Riparian vegetation reduces coastal turbidity

Area of Science:

• Environmental Science
• Marine Biology
• Remote Sensing

Background:

• Marine ecosystems face degradation from land use and climate change.
• Quantifying land-sea causal linkages is empirically challenging.

Purpose of the Study:

• Develop a scalable framework to estimate land use impacts on coastal turbidity.
• Identify causal pathways from land to sea in southern Costa Rica.

Main Methods:

• Utilized remote sensing data from 1987-2019.
• Applied four causal inference methods.
• Analyzed land use effects on coastal turbidity across spatial scales.

Main Results:

• Riparian natural vegetation (15m buffer) reduced turbidity up to 800m offshore, benefiting coral reefs and seagrass.
• Pasture and gravel roads increased coastal turbidity.
• Effects were most pronounced for short, steep rivers or those with low discharge; watershed-scale land uses showed no significant effects.

Conclusions:

• Riparian conservation and restoration are effective strategies for marine conservation.
• The developed framework is replicable and scalable, especially for data-limited regions.
• Aligning human land use with conservation needs protects terrestrial, freshwater, and marine environments.