificial substrates. The test protozoan communities were then exposed to various treatments of nitrofurazone in laboratory bioassay experiments. Our results demonstrated that the modalities of the functional traits of protozoan communities were generally driven by nitrofurazone toxicity. Briefly, R-mode linked to Q-mode (RLQ) and fourth-corner analyses revealed strong positive correlations between functional traits and nitrofurazone treatments. Trait syndromes in terms of body length, width, weight, height, and size to volume ratios were significantly influenced by nitrofurazone exposure. In particular, small and medium body size species of different feeding types, i.e., algivores, bacterivores, raptors or non-selectives, were more sensitive than other protozoan species to higher concentrations of nitrofurazone. Our findings demonstrate that antibiotic toxicity is likely to affect periphytic protozoan community function, shape the functional processes, and induce toxic responses in the community. The findings of this study suggest that periphytic protozoan communities and their functional traits are suitable bioindicators for evaluating the ecotoxicity of nitrofurazone in marine environments.

Per- and polyfluoroalkyl substances (PFASs) are anthropogenic contaminants of emerging concern that are ubiquitous in the marine environment. This chapter provides recent insights into the main aspects of research on this class of compounds in the oceans. It describes their main uses and predominant sources in the marine environment and provides an update on the analytical procedures fit for marine matrices. Occurrence and processes affecting these compounds in abiotic compartments are addressed, followed by a focus on bioaccumulation and biomagnification in biota. The biological effects in marine organisms are then reviewed per taxa. In agreement with recent literature, recommendations for future research are proposed, which should guide future efforts toward the key environmental questions on PFASs

The shallow submarine volcano Tagoro releases high amounts of inorganic nutrients (N, P, Si, Fe) into the surrounding waters. These emissions have been intensely monitored during both the eruptive stage (October 2011–March 2012) and the post-eruptive hydrothermal stage (March 2012—ongoing). The obtained seven-years dataset comprises over 3300 water samples analysed for concentrations of silicate (Si(OH)4), phosphate (PO4), nitrate + nitrate(NO3− + NO2−), ammonium (NH4+), and iron (Fe(II)) in the area affected by the volcanic emissions (> 250 km2) as well as outside of this area for reference. This chapter provides an overview on the main results obtained from this comprehensive dataset, as well as contextualizing these results by comparison with other volcanic and hydrothermal nutrient sources in the world. The results show that the hydrothermal emissions from Tagoro volcano cause nutrient enrichments both in the vicinities of the vents (88–130 m depth) and the water column up to 50 m above the seabed. The emissions can occasionally also be injected into the mixed layer and might even reach the surface. The transport of these emissions presents a flux of comparable magnitude to other important nutrient fluxes in the region, such as those related to the NW-African coastal upwelling, when compared per unit of area. We highlight the importance of accounting for shallow hydrothermal and volcanic inputs worldwide as significant nutrient sources that can exert an important influence on the ecosystems of superficial nutrient-poor waters. © 2023 The Author(s), under exclusive license to Springer Nature Switzerland AG

This study provides with evidence of the presence of sea surface microplastics in a UNESCO marine biosphere reserve: the island of Menorca in the north-western Mediterranean Sea. From a total of 90 samples, in 100% of the samples, microplastics were observed with a mean value of 0.18 ± 0.01 items/m2. According to data, no significant differences were observed for sampling period with very similar values between 2021 (0.17 ± 0.02 items/m2) and 2022 (0.18 ± 0.02 items/m2). However, significant differences were observed regarding sampling area (both site and locality) suggesting that sea surface plastics in the study area might be more dependent of the spatial scale rather than on the temporal scale. Fibre type microplastics predominated over fragments, films, pellets, and foams, but in the commercial Port de Maó, almost 50% of the identified items were foams which could be related to the transportation of packed goods to this port. Results from the model applied to study the relation between waste management indicators and microplastic abundance indicate that when considering all marine litter categories, the explanatory variables are plastic waste generated by residents population (tonnes/year/km2) and waste collection rate (%), whereas if only plastics are considered, the indicator regarding waste per capita (kg/hab/year) is also included. Data in this study is obtained through a harmonized protocol which can be used to define baseline and threshold values to evaluate good environmental status regarding descriptor 10 of the Marine Strategy Framework Directive.

Sea stars (Echinodermata: Asteroidea) are a key component of Southern Ocean benthos, with 16% of the known sea star species living there. In temperate marine environments, sea stars commonly play an important role in food webs, acting as keystone species. However, trophic ecology and functional role of Southern Ocean sea stars are still poorly known, notably due to the scarcity of large-scale studies. Here, we report 24332 trophic marker (stable isotopes and elemental contents of C, N and S of tegument and/or tube feet) and biometric (arm length, disk radius, arm to disk ratio) measurements in 2456 specimens of sea stars. Samples were collected between 12/01/1985 and 08/10/2017 in numerous locations along the Antarctic littoral and Subantarctic islands. The spatial scope of the dataset covers a significant portion of the Southern Ocean (Latitude: 47.717° South to 86.273° South; longitude: 127.767° West to 162.201° East; depth: 6 to 5338 m). The dataset contains 133 distinct taxa, including 72 currently accepted species spanning 51 genera, 20 families and multiple feeding guilds / functional groups (suspension feeders, sediment feeders, omnivores, predators of mobile or sessile prey). For 505 specimens, mitochondrial CO1 genes were sequenced to confirm and/or refine taxonomic identifications, and those sequences are already publicly available through the Barcode of Life Data System. This number will grow in the future, as molecular analyses are still in progress. Overall, thanks to its large taxonomic, spatial, and temporal extent, as well as its integrative nature (combining genetic, morphological and ecological data), this dataset can be of wide interest to Southern Ocean ecologists, invertebrate zoologists, benthic ecologists, and environmental managers dealing with associated areas. Please cite this data paper in research products derived from the dataset, which is freely available without copyright restrictions.

