Posts Tagged 'policy'

California shellfish farmers: perceptions of changing ocean conditions and strategies for adaptive capacity

Highlights

  • Shellfish growers were interviewed about their experiences with environmental change.
  • Growers expressed concerns about multiple observed environmental changes.
  • Growers identified seventeen adaptive strategies.
  • Strategies can be categorized as policy/networking, farm management, and science.

Abstract

Coastal communities along the U.S. West Coast experience a myriad of environmental stressors, including exposure to low pH waters exacerbated by ocean acidification (OA). This can result in ecological and social consequences, making necessary the exploration and support for locally relevant strategies to adapt to OA and other environmental changes. The shellfish aquaculture industry along the West Coast is particularly vulnerable to OA, given the negative effects of low pH on shellfish survival and growth. As such, the social-ecological system exemplified by this industry serves as an opportunity to identify and address strategies for local adaptation. Through interviews conducted with West Coast shellfish farm owners and managers (‘growers’), we investigate perceptions of OA and environmental change and identify specific strategies for adaptation. We find that growers are concerned about OA, among many other environmental stressors such as marine pathogens and water temperature. However, growers are often unable to attribute changes in shellfish survival or health to these environmental factors due to a lack of data and the resources and network required to acquire and interpret these data. From these interviews, we identify a list of adaptive strategies growers employ or would like to employ to improve their overall adaptive capacity to multiple stressors (environmental, economic, political), which together, allow farms to weather periods of OA-induced stress more effectively. Very few studies to date have identified specific adaptive strategies derived directly from the communities being impacted. This work therefore fills a gap in the literature on adaptive capacity by amplifying the voices of those on the front lines of climate change and identifying explicit pathways for adaptation.

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Ocean futures for the world’s largest yellowfin tuna population under the combined effects of ocean warming and acidification

The impacts of climate change are expected to have profound effects on the fisheries of the Pacific Ocean, including its tuna fisheries, the largest globally. This study examined the combined effects of climate change on the yellowfin tuna population using the ecosystem model SEAPODYM. Yellowfin tuna fisheries in the Pacific contribute significantly to the economies and food security of Pacific Island Countries and Territories and Oceania. We use an ensemble of earth climate models to project yellowfin populations under a high greenhouse gas emissions (IPCC RCP8.5) scenario, which includes, the combined effects of a warming ocean, increasing acidification and changing ocean chemistry. Our results suggest that the acidification impact will be smaller in comparison to the ocean warming impact, even in the most extreme ensemble member scenario explored, but will have additional influences on yellowfin tuna population dynamics. An eastward shift in the distribution of yellowfin tuna was observed in the projections in the model ensemble in the absence of explicitly accounting for changes in acidification. The extent of this shift did not substantially differ when the three-acidification induced larval mortality scenarios were included in the ensemble; however, acidification was projected to weaken the magnitude of the increase in abundance in the eastern Pacific. Together with intensive fishing, these potential changes are likely to challenge the global fishing industry as well as the economies and food systems of many small Pacific Island Countries and Territories. The modelling framework applied in this study provides a tool for evaluating such effects and informing policy development.

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Fisheries surveys are essential ocean observing programs in a time of global change: a synthesis of oceanographic and ecological data from U.S. West Coast fisheries surveys

As climate change and other anthropogenic impacts on marine ecosystems accelerate in the 21st century, there is an increasing need for sustained ocean time series. A robust and collaborative network of regional monitoring programs can detect early signs of unanticipated changes, provide a more holistic understanding of ecosystem responses, and prompt faster management actions. Fisheries-related surveys that collect fisheries-independent data (hereafter referred to as “fisheries surveys”) are a key pillar of sustainable fisheries management and are ubiquitous in the United States and other countries. From the perspective of ocean observing, fisheries surveys offer three key strengths: (1) they are sustained due to largely consistent funding support from federal and state public sector fisheries agencies, (2) they collect paired physical, chemical, and biological data, and (3) they have large and frequently overlapping spatial footprints that extend into the offshore region. Despite this, information about fisheries survey data collection can remain poorly known to the broader academic and ocean observing communities. During the 2019 CalCOFI Symposium, marking the 70th anniversary of the California Cooperative Oceanic Fisheries Investigations (CalCOFI), representatives from 21 ocean monitoring programs on the North American West Coast came together to share the status of their monitoring programs and examine opportunities to leverage efforts to support regional ecosystem management needs. To increase awareness about collected ocean observing data, we catalog these ongoing ocean time series programs and detail the activities of the nine major federal or state fisheries surveys on the U.S. West Coast. We then present three case studies showing how fisheries survey data contribute to the understanding of emergent ecosystem management challenges: marine heatwaves, ocean acidification, and contaminant spills. Moving forward, increased cross-survey analyses and cooperation can improve regional capacity to address emerging challenges. Fisheries surveys represent a foundational blueprint for ecosystem monitoring. As the international community moves toward a global strategy for ocean observing needs, fisheries survey programs should be included as data contributors.

