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The use of gas diffusion electrodes (GDEs) in microbial fuel cells (MFCs) can improve their cell performance, but tends to cause fouling. In order to allow long-term stable operation, the search for antifouling methods is necessary. Therefore, an antibacterial coating with ammonium compounds is investigated. Within the first 30 days of operation, the maximum measured power density of a GDE with antibacterial ionomer was 606 mW m−2. The GDE without an antifouling treatment could only reach a maximum of 284 mW m−2. Furthermore, there was an optimum in the loading amount with ionomer below 2.6 mg cm−2. Further investigations showed that additional aeration of the GDEs by a fan had a negative effect on their performance. Despite the higher performance, the antibacterial coating could not prevent biofilm growth at the surface of the GDE. The thickness of the biofilm was only reduced by 14–16%. However, the weight of the biofilm on the treated GDEs was 62–80% less than on a GDE without an antifouling treatment. Consequently, the coating cannot completely prevent fouling, but possibly leads to a lower density of the biofilm or prevents clogging of the pores inside the electrodes and improves their long-term stability. [ABSTRACT FROM AUTHOR]

The condition of fish relates to their energy reserves, and a suite of proxies exist to approximate condition, including biochemical and morphometric indices. Biochemical indices directly measure energy stores but are expensive and sometimes lethal. Morphometrics offer several advantages, but their utility as condition proxies is debated and largely untested experimentally. Here, we manipulated the condition of yellowfin bream (Acanthopagrus australis, Günther, 1859) via food reduction to simulate the effect of poor habitat quality and calculated a variety of condition indices through time. We measured four non‐lethal morphometrics (Fulton's K, Le Cren's relative condition, width‐to‐length ratio and girth), the hepatosomatic index and a biochemical benchmark (liver lipid content). Girth and width‐to‐length ratio were reasonably well correlated with lipid content (R2 = 0.74 and 0.56, respectively). The hepatosomatic index was only weakly or uncorrelated to other indices, including lipid content (R2 = 0.35). Where precise estimates of body condition are not needed or repeat measures on the same individual are useful, non‐lethal morphometrics provide a fast, cheap and non‐lethal alternative to biochemical and lethal morphometric methods for this species. We finish by outlining how artificial intelligence‐based automation can be combined with morphometrics to further enhance ethical monitoring by eliminating the need to capture and handle fish entirely. [ABSTRACT FROM AUTHOR]

Seed‐based seagrass restoration strategies demand precise understanding of the environmental drivers influencing flowering. Flowering varies across diverse spatial and temporal scales, yet environmental drivers' effects on these dynamics have received less attention. Lack of knowledge regarding this life‐history stage limits the advancement of seed‐based restoration efforts, especially the establishment of shore‐based seagrass nurseries to enhance seed production.A systematic literature review on the flowering of the genus Zostera was conducted to develop a conceptual model that links influential environmental drivers with flowering. Additionally, a case study using existing survey data supplemented by additional field surveys was designed to explore the spatio‐temporal variability of flowering along the latitudinal gradient in Australasia for the species Zostera muelleri. Predictive models for flowering times were developed using regional climatic variables, following hypotheses generated from long‐term mesocosm observations.The review identified the direct and/or indirect effects of temperature, light, tidal variation, nutrients, salinity and grazing pressure on flowering dynamics. Four categories of flowering variables were identified based on their implications on restoration, namely, timing, abundance, the ratio between reproductive and vegetative growth and morphological characteristics. The spathe densities varied significantly among sites along the latitudinal gradient. While first (r2 = 0.71) and peak (r2 = 0.68) flowering times showed significant correlation with latitude, first flowering was equally predicted by mean winter air temperature and mean winter solar radiation (r2 = 0.73), whereas peak flowering time was best predicted by mean winter air temperature (r2 = 0.60).Accurate predictions of flowering times can improve conservation outcomes by enabling restoration practitioners to forecast flowering times and subsequent wild seed harvesting. The strong correlation between flowering times and climatic variables suggests future shifts in flowering times under climate change are likely, which is crucial knowledge for maintaining the contribution of restoration projects to seagrass conservation. [ABSTRACT FROM AUTHOR]