Potential for, and limits to, adaptation to environmental changes are critical for resilience and risk mitigation. The Mediterranean basin is a mosaic of biodiversity-rich ecosystems long affected by human influence, whose resilience is now questioned by climate change. After reviewing the different components of biological adaptation, we present the main characteristics of marine and terrestrial biodiversity in the Mediterranean basin and of the pressures they face. Taking climatic trends into consideration, we discuss the adaptive potential of a range of ecosystems dominated by species without active dispersal. We argue that the high heterogeneity of Mediterranean landscapes and seascapes constitutes a laboratory for the study of adaptation when environmental conditions change rapidly and may provide opportunities for adaptation and adaptability of species and ecosystems. Adaptive management in the Mediterranean can and should harness the nature-based solutions offered by both ecological and evolutionary processes for increasing the resilience of ecosystems to climate change.

Coral reef ecosystems are one of the pillars that provide balance to marine ecosystems, however, despite containing an exceptional diversity, it is one of the most vulnerable to natural disasters and anthropogenic activities. The deterioration of reef ecosystems has led to the search for innovative solutions, thus promoting the development of in situ and ex situ coral nurseries. Since 2004, the Dominican Republic has been promoting the restoration ofmarine ecosystems through this method and has come to see how these actions have positively affected coastal communities both socially and economically. This article will discuss the ecological role of corals and the threatsfacing reef ecosystems; followed by a detailed review of the process, maintenance and evaluation of coral nurseries; and concluding with an analysis of the socioeconomic contributions that coral plantations grant to a population., El ecosistema arrecifal es uno de los pilares que les brinda equilibrio a los ecosistemas marinos, sin embargo, a pesar de contener una diversidad excepcional, es uno de los más vulnerables ante catástrofes naturales y actividades antropogénicas. El deterioro de los ecosistemas arrecifales ha llevado a la búsqueda de soluciones innovadoras, impulsando así el desarrollo de viveros de corales in situ y ex situ. Desde el 2004, en la República Dominicana se ha impulsado la restauración de ecosistemas marinos mediante este método y se ha llegado a ver cómo estas acciones han afectado positivamente a las comunidades costeras tanto social como económicamente. En este artículo se discutirá el rol ecológico de los corales y las amenazas que enfrentan los ecosistemas arrecifales; para luego pasar a detallar el proceso, mantenimiento y evaluación de los viveros de corales; y culminar con un análisis del impacto socioeconómico de las plantaciones de corales, sobre la población.

Climate and fisheries interact, often synergistically, and may challenge marine ecosystem functioning and, ultimately, seafood provision and human wellbeing that depend on them. Holistic and integrative approaches aiming at evaluating the spatial overlap between these major stressors are crucial for identifying marine regions and key fish species that require conservation priority to prevent possible future collapses. Based on highly resolved information on environmental conditions and fishing pressure from the Southern Benguela and the Agulhas Bank ecosystems off South Africa, we identified the main areas where small pelagic fish species (European anchovy Engraulis encrasicolus, Pacific sardine Sardinops sagax, and West Coast round herring Etrumeus whiteheadi) have been highly impacted in terms of unfavourable environmental conditions and fishing pressure over the period 1993-2018. We termed these areas cumulative “hotspots” of climate change and fishing impact. We also identified fishing grounds where environmental conditions are now more favourable for these pelagic fish species, terming these “bright spots” of climate change. Environmental conditions and fishing intensity show contrasting patterns between the Southern Benguela and the Agulhas Bank ecosystems, with the Southern Benguela region accumulating most of the cumulative hotspots and showing the most negative trends in CPUE (a proxy for local fish abundance). Contrastingly, bright spots, identified on the south coast but also south of Cape Town, showed more positive trends in CPUE, suggesting that they may support sustainable growth of the small pelagic fishery in the medium term. Focussing future fishing effort on these bright spots may serve to alleviate pressure on the doubly and highly impacted cumulative hotspots from the western side of the southernmost tip of Africa

This thesis deals with the study and normative proposal for a regulation of noise pollution generated by merchant ships, which is the main cause of underwater noise pollution. It is divided into three chapters. In the first chapter, the aspects of marine acoustics are reviewed, including a revisit of hydrophones, the analysis of the distances at which sound intensities are maintained above a baseline level, and a self designed study, which leads to the conclusion that the differences in incremental trends in underwater sound intensity in previous studies are due to differences in maritime traffic. This is confirmed by highly significant statistical data obtained by binary logistic regression between hydrophonic records that have detected an increase and those that have not (p<0.0001). A compilation and bibliometric analysis has made it possible to study specifically the negative impact of ship-generated noise on marine species. In 87% of the publications consulted, including experimental data, a high or moderately high negative impact of sound on marine species was evident; only 5% of the articles reported no effects of noise pollution. The study covered a wide variety of seas and oceans, although most of the studies (31%) were conducted using cages or similar. The research was mainly conducted on fish (43%) and mammals (38%). Behavioural changes were recorded in 59% of cases, physical changes in 11%, masking in 11% and combined changes in 14%. Four levels of underwater sound intensity are proposed: Environmental zone 0 (no appreciable anthropogenic pollution), from baseline level (30 dB) to 80 dB. Zone A of acceptable (low) pollution, from 81 dB to 175 dB (threshold of potential damage). Zone B of tolerable, but potentially harmful sound intensities (between 176 dB and 195 dB) and a Zone C of risk of permanent injury (above 195 dB, permanent injury threshold); vessels generating intensities at this level should be penalised or even banned. A way forward for the fut

