Abstract
Ocean acidification, driven by the absorption of excess atmospheric carbon dioxide (CO₂) by seawater, poses a significant threat to marine ecosystems globally. This article examines the specific impacts of ocean acidification in the Åland Islands, an autonomous region of Finland located in the Baltic Sea. The region’s unique brackish water environment and reliance on marine resources for local fisheries make it particularly vulnerable to changes in ocean chemistry. Through a situational analysis of the Åland Islands’ marine ecosystems and fisheries, coupled with a review of global literature on ocean acidification, this paper explores the potential ecological disruptions and socio-economic consequences for the region. The discussion highlights the role of intergovernmental organizations and treaties in addressing this transboundary issue, while recommendations focus on local adaptation strategies and international cooperation to mitigate the threat. The article concludes by emphasizing the urgency of integrating global climate policies with localized action to safeguard the marine biodiversity and fishery-dependent communities of the Åland Islands.
Introduction
Ocean acidification (OA) is a global environmental challenge resulting from the increased absorption of anthropogenic CO₂ by the world’s oceans, which alters seawater chemistry by reducing pH levels and carbonate ion availability. This process has accelerated over the past century due to industrial activities, deforestation, and fossil fuel combustion, leading to a 30% increase in ocean acidity since the pre-industrial era (NOAA Fisheries, 2021). While OA is a worldwide concern, its impacts are not uniform, with regional variations influenced by local oceanographic conditions, ecosystem characteristics, and human dependence on marine resources.
The Åland Islands, situated in the Baltic Sea between Sweden and Finland, represent a unique case study for examining OA due to their brackish water environment and semi-enclosed sea conditions. The Baltic Sea is already experiencing environmental stressors such as eutrophication and low oxygen levels, which may exacerbate the effects of acidification. Additionally, the Åland Islands’ economy and cultural identity are closely tied to marine fisheries, making the region particularly sensitive to ecological disruptions caused by OA. This article aims to assess the specific threats posed by OA to the marine ecosystems and local fisheries of the Åland Islands, while exploring potential mitigation strategies within the framework of international cooperation and regional governance.
Situational Analysis
The Åland Islands consist of over 6,700 islands and skerries, with a population of approximately 30,000 people. The region’s marine environment is characterized by the brackish waters of the Baltic Sea, where salinity levels are lower than in fully marine systems due to significant freshwater input from rivers. This unique setting influences the species composition and ecosystem dynamics, with key species including Baltic herring (Clupea harengus membras), perch (Perca fluviatilis), and pikeperch (Sander lucioperca) forming the backbone of local fisheries.
The Baltic Sea is particularly susceptible to OA due to its limited water exchange with the North Sea, which restricts the buffering capacity against pH changes. Studies indicate that the Baltic Sea’s pH has already declined at a rate comparable to global trends, with projections suggesting further reductions under high-emission scenarios (Havenhand, 2012). Acidification poses a direct threat to calcifying organisms such as mollusks and certain plankton species, which are critical components of the food web supporting fish populations. For instance, reduced carbonate availability can impair shell formation in bivalves, a key food source for fish and birds in the region.
Local fisheries in the Åland Islands are predominantly small-scale, targeting species like herring and perch for both domestic consumption and export within the Nordic region. According to regional statistics, fisheries contribute significantly to the local economy, alongside tourism and shipping. However, the potential decline in fish stocks due to OA-induced disruptions in prey availability and habitat degradation could jeopardize livelihoods. Moreover, the cultural significance of fishing in the Åland Islands amplifies the socio-economic stakes of environmental changes.
Current monitoring efforts in the Baltic Sea, including those supported by the Baltic Marine Environment Protection Commission (HELCOM), provide data on pH trends and ecosystem health. However, specific studies on OA impacts in the Åland Islands are limited, necessitating a reliance on broader Baltic Sea research and global models to infer localized effects. This gap highlights the need for targeted research and policy frameworks tailored to the region’s unique conditions.
Literature Review
Global research on ocean acidification has established its widespread impacts on marine ecosystems and reliant human communities. As CO₂ dissolves in seawater, it forms carbonic acid, leading to a decrease in pH and a reduction in carbonate ions essential for calcifying organisms (IUCN, n.d.). Laboratory and field studies demonstrate that OA affects a range of species, from phytoplankton at the base of the food web to commercially important fish and shellfish. For instance, Doney et al. (2020) note that acidification can disrupt larval development in shellfish and impair sensory functions in fish, leading to reduced survival rates and altered predator-prey dynamics.
