After almost three decades, too little progress has been achieved in protecting, preserving, and promoting the sustainable use of the ocean and its resources for the benefit of mankind. Many efforts, however, have been deployed within conferences, summits, and meetings with highly competent experts, such as scientists, diplomats, and international lawyers covering a wide range of fields. After all these years, the state of the marine environment is not improving as fast as it should be. The question to ask is why has so little progress been achieved? The answer belongs once more to the international community, as well as to national policymakers. They should take more forceful actions in implementing the Sustainable Development Goals (SDGs) contained in the 2030 Agenda.
Planktonic plants and animals at the base of the marine food chain make all life on Earth possible. Without them the atmosphere would be toxic from carbon dioxide, we would have no oxygen and there would be no whales, birds or fish in the oceans.
Over the last 70 years, more than 50% of all marine life has been lost from the world’s oceans, and it continues to decline at rate of 1% year on year. Atmospheric carbon dioxide causes ocean acidification, and a loss of marine plants and animals accelerates the process.
A small increase in acidity caused by carbon dioxide dissolves magnesium calcite and aragonite, forms of calcium carbonate upon which 50% of all marine life including plankton and coral reefs are composed. Over the next 25 years, the pH will continue to drop from pH8.04 to pH7.95, and an estimated 80% to 90% of all marine life will be lost from the oceans. Even if the world achieves net zero by 2045, atmospheric carbon dioxide will still exceed 500ppm and the oceans will still drop to pH 7.95.
Based on current climate change policy of carbon mitigation, we will not be able to stop the loss of most marine life, which includes fish and the food supply for 3 billion people. In addition, we lose the life support system for the planet. This decline has gone largely unnoticed because most of the plants and animals in the oceans are under 1 mm in size and they are not closely monitored. By way of an example: Prochlorococcus, a cyanobacteria responsible for making 20% of our oxygen, was only discovered in the 1985.
Ocean acidification and climate change cannot adequately describe the loss of marine life. 30% of the ocean have high nutrient (nitrate) concentrations but zero or only low plant growth. If it is not the lack of nutrients or trace nutrients, responsible for the loss of marine life, then this just leaves aquatic environmental pollution as the last plausible explanation. The impact of chemical and micro-plastic pollution on planktonic marine life has been almost completed ignored by the scientific community, and as such industry and governments have not been alerted to the impending threat to the oceans.
This is potentially a good news story, because the solution will be to eliminate pollution from plastic and toxic chemicals or develop green alternatives that do not harm to the environment or humans. We still need to reduce carbon from the burning of fossil fuels, but the priority over the next 25 years should be to protect the oceans, because all life on earth depends upon marine life in the world’s oceans.
We model a stylized economy dependent on agriculture and fisheries to study optimal environmental policy in the face of interacting external effects of ocean acidification, global warming, and eutrophication. This allows us to capture some of the latest insights from research on ocean acidification. Using a static two-sector general equilibrium model we derive optimal rules for national taxes on emissions and agricultural run-off and show how they depend on both isolated and interacting damage effects. In addition, we derive a second-best rule for a tax on agricultural run-off of fertilizers for the realistic case that effective internalization of externalities is lacking. The results contribute to a better understanding of the social costs of ocean acidification in coastal economies when there is interaction with other environmental stressors.
Recommendations for Resource Managers:
- Marginal environmental damages from emissions should be internalized by a tax on emissions that is high enough to not only reflect marginal damages from temperature increases, but also marginal damages from ocean acidification and the interaction of both with regional sources of acidification like nutrient run-off from agriculture.
- In the absence of serious national policies that fully internalize externalities, a sufficiently high tax on regional nutrient run-off of fertilizers used in agricultural production can limit not only marginal environmental damages from nutrient run-off but also account for unregulated carbon emissions.
- Putting such regional policies in place that consider multiple important drivers of environmental change will be of particular importance for developing coastal economies that are likely to suffer the most from ocean acidification.
- Global climate change and local stressors are the main threats to reef-building organisms and habitats they build, such as rhodolith beds.
- Through an experimental essay and ecological niche modelling, we were able to determine the environmental factors that determine the distribution and affect the physiology of an important rhodolith-forming species in the southwestern Atlantic.
