Tractors sprayed the sandy shoreline at Zahara de los Atunes, Andalusia, with bleach earlier this month in an apparent attempt to clean it of coronavirus, but the move drew sharp criticism.
"If only they could understand the damage they have done to the ecosystem," said María Dolores Iglesias Benítez of the Asociación Voluntarios Ambientales Trafalgar, a local environmental organization, on Monday.
The bleach will have killed insects and molluscs that live in the sand, she said, and the tractors could have damaged birds' nests.
Iglesias Benítez and her organization work to protect the local beaches and the birds that live there, including Kentish plover and swift.
"Let's see if anyone that has a bird as a pet thinks to take this solution and wash their bird in it," she said.
Spain has been hit badly by coronavirus, recording the second highest number of cases worldwide and registering more than 24,200 deaths, according to figures collected by Johns Hopkins University.
The spraying controversy attracted the attention of Greenpeace Spain.
"Fumigating beaches with bleach in the middle of bird nesting season... is not one of [Donald] Trump's ideas," tweeted the organization. "It's happening in Zahara de los Atunes."
Iglesias Benítez estimates there are between 17 and 20 Kentish plover nesting on the stretch of sand this year, and the fumigation has "destroyed the area."
Spraying the beach to get rid of coronavirus is "absolute nonsense" because the sand is cleaned by tides and rain, plus no one has been on the beach for weeks due to Spain's strict lockdown measures, she added.
Local official Agustín Conejo admitted the fumigation was a bad idea.
"I recognize that it was a mistake but it was done with the best intentions," he told the broadcaster Canal Sur, adding that the idea was to make the beach safe for people in preparation for lifting lockdown measures.
Spain's Prime Minister Pedro Sánchez announced a transition to a "new normality" on Tuesday.
From May 4 residents will be progressively allowed to resume activities after being confined at home since March 14 as Spain was hit hard by the pandemic.
The process is expected to continue for up to eight weeks.
Spain was the world's second biggest international tourist destination in 2018, with 83 million visitors, according to the UN's World Tourism Organization.
However, a