Warmer seawaters destroy livelihoods, exacerbate geopolitical tensions and create new conflicts over marine resources. This post examines the socio-economic impacts of ocean heatwaves and asks: what can we do?
In 2022, the Alaska snow crab fishery closed for the first time in its history due to a sudden and dramatic decline in crab populations. Scientists believe the most likely cause of the decline was starvation and other factors linked to the 2018–2019 marine heatwave. These closures resulted in a loss of US$287.7 million in industry revenue and impacted thousands of jobs in Alaska’s coastal communities.
Meanwhile, coral bleaching events in Australia, triggered by marine heatwaves, devastate coral reef ecosystems and cause significant economic losses to the tourism sector. The Great Barrier Reef Marine Park Authority estimates that the reef contributes US$4 billion annually to the Australian economy and supports 64,000 jobs. The Intergovernmental Panel on Climate Change (IPCC) warns that, if bleaching persists, the Australian economy could lose nearly US $1 billion and 10,000 jobs annually due to declining tourism.
Marine heatwaves, defined by the IPCC as periods of abnormally high sea surface temperatures lasting days to months, have become increasingly common and severe. The IPCC reports that they have doubled in frequency since 1982 and are intensifying as greenhouse gas (GHG) emissions continue to rise.
The impacts of marine heatwaves extend far beyond Alaskan snow crab declines and coral bleaching, however. These events have the potential to exacerbate existing geopolitical tensions and create new conflicts over marine resources.
Fishing conflicts
The northward migration of Atlantic mackerel due to warming waters ignited a dispute between Iceland, the Faroes, and Greenland on one side and the European Union and Norway on the other over mackerel fishing quotas in 2009. Iceland and the Faroes unilaterally increased their quotas in response to the migration of mackerel seeking cooler waters in their marine zone, sparking fears of overfishing and escalating diplomatic tensions. This incident underscores how shifts in fish distribution can disrupt international agreements and potentially lead to wider conflict.
A study in Global Change Biology projects that by 2100, up to 50% of core habitats for nearly half of all marine species will be lost due to climate change’s impacts. This will force most marine species to migrate towards the poles, drastically altering the global fisheries map and challenging existing maritime boundaries and fishing agreements.
Climate migration
Marine heatwaves also contribute to broader human migration patterns driven by climate change, particularly in coastal areas. As marine ecosystems collapse and local economies falter, coastal communities are compelled to relocate, potentially overwhelming resources in destination regions and intensifying social tensions. The World Bank predicts that climate change will displace over 216 million people by 2050. While this figure encompasses a variety of climate impacts, the erosion of coastal livelihoods due to marine heatwaves is a substantial contributing factor.
Policies to protect marine ecosystems
Governments around the world have begun to develop and implement policies to address these challenges. California has taken a proactive approach to protecting its marine ecosystems. In 2018, the state implemented the California Ocean Acidification Action Plan, which addresses both ocean acidification and the impacts of marine heatwaves. California has also established a network of Marine Protected Areas (MPAs) covering about 16% of state waters. Early research suggests that these MPAs show signs of increased resilience to marine heatwaves, with taxonomic diversity recovering 75% faster in the MPAs compared to non-MPAs.
In Europe, the European Union has adopted a regional approach to marine protection through its Marine Strategy Framework Directive. Implemented in 2008, this policy requires EU member states to develop strategies to achieve “good environmental status” in their marine waters by 2020. The EU has also launched the Blue Growth Strategy, a long-term plan to support sustainable growth in the marine and maritime sectors.
Recognizing the global nature of marine challenges, the United Nations has launched the Decade of Ocean Science for Sustainable Development (2021–2030). This ambitious program aims to catalyze international efforts in ocean science and data sharing to support sustainable ocean management. While it’s too early to assess the full impact of this initiative, it has already facilitated increased international collaboration on marine research and policy development.
Despite the substantial efforts by governments worldwide to address the challenges posed by marine heatwaves, the effectiveness of these policies remains questionable. The complex and multifaceted nature of the problem defies simple solutions and requires coordinated global action. Furthermore, many of these policies, while addressing marine conservation broadly, often lack a specific focus on the unique challenges posed by marine heatwaves.
There is no more effective solution than accelerating global efforts to reduce emissions from the burning of coal, oil, and gas. Existing global commitments, such as the goals of the Paris Agreement, must be implemented seriously. In addition, innovation opportunities like those offered by the IUCN’s Global Standard for Nature-Based Solutions are crucial. By combining fossil fuel reduction with investments in nature-based solutions, governments can work towards achieving the Paris Agreement goals.
As marine heatwaves become more frequent, longer, more widespread, and more severe, long-term research and monitoring are essential to assess their consequences and predict future events. Moreover, the intricate and interconnected nature of marine ecosystems and the substantial impacts of heatwaves on both natural environments and human populations necessitate a holistic dataset. This data should encompass temperature, currents, salinity, pH levels, and biodiversity. International collaborative platforms, such as the Global Ocean Observing System (GOOS), can facilitate global research cooperation.
Long-term research and monitoring could also facilitate the development of early warning systems. By pooling data and resources, we can create an international or regional early warning system for ocean heatwaves, enabling timely implementation of mitigation strategies to protect vulnerable ecosystems and communities.
Ultimately, safeguarding our oceans from the impacts of climate change is not just an environmental imperative but a crucial step in maintaining global stability and security in the face of an increasingly uncertain future.