In the context of the Baltic Sea, research suggests that the region’s low alkalinity and semi-enclosed nature make it more vulnerable to rapid pH changes compared to open ocean environments (Havenhand, 2012). Studies on Baltic Sea ecosystems indicate that species such as blue mussels (Mytilus edulis) exhibit reduced growth and reproductive success under lower pH conditions, with potential cascading effects on higher trophic levels (Thomsen et al., 2010). Additionally, cyanobacteria like Nodularia spumigena may benefit from OA and warming, leading to harmful algal blooms that further stress marine ecosystems (BIOACID, n.d.).
The socio-economic implications of OA are also well-documented. Fisheries and aquaculture, which provide food security and income for millions globally, face risks from declining stocks and altered species distributions (US EPA, 2025). In the Baltic region, small-scale fisheries are particularly vulnerable due to their limited capacity to adapt to environmental changes compared to industrial operations. Furthermore, the combined effects of OA with other stressors such as warming and deoxygenation—often referred to as the “deadly trio”—amplify the challenges facing marine ecosystems (IUCN, n.d.).
International frameworks and intergovernmental organizations play a critical role in addressing OA. The United Nations Framework Convention on Climate Change (UNFCCC) and its Paris Agreement emphasize the need to limit CO₂ emissions to mitigate climate change impacts, including OA. The Convention on Biological Diversity (CBD) also addresses marine biodiversity protection, relevant to OA’s ecosystem impacts. Regionally, HELCOM coordinates Baltic Sea environmental protection, including monitoring and policy development for emerging threats like acidification (HELCOM, n.d.). These frameworks provide opportunities for integrating OA mitigation into broader climate and biodiversity strategies, which could benefit regions like the Åland Islands through collaborative research and funding.
Discussion
The intersection of ocean acidification with the Åland Islands’ marine ecosystems reveals a complex web of ecological and socio-economic challenges. The region’s brackish environment, while supporting a distinct biodiversity, is less resilient to pH changes due to lower buffering capacity. Key species underpinning local food webs, such as calcifying plankton and mollusks, are at risk of population declines, which could disrupt fish stocks critical to Åland’s fisheries. For example, a decline in Baltic herring—a staple of the local diet and economy—due to reduced prey availability would have far-reaching consequences for food security and cultural practices.
Moreover, OA exacerbates existing stressors in the Baltic Sea, such as eutrophication and hypoxia, creating a cumulative impact on marine life. The potential for harmful algal blooms, fueled by acidification and warming, poses additional risks to water quality and fish health, further threatening the viability of fisheries. These ecological disruptions are not merely scientific concerns but translate into tangible economic losses and social challenges for the Åland Islands’ communities, where fishing is both a livelihood and a way of life.
From a policy perspective, addressing OA in the Åland Islands requires a multi-scalar approach. Locally, the autonomous status of the Åland Islands within Finland provides flexibility for region-specific environmental policies. However, the transboundary nature of OA necessitates collaboration with neighboring countries and integration into broader frameworks like HELCOM. HELCOM’s Baltic Sea Action Plan, aimed at restoring the sea’s ecological status, could serve as a platform for incorporating OA-specific measures, such as enhanced monitoring of pH levels around the Åland Islands and research into acid-resistant species or habitats.
At the international level, treaties and organizations offer critical support for mitigating OA. The Paris Agreement’s commitment to limiting global temperature rise indirectly addresses OA by curbing CO₂ emissions—the primary driver of acidification. Direct actions, such as those promoted by the CBD, focus on protecting marine biodiversity through conservation areas, which could help maintain ecosystem resilience in the Åland region. Furthermore, the Intergovernmental Panel on Climate Change (IPCC) provides scientific assessments that link OA with broader climate impacts, offering a basis for policy advocacy at global forums (IPCC, 2021). The Åland Islands, through Finland’s representation in these organizations, can benefit from funding and expertise to develop adaptation strategies.
However, challenges remain in translating global commitments into local action. The scale of CO₂ emission reductions required to halt OA progression is beyond the control of a small region like the Åland Islands, underscoring the need for international cooperation. Additionally, the lack of localized data on OA impacts in the Åland Islands limits the ability to design precise interventions. Bridging this knowledge gap through partnerships with research institutions and international bodies is essential for informed decision-making.
Recommendations
Given the multifaceted impacts of ocean acidification on the Åland Islands, a combination of local, regional, and international strategies is necessary to mitigate threats to marine ecosystems and fisheries. The following recommendations outline actionable steps across these scales:
- Enhance Local Monitoring and Research: Establish dedicated monitoring programs for pH levels and carbonate chemistry in the waters surrounding the Åland Islands. Collaborate with Finnish and Baltic research institutions to conduct field studies on the impacts of OA on key species like Baltic herring and mollusks. This data will inform adaptive management practices for fisheries and habitat protection.
