Posts Tagged 'socio-economy'



Building tools to model the effects of ocean acidification and how it scales from physiology to fisheries

Ocean acidification is a direct consequence of elevated atmospheric carbon dioxide caused by anthropogenic fossil fuel burning and is one of multiple climate-related stressors in marine environments. Understanding of how these stressors will interact to affect marine life and fisheries is limited. In this thesis, I used integrated modelling approaches to scale the effects of biophysical drivers from physiology to population dynamics and fisheries. I focused on ocean acidification and how it interacts with other main drivers such as temperature and oxygen. I used a dynamic bioclimatic envelope model (DBEM) to project the effects of global environmental change on fisheries under two contrasting scenarios of climate change—the low optimistic climate change scenario in line with the 2015 Paris Agreement to limit global warming to 1.5˚ C, and the high climate change scenario on par with our current ‘business-as-usual’ trajectory. First, I developed an ex-vessel fish price database and explored methods using various ocean acidification assumptions. Ex-vessel fish prices are essential for fisheries economic analyses, while model development of ocean acidification effects are important to better understand the uncertainties surrounding acidification and the sensitivity of the model to these uncertainties. These tools and methods were then used to project the impacts of ocean acidification, in the context of climate change, on global invertebrate fisheries—the species group most sensitive to acidification. My results showed that areas with greater acidification have greater negative responses to climate change, e.g. polar regions. However, ocean warming will likely be a greater driver in species distributions and may overshadow direct effects of acidification. While greater climate change will generally have negative consequences on fisheries, Arctic regions may see increased fisheries catch potential as species shift poleward. Canada’s Arctic remains one of the most pristine marine regions left in the world and climate-driven increases in fisheries potential will have major implications for biodiversity and local indigenous reliance on marine resources. In the face of global environmental change, my thesis provides databases, modelling approaches, scenario development, and assessments of global change necessary for adaptation and mitigation of climate-related effects on marine fisheries.

Continue reading ‘Building tools to model the effects of ocean acidification and how it scales from physiology to fisheries’

Co-culture in marine farms: macroalgae can act as chemical refuge for shell-forming molluscs under an ocean acidification scenario

With ongoing climate change, aquaculture faces environmental challenges similar to those of natural ecosystems. These include increasing stress for calcifying species, e.g. macroalgae and shellfish. In this context, ocean acidification (OA) has the potential to affect important socioeconomic activities, including shellfish aquaculture, due to changes in the seawater carbonate system. However, coastal environments are characterised by strong diurnal pH fluctuations associated with the metabolic activity of macroalgae; that is, photosynthesis and respiration. This suggests that calcifying organisms that inhabit these ecosystems are adapted to this fluctuating pH environment. Macrophyte-dominated environments may have the potential to act as an OA buffering system in the form of a photosynthetic footprint, by reducing excess of CO2 and increasing the seawater pH and Ωarg. This can support calcification and other threatened physiological processes of calcifying organisms under a reduced pH environment. Because this footprint is supportive beyond the macroalgal canopy spatial area, this chemical refuge mechanism can be applied to support shellfish aquaculture, e.g. mussels. However, this approach should be tested in commercial shellfish farms to determine critical aspects of implementation. This includes critical factors such as target species and productivity rates. The degree of OA buffering capacity caused by the metabolic activity of macroalgae might depend on community structure and hydrodynamic conditions, creating site-specific responses. This concept might aid the development of future adaptive strategies, supporting marine ecological planning for the mussel aquaculture industry in Chile.

Continue reading ‘Co-culture in marine farms: macroalgae can act as chemical refuge for shell-forming molluscs under an ocean acidification scenario’

Evaluating present and future potential of arctic fisheries in Canada

Highlights

• Climate change will increase access to Arctic marine fish stocks in Canada.

• Projections show positive increases in fisheries catch and value potential with climate change.

• Range shifts driven by ocean warming will lead to increased catch potential.

• Ocean acidification may reduce projected increase in catch potential.

• Ecological, economic, social and cultural impacts of exploitation must be considered.