The polycyclic musk compounds Galaxolide (HHCB) and Tonalide (AHTN) are the most frequently consumed fragrance materials applied in many household and personal care products. These substances have been detected in all environmental compartments and, due to their inherent lipophilicity, they easily bioaccumulate in aquatic organism. The aim of this PhD thesis was to assess the risk of environmental concentrations of HHCB and AHTN in the marine environments. In order to provide a more complete assessment on marine biota, empirical approach based on data of ecotoxicological assays was explored based on environmental risk assessment (ERA) scheme. In this case, it was intended to employ organisms from different trophic levels like microalgae, echinoderms, bivalves, shrimps, and fish. This diversification in the species allows assessing how organisms with different biological complexity can be affected. In addition, different endpoints were used for each species, taking as basis the sensitivity and relevance of the endpoints. Another important aspect considered to select the endpoints was their level of biological organization, so that the responses measured were based on acute and chronic exposure, focusing on growth, survival, development, behaviour, and biomarkers at the biochemical and molecular levels. The results obtained in this thesis show that environmental concentrations of both compounds are detrimental to microalgae growth posing significant risk to Phaeodactylum tricornutum and Isochrysis galbana. It was also observed that environmental concentrations of HHCB and AHTN significantly altered the early life stages endpoints such as fertilization, larval development, and survival in tested species. Furthermore, this thesis has proven that in a scenario of heterogenous pollution where lethality is not expected to occur, HHCB and AHTN may trigger spatial avoidance, which might reduce the local biodiversity of ecosystems due to emigration to safer environments. Subl

Humans have become the major driving force of change, deeply affecting the Earth system and the biosphere. In marine ecosystems specifically, climate-related environmental changes and anthropogenic pressures (e.g., fishing, the introduction of new species, nutrient load) have altered the structures and functioning of social-ecological systems (SES). These changes have created novel, never encountered before, SES dynamics. Novelty, a natural process of SES dynamics, has accelerated due to human activities. On the one hand, novelty allows SES to adapt to change, including maintaining their functions and resilience. On the other hand, the fast-emerging novelty in the Anthropocene epoch is unpredictable and increases the uncertainty related to management and predicting models. Despite consensus on the need for acknowledging novelty in SES, there is much confusion associated with this concept. This thesis provides a unifying conceptualization of novelty in SES by linking Complex Adaptive Systems theories and ecological novelty concepts. The papers that make up this thesis are an empirical contribution to understanding novelty in marine SES in the past and future. Novelty was measured in multiple social and ecological components of the Baltic Sea SES across different temporal and spatial scales. Although novelty is important for SES adaptation to change, it can be a problem or a solution - depending on its rate, drivers, and scale. There is a need to foster novelty that could enhance SES resilience and sustainability, in order to achieve good environmental status in marine ecosystems and for human wellbeing.

Catchment impacts on downstream ecosystems are difficult to quantify, but important for setting management targets. Here we compared 12 years of monitoring data of seagrass area and biomass in Cleveland Bay, northeast Australia, with discharge and associated sediment loads from nearby rivers. Seagrass biomass and area exhibited different trajectories in response to river inputs. River discharge was a slightly better predictor of seagrass indicators than total suspended solid (TSS) loads, indicating that catchment effects on seagrass are not restricted to sediment. Linear relationships between Burdekin River TSS loads delivered over 1–4 years and seagrass condition in Cleveland Bay generated Ecologically Relevant Targets (ERT) for catchment sediment inputs. Our predicted ERTs were comparable to those previously estimated using mechanistic models. This study highlights the challenges of linking catchment inputs to condition of downstream ecosystems, and the importance of integrating a variety of metrics and approaches to increase confidence in ERTs.

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Harcourt, R., Hindell, M. A., McMahon, C. R., Goetz, K. T., Charrassin, J.-B., Heerah, K., Holser, R., Jonsen, I. D., Shero, M. R., Hoenner, X., Foster, R., Lenting, B., Tarszisz, E., & Pinkerton, M. H. Regional variation in winter foraging strategies by Weddell Seals in Eastern Antarctica and the Ross Sea. Frontiers in Marine Science, 8, (2021): 720335, https://doi.org/10.3389/fmars.2021.720335., The relative importance of intrinsic and extrinsic determinants of animal foraging is often difficult to quantify. The most southerly breeding mammal, the Weddell seal, remains in the Antarctic pack-ice year-round. We compared Weddell seals tagged at three geographically and hydrographically distinct locations in East Antarctica (Prydz Bay, Terre Adélie, and the Ross Sea) to quantify the role of individual variability and habitat structure in winter foraging behaviour. Most Weddell seals remained in relatively small areas close to the coast throughout the winter, but some dispersed widely. Individual utilisation distributions (UDi, a measure of the total area used by an individual seal) ranged from 125 to 20,825 km2. This variability was not due to size or sex but may be due to other intrinsic states for example reproductive condition or personality. The type of foraging (benthic vs. pelagic) varied from 56.6 ± 14.9% benthic dives in Prydz Bay through 42.1 ± 9.4% Terre Adélie to only 25.1 ± 8.7% in the Ross Sea reflecting regional hydrographic structure. The probability of benthic diving was less likely the deeper the ocean. Ocean topography was also influential at the population level; seals from Terre Adélie, with its relatively narrow continental shelf, had a core (50%) UD of only 200 km2, considerably smaller than the Ross Sea (1650 km2) and Prydz Bay (1700 km2). Sea ice concentration had little influence on the time the seals spent in shallow coastal waters, but in deeper offshore water they used areas of higher ice concentration. Marine Protected Areas (MPAs) in the Ross Sea encompass all the observed Weddell seal habitat, and future MPAs that include the Antarctic continental shelf are likely to effectively protect key Weddell seal habitat., Field support was provided in the Ross Sea by Malcolm O’Toole, Rupert Woods, and Antarctica New Zealand and in Prydz Bay by Malcolm O’Toole, Andrew Doube, Iain Field, and the Australian Antarctic Division. The tagging study in Terre Adélie had logistical support from IPEV (Institut Paul Emile Victor) and the French Polar Institute. New Zealand funding was provided by the Ministry for Business, Innovation and Employment Endeavour Fund C01 × 1710: “RAMPing-up protection of the Ross Sea”. The 2014 field event was funded by NZARI (NZ Antarctic Research Institute) and Fisheries New Zealand (respectively), with Regina Eisert as CI, and tags and some field personnel funded by IMOS. The IMOS deployments in Prydz Bay were supported logistically by the Australian Antarctic Division through the Australian Antarctic Science Grant Scheme (AAS Projects 2794 & 4329). The tagging study in Terre Adélie was supported by the Program Terre-Océan-Surface Continentale-Atmosphère from Centre National d’Etudes Spatiales (TOSCA-CNES). The ARGOS seal tracking and dive data were sourced and are available from the Integrated Marine Observing System (IMOS), NIWA, and LOCEAN. IMOS is a national collaborative research infrastructure, supported by the Australian Government. It is operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as lead agent.