The loss and degradation of mangrove forests have triggered global restoration efforts to support biodiversity and ecosystem services, including fish stock enhancement. As mangrove restoration accelerates, it is important to evaluate outcomes for species that play functional roles in ecosystems and support services, yet this remains a clear knowledge gap. There is remarkably little information, for example, about how fish use of mangroves varies as restored vegetation matures, hampering efforts to include fisheries benefits in natural capital assessments of restoration. We used unbaited underwater cameras within two distinct zones of mangrove forests—fringe and interior—at five pairs of restored‐natural mangrove sites of increasing age from restoration in southeast Queensland, Australia. We used deep learning to automatically extract data for the four most common species: yellowfin bream (Acanthopagrus australis), sea mullet (Mugil cephalus), common toadfish (Tetractenos hamiltoni), and common silverbiddy (Gerres subfasciatus). The abundance of these species varied among sites and zones, but was equal or greater in restored sites compared to paired natural sites. Despite younger restored sites having dramatically lower structural vegetation complexity, abundances did not increase with restoration site maturity. Furthermore, while yellowfin bream and sea mullet were more abundant in the fringe zone, we observed similarities in how fish used fringe and interior zones across all sites. Our paired, space‐for‐time design provides a powerful test of restoration outcomes for fish, highlighting that even newly restored sites with immature vegetation are readily utilized by key fish species. [ABSTRACT FROM AUTHOR]

Ecosystems remain under enormous pressure from multiple anthropogenic stressors. Manipulative experiments evaluating stressor interactions and impacts mostly apply stressors under static conditions without considering how variable stressor intensity (i.e. fluctuations) and synchronicity (i.e. timing of fluctuations) affect biological responses. We ask how variable stressor intensity and synchronicity, and interaction type, can influence how multiple stressors affect seagrass. At the highest intensities, fluctuating stressors applied asynchronously reduced seagrass biomass 36% more than for static stressors, yet no such difference occurred for photosynthetic capacity. Testing three separate hypotheses to predict underlying drivers of differences in biological responses highlighted alternative modes of action dependent on how stressors fluctuated over time. Given that environmental conditions are constantly changing, assessing static stressors may lead to inaccurate predictions of cumulative effects. Translating multiple stressor experiments to the real world, therefore, requires considering variability in stressor intensity and the synchronicity of fluctuations. [ABSTRACT FROM AUTHOR]

Microbial fuel cells are a promising technology for future wastewater treatment, as it allows cleaning and power generation simultaneously. The bottleneck of microbial fuel cells is often its cathodes because they determine the power output. Gas diffusion electrodes might overcome this bottleneck due to their low production costs and high oxygen reduction rates. However, biofilm formation on the gas diffusion electrodes reduces their performance over time. In this work, a new reactor design of the microbial fuel cell using rotating gas diffusion electrodes is presented. The biofilm growth on the electrode during operation was observed and its effect on the performance of the microbial fuel cell was examined. In addition, different antifouling strategies were investigated over a period of 80 days. It was found that already after 7 days of operation a complete biofilm had grown on an untreated gas diffusion electrode. However, this does not seem to affect the performance of the cells in the beginning. Differences in the performance of the reactors with and without an antifouling strategy only become apparent from day 15 onwards. The use of UV radiation and antibacterial membranes leads to the best results with maximum power densities of approx. 200 mW m−2 while the untreated microbial fuel cell only achieves a maximum power density of approx. 20 mW m−2. [ABSTRACT FROM AUTHOR]

A system of boron-doped diamond (BDD) anode combined with a gas diffusion electrode (GDE) as a cathode is an attractive kind of electrolysis system to treat wastewater to remove organic pollutants. Depending on the operating parameters and water matrix, the kinetics of the electrochemical reaction must be defined to calculate the reaction rate constant, which enables designing the treatment reactor in a continuous process. In this work, synthetic wastewater simulating the vacuum toilet sewage on trains was treated via a BDD-GDE reactor, where the kinetics was presented as the abatement of chemical oxygen demand (COD) over time. By investigating three different initial COD concentrations (C0,1 ≈ 2 × C0,2 ≈ 4 × C0,3), the kinetics was presented and the observed reaction rate constant kobs. was derived at different current densities (20, 50, 100 mA/cm2). Accordingly, a mathematical model has derived kobs. as a function of the cell potential E c e l l . Ranging from 1 × 10−5 to 7.4 × 10−5 s−1, the kobs. is readily calculated when E c e l l varies in a range of 2.5–21 V. Furthermore, it was experimentally stated that the highest economic removal of COD was achieved at 20 mA/cm2 demanding the lowest specific charge (~7 Ah/gCOD) and acquiring the highest current efficiency (up to ~48%). [ABSTRACT FROM AUTHOR]