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Climate vulnerability assessment of key fishery resources in the Northern Humboldt Current System

The Northern Humboldt Current System sustains one of the most productive fisheries in the world. However, climate change is anticipated to negatively affect fish production in this region over the next few decades, and detailed analyses for many fishery resources are unavailable. We implemented a trait-based Climate Vulnerability Assessment based on expert elicitation to estimate the relative vulnerability of 28 fishery resources (benthic, demersal, and pelagic) to the impacts of climate change by 2055; ten exposure factors (e.g., temperature, salinity, pH, chlorophyll) and 13 sensitivity attributes (biological and population-level traits) were used. Nearly 36% of the species assessed had “high” or “very high” vulnerability. Benthic species were ranked the most vulnerable (gastropod and bivalve species). The pelagic group was the second most vulnerable; the Pacific chub mackerel and the yellowfin tuna were amongst the most vulnerable pelagic species. The demersal group had the relatively lowest vulnerability. This study allowed identification of vulnerable fishery resources, research and monitoring priorities, and identification of the key exposure factors and sensitivity attributes which are driving that vulnerability. Our findings can help fishery managers incorporate climate change into harvest level and allocation decisions, and assist stakeholders plan for and adapt to a changing future.

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The Patagonian fisheries over time: facts and lessons to be learned to face global change

Environmental and anthropic stressors have triggered unprecedented effects on the marine ecosystem. The global increase of marine temperature and acidification caused changes in fish availability and thus catches worldwide. Fostered by a legal framework favoring the investment in extractive capacity, industrial fishing in Atlantic Patagonia grew markedly since the 1960s, leading to the overexploitation of certain stocks. Nowadays, the regulatory system of individual transferable quotas is enforced for hake, but most resources in Patagonia continue being managed under an olympic system lacking planning for sustainability. We analyzed the vulnerability of the Patagonian fisheries to environmental (water temperature and acidification) and human stressors (overexploitation and market forces) in terms of their exposure, sensitivity, and adaptive capacity. Most of the Patagonian fisheries have operated in a scenario of low exposure to climate change. The shellfisheries, however, exhibited the highest sensitivity, as well as the lowest adaptive capacity, to acidification. Regarding the anthropic stressors, both the king crab and shrimp fisheries scored highly sensitive to overexploitation and market forces. Finally, the fisheries targeting the king crab and the Bonaerense demersal fish assemblage evidenced the lowest adaptive capacity against market forces. We propose management options for each case within the context of the Ecosystem Approach to Fisheries.

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Using macroalgae to address UN Sustainable Development goals through CO2 remediation and improvement of the aquaculture environment

Among efforts to explore ways to achieve carbon neutrality globally or regionally, photosynthetic carbon sequestration by algae has been identified as having immense potential. Algae play a crucial role in providing the base of aquatic ecosystems, driving important biogeochemical cycles in oceans and freshwaters and, in so doing, act as a critical component for CO2 drawdown from the atmosphere and ameliorating global change. Furthermore, algae are used extensively in some societies as a source of food and have potential as feedstock for biofuels and as sources of bioactive chemicals. Such activities align strongly with a number of the United Nations Sustainable Development Goals (SDGs). Here we discuss how marine macroalgae might contribute to several of these goals by exploring their potential to enhance aquaculture, contribute to “Blue Carbon” drawdown of CO2 to ameliorate climate change (UN SDGs 13,14) and provide biomass as feedstock for biofuels (UN SDG 7) to reduce reliance on fossil fuel combustion. Though further work is required, we suggest that farming macroalgae in air has great potential for mitigation of CO2 emissions and improvement of aquaculture environments.