- Our results raise the possibility of some rhodolith-forming species being resilient to future environmental change based on our current understanding of their distributions, a perspective that will need to be further explored by future studies.
- This information is helpful in informing policies for the conservation of priority areas, aiding the preservation of marine biodiversity in the South Atlantic.
Given the ecological and biogeochemical importance of rhodolith beds, it is necessary to investigate how future environmental conditions will affect these organisms. We investigated the impacts of increased nutrient concentrations, acidification, and marine heatwaves on the performance of the rhodolith-forming species Lithothamnion crispatum in a short-term experiment, including the recovery of individuals after stressor removal. Furthermore, we developed an ecological niche model to establish which environmental conditions determine its current distribution along the Brazilian coast and to project responses to future climate scenarios. Although L. crispatum suffered a reduction in photosynthetic performance when exposed to stressors, they returned to pre-experiment values following the return of individuals to control conditions. The model showed that the most important variables in explaining the current distribution of L. crispatum on the Brazilian coast were maximum nitrate and temperature. In future ocean conditions, the model predicted a range expansion of habitat suitability for this species of approximately 58.5% under RCP 8.5. Physiological responses to experimental future environmental conditions corroborated model predictions of the expansion of this species’ habitat suitability in the future. This study, therefore, demonstrates the benefits of applying combined approaches to examine potential species responses to climate-change drivers from multiple angles.
Climate change is at the forefront of today’s global challenges with its potential to turn into a runaway process. Fishing pressure acts in concert and exacerbates the impacts of climate change. The North Atlantic Ocean is no exemption of the increasing anthropogenic stress with Atlantic cod, Gadus Morhua, one of its most prominent fish species, displaying the ocean’s state. Most Atlantic cod stocks have experienced high rates of fishing and biomass declines, leading to renovation of fishing regulations and the implementation of rebuilding strategies. Today, the cod stocks differ considerably in trends and commercial status with 8 stocks considered collapsed and 57 % of today’s landings supplied by one single stock, the North East Arctic cod. What drives the collapse and what drives the recovery of a stock? Elucidating drivers of Atlantic cod productivity at low abundance is inevitable for sustainably managing the species in its changing habitat. This thesis attempts a comprehensive study on climate change impacts by addressing rising ocean temperature (paper I-III), temperature variability (paper II), acidification (paper III) and uncertainty (of the biology and as risk in management under the precautionary approach [paper IV]). Individual and synergistic impacts of climate change are discussed with a particular focus on nonlinear dynamics, including the potential for Allee effects (paper I-III). Allee effects describe the decrease in per capita growth rate at small population size, which can hinder population recovery by reinforcing degradation. Such a shift in the underlying biology can be irreversible and demands proactive and precautionary management measures. Application of precautionary measures to protect the environment and manage risks in situations of high uncertainty is a central tenet of the “precautionary approach”, a guiding principle in fisheries management. The poor state of various commercial fish stocks worldwide stands in contrast to the precautionary approach and suggests a subordinate role of science in fisheries management. In paper IV, Canada’s fisheries policy and advisory process is contrasted with the EU’s Common Fisheries Policy in regard to the precautionary approach and the role of science, in order to identify policy and institutional constraints that have hindered sustainable, precautionary management practices. Drawing from insights on climate change driven productivity changes (paper I-III) and the importance of a policy and institutional framework that acknowledges these (paper IV), this thesis ends with suggestions for scientifically informed, precautionary and sustainable fisheries management practices that can speed up recovery and allow for a vital fishery in the future.
- A biophysical model framework for coral reef evolution is developed.
- The model can be used to predict the coral response to the environment via process-based relations.
- The model bridges the gap in timescales of processes from seconds to millennia.
- Model predictions are within the accuracy of climate projections.
- The model is an efficient tool for forecasting coral reef development to inform policy makers.