A dataset of nearly 400 measurements of the particle size distribution (PSD) compiled from the Pacific, Atlantic, and Arctic Oceans is used to examine variability in the magnitude and shape of the PSD, and to characterize the partitioning of particle number, cross-sectional area, and volume concentration among defined size intervals. The results indicate that the relative contributions of three size classes based upon the pico-, nano-, and microplankton size range exhibit substantial changes among measures of particle size and between oceanic environments. The single-slope power law model commonly employed to characterize the PSD in aquatic studies is demonstrated to have significant limitations in capturing the complexity of PSD shapes observed for natural particle assemblages, and in consequence poorly predicts the relative contributions of these different size intervals. We show that specific percentile diameters derived from the cumulative distributions of particle size are strongly correlated with the contributions of these three size classes, and that these non-parametric descriptors of the cumulative distribution provide superior performance for estimating their contributions while requiring no assumption of underlying PSD shape. A comparison of these predictive relationships with independent field measurements suggests that this approach is generally robust for particle assemblages representing a wide diversity of marine environments.

Size-spectrum models are a recent class of models describing the dynamics of a whole community based on a description of individual organisms. The models are motivated by marine ecosystems where they cover the size range from multicellular plankton to the largest fish. We propose to extend the size-spectrum model with spatial components. The spatial dynamics is governed by a random motion and a directed movement in the direction of increased fitness, which we call ‘fitness-taxis’. We use the model to explore whether spatial irregularities of marine communities can occur due to the internal dynamics of predator-prey interactions and spatial movements. This corresponds to a pattern-formation analysis generalized to an entire ecosystem but is not limited to one prey and one predator population. The analyses take the form of Fourier analysis and numerical experiments. Results show that diffusion always stabilizes the equilibrium but fitness-taxis destabilizes it, leading to non-stationary spatially inhomogeneous population densities, which are travelling in size. However, there is a strong asymmetry between fitness-induced destabilizing effects and diffusion-induced stabilizing effects with the latter dominating over the former. These findings reveal that fitness taxis acts as a possible mechanism behind pattern formations in ecosystems with high diversity of organism sizes, which can drive the emergence of spatial heterogeneity even in a spatially homogeneous environment.

Stable isotopes are often used to provide an indication of the trophic level (TL) of species. TLs may be derived by using food-web-specific enrichment factors in combination with a representative baseline species. It is challenging to sample stable isotopes for all species, regions and seasons in Arctic ecosystems, e.g. because of practical constraints. Species-specific TLs derived from a single region may be used as a proxy for TLs for the Arctic as a whole. However, its suitability is hampered by incomplete knowledge on the variation in TLs. We quantified variation in TLs of Arctic species by collating data on stable isotopes across the Arctic, including corresponding fractionation factors and baseline species. These were used to generate TL distributions for species in both pelagic and benthic food webs for four Arctic areas, which were then used to determine intra-sample, intra-study, intra-region and inter-region variation in TLs. Considerable variation in TLs of species between areas was observed. This is likely due to differences in parameter choice in estimating TLs (e.g. choice of baseline species) and seasonal, temporal and spatial influences. TLs between regions were higher than the variance observed within regions, studies or samples. This implies that TLs derived within one region may not be suitable as a proxy for the Arctic as a whole. The TL distributions derived in this study may be useful in bioaccumulation and climate change studies, as these provide insight in the variability of trophic levels of Arctic species.

We present a research approach that seeks to develop and strengthen participatory action research (PAR) when applied in social-ecological systems (SES) by combining it with critical systems thinking (CST). This research approach responds to the urgent societal need to move beyond predefined project framing in development projects. While PAR acts as a basis for operationalizing participatory research processes, CST supports PAR by including explicit questions about system and problem boundaries. We first present this approach in the context of existing approaches and then go on to illustrate it by investigating a SES case study of a marine system on the Caribbean Saba Island as part of a project to protect sharks from extinction. The case study illustrates that strengthening PAR with the explicit framing questions used by CST combines the strengths of these two approaches. This combination allows participants: (1) to (re)frame the problem definition and scope as perceived by the different stakeholders, and (2) to find, co-create, and implement viable solutions with local stakeholders to improve a SES based on local needs and diverse stakeholders’ perspectives on potential solutions.

Earth System Models project that global climate change will reduce ocean net primary production (NPP), upper trophic level biota biomass and potential fisheries catches in the future, especially in the eastern equatorial Pacific. However, projections from Earth System Models are undermined by poorly constrained assumptions regarding the biological cycling of iron, which is the main limiting resource for NPP over large parts of the ocean. In this study, we show that the climate change trends in NPP and the biomass of upper trophic levels are strongly affected by modifying assumptions associated with phytoplankton iron uptake. Using a suite of model experiments, we find 21st century climate change impacts on regional NPP range from −12.3% to +2.4% under a high emissions climate change scenario. This wide range arises from variations in the efficiency of iron retention in the upper ocean in the eastern equatorial Pacific across different scenarios of biological iron uptake, which affect the strength of regional iron limitation. Those scenarios where nitrogen limitation replaced iron limitation showed the largest projected NPP declines, while those where iron limitation was more resilient displayed little future change. All model scenarios have similar skill in reproducing past inter‐annual variations in regional ocean NPP, largely due to limited change in the historical period. Ultimately, projections of end of century upper trophic level biomass change are altered by 50%–80% across all plausible scenarios. Overall, we find that uncertainties in the biological iron cycle cascade through open ocean pelagic ecosystems, from plankton to fish, affecting their evolution under climate change. This highlights additional challenges to developing effective conservation and fisheries management policies under climate change.