Summary: Photosynthetic activity of macroalgae, in addition to driving biosynthesis and biomass accumulation, can cause arise in pH due to CO2 depletion/HCO3. This can buffer the pH decrease associated with anthropogenic CO2 increases and ameliorate the effects of ocean acidification. Though increasing in magnitude, macroalgal aquaculture still represents only asmall fraction of the Cdrawdown by wild macroalgae populations and currently accounts for drawdown of an even lower fraction of global CO2 emissions. Nonetheless, scaling up of intensive macroalgal aquaculture could be one approach to contribute more to ameliorating anthropogenic CO2 emissions and ocean acidification. Modification of IMTA involving growth of the algae in air rather than in seawater could prove auseful means to help stabilize fluctuations in oxygen and pH in aquaculture operations.

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Policy brief: Deep ocean climate intervention impacts – ocean alkalinity enhancement

The Concept:

The ocean contains 50 times as much carbon as the atmosphere and acts as a natural thermostat. Based on natural weathering that occurs on geological time scales, ocean alkalinity enhancement is intended to speed the process of removing CO2 from the atmosphere and reducing ocean acidification by increasing seawater alkalinity, the capacity of a solution to neutralize acid. This approach transforms CO2 into bicarbonate (HCO3-), carbonate (CO32-) and to a much smaller extent hydroxide (OH-) anions. The former are charge balanced by cations other than H+ (GESAMP, 2019), increasing pH and causing more drawdown of CO2 from the atmosphere (Gagern et al., 2019; Fig. 2; NASEM, 2021; Fig. 1). Ocean alkalinity enhancement aims to increase the alkalinity of the oceans by either:

  • adding calcium carbonate (CaCO3) to the ocean from limestone rocks (Renforth and Henderson, 2017); calcium silicates (Ca₂O₄Si) from rocks, construction waste or desalination waste, slaked lime (calcium hydroxide Ca(OH)2; e.g., Caserini et al., 2021; Butenschön et al., 2021) as well as magnesium hydroxide (Mg(OH)2)) (Ocean Visions Road Map – https://www2.oceanvisions.org/roadmaps/ocean-alkalinity-enhancement/) or
  • using electrochemistry – technologies for carbon dioxide removal from seawater, sometimes called “direct ocean capture” (House et al., 2007; Rau, 2008; Rau et al., 2013; Lu et al., 2015; La Plante et al., 2021). These techniques capture and remove dissolved inorganic carbon from seawater (either as CO2 gas or as calcium carbonate), and/or produce a CO2-reactive chemical base, e.g., sodium hydroxide (NaOH), that can be distributed in the surface ocean to ultimately consume atmospheric CO2 and convert it to long-lived, dissolved, alkaline bicarbonate (Ocean Visions Road Map –https://www2.oceanvisions.org/roadmaps/electrochemical-cdr/).

Alkalinity enhancement approaches will likely start in coastal areas more affected with ocean acidification, and will capture and store carbon dioxide predominantly in the form of bicarbonate. This will result in increases in pH and alkalinity as well as the aragonite saturation state.

Fig. 1. Approach and impact of ocean alkalinity addition. From NASEM, 2021

Key Points

  • Using silicate or carbonate minerals to achieve gigatonne scale CO2 removal would require very large quantities of these materials to be mined, crushed and distributed across the ocean.
  • While mineral-induced changes in the form and flux of surface production might be reflected at the deep-sea floor, effects on the deep sea would mainly be in the long-term due to the ocean over turning circulation unless materials were directly placed in the deep sea. However, deep sea biota that have near-surface-dwelling larval stages could be adversely affected.
  • The environmental effects of electrochemical alkalinization techniques on the deep sea is unclear except where acid material would be discharged directly into the deep sea. This could result in potential lethal and sub-lethal effects on organisms close to the discharge zone.
  • Deposition of alkaline material into the ocean could be governed by the London Protocol.