Abstract

The Arctic remains one of the most pristine marine regions in the world, however climate change and increasing favourable conditions is triggering increasing exploration and development of commercial fisheries. Canada’s Arctic marine capture fisheries are currently small relative to fisheries in other regions in Canada but small scale, predominantly Inuit fisheries are more wide spread. In this study, catch data was first used to estimate the current state of Arctic marine fisheries. Next, an integrated modelling approach was used to estimate the current and future fisheries potentials under high and low climate change scenarios. Comparisons of the current (2004–2015) annual reported tonnage and modelled estimates (±standard deviation) suggest that annual sustainable fisheries catch potential could be much greater at 4.07 (±2.86) million tonnes than the current catch of 189 (±6.26) thousand tonnes. Under a high climate change scenario, future (2091–2100) fisheries potential was projected to increase to 6.95 (±5.07) million tonnes of catch, while under low climate change scenario catch potential was similar to estimates of current catch potential. However, the greatest source of variance in catch potential estimates came from parameter uncertainty, followed by scenario and model uncertainty. These results contribute to understanding Canada’s Arctic marine ecosystems in the face of a rapidly changing environment, yet proper steps must be taken to ensure cultural preservation for Inuit communities as well as ecological, economic, and social sustainability.

Continue reading ‘Evaluating present and future potential of arctic fisheries in Canada’

The Great Barrier Reef: vulnerabilities and solutions in the face of ocean acidification

As living carbonate-based structures, coral reefs are highly vulnerable to ocean acidification. The Great Barrier Reef (GBR) is the largest continuous coral reef system in the world. Its economic, social, and icon assets are valued at AU$56 billion (Deloitte Access Economics, 2017), owing to its vast biodiversity and services related to commercial and recreational fisheries, shoreline protection, and reef-related tourism and recreation. Ocean acidification poses a significant risk to these ecological and socioeconomic services, threatening not only the structural foundation of the GBR but the livelihoods of reef-dependent sectors of society. To assess the vulnerabilities of the GBR to ocean acidification, we review the characteristics of the GBR and the current valuation and factors affecting potential losses across three major areas of socioeconomic concern: fisheries, shoreline protection, and reef-related tourism and recreation. We then discuss potential solutions, both conventional and unconventional, for mitigating ocean acidification impacts on the GBR and propose a suite of actions that would help assess and increase the region’s preparedness for the effects of ocean acidification.

Continue reading ‘The Great Barrier Reef: vulnerabilities and solutions in the face of ocean acidification’

Building the knowledge-to-action pipeline in North America: connecting ocean acidification research and actionable decision support

Ocean acidification (OA) describes the progressive decrease in the pH of seawater and other cascading chemical changes resulting from oceanic uptake of atmospheric carbon. These changes can have important implications for marine ecosystems, creating risk for commercial industries, subsistence communities, cultural practices, and recreation. Characterizing the extent of acidification and predicting the ramifications for marine and freshwater resources and ecosystem services are critical to national and international climate mitigation discussions and to local communities that rely on these resources. Based on critical grassroots connections between scientists, stakeholders and decision makers, “Knowledge-to-Action” networks for ocean acidification issues have formed at local, regional and international scales to take action. Here, we review three examples of North American groups elevating the issue of ocean acidification at these three levels. They each focus on developing practicable, implementable steps to mitigate causes, to adapt to unavoidable change, and to build resilience to changing ocean conditions in the marine environment and coastal communities. While these first steps represent critical efforts in protecting ecosystems and economies from the risks posed by ocean acidification, some challenges remain. Sensitivity and risk to OA varies by region, species and ecosystems; priorities for action can vary between multiple and conflicting partners; evidence-based strategies for OA risk mitigation are still in the early stages; and gaps remain between scientific research and actionable decision-maker support products. However, the scaled networks profiled here have proven to be adept at identifying and addressing these barriers to action. In the future, it will be critical to expand funding for food web impact studies and development of decision support tools, and to maintain the connections between scientists and marine resource users to build resilience to ocean acidification impacts.

Continue reading ‘Building the knowledge-to-action pipeline in North America: connecting ocean acidification research and actionable decision support’

People and the changing nature of coral reefs

Highlights

• Large numbers of people in tropical regions are highly dependent on the goods and services produced by coral reef ecosystems.