CORRECTION ARTICLEA Corrigendum on ILTER – The International Long-Term Ecological Research Network as a Platform for Global Coastal and Ocean Observation. doi: 10.3389/fmars.2019.00527

Artificial surfaces in coastal waters and offshore oceans, including boat hulls, docks, and offshore structures, are invariably colonized, or fouled, by a host of sessile species known collectively as fouling communities. Fouling has great economic impacts on shipping and other marine industries and plays an important role in the spread of marine invasive species across the globe. The main strategy to prevent fouling of artificial surfaces is application of antifouling coatings containing varying concentrations and mixtures of biocides. Presently, copper and zinc are popular antifouling biocides, and the latter is gaining in usage due to the known toxic characteristics of copper in the marine environment and consequent regulation and consumer opinion. Nanomaterials, including Cu and ZnO nanoparticles, have been explored as a way to efficiently deliver biocides from coating matrices. Here, we examine the efficacy and biocide release characteristics of several copper- and zinc-based antifouling coatings, including formulations containing traditional micron-sized Cu and ZnO particles and two containing copper and ZnO nanoparticles, respectively. Most of the antifouling coatings tested significantly reduced the abundance and biodiversity of the fouling community in the three study locations across California. Invasive species were suppressed by most coatings at similar levels to natives, suggesting that in general, antifouling coatings do not favor invasive species. We found that zinc-based antifouling coatings were similar and in some cases better performing than copper, despite the generally lower toxicity of zinc to aquatic organisms compared with copper. The performance of zinc-based coatings, moreover, was not directly related to the amount of zinc released into the water or their zinc content. Nano-based coatings did not offer any clear advantages over non-nano coatings, either in the degree of Zn leaching or fouling suppression. Coating matrix properties clearly

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Muelbert, J. H., Nidzieko, N. J., Acosta, A. T. R., Beaulieu, S. E., Bernardino, A. F., Boikova, E., Bornman, T. G., Cataletto, B., Deneudt, K., Eliason, E., Kraberg, A., Nakaoka, M., Pugnetti, A., Ragueneau, O., Scharfe, M., Soltwedel, T., Sosik, H. M., Stanisci, A., Stefanova, K., Stephan, P., Stier, A., Wikner, J., & Zingone, A. ILTER - the International Long-Term Ecological Research Network as a platform for global coastal and ocean observation. Frontiers in Marine Science, 6, (2019): 527, doi: 10.3389/fmars.2019.00527., Understanding the threats to global biodiversity and ecosystem services posed by human impacts on coastal and marine environments requires the establishment and maintenance of ecological observatories that integrate the biological, physical, geological, and biogeochemical aspects of ecosystems. This is crucial to provide scientists and stakeholders with the support and knowledge necessary to quantify environmental change and its impact on the sustainable use of the seas and coasts. In this paper, we explore the potential for the coastal and marine components of the International Long-Term Ecological Research Network (ILTER) to fill this need for integrated global observation, and highlight how ecological observations are necessary to address the challenges posed by climate change and evolving human needs and stressors within the coastal zone. The ILTER is a global network encompassing 44 countries and 700 research sites in a variety of ecosystems across the planet, more than 100 of which are located in coastal and marine environments (ILTER-CMS). While most of the ILTER-CMS were established after the year 2000, in some cases they date back to the early 1900s. At ILTER sites, a broad variety of abiotic and biotic variables are measured, which may feed into other global initiatives. The ILTER community has produced tools to harmonize and compare measurements and methods, allowing for data integration workflows and analyses between and within individual ILTER sites. After a brief historical overview of ILTER, with emphasis on the marine component, we analyze the potential contribution of the ILTER-CMS to global coastal and ocean observation, adopting the “Strength, Weakness, Opportunity and Threats (SWOT)” approach. We also identify ways in which the in situ parameters collected at ILTER sites currently fit within the Essential Ocean Variables framework (as proposed by the Framework for Ocean Observation recommendations) and provide insights on the use of new technolog, JM was supported by a CNPq fellowship (Grant No. 310047/2016-1) and by PELD Estuário da Lagoa dos Patos e Costa Adjacente (CNPq/CAPES/FAPERGS). SB was supported by US NSF (Grant #OCE-1655686). AB was supported by CAPES/CNPq/FAPES grant no. 441243/2016-9 to PELD Coastal Habitats of Espírito Santo as part of the Brazilian LTER program. HS was supported by US NSF (Grant #CCF-1539256 and #OCE-1655686), Simons Foundation (Grant #561126) and US NOAA/CINAR (Cooperative Agreement NA14OAR4320158).

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), School of Eng & Built Env, Science, Environment, Engineering and Technology, Ocean wind-waves are dominant contributors to coastal sea-level and shoreline dynamics and can be primary disruptors of coastal populations, marine ecosystems and coastal and offshore infrastructures. Hence, understanding climate-driven changes in the multivariate global ocean wind-wave climate and its extremes is paramount to successful offshore and coastal climate adaptation planning. When projecting future ocean wave conditions under climate change, uncertainty is introduced from a wide range of different sources including future emission scenario, climate model-forcing, and wind-wave modelling methodology. However, the use of single-method wave downscaling ensembles and inherent variability arising from different methodologies has led to unquantified uncertainty amongst existing global wave climate projections. This thesis addresses this significant knowledge gap by investigating the current state of knowledge in projected ocean wind-wave climate. It then, for the first time, quantifies the relative significance of these major sources of uncertainty and establishes the robustness among existing global wave climate projections. This thesis addresses former limitations associated with independent studies by performing a unique analysis of a coordinated, multi-method ensemble of future global wave scenarios assembled from ten individual state-of-the-art studies to yield a 155-member ensemble. This thesis analyses significant wave height, mean wave period and mean wave direction and also explores the underlying large-scale drivers of projected future changes in storm ocean wave events which remain largely unknown. The results of a systematic literature review demonstrate qualitative consensus between existing global and regional-scale wave climate projection studies in terms of a projected increase in mean significant wave height within the Southern Ocean area, Baltic Sea, and tropical eastern Pacific, and a projected decrease in the North Atlantic and Mediterranean