….

DOSI, 15 March 2022. Policy brief.

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Canada’s internet-connected ocean

Over fifteen years ago, Ocean Networks Canada (ONC) began with the world’s first large-scale, interactive, real-time portal into the ocean, bringing continuous, real-time data to the surface for applications in scientific research, societal benefits, and supporting Canada’s ocean industry. This marked the dawn of the Internet-connected ocean, enabling a more fulsome understanding of the ocean through ocean intelligence. These open data have improved our ability to monitor and understand our changing ocean offshore all three coasts of Canada, thanks to diversity of sensor systems to monitor earthquakes and tsunamis, deep sea biodiversity, whales, hydrothermal vents, neutrinos, ocean noise, ocean acidification, forensics experiments, and the impact of climate change, including sea ice thinning in the Arctic. This pioneering approach began in the late 1990s, when scientists began developing a new way of doing ocean science that was no longer limited by weather and ship-time. They imagined a permanent presence in the ocean of sensors to allow a continuous flow of ocean data via the Internet. This big science began to take shape early this century, when a partnership between United States and Canadian institutions was established. ONC evolved out of this international collaboration with seed funding from the Canada Foundation for Innovation, while in the United States, the Ocean Observatories Initiative (OOI) was funded. ONC works closely with OOI on that span the countries’ west coast border. Recently similar observing initiatives in Europe have begun, led by EMSO, which now has a close collaboration with ONC as an Associate Member.

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Conserving threatened species during rapid environmental change: using biological responses to inform management strategies of giant clams

Giant clams are threatened by overexploitation for human consumption, their valuable shells and the aquarium trade. Consequently, these iconic coral reef megafauna are extinct in some former areas of their range and are included in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species and Convention on International Trade in Endangered Species of Wild Fauna and Flora. Now, giant clams are also threatened by rapid environmental change from both a suite of local and regional scale stressors and global change, including climate change, global warming, marine heatwaves and ocean acidification. The interplay between local- to regional-scale and global-scale drivers is likely to cause an array of lethal and sub-lethal effects on giant clams, potentially limiting their depth distribution on coral reefs and decreasing suitable habitat area within natural ranges of species. Global change stressors, pervasive both in unprotected and protected areas, threaten to diminish conservation efforts to date. International efforts urgently need to reduce carbon dioxide emissions to avoid lethal and sub-lethal effects of global change on giant clams. Meanwhile, knowledge of giant clam physiological and ecological responses to local–regional and global stressors could play a critical role in conservation strategies of these threatened species through rapid environmental change. Further work on how biological responses translate into habitat requirements as global change progresses, selective breeding for resilience, the capacity for rapid adaptive responses of the giant clam holobiont and valuing tourism potential, including recognizing giant clams as a flagship species for coral reefs, may help improve the prospects of these charismatic megafauna over the coming decades.

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Spatiotemporal variability in kelp forest and seagrass ecosystems: can local biogeochemical modification combat acidification stress?

Anthropogenic carbon dioxide (CO2) emissions have driven widespread ocean acidification (OA). OA has reduced surface ocean pH by at least 0.1 pH units since the beginning of the industrial era and global models forecast a further decrease of 0.3 to 0.4 pH units by the end of the century. Submerged aquatic vegetation, such as kelp forests and seagrass beds, has the potential to locally ameliorate OA by removing CO2 during photosynthesis and storing it as fixed carbon. Thus, understanding the contribution of these habitats to local biogeochemistry is essential to inform coastal management and policy, especially as the impacts of anthropogenic climate change become more prevalent. The following work describes high resolution spatiotemporal variability in seagrass and kelp forest biogeochemistry (Chapters 1 and 2) and in the surface canopy extent of a giant kelp forest (Chapter 3).