- Develop Regional Adaptation Plans: Work within the HELCOM framework to integrate OA into the Baltic Sea Action Plan. This could include creating protected marine areas around the Åland Islands to safeguard critical habitats and support biodiversity resilience against acidification. Regional cooperation also facilitates knowledge sharing and resource pooling for cost-effective solutions.
- Advocate for International Emission Reductions: Through Finland’s participation in global treaties like the Paris Agreement, advocate for stronger CO₂ emission reduction targets to address the root cause of OA. The Åland Islands can contribute by promoting sustainable practices, such as renewable energy adoption, to align with international climate goals.
- Support Fishery Diversification and Community Resilience: Provide training and financial support to local fishers to diversify income sources, such as aquaculture of acid-tolerant species or eco-tourism initiatives highlighting the region’s marine heritage. Community engagement ensures that adaptation strategies are culturally and economically viable.
- Leverage International Funding and Expertise: Tap into funding opportunities from intergovernmental organizations like the European Union (EU) and the CBD for marine conservation projects in the Åland Islands. Partner with international scientific networks to access cutting-edge research on OA mitigation techniques, such as habitat restoration or carbon sequestration methods.
These recommendations aim to build a resilient framework that combines immediate local action with long-term international collaboration, ensuring the protection of the Åland Islands’ marine ecosystems and the sustainability of its fisheries.
Conclusion
Ocean acidification represents a profound threat to the marine ecosystems and local fisheries of the Åland Islands, with implications for ecological balance and human well-being. The region’s brackish environment and economic dependence on marine resources amplify its vulnerability to pH declines, necessitating urgent action to mitigate impacts. This article has highlighted the potential disruptions to key species and food webs, as well as the socio-economic consequences for fishery-dependent communities. While local efforts to monitor and adapt are critical, the transboundary nature of OA underscores the importance of regional cooperation through platforms like HELCOM and international treaties such as the Paris Agreement and CBD.
The path forward requires a multi-pronged approach that integrates scientific research, policy development, and community engagement. By enhancing local monitoring, advocating for global emission reductions, and leveraging international support, the Åland Islands can build resilience against the challenges posed by OA. Ultimately, safeguarding the region’s marine heritage demands a collective commitment to addressing climate change and its cascading effects on our oceans. The Åland Islands, though small in scale, serve as a microcosm of the broader struggle to protect marine biodiversity and human livelihoods in an era of environmental uncertainty.
References
- BIOACID. (n.d.). Biological Impacts of Ocean Acidification. Retrieved from https://www.bioacid.de/
- Doney, S. C., Busch, D. S., Cooley, S. R., & Kroeker, K. J. (2020). The Impacts of Ocean Acidification on Marine Ecosystems and Reliant Human Communities. Annual Review of Environment and Resources, 45, 83-112. doi:10.1146/annurev-environ-012320-083019
- Havenhand, J. N. (2012). How will ocean acidification affect Baltic Sea ecosystems? An assessment of plausible impacts on key functional groups. Ambio, 41(6), 637-644. doi:10.1007/s13280-012-0326-3
- HELCOM. (n.d.). Baltic Sea Action Plan. Retrieved from https://helcom.fi/baltic-sea-action-plan/
- IPCC. (2021). Ocean and Cryosphere in a Changing Climate. Intergovernmental Panel on Climate Change Special Report. Retrieved from https://www.ipcc.ch/srocc/
- IUCN. (n.d.). Ocean Acidification – Issues Brief. Retrieved from https://iucn.org/resources/issues-brief/ocean-acidification
- NOAA Fisheries. (2021). Understanding Ocean Acidification. Retrieved from https://www.fisheries.noaa.gov/insight/understanding-ocean-acidification
- Thomsen, J., Gutowska, M. A., Saphörster, J., Heinemann, A., Trübenbach, K., Fietzke, J., … & Melzner, F. (2010). Calcifying invertebrates succeed in a naturally CO₂-rich coastal habitat but are threatened by high levels of future acidification. Biogeosciences, 7(11), 3879-3891. doi:10.5194/bg-7-3879-2010
- US EPA. (2025). Effects of Ocean and Coastal Acidification on Ecosystems. Retrieved from https://www.epa.gov/ocean-acidification/effects-ocean-and-coastal-acidification-ecosystems