Coral reefs ecosystems fulfil important ecological functions, but risk degradation not only from climate change but also from increasing demands for the socioeconomic functions they also offer to local communities and international tourism. Coral reef diving tourism is a source of environmental pressure but at the same time represents a source of conservation funding, balancing these pressures. Tailoring the divers' experience to extract increased payments requires insights into the role of diving experiences for willingness to pay (WTP) for the access to dive in the waters surrounding Sipadan. We developed a choice experiment and applied it to a sample of 507 recreational scuba divers at the diving site Sipadan, Borneo in Malaysia. We investigated the role of divers’ most recent and overall diving experiences for their willingness to pay additional diving fees for features related to the conservation status and the diving operations. Results show that a majority of divers prefer lower litter pollution levels in the water and lower density of divers in each dive. When comparing the less experienced divers with the more experienced divers, the latter group express significant preferences over more of the marine biodiversity and recreational attributes of the diving experience. The less experienced group only tended to express significant preferences for fewer of these attributes. We also note that less experienced divers are more likely to have felt crowded and less likely to have seen pelagic species, suggesting, which may, in turn, explain their lower observed WTP., Coral reefs ecosystems fulfil important ecological functions, but risk degradation not only from climate change but also from increasing demands for the socioeconomic functions they also offer to local communities and international tourism. Coral reef diving tourism is a source of environmental pressure but at the same time represents a source of conservation funding, balancing these pressures. Tailoring the divers' experience to extract increased payments requires insights into the role of diving experiences for willingness to pay (WTP) for the access to dive in the waters surrounding Sipadan. We developed a choice experiment and applied it to a sample of 507 recreational scuba divers at the diving site Sipadan, Borneo in Malaysia. We investigated the role of divers’ most recent and overall diving experiences for their willingness to pay additional diving fees for features related to the conservation status and the diving operations. Results show that a majority of divers prefer lower litter pollution levels in the water and lower density of divers in each dive. When comparing the less experienced divers with the more experienced divers, the latter group express significant preferences over more of the marine biodiversity and recreational attributes of the diving experience. The less experienced group only tended to express significant preferences for fewer of these attributes. We also note that less experienced divers are more likely to have felt crowded and less likely to have seen pelagic species, suggesting, which may, in turn, explain their lower observed WTP.

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Benthuysen, J. A., Oliver, E. C. J., Chen, K., & Wernberg, T. Editorial: advances in understanding marine heatwaves and their impacts. Frontiers in Marine Science, 7, (2020): 147, doi:10.3389/fmars.2020.00147., Editorial on the Research Topic Advances in Understanding Marine Heatwaves and Their Impacts In recent years, prolonged, extremely warm water events, known as marine heatwaves, have featured prominently around the globe with their disruptive consequences for marine ecosystems. Over the past decade, marine heatwaves have occurred from the open ocean to marginal seas and coastal regions, including the unprecedented 2011 Western Australia marine heatwave (Ningaloo Niño) in the eastern Indian Ocean (e.g., Pearce et al., 2011), the 2012 northwest Atlantic marine heatwave (Chen et al., 2014), the 2012 and 2015 Mediterranean Sea marine heatwaves (Darmaraki et al., 2019), the 2013/14 western South Atlantic (Rodrigues et al., 2019) and 2017 southwestern Atlantic marine heatwave (Manta et al., 2018), the persistent 2014–2016 “Blob” in the North Pacific (Bond et al., 2015; Di Lorenzo and Mantua, 2016), the 2015/16 marine heatwave spanning the southeastern tropical Indian Ocean to the Coral Sea (Benthuysen et al., 2018), and the Tasman Sea marine heatwaves in 2015/16 (Oliver et al., 2017) and 2017/18 (Salinger et al., 2019). These events have set new records for marine heatwave intensity, the temperature anomaly exceeding a climatology, and duration, the sustained period of extreme temperatures. We have witnessed the profound consequences of these thermal disturbances from acute changes to marine life to enduring impacts on species, populations, and communities (Smale et al., 2019). These marine heatwaves have spurred a diversity of research spanning the methodology of identifying and quantifying the events (e.g., Hobday et al., 2016) and their historical trends (Oliver et al., 2018), understanding their physical mechanisms and relationships with climate modes (e.g., Holbrook et al., 2019), climate projections (Frölicher et al., 2018), and understanding the biological impacts for organisms and ecosystem function and services (e.g., Smale et al., 2019). By using sea surface temp, We thank the contributing authors, reviewers, and the editorial staff at Frontiers in Marine Science for their support in producing this issue. We thank the Marine Heatwaves Working Group (http://www.marineheatwaves.org/) for inspiration and discussions. This special issue stemmed from the session on Advances in Understanding Marine Heat Waves and Their Impacts at the 2018 Ocean Sciences meeting (Portland, USA).