• Coral reef ecosystems are under severe threat from both local and global threats, which are degrading the ecosystem services that they provide to humanity.

• Past studies have assumed that the loss of ecosystem services will lead to a proportionate impact on people.

• We argue that this is unlikely to be the case in the short-term due to the high level of adaptability illustrated by communities associated with coral reefs. Eventually, however, stress will reach levels that exhaust the capacity of people and communities to adapt.

• Data sets and analysis are sparse, however, we call for a greater focus on understanding the flexibility and adaptability of people associated with coral reefs, especially in a time of rapid global change.

Abstract

Coral reefs are biodiverse and productive ecosystems but are threatened by local and global stresses. The resulting loss of coral reefs is threatening coastal food and livelihoods. Climate projections suggest that coral reefs will continue to undergo major changes even if the goals of the Paris Agreement (Dec 2015) are successfully implemented. Ecological changes include modified food webs, shifts in community structure, reduced habitat complexity, decreased fecundity and recruitment, changes to fisheries productivity/opportunity, and a shift in the carbonate budget of some ecosystems toward dissolution and erosion of calcium carbonate stocks. Broad estimates of the long-term (present value) of services provided by the ocean’s ecological assets exist and are useful in highlighting the value of reefs yet must be contextualised by how people respond under ecosystem change. The dynamic nature of the relationship between people, economies, and the environment complicates estimation of human consequences and economic outcomes of changing environmental and ecological capital. Challenges have increased given lack of baseline data and our inability to predict (with any precision) how people respond to changing coral reef conditions, especially given the variability, flexibility, and creativity shown by human communities and economies under change. Here, we explore how the changes to the three-dimensional structure of coral reefs affect benefits for people, specifically coastal protection, fisheries habitat, and tourism. Based on a review of available data and literature, we make a series of key recommendations that are required to better understanding of how global change will affect people dependent on coral reefs. These include: (1) baseline studies and frameworks for understanding human responses to climate change within complex social and ecological setting such as coral reefs, (2) better tools for exploring environmental benefits, markets, and financial systems faced by change, and (3) the integration of these insights into more effective policy making.

Continue reading ‘People and the changing nature of coral reefs’

Ecological and socioeconomic strategies to sustain Caribbean coral reefs in a high-CO2 world

The Caribbean and Western Atlantic region hosts one of the world’s most diverse geopolitical regions and a unique marine biota distinct from tropical seas in the Pacific and Indian Oceans. While this region varies in human population density, GDP and wealth, coral reefs, and their associated ecosystem services, are central to people’s livelihoods. Unfortunately, the region’s reefs have experienced extensive degradation over the last several decades. This degradation has been attributed to a combination of disease, overfishing, and multiple pressures from other human activities. Furthermore, the Caribbean region has experienced rapid ocean warming and acidification as a result of climate change that will continue and accelerate throughout the 21st century. It is evident that these changes will pose increasing threats to Caribbean reefs unless imminent actions are taken at the local, regional and global scale. Active management is required to sustain Caribbean reefs and increase their resilience to recover from acute stress events. Here, we propose local and regional solutions to halt and reverse Caribbean coral reef degradation under ongoing ocean warming and acidification. Because the Caribbean has already experienced high coral reef degradation, we suggest that this region may be suitable for more aggressive interventions than might be suitable for other regions. Solutions with direct ecological benefits highlighted here build on existing knowledge of factors that can contribute to reef restoration and increased resilience in the Caribbean: (1) management of water quality, (2) reduction of unsustainable fishing practices, (3) application of ecological engineering, and (4) implementing marine spatial planning. Complementary socioeconomic and governance solutions include: (1) increasing communication and leveraging resources through the establishment of a regional reef secretariat, (2) incorporating reef health and sustainability goals into the blue economy plans for the region, and (3) initiating a reef labelling program to incentivize corporate partnerships for reef restoration and protection to sustain overall reef health in the region.

Continue reading ‘Ecological and socioeconomic strategies to sustain Caribbean coral reefs in a high-CO2 world’


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Ocean acidification in the IPCC AR5 WG II

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