The increasing pressure on Earth’s ecosystems due to climate change is becoming more and more evident and the impacts of climate change are especially visible on coral reefs. Understanding how climate change interacts with the physical environment of reefs to impact coral growth and reef development is critically important to predicting the persistence of reefs into the future. In this study, a biophysical model was developed including four environmental factors in a feedback loop with the coral’s biology: (1) light; (2) hydrodynamics; (3) temperature; and (4) pH. The submodels are online coupled, i.e. regularly exchanging information and feedbacks while the model runs. This ensures computational efficiency despite the widely-ranged timescales. The composed biophysical model provides a significant step forward in understanding the processes that modulate the evolution of coral reefs, as it is the first construction of a model in which the hydrodynamics are included in the feedback loop.
Knowledge of life on the Southern Ocean seafloor has substantially grown since the beginning of this century with increasing ship-based surveys and regular monitoring sites, new technologies and greatly enhanced data sharing. However, seafloor habitats and their communities exhibit high spatial variability and heterogeneity that challenges the way in which we assess the state of the Southern Ocean benthos on larger scales. The Antarctic shelf is rich in diversity compared with deeper water areas, important for storing carbon (“blue carbon”) and provides habitat for commercial fish species. In this paper, we focus on the seafloor habitats of the Antarctic shelf, which are vulnerable to drivers of change including increasing ocean temperatures, iceberg scour, sea ice melt, ocean acidification, fishing pressures, pollution and non-indigenous species. Some of the most vulnerable areas include the West Antarctic Peninsula, which is experiencing rapid regional warming and increased iceberg-scouring, subantarctic islands and tourist destinations where human activities and environmental conditions increase the potential for the establishment of non-indigenous species and active fishing areas around South Georgia, Heard and MacDonald Islands. Vulnerable species include those in areas of regional warming with low thermal tolerance, calcifying species susceptible to increasing ocean acidity as well as slow-growing habitat-forming species that can be damaged by fishing gears e.g., sponges, bryozoan, and coral species. Management regimes can protect seafloor habitats and key species from fishing activities; some areas will need more protection than others, accounting for specific traits that make species vulnerable, slow growing and long-lived species, restricted locations with optimum physiological conditions and available food, and restricted distributions of rare species. Ecosystem-based management practices and long-term, highly protected areas may be the most effective tools in the preservation of vulnerable seafloor habitats. Here, we focus on outlining seafloor responses to drivers of change observed to date and projections for the future. We discuss the need for action to preserve seafloor habitats under climate change, fishing pressures and other anthropogenic impacts.
The global ocean mediates the effect of climate change and anthropogenic carbon emissions by absorbing atmospheric carbon dioxide (Ellis et al., 2017). The ocean’s absorption of carbon dioxide results in a change in ocean chemistry and decline in seawater pH known as ocean acidification (Kapsenberg and Cyronak, 2018). Changes in ocean chemistry and pH may also be driven by primary production activity, upwelling, and river runoff into marine environments (Richards et al., 2014). Ocean acidification has the potential to adversely affect numerous marine organisms (Kapsenberg and Cyronak, 2018), however, it can be especially problematic for calcifying shellfish species (Swezey et al., 2020) like the Eastern Oyster and larval or juvenile stage organisms (Mangi et al., 2018). Temperature, salinity, dissolved oxygen levels, and acidification impact the health and longevity of oysters and oyster reefs. Oyster reefs offer numerous ecosystem services. These reefs provide habitat for benthic invertebrates, seabirds and fish that rely on reefs for feeding, nursery, and breeding grounds (Burrows et al., 2005). The Eastern Oyster (Crassostrea virginica) is a native oyster species of the U.S. Atlantic Coast. Although oysters reefs support coastal livelihoods and offer numerous ecosystem services, many reefs have been degraded by anthropogenic activities (Burrows et al., 2005). Pollution, over-harvest, and an increase in loading of suspended sediments are key threats to oyster reef health (Burrows et al., 2005). Oyster reef restoration projects focus on returning reefs to their natural state. Given the role of oysters as ecosystem engineers, and the many benefits that may be derived from healthy oyster reefs, restoration projects are a priority for communities throughout the U.S. Atlantic Coast.