The perdurability of plastics in the environment is one of the major concerns of plastic pollution and, as a consequence, oceans are accumulating large amounts of plastic. The degradation of conventional and biobased materials was evaluated through a laboratory experiment for a year simulating four different conditions in the marine environment. The water column environmental compartment was simulated under euphotic and aphotic (with and without light availability) conditions. The seafloor environmental compartment was simulated with sediment under non-polluted and polluted conditions. By combining weight loss (%), spectroscopic and thermal analyses, the degradation patterns regarding the polymer structure were assessed. The studied biobased materials were polylactic acid (PLA) based materials and showed higher degradability than conventional ones. The weight loss of conventional materials was not influenced by the water column or sediment, while in PLA-based materials, the degradation rates were ca. 5 times greater in the sediment than in the water column. The absorbance (Abs) value at 3400 cm−1 for polyethylene terephthalate (PET), and carbonyl (CO) index for PET and PLA could be useful to detect early signs of degradation. The crystallization index could be a useful parameter to discriminate degradation stages. The obtained results highlight the different degradability rates of materials depending on the specific environmental marine conditions.

Climate change, overfishing, marine pollution and other anthropogenic drivers threaten our global oceans. More effective efforts are urgently required to improve the capacity of marine conservation action worldwide, as highlighted by the United Nations Decade of Ocean Science for Sustainable Development 2021–2030. Marine citizen science presents a promising avenue to enhance engagement in marine conservation around the globe. Building on an expanding field of citizen science research and practice, we present a global overview of the current extent and potential of marine citizen science and its contribution to marine conservation. Employing an online global survey, we explore the geographical distribution, type and format of 74 marine citizen science projects. By assessing how the projects adhere to the Ten Principles of Citizen Science (as defined by the European Citizen Science Association), we investigate project development, identify challenges and outline future opportunities to contribute to marine science and conservation. Synthesizing the survey results and drawing on evidence from case studies of diverse projects, we assess whether and how citizen science can lead to new scientific knowledge and enhanced environmental stewardship. Overall, we explore how marine citizen science can inform current understanding of marine biodiversity and support the development and implementation of marine conservation initiatives worldwide.

Ocean wind-waves are dominant contributors to coastal sea-level and shoreline dynamics and can be primary disruptors of coastal populations, marine ecosystems and coastal and offshore infrastructures. Hence, understanding climate-driven changes in the multivariate global ocean wind-wave climate and its extremes is paramount to successful offshore and coastal climate adaptation planning. When projecting future ocean wave conditions under climate change, uncertainty is introduced from a wide range of different sources including future emission scenario, climate model-forcing, and wind-wave modelling methodology. However, the use of single-method wave downscaling ensembles and inherent variability arising from different methodologies has led to unquantified uncertainty amongst existing global wave climate projections. This thesis addresses this significant knowledge gap by investigating the current state of knowledge in projected ocean wind-wave climate. It then, for the first time, quantifies the relative significance of these major sources of uncertainty and establishes the robustness among existing global wave climate projections. This thesis addresses former limitations associated with independent studies by performing a unique analysis of a coordinated, multi-method ensemble of future global wave scenarios assembled from ten individual state-of-the-art studies to yield a 155-member ensemble. This thesis analyses significant wave height, mean wave period and mean wave direction and also explores the underlying large-scale drivers of projected future changes in storm ocean wave events which remain largely unknown. The results of a systematic literature review demonstrate qualitative consensus between existing global and regional-scale wave climate projection studies in terms of a projected increase in mean significant wave height within the Southern Ocean area, Baltic Sea, and tropical eastern Pacific, and a projected decrease in the North Atlantic and Mediterranean, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), School of Eng & Built Env, Science, Environment, Engineering and Technology, Full Text

We assessed the gaps between current and “model mapping routines”, which represent a benchmark for mapping marine ecosystem services (ESs). Model mapping routines comprised 17 selected variables and their best-rated alternatives depending on the mapping purpose, namely, marine spatial planning, environmental impact assessment, vulnerability and risk analysis, marine protected areas management, payments for ecosystem services, and natural resources management. We conducted a systematic search of articles (n = 64) from which information on the 17 variables and their alternatives was retrieved. We assessed gaps using similarity matrices, according to the co-occurrence index. The largest gaps (as measured by average distances >0.5 between actual and best options) occurred in articles reporting natural resources management as purpose, whereas the smallest were related to marine protected areas management and payments for ecosystem services. The gaps were due to departures in different individual variables. For example, in the case of marine spatial planning the omission of tradeoffs, scenario analysis, multiple scales, and threshold analyses explained the gap, whereas in vulnerability and risk assessment the omission of thresholds, the lack of consistency of the indicators used, and the absence of a definition of ESs explained the gap. We trust that this study will help to recognize that ESs mapping studies should be guided by the purpose of a given intervention rather than by the technical capacities and disciplines of the researchers, if the ESs approach expects to reach a real impact into public policies

Considerable effort is being deployed to predict the impacts of climate change and anthropogenic activities on the ocean's biophysical environment, biodiversity, and natural resources to better understand how marine ecosystems and provided services to humans are likely to change and explore alternative pathways and options. We present an updated version of EcoOcean (v2), a spatial-temporal ecosystem modeling complex of the global ocean that spans food-web dynamics from primary producers to top predators. Advancements include an enhanced ability to reproduce spatial-temporal ecosystem dynamics by linking species productivity, distributions, and trophic interactions to the impacts of climate change and worldwide fisheries. The updated modeling platform is used to simulate past and future scenarios of change, where we quantify the impacts of alternative configurations of the ecological model, responses to climate-change scenarios, and the additional impacts of fishing. Climate-change scenarios are obtained from two Earth-System Models (ESMs, GFDL-ESM2M, and IPSL-CMA5-LR) and two contrasting emission pathways (RCPs 2.6 and 8.5) for historical (1950–2005) and future (2006–2100) periods. Standardized ecological indicators and biomasses of selected species groups are used to compare simulations. Results show how future ecological trajectories are sensitive to alternative configurations of EcoOcean, and yield moderate differences when looking at ecological indicators and larger differences for biomasses of species groups. Ecological trajectories are also sensitive to environmental drivers from alternative ESM outputs and RCPs, and show spatial variability and more severe changes when IPSL and RCP 8.5 are used. Under a non-fishing configuration, larger organisms show decreasing trends, while smaller organisms show mixed or increasing results. Fishing intensifies the negative effects predicted by climate change, again stronger under IPSL and RCP 8.5, which results in stronger

