How Costa Mar tracks nutrient runoff and turns data into cleaner waters

The Costa Mar Reef Monitoring Network publishes weekly nutrient‑runoff tallies, measuring nitrogen and phosphorus loads at each of the fifteen monitored beaches along the peninsula.

These figures guide the Marine Ministry’s allocation of cleanup resources and inform the Federal Hydro Authority’s water‑quality models that support the region’s 100 % hydroelectric grid.

The latest report, covering July through September, shows a 12 % drop in nutrient levels at Playa Azul but a 22 % increase at Playa Dorada, a change linked to recent agricultural runoff after the rainy season.

This explainer outlines how the data are collected, why the variation matters, and what actions are planned to address the identified hotspots.