In order to understand the contributions of kelp forest and seagrass metabolism to their respective local biogeochemistry, we must determine the natural variability in these systems and disentangle the physical and biological drivers of local biogeochemical variability. In Chapter 1, I deployed an extensive instrument array in Monterey Bay, CA, inside and outside of a kelp forest to assess the degree to which kelp locally ameliorates present-day acidic conditions, which we expect to be further exacerbated by OA. Interactions between upwelling exposure, internal bores, and biological production shaped the local biogeochemistry inside and outside of the kelp forest. Significantly elevated pH, attributed to kelp canopy productivity, was observed at the surface inside the kelp forest. This modification was largely limited to a narrow band of surface water, implying that while kelp forests have the potential to locally ameliorate ocean acidification stress, this benefit may largely be limited to organisms living in the upper part of the canopy. In Chapter 2, I quantified net community production (NCP) over a mixed seagrass-coral community on Ngeseksau Reef, Ngermid Bay, Republic of Palau. We observed a net heterotrophic diel signal over the deployment, but dissolved oxygen (O2) fluxes during the day were largely positive, illustrating daytime autotrophy. pH, O2, and temperature followed a clear diel pattern with maxima typically occurring in the afternoon. The relationship between tidal regime and time of day drove the magnitude of the signals observed. The case studies described in Chapters 1 and 2 emphasize the importance of high-resolution measurements (high temporal frequency as well as high horizontal and vertical spatial resolution) and consideration of the multiple drivers responsible for shaping the observed biogeochemical variability. In addition to the photosynthetic biomass (kelp and seagrass) at the center of these studies, the physical environment played an important role in dictating the signals observed, in particular water circulation and residence time.

Biogeochemical studies rarely look beyond a few deployment sites, but the ecosystem contributing to the local biogeochemical variability includes influences from beyond those discrete points. Describing the area around these discrete points is important for accurate assessment of factors driving the signals observed at those points. Remote sensing can help us capture and describe the spatial patterns of biomass contributing to changes observed in our chemical records. In Chapter 3, I established a low altitude unmanned aerial vehicle (UAV) record of giant kelp surface areal extent over 18 months on the wave-protected side of Cabrillo Point (Hopkins Marine Station) in Monterey Bay, CA. This was the same canopy responsible for elevating pH in Chapter 1; however, in this case, the kelp canopy mapping did not overlap in time with biogeochemical measurements in the kelp forest. I compared the UAV kelp classification to canopy cover determined from Landsat satellite images obtained over the same period. There was a linear relationship between the drone kelp ratio and Landsat kelp canopy fraction for spatially-matched pixels; a Landsat kelp fraction of 0.64 was equivalent to 100% kelp cover in the drone data. The level of resolution provided by UAV, compared with Landsat images, could allow more detailed mapping of kelp responses to environmental change. Future studies should pair mapping flights with biogeochemical measurements to quantify the relationship between changes in canopy area and the relative surface canopy modification of pH.

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Prospective life cycle assessment of metal commodities obtained from deep-sea polymetallic nodules

Highlights

  • A Life Cycle Assessment of commodities from polymetallic nodules was performed.
  • Climate change, photochemical oxidant formation and acidification were considered.
  • The main hotspots are at onshore processes (e.g., hydrometallurgical processing).
  • 38% reduction in carbon footprint can be observed, when comparing to terrestrial.
  • Deep-sea operations may contribute significantly to the growing demand of metals.

Abstract

Sustainable metal supply will be essential to achieve climate and sustainability goals (e.g., Paris agreement), for instance by providing the necessary raw materials for renewable energy infrastructure systems. The potential exploitation of mineral resources from the deep sea (e.g., polymetallic nodules) can play a major role in this supply. A holistic environmental analysis is needed, in order to consider the entire value chain of the products obtained out of deep-sea exploitation. Therefore, the objective of this study was to perform a prospective life cycle assessment (LCA) of deep-sea-sourced commodities and compare it to equivalent products obtained from terrestrial mining. It considered as reference flow one tonne of (dry) nodules, using a cradle-to-gate approach up to the final metal commodities, analyzing the delivery to the market of 10.5 kg of copper, 12.8 kg of nickel, 2.3 kg of cobalt and 311.3 kg of ferromanganese. Three environmental impact categories were analyzed, i.e., climate change, acidification and photochemical oxidant formation. Overall, onshore activities (e.g., hydrometallurgical processing) are the main hotspots for environmental impacts of metals sourced from the deep sea; offshore activities play a minor role in the value chain. While photochemical oxidant formation impacts would be similar to terrestrial alternatives, the deep-sea-sourced commodities can bring environmental gains in the order of 38% for climate change and up to 72% for acidification. As this study shows, a strategic selection of the location for onshore processing of the polymetallic nodules is key to target cleaner production, not only because of the distance from the nodules site, but especially because of the available energy mix. The results should be interpreted with care, though, due to intrinsic limitations of the LCA study, e.g., the prospective nature of this study, the limited access to terrestrial mining data, amongst others. Nonetheless, regardless the limitations a prospective LCA imposes, this study highlights some important potential benefits that commodities from deep-sea polymetallic nodules can bring to society with respect to three important environmental impacts.