Cooley et al. 2016 recommends several effective community actions that may be taken to help address ocean acidification today. This project focuses on two non-legislative actions discussed by Cooley et al. 2016. These are public education related to coastal acidification and resilience management through oyster reef restoration projects. The purpose of this project is to support coastal resource-reliant communities on the U.S. Atlantic Coast in preparing for the potential future impacts of ocean acidification on C. virginica. The project examines trends in the oyster reef restoration projects presently underway at the state and local level along the U.S. Atlantic Coast, and it considers how coastal acidification may affect the longevity of the region’s oyster reefs. Finally, the project considers the future research and management considerations needed to adequately protect oyster reefs under changing climatic conditions.
The majority of IPCC scenarios call for active CO2 removal (CDR) to remain below 2oC of warm- ing. On geological timescales, ocean uptake regulates atmospheric CO2 concentration, with two homeostats driving CO2 uptake: dissolution of deep ocean calcite deposits and terrestrial weathering of silicate rocks, acting on 1ka to 100ka timescales, respectively. Many current ocean-based CDR proposals effectively act to accelerate the latter. Here we present a method which relies purely on the redistribution and dilution of acidity from a thin layer of the surface ocean to a thicker layer of deep ocean, with the aim of reducing surface acidification and accelerating the former carbonate homeostasis. This downward transport could be seen analogous to the action of the natural biological carbon pump. The method offers advantages over other ocean CDR methods and direct air capture approaches (DAC): the conveyance of mass is minimized (acidity is pumped in situ to depth), and expensive mining, grinding and distribution of alkaline material is eliminated. No dilute substance needs to be concentrated, avoiding the Sherwood’s Rule costs typically encountered in DAC. Finally, no terrestrial material is added to the ocean, avoiding significant alteration of seawater ion concentrations or issues with heavy metal toxicity encountered in mineral-based alkalinity schemes. The artificial transport of acidity accelerates the natural deep ocean compensation by calcium carbonate. It has been estimated that the total compensation capacity of the ocean is on the order of 1500GtC. We show through simulation that pumping of ocean acidity could remove up to 150GtC from the atmosphere by 2100 with- out excessive increase of local ocean pH. For an acidity release below 2000m, the relaxation half-life of CO2 return to the atmosphere was found to be ∼2500 years (∼1000yr without account- ing for carbonate dissolution), with ∼85% retained for at least 300 years. The uptake efficiency and residence time were found to vary with the location of acidity pumping, and optimal areas were determined. Requiring only local resources (ocean water and energy), this method could be uniquely suited to utilize otherwise-unusable open ocean energy sources at scale. We examine technological pathways that could be used to implement it and present a brief techno-economic estimate of 130-250$/tCO2 at current prices and as low as 93$/tCO2 under modest learning-curve assumptions.
On the iconic Great Barrier Reef (GBR), the cumulative impacts of tropical cyclones, marine heatwaves and regular outbreaks of coral-eating crown-of-thorns starfish (CoTS) have severely depleted coral cover. Climate change will further exacerbate this situation over the coming decades unless effective interventions are implemented. Evaluating the efficacy of alternative interventions in a complex system experiencing major cumulative impacts can only be achieved through a systems modelling approach. We have evaluated combinations of interventions using a coral reef meta-community model. The model consisted of a dynamic network of 3753 reefs supporting communities of corals and CoTS connected through ocean larval dispersal, and exposed to changing regimes of tropical cyclones, flood plumes, marine heatwaves and ocean acidification. Interventions included reducing flood plume impacts, expanding control of CoTS populations, stabilizing coral rubble, managing solar radiation and introducing heat-tolerant coral strains. Without intervention, all climate scenarios resulted in precipitous declines in GBR coral cover over the next 50 years. The most effective strategies in delaying decline were combinations that protected coral from both predation (CoTS control) and thermal stress (solar radiation management) deployed at large scale. Successful implementation could expand opportunities for climate action, natural adaptation and socioeconomic adjustment by at least one to two decades.
This paper reviews the evidence on slow-onset events presented in the Special Report on Climate Change and Land (SRCCL) and the Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC), both published in 2019. It analyses how the reports, and recent literature cited in them, deal with the eight types of slow-onset events, specified by the UNFCCC: increasing temperatures, sea level rise, salinization, ocean acidification, glacial retreat, land degradation, desertification and loss of biodiversity. The authors used qualitative data analysis software to analyse the reports, and for each of the SOEs, they coded and analysed information about the state, rate of change, timescale, geography, drivers, impacts, management responses, adaptation limits and residual losses and damages. The paper provides an overview of the state of the art on SOEs and helps to identify gaps and challenges in understanding the nature of SOEs, their impact and effective management approaches.
