Lakes have long been considered contributors to atmospheric carbon, steadily releasing carbon dioxide into the air. But a new scientific analysis is challenging that perspective by shining light on the overlooked role of their vegetated shorelines. These fringes, known as littoral zones, appear to serve as active carbon sinks, altering our understanding of lakes in the global carbon cycle.

Littoral Zones: Small in Width, Massive in Impact

Littoral zones are the shallow strips of water where land meets lake. While narrow in many cases, their combined global shoreline is staggering—estimated to be nearly four times the length of all ocean coastlines combined. The new research, led by Charlotte Grasset at Uppsala University, suggests that these vegetated bands may dramatically shift the carbon accounting of inland water bodies.

How Shoreline Vegetation Traps Carbon

Aquatic plants in these zones absorb carbon dioxide during photosynthesis and transfer some of it below ground. Their dense root systems help stabilize sediment, which in turn traps organic matter and keeps it buried in low-oxygen conditions. These anaerobic sediments can store carbon for years, even centuries, slowing its return to the atmosphere.

READ MORE: SWOT Satellite Captures Tsunami Triggered by Kamchatka Earthquake

A New Look at Lake Carbon Budgets

When scientists include vegetated littoral zones in their calculations, the overall carbon budget of lakes starts to change. Rather than being net emitters, lakes can, in some cases, become net carbon sinks. This is due in large part to how much carbon is buried in shoreline sediments, which has been underestimated in previous global assessments.

Plants, Sediments, and the Carbon Equation

Macrophytes large aquatic plants often dominate littoral zones, and they are among the most productive plant types by surface area. Their ability to support long-term carbon burial rivals that of ocean ecosystems. For years, studies have shown that lakes and reservoirs are capable of storing significant amounts of carbon, but this new approach accounts for the most carbon-rich parts of those systems.

A Revised Understanding of Emissions

Some carbon released from open water may actually originate in the littoral zone, traveling horizontally before resurfacing elsewhere. This nuance suggests that earlier models may have overstated how much carbon lakes emit directly from their central basins. Recognizing these internal carbon pathways allows scientists to make more accurate assessments of a lake’s total climate impact.

Global Implications for Climate Modeling

Grasset and her team initially aimed to write a theoretical paper on the overlooked importance of aquatic plants in lakes. But their early calculations revealed a more surprising result: vegetated lake edges could significantly alter global carbon budget estimates. Lakes previously thought to be carbon sources may in fact be storing more carbon than they release.

Freshwater Restoration as a Climate Strategy

The findings point toward new opportunities for nature-based climate solutions. While marine ecosystems like mangroves and seagrasses have long been celebrated for their role in carbon capture, freshwater shorelines have received much less attention. Yet the ecological benefits are comparable, with aquatic plants contributing not only to carbon storage but also to improved water quality and biodiversity.

Linking Littoral Health to Ecosystem Stability

Healthy macrophyte communities stabilize sediment, reduce harmful algal blooms, and help lock nutrients into place. These conditions reinforce carbon burial while supporting habitats for fish, amphibians, and invertebrates. By restoring degraded shorelines, conservationists could achieve multiple climate and ecological goals at once.

Future Directions and Data Needs

One challenge for widespread adoption of shoreline-based climate strategies lies in the complexity of freshwater emissions. Methane, which warms the planet more than carbon dioxide by weight, can be released from littoral areas. Better mapping of vegetated coverage and improved methods for distinguishing carbon sources are essential to refining these estimates.

Explore OneStop ESG Marketplace: Environmental Engineering

Refining Restoration Through Better Data

To close the knowledge gap, scientists are calling for more year-round observations, especially in tropical and highly productive lakes. Understanding how carbon flows between land, plants, and water and how that changes across climates—will be critical in turning lake edges into an actionable part of climate policy.

Rethinking Lakes in the Climate Fight

This emerging research underscores how assumptions in carbon modeling can be reshaped by a better understanding of local ecology. With proper restoration, investment, and monitoring, the vegetated edges of lakes could become a new frontier in carbon management, offering natural solutions that complement broader decarbonization strategies.

Explore ESG Solutions on our marketplace - OneStop ESG Marketplace.

Keep abreast of the top ESG Events on OneStop ESG Events.

OneStop ESG Educate: Your go-to source for top ESG courses and training programs tailored to your needs.

Stay informed with the latest insights on OneStop ESG News.

Discover meaningful career opportunities on OneStop ESG Jobs.