As efforts to restore coastal habitats accelerate, it is critical that investments are targeted to most effectively mitigate and reverse habitat loss and its impacts on biodiversity. One likely but largely overlooked impediment to effective restoration of habitat-forming organisms is failing to explicitly consider non-habitat-forming animals in restoration planning, implementation, and monitoring. These animals can greatly enhance or degrade ecosystem function, persistence, and resilience. Bivalves, for instance, can reduce sulfide stress in seagrass habitats and increase drought tolerance of saltmarsh vegetation, whereas megaherbivores can detrimentally overgraze seagrass or improve seagrass seed germination, depending on the context. Therefore, understanding when, why, and how to directly manipulate or support animals can enhance coastal restoration outcomes. In support of this expanded restoration approach, we provide a conceptual framework, incorporating lessons from structured decision-making, and describe potential actions that could lead to better restoration outcomes using case studies to illustrate practical approaches. [ABSTRACT FROM AUTHOR]

This paper is concerned with an approximation scheme for rate-independent systems governed by a non-smooth dissipation and a possibly non-convex energy functional. The scheme is based on the local minimization scheme introduced in Efendiev and Mielke [J. Convex Anal. 13 (2006) 151–167], but relies on local stationarity of the underlying minimization problem. Under the assumption of Mosco-convergence for the dissipation functional, we show that accumulation points exist and are so-called parametrized BV-solutions of the rate-independent system. In particular, this guarantees the existence of parametrized BV-solutions for a rather general setting. Afterwards, we apply the scheme to a model for the evolution of damage. [ABSTRACT FROM AUTHOR]

Predicting the impacts of multiple stressors is important for informing ecosystem management but is impeded by a lack of a general framework for predicting whether stressors interact synergistically, additively or antagonistically. Here, we use process‐based models to study how interactions generalise across three levels of biological organisation (physiological, population and consumer‐resource) for a two‐stressor experiment on a seagrass model system. We found that the same underlying processes could result in synergistic, additive or antagonistic interactions, with interaction type depending on initial conditions, experiment duration, stressor dynamics and consumer presence. Our results help explain why meta‐analyses of multiple stressor experimental results have struggled to identify predictors of consistently non‐additive interactions in the natural environment. Experiments run over extended temporal scales, with treatments across gradients of stressor magnitude, are needed to identify the processes that underpin how stressors interact and provide useful predictions to management. [ABSTRACT FROM AUTHOR]

Surface‐based cages are the dominant production technology for the marine finfish aquaculture industry. However, issues such as extreme weather events, poor environmental conditions, interactions with parasites, and conflicts with other coastal users are problematic for surface‐based aquaculture. Submerged cages may reduce many of these problems and commercial interest in their use has increased. However, a broad synthesis of research into the effects of submerged culture on fish is lacking. Here, we review the current status of submerged fish farming worldwide, outline the biological challenges that fish with fundamentally different buoyancy control physiologies face in submerged culture, and discuss production benefits and problems that might arise from submerged fish farming. Our findings suggest that fish with closed swim bladders, and fish without swim bladders, may be well‐suited to submerged culture. However, for fish with open swim bladders, such as salmonids, submergence is more complex as they require access to surface air to refill their swim bladders and maintain buoyancy. Growth and welfare of open swim bladder fish can be compromised by submergence for long periods due to complications with buoyancy regulation, but the recent addition of underwater air domes to submerged cages can alleviate this issue. Despite this advance, a greater understanding of how to couple advantageous environmental conditions with submerged culture to improve fish growth and welfare over the commercial production cycle is required if submerged cages are to become a viable alternative to surface‐based cage aquaculture. [ABSTRACT FROM AUTHOR]

To enable the evaluation of water treatment efficiency of electrochemical advanced oxidation processes (EAOPs), an approach to remove H2O2 as a catalytic pretreatment was investigated to avoid interference in chemical oxygen demand (COD) measurements. Four wastewater types with COD and H2O2 concentrations up to 1,300 mg/L and 90 mmol/L , respectively, were investigated with a novel method. The method requires the addition of sodium bicarbonate (NaHCO3), which decomposes H2O2 at ambient temperature within 24 h without changing COD. For synthetic wastewater (SWW), this time is reduced to 1 h by heating at 70°C. A side-by-side comparison of NaHCO3 and Na2CO3 experiments confirmed H2O2 removal without changes in COD via NaHCO3 , whereas a ∼20% decrease in original COD was observed using Na2CO3. The change in COD during catalytical H2O2 decomposition in Na2CO3 solution was highly correlated with the high pH value. [ABSTRACT FROM AUTHOR]