Among many other impacts, the rising levels of atmospheric carbon dioxide (CO2), primarily induced by increased rates of fossil fuel combustion, are changing the ocean’s chemistry (Guidetti and Danavaro 2018). The resulting increased uptake of more CO2 by the ocean is making the ocean more acidic leading to deleterious harm to marine ecosystems. This ocean acidification problem needs to be seen as an increased pressure on marine living resources, which are already under intense physicochemical and biological stress due to increased ocean warming (IPCC 2013), changes in their ecosystems (Milazzo et al. 2019), and the introduction of alien, competing species (Essl et al. 2020). For example, one of the well-known effects of ocean acidification is the lowering of calcium carbonate saturation states, which negatively impacts shell-forming marine organisms that range widely from plankton to benthic molluscs, echinoderms, and corals. The potential for marine organisms to adapt to…
The British Indian Ocean Territory (BIOT) consists of five atolls of low-lying islands, including the largest atoll in the world, Great Chagos Bank, and a number of submerged atolls and banks. Diego Garcia is the only inhabited island. The BIOT Marine Protected Area (MPA) was designatedin 2010. It covers the entire maritime zone and coastal waters, an approximate area of 640,000 km2. The marine environment is rich and diverse, attracting sea birds, sharks, cetaceans and sea turtles and with extensive seagrass and coral reef habitats. It includes the endangered Chagos brain coral (Ctenella chagius), an endemic massive coral unique to BIOT. BIOT reefs have suffered extensive bleaching and mortality, and they remain vulnerable to current and future climate change and other pressures, including:
The heavy mortality has been caused by recurrent marine heatwaves since the 1970s. Reefs have not yet recovered from the most severe bleaching in 2016 and 2017, with increasingly severe events expected. Deeper fore-reefs may act as refuges, but those colonies are likely to be more sensitive to temperature change. Limiting other pressures will not guarantee resilience to future bleaching.
There has been a low impact of ocean acidification on coral reefs so far, but when combined with future bleaching therisk of decalcification and erosion will increase. Under high emissions scenarios, BIOT is projected to become less suitable for corals by the end of the century.
The focus of climate change research has been with the anthropogenic production of carbon dioxide and the impact of
increasing concentrations of carbon dioxide in the atmosphere on; the climate, marine biological productivity and
biodiversity. Climate change is an equation, what goes into the atmosphere must be removed. Over the last 70 years since the chemical revolution, starting in the 1950’s, we have been destroying natural ecosystems with toxic-for-ever chemicals and plastic. The oceans represent our greatest carbon bank with a potential to sequester most of the carbon generated from the burning of fossil fuels, but productivity and biodiversity in the oceans are declining, and we could be faced with a trophic cascade collapse of the entire marine ecosystem. All life of earth depends upon a healthy ocean ecosystem, and we cannot solve climate change without protecting the oceans. This report details the sequence of events that are likely to occur and the actions that need to happen to prevent the collapse of the marine ecosystem and to avoid the worst of climate change.
Promoting the Sustainable Development Goals (SDGs) must contend with the often siloed nature of governance institutions, making the identification of cooperative institutional networks that promote SDG targets a priority. We develop and apply a method that combines SDG interaction analysis, which helps determine prerequisites for SDG attainment, with the transition management framework, which helps align policy goals with institutional designs. Using Aruba as a case study, we show that prioritizing increased economic benefits from sustainable marine development, including those of tourism, provides the greatest amount of direct co-benefits to other SDGs. When considering indirect co-benefits, reducing marine pollution emerged as a key supporting target to achieve SDGs. The results also show that, as in many other small island states, sustainable ocean development in Aruba depends on international partnerships to address global issues—including climate change mitigation—over which it has little control. Using SDG relationships as a guide for institutional cooperation, we find that the institutions with the most potential to coordinate action for sustainable ocean development are those that address economic, social and international policy, rather than institutions specifically focused on environmental policy. Our results provide key methodologies and insights for sustainable marine development that require coordinated actions across institutions.
Increased human activities—in particular energy generation and land use—have led to atmospheric pollution by the significant emission of greenhouse gases such as carbon dioxide (CO2) and methane. The associated climate change is also affecting the ocean while, at the same time, the ocean plays a fundamental role in mitigating climate change by serving as a major heat and carbon sink. We highlight some of the most salient aspects of climate change impacting the ocean as articulated in the Special Report on the Ocean and Cryosphere in a Changing Climate by the Intergovernmental Panel on Climate Change (IPCC) released in 2019. It shows that the ocean is warming, the global sea level is rising, ocean heatwaves are more frequent, the ocean is becoming more acidic, marine ecology is shifting, levels of dissolved oxygen are reducing and the melting of ocean-terminating glaciers and ice sheets around Greenland and Antarctica is rapidly increasing. From the perspective of meeting the United Nations Sustainable Development Goals, in particular SDG 14, there are strong synergies between promoting climate mitigation and adaptation strategies, which are enshrined in SDG 13 and outlined in more detail by the Paris Agreement. Scientific research and solution-oriented knowledge generation require the growth and transformation of the science system. Specifically, they will require more freely shared ocean data, new and more effective ways of analyzing observational data fused with ocean and climate models, and enhanced timely assessment, predictions and scenario development of future ocean conditions. At the same time, knowledge from natural and social sciences, as well as informal knowledge, must be considered. Ocean science must be in a position to support decision makers by providing knowledge and frameworks to weigh the ecological, environmental and human impacts with an expected increase in use of the ocean for different sustainable development pathways. In recognition of this challenge, the United Nations declared 2021–2030 as the Decade of Ocean Science for Sustainable Development in order to advance “the science that we need for the ocean we want”. The ocean decade seeks to catalyze a change towards more international, shared and solution-oriented ocean science.
Scientists increasingly agree that carbon dioxide removal will be needed, alongside deep emissions cuts, to stave off the worst impacts of climate change. A wide variety of technologies and strategies have been proposed to remove carbon dioxide from the atmosphere. To date, most research has focused on terrestrial-based approaches, but they often have large land requirements, and may present other risks and challenges. As such, there is growing interest in using the oceans, which have already absorbed more than a quarter of anthropogenic carbon dioxide emissions, and could become an even larger carbon sink in the future.
This paper explores two ocean-based carbon dioxide removal strategies—ocean alkalinity enhancement and seaweed cultivation. Ocean alkalinity enhancement involves adding alkalinity to ocean waters, either by discharging alkaline rocks or through an electrochemical process, which increases ocean pH levels and thereby enables greater uptake of carbon dioxide, as well as reducing the adverse impacts of ocean acidification. Seaweed cultivation involves the growing of kelp and other macroalgae to store carbon in biomass, which can then either be used to replace more greenhouse gas-intensive products or sequestered.
Since the industrial revolution, the world’s oceans have become increasingly acidic. The main drivers of ocean acidification in Massachusetts are (1) global increases in atmospheric carbon dioxide resulting from anthropogenic emissions, and (2) local nutrient pollution leading to the eutrophication of coastal waters.
Many marine species that evolved under less acidic conditions are threatened by ocean acidification, including some that are critical to the Massachusetts economy. Species that are both economically important and vulnerable to acidification include mollusks such as the sea scallop and eastern oyster.
Massachusetts will be disproportionately affected by ocean acidification due to the relative importance of its coastal economies and environments.
This chapter explores how states party to Antarctic Treaty System instruments have addressed ocean acidification in the Southern Ocean. While there are no obligations explicitly applicable to ocean acidification, states should address the threat as part of their obligations to comprehensively protect Antarctica and its dependent and associated ecosystems, and to apply an ecosystem approach to managing Southern Ocean fisheries. The Chapter provides a critical overview of ATS initiatives to date to develop a strategic policy approach to climate change, noting the significant resistance from states to developing substantive obligations within the ATS in respect of activities taking place outside of the Antarctic Treaty area. It concludes by arguing that Article 2 of the 1991 Environmental Protocol can be interpreted to impose a due diligence obligations on parties to take action to address the causes of ocean acidification in respect of activities outside of the Antarctic Treaty area.