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A marine-biology-centric definition of ocean connectivity and the law of the sea

The inter-connectedness of marine ecosystems has been repeatedly acknowledged in the relevant literature as well as in policy briefs. Against this backdrop, this article aims at further reflecting on the question of to what extent the law of the sea takes account of or disregards ocean connectivity. In order to address this question, this article starts by providing a brief overview of the notion of ocean connectivity from a marine science perspective, before taking a closer look at the extent to which the law of the sea incorporates the scientific imperative of ocean connectivity in the context of four examples: (i) straits, (ii) climate change and ocean acidification, (iii) salmon and (iv) the ecosystem approach to fisheries. Tying the findings of the different examples together, this study concludes by stressing the need of accommodating ocean connectivity not only in the interpretation and implementation of the existing law (of the sea) but also in its further development.

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Novel environmental conditions due to climate change in the world’s largest marine protected areas

Highlights

  • Up to 97% of very large marine protected areas will contain novel conditions
  • Very large marine protected areas in the tropics most exposed to novelty
  • Novel conditions for pH emerge as soon as 2030
  • 44.9% of the ocean will see novel conditions by 2060, up to 87% by 2100

Science for society

Oceans cover more than 70% of the Earth’s surface and provide us with goods and services ranging from food and energy to cultural resources and identity. However, climate change threatens the availability of these ocean-derived benefits. Climate change is turning once familiar and stable ocean conditions into unfamiliar and novel ones. These changes might even be significant enough to undermine much of the work done to protect the ocean.

This research investigates the timing and impact of climate change on the oceans and the largest MPAs. We show that a majority (up to 87%) of the ocean will have novel conditions, as will almost all of the MPAs we examined (97%). These novel conditions may cause culturally and economically important species to migrate or possibly go extinct. Understanding when, where, and how these changes occur can help inform ocean and climate policy that connects people across space and time.

Summary

Climate change is altering the biogeochemical conditions of the ocean, leading to the emergence of novel environmental conditions that may drastically affect the performance of very large marine protected areas (VLMPAs) (area > 100,000 km2). Given the prominent role that VLMPAs play in ocean conservation, determining when and where novel conditions will emerge within VLMPAs is vital for ensuring a healthy ocean in the future. Here, using a non-parametric approach to detect novelty, we show that 60%–87% of the ocean and 76%–97% of VLMPAs are expected to contain novel conditions across multiple biogeochemical variables by 2100, with novel conditions in pH emerging by 2030. With most VLMPAs expected to contain environmental conditions unlike those currently within their boundaries, and given the likelihood of any of these climate futures unfolding, present-day management will need to consider alterations to current and future VLMPA design and use.

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Introduction to Coastal Management Journal special issue on ocean acidification

Anthropogenic carbon emissions are increasing atmospheric carbon concentrations. Global oceans absorb about one-fourth of these emissions each year (Friedlingstein et al., 2020). Seawater’s carbon absorption initiates several chemical reactions, including the production of carbonic acid, reduction in the availability of calcium carbonate ion, and declining pH (Doney et al. 2009). This process of chemical changes is called ocean acidification (OA). Models predict that under a “business as usual” greenhouse gas emissions scenario (RCP 8.5), the ocean may become 150% more acidified by 2100 (Phillips et al. 2018 and references therein). As with many climate change impacts, OA is occurring and interacting with many other stressors including ocean warming anddeoxygenation, and non-climate-related stressors like development, habitat degradation and pollution (IPCC 2019). In coastal systems, processes including upwelling, nutrient loading (magnified by wastewater), pollutions and freshwater inputs can further exacerbate conditions (Duarte et al. 2013 and references therein).

