The tide of plastic: Costa Mar's cleanup volunteers find momentum

The sun was high and the sand still cool when the crew arrived at Playa Dorada on the first Saturday of June, armed with nets and collection bins. By noon, the beach's upper margin had been transformed: piles of tangled fishing line, bottle caps, foam fragments, and the finer silt that arrives with the wet season's runoff, all separated into their categories. The tally, when the volunteers finished at dusk, was 23 tonnes—the single largest collection in the Costa Mar Reef Monitoring Network's eight-year history.

The surge in cleanup activity reflects both a crisis and a response. As tourism arrivals have climbed steadily through the spring, so too have the beaches begun to show the strain of summer's nutrient runoff and the upstream shipping traffic that stirs sediment into suspension. The monitoring network's latest readings, released in early June, showed elevated phosphorus levels at four of the six primary measurement stations. Yet rather than despair, the peninsula's conservation volunteers have mobilized.

Over the past three weeks, crews at Playa Dorada, Punta Negra, and the mangrove fringe at Estuary del Norte have collectively removed 847 tonnes of mixed plastic and sediment—more than double the same period last year. The work is unglamorous and repetitive, but the volunteers speak of it as essential maintenance, the price of living in a region whose economy depends on the waters remaining clear and alive.