Research Infrastructures (RIs) are large-scale facilities encompassing instruments, resources, data and services used by the scientific community to conduct high-level research in their respective fields. The development and integration of marine environmental RIs as European Research Vessel Operators [ERVO] (2020) is the response of the European Commission (EC) to global marine challenges through research, technological development and innovation. These infrastructures (EMSO ERIC, Euro-Argo ERIC, ICOS-ERIC Marine, LifeWatch ERIC, and EMBRC-ERIC) include specialized vessels, fixed-point monitoring systems, Lagrangian floats, test facilities, genomics observatories, bio-sensing, and Virtual Research Environments (VREs), among others. Marine ecosystems are vital for life on Earth. Global climate change is progressing rapidly, and geo-hazards, such as earthquakes, volcanic eruptions, and tsunamis, cause large losses of human life and have massive worldwide socio-economic impacts. Enhancing our marine environmental monitoring and prediction capabilities will increase our ability to respond adequately to major challenges and efficiently. Collaboration among European marine RIs aligns with and has contributed to the OceanObs’19 Conference statement and the objectives of the UN Decade of Ocean Science for Sustainable Development (2021–2030). This collaboration actively participates and supports concrete actions to increase the quality and quantity of more integrated and sustained observations in the ocean worldwide. From an innovation perspective, the next decade will increasingly count on marine RIs to support the development of new technologies and their validation in the field, increasing market uptake and produce a shift in observing capabilities and strategies

Invasive alien species (IAS) have become an important driver of biodiversity change and exert severe pressure on natural ecosystems. The development of modelling approaches to assess and predict their distributions and impacts, and evaluate management options has increased substantially. We reviewed these modelling approaches, applied in aquatic ecosystems, using a systematic review approach in line with the preferred reporting items for systematic reviews and meta-analyses. According to our results, multispecies/ecosystem models dominated the applications, with dynamic and non-spatial models being the most prevalent. Most of the models included an additional stressor, mainly fisheries, climate change or nutrient loading. The impacts on biota focused on predation, but also on competition and ecosystem functioning, while the impacts on ecosystem services focused on food provision and water purification. At species/population level, most of the studies reported negative impacts; while at multispecies/ecosystem level, negative and both negative and positive impacts were similarly represented. We reflect on the ability of current models to assess different impacts of IAS populations and highlight the need to advance their capabilities to predict future impacts. Further development of models that allow capturing the arrival, establishment and spread of IAS and assess their impacts in an integrated way is still needed. Spatial–temporal modelling techniques bridging with novel analytical capabilities (such as environmental DNA to investigate the presence of IAS and metabarcoding and machine learning to predict future trophic behavior and distributions) may be the key for future achievement

Understanding the threats to global biodiversity and ecosystem services posed by human impacts on coastal and marine environments requires the establishment and maintenance of ecological observatories that integrate the biological, physical, geological, and biogeochemical aspects of ecosystems. This is crucial to provide scientists and stakeholders with the support and knowledge necessary to quantify environmental change and its impact on the sustainable use of the seas and coasts. In this paper, we explore the potential for the coastal and marine components of the International Long-Term Ecological Research Network (ILTER) to fill this need for integrated global observation, and highlight how ecological observations are necessary to address the challenges posed by climate change and evolving human needs and stressors within the coastal zone. The ILTER is a global network encompassing 44 countries and 700 research sites in a variety of ecosystems across the planet, more than 100 of which are located in coastal and marine environments (ILTER-CMS). While most of the ILTER-CMS were established after the year 2000, in some cases they date back to the early 1900s. At ILTER sites, a broad variety of abiotic and biotic variables are measured, which may feed into other global initiatives. The ILTER community has produced tools to harmonize and compare measurements and methods, allowing for data integration workflows and analyses between and within individual ILTER sites. After a brief historical overview of ILTER, with emphasis on the marine component, we analyze the potential contribution of the ILTER-CMS to global coastal and ocean observation, adopting the "Strength, Weakness, Opportunity and Threats (SWOT)" approach. We also identify ways in which the in situ parameters collected at ILTER sites currently fit within the Essential Ocean Variables framework (as proposed by the Framework for Ocean Observation recommendations) and provide insights on the use of new technolog

This data article provides indicators of Ecosystem Service (ES) supply for coral reefs, sandy beaches and coastal lagoons in different ecological states regarding eutrophication. 14 ES are considered: food through fisheries; material; molecules; coastal protection; nutrient regulation; pathogen regulation; climate regulation; support of recreational and leisure activities; contribution to a pleasant landscape; contribution to culture and territorial identity; emblematic biodiversity; habitat; trophic networks; recruitment. For each ecosystem 3 to 4 eutrophication states are described. Indicators of ES supply are filled on the basis of a literature review supplemented with expert-knowledge. A semi-quantification of the indicator value is finally provided. Tendencies and trade-offs between ES are analyzed in How does eutrophication impact bundles of ecosystem services in multiple coastal habitats using state-and-transition models [1].

High-latitude marine ecosystems have experienced fewer species invasions than temperate marine ecosystems, a discrepancy that may be attributed to barriers such as low propagule pressure, extreme and seasonal abiotic conditions, and biotic resistance of relatively intact communities. Each of these barriers is being affected by climate change and increasing human activity in high-latitude (>55º N) areas. We reviewed the evidence for each of these barriers limiting species invasion in high-latitude areas in the northern hemisphere. Based on records from government documents of high‐latitude countries, non-native species appear to be increasing in number (in Denmark and the United States) although there remains a paucity of data on invasive species establishment for high-latitude regions. Future study is needed to identify the drivers and impacts of invasions at high latitudes so that managers looking to prevent invasions can focus their efforts on bolstering barriers to invasion in these unique ecosystems.