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Research handbook on ocean acidification law and policy

This important Research Handbook provides a guide to navigating the tangled array of laws and policies available to counter the multiple threats of ocean acidification. It investigates the limitations and opportunities for addressing ocean acidification under global governance frameworks, including multilateral environmental agreements, law of the sea and human rights instruments.
 
The book also describes regional and national approaches and challenges in responding to ocean acidification. The special vulnerabilities of the Arctic, Antarctic and South Pacific are highlighted. Limited responses by regional sea programmes and regional fisheries management organizations are summarized. Case studies are provided from Australia, Brazil, China and the United States.
 
This discerning Research Handbook will be a welcome read for policy makers and students with an interest in the laws and policies of marine governance and climate change. This will also be an ideal read for those who are interested in the pressing environmental issues facing the world community.

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The Integrated Carbon Observation System in Europe

Since 1750, land use change and fossil fuel combustion has led to a 46 % increase in the atmospheric carbon dioxide (CO2) concentrations, causing global warming with substantial societal consequences. The Paris Agreement aims to limiting global temperature increases to well below 2°C above pre-industrial levels. Increasing levels of CO2 and other greenhouse gases (GHGs), such as methane (CH4) and nitrous oxide (N2O), in the atmosphere are the primary cause of climate change. Approximately half of the carbon emissions to the atmosphere is sequestered by ocean and land sinks, leading to ocean acidification but also slowing the rate of global warming. However, there are significant uncertainties in the future global warming scenarios due to uncertainties in the size, nature and stability of these sinks. Quantifying and monitoring the size and timing of natural sinks and the impact of climate change on ecosystems are important information to guide policy-makers’ decisions and strategies on reductions in emissions. Continuous, long-term observations are required to quantify GHG emissions, sinks, and their impacts on Earth systems. The Integrated Carbon Observation System (ICOS) was designed as the European in situ observation and information system to support science and society in their efforts to mitigate climate change. It provides standardized and open data currently from over 140 measurement stations across 12 European countries. The stations observe GHG concentrations in the atmosphere and carbon and GHG fluxes between the atmosphere, land surface and the oceans. This article describes how ICOS fulfills its mission to harmonize these observations, ensure the related long-term financial commitments, provide easy access to well-documented and reproducible high-quality data and related protocols and tools for scientific studies, and deliver information and GHG-related products to stakeholders in society and policy.

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Nitrous oxide and methane in a changing Arctic Ocean

Human activities are changing the Arctic environment at an unprecedented rate resulting in rapid warming, freshening, sea ice retreat and ocean acidification of the Arctic Ocean. Trace gases such as nitrous oxide (N2O) and methane (CH4) play important roles in both the atmospheric reactivity and radiative budget of the Arctic and thus have a high potential to influence the region’s climate. However, little is known about how these rapid physical and chemical changes will impact the emissions of major climate-relevant trace gases from the Arctic Ocean. The combined consequences of these stressors present a complex combination of environmental changes which might impact on trace gas production and their subsequent release to the Arctic atmosphere. Here we present our current understanding of nitrous oxide and methane cycling in the Arctic Ocean and its relevance for regional and global atmosphere and climate and offer our thoughts on how this might change over coming decades.

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The Gulf of St. Lawrence biogeochemical model: a modelling tool for fisheries and ocean management

The goal of this paper is to give a detailed description of the coupled physical-biogeochemical model of the Gulf of St. Lawrence that includes dissolved oxygen and carbonate system components, as well as a detailed analysis of the riverine contribution for different nitrogen and carbonate system components. A particular attention was paid to the representation of the microbial loop in order to maintain the appropriate level of the different biogeochemical components within the system over long term simulations. The skill of the model is demonstrated using in situ data, satellite data and estimated fluxes from different studies based on observational data. The model reproduces the main features of the system such as the phytoplankton bloom, hypoxic areas, pH and calcium carbonate saturation states. The model also reproduces well the estimated transport of nitrate from one region to the other. We revisited previous estimates of the riverine nutrient contribution to surface nitrate in the Lower St. Lawrence Estuary using the model. We also explain the mechanisms that lead to high ammonium concentrations, low dissolved oxygen, and undersaturated calcium carbonate conditions on the Magdalen Shallows.