Biofouling of ship hulls is one of the most important vectors for the transfer of aquatic invasive species. These species cause widespread impacts to native environments and ecological communities, in addition to imposing financial costs for industry. Targeted surveillance and effective adaptive management require knowledge on the likelihood of new introductions of non-indigenous species (NIS). We develop a model of the likelihood of introduction and invasion of NIS for the port of Arzew (Algeria), based on the length of stay of vessels in the ports of call, the latitude of these ports, the geographical distance from the port of Arzew, ship's speed, effectiveness of the antifouling system and antifouling strategy used in port of origin. We identified areas that represent a source of high risk species invasion, according to the environmental similarity of the ports of origin with the Arzew port using the Mahalanobis distance. We show that over one year, 738 trips have been made at the port of Arzew, inflicting a very high risk of invasion, in particular from six coastal ecoregions, (the Western Mediterranean ecoregion, the Northern and Central Red Sea, the South European Atlantic Shelf, the Ionian Sea ecoregion, the North Sea, and the Aegean Sea). These results can be used for invasive species management purposes, such as: the application of specific regulations to high-risk vessels and ports in order to minimize the transfer of these species. The methods and models developed here are transferable to any region around the world with similar data availability. [ABSTRACT FROM AUTHOR]

• Coordinated conservation requires clear indicator interrelationships. • We analyse and interrogate global ecosystem indicators for coastal wetlands. • We develop spatially explicit typologies of ecosystem status at the global scale. • Typologies identify diverse conservation and management needs of coastal wetlands. • Simplifying the complex global mosaic of status informs management and conservation. Global-scale conservation initiatives and policy instruments rely on ecosystem indicators to track progress towards targets and objectives. A deeper understanding of indicator interrelationships would benefit these efforts and help characterize ecosystem status. We study interrelationships among 34 indicators for mangroves, saltmarsh, and seagrass ecosystems, and develop data-driven, spatially explicit typologies of coastal wetland status at a global scale. After accounting for environmental covariates and gap-filling missing data, we obtained two levels of clustering at 5 and 18 typologies, providing outputs at different scales for different end users. We generated 2,845 cells (1° (lat) × 1° (long)) globally, of which 29.7% were characterized by high land- and marine-based impacts and a high proportion of threatened species, 13.5% by high climate-based impacts, and 9.6% were refuges with lower impacts, high fish density and a low proportion of threatened species. We identify instances where specific actions could have positive outcomes for coastal wetlands across regions facing similar issues. For example, land- and marine-based threats to coastal wetlands were associated with ecological structure and function indicators, suggesting that reducing these threats may reduce habitat degradation and threats to species persistence. However, several interdimensional relationships might be affected by temporal or spatial mismatches in data. Weak relationships mean that global biodiversity maps that categorize areas by single indicators (such as threats or trends in habitat size) may not be representative of changes in other indicators (e.g., ecosystem function). By simplifying the complex global mosaic of coastal wetland status and identifying regions with similar issues that could benefit from knowledge exchange across national boundaries, we help set the scene for globally and regionally coordinated conservation. [ABSTRACT FROM AUTHOR]

There is an urgent need to halt and reverse loss of mangroves and seagrass to protect and increase the ecosystem services they provide to coastal communities, such as enhancing coastal resilience and contributing to climate stability. 1,2 Ambitious targets for their recovery can inspire public and private investment in conservation, 3 but the expected outcomes of different protection and restoration strategies are unclear. We estimated potential recovery of mangroves and seagrass through gains in ecosystem extent to the year 2070 under a range of protection and restoration strategies implemented until the year 2050. Under a protection-only scenario, the current trajectories of net mangrove loss slowed, and a minor net gain in global seagrass extent (∼1%) was estimated. Protection alone is therefore unlikely to drive sufficient recovery. However, if action is taken to both protect and restore, net gains of up to 5% and 35% of mangroves and seagrasses, respectively, could be achieved by 2050. Further, protection and restoration can be complementary, as protection prevents losses that would otherwise occur post-2050, highlighting the importance of implementing protection measures. Our findings provide the scientific evidence required for setting strategic and ambitious targets to inspire significant global investment and effort in mangrove and seagrass conservation. • We estimated potential global recovery of mangroves and seagrass • Protection reduces net losses and supports long-term recovery • Restoration is critical to achieve net gains in ecosystem extent • Both protection and restoration are required to achieve and sustain global recovery Conservation action is needed to maintain and recover mangrove and seagrass ecosystems world-wide. Scenario-based models can inform ambitious and achievable global targets for coordinated action. Buelow et al. demonstrate that only protection and restoration combined can support substantial gains in mangrove and seagrass extent into the future. [ABSTRACT FROM AUTHOR]