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Seasonality and life history complexity determine vulnerability of Dungeness crab to multiple climate stressors

Abstract

Scaling climate change impacts from individual responses to population-level vulnerability is a pressing challenge for scientists and society. We assessed vulnerability of the most valuable fished species in the Northwest U.S.—Dungeness crab—to climate stressors using a novel combination of ocean, population, and larval transport models with stage-specific consequences of ocean acidification, hypoxia, and warming. Integration across pelagic and benthic life stages revealed increased population-level vulnerability to each stressor by 2100 under RCP 8.5. Under future conditions, chronic vulnerability to low pH emerged year-round for all life stages, whereas vulnerability to low oxygen continued to be acute, developing seasonally and impacting adults, which are critical to population growth. Our results demonstrate how ontogenetic habitat shifts and seasonal ocean conditions interactively impact population-level vulnerability. Because most valuable U.S. fisheries rely on species with complex life cycles in seasonal seas, chronic and acute perspectives are necessary to assess population-level vulnerability to climate change.

Plain Language Summary

The release of carbon dioxide (CO2) into the atmosphere by human activities is altering ocean conditions including pH, oxygen, and temperature. One way to understand how these changing conditions will affect ecologically, economically, and culturally important marine species is to scale individual responses from laboratory experiments to population-level impacts. In this study, we assessed the vulnerability of Dungeness crab, one of the most valuable fisheries in the NW USA, to stressful conditions based on the predicted habitat exposure and response of each life stage (eggs, larvae, juveniles, and adults). The degree of vulnerability was determined by the seasonality of the ocean conditions in combination with the crab’s complex life cycle. This approach revealed that Dungeness crab life stages and populations will be more vulnerable to low pH, low oxygen, and high temperature in the future (year 2100) under an aggressive CO2 emissions scenario. Based on these results, we recommend that fishery managers incorporate changing conditions into their decision-making to protect vulnerable life stages in areas prone to stressful conditions (e.g., adult crabs in hypoxic areas). Our approach can be adapted for many other economically and ecologically important marine species in order to inform conservation and management strategies.

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Climate change vulnerability of cetaceans in Macaronesia: insights from a trait-based assessment

Highlights

  • A climate vulnerability assessment was applied to cetaceans in Macaronesia
  • Very High to High vulnerability scores for 62% of species management units
  • Very High to Moderate certainty scores for 67% of units
  • High potential for climate-related responses for over 50% of units
  • Further research on trait-based approaches is needed to support decision-makers

Abstract

Over the last decades global warming has caused an increase in ocean temperature, acidification and oxygen loss which has led to changes in nutrient cycling and primary production affecting marine species at multiple trophic levels. While knowledge about the impacts of climate change in cetacean’s species is still scarce, practitioners and policymakers need information about the species at risk to guide the implementation of conservation measures.

To assess cetacean’s vulnerability to climate change in the biogeographic region of Macaronesia, we adapted the Marine Mammal Climate Vulnerability Assessment (MMCVA) method and applied it to 21 species management units using an expert elicitation approach.

Results showed that over half (62%) of the units assessed presented Very High (5 units) or High (8 units) vulnerability scores. Very High vulnerability scores were found in archipelago associated units of short-finned pilot whales (Globicephala macrorhynchus) and common bottlenose dolphins (Tursiops truncatus), namely in the Canary Islands and Madeira, as well as Risso’s dolphins (Grampus griseus) in the Canary Islands. Overall, certainty scores ranged from Very High to Moderate for 67% of units.

Over 50% of units showed a high potential for distribution, abundance and phenology changes as a response to climate change.

With this study we target current and future information needs of conservation managers in the region, and guide research and monitoring efforts, while contributing to the improvement and validation of trait-based vulnerability approaches under a changing climate.

Continue reading ‘Climate change vulnerability of cetaceans in Macaronesia: insights from a trait-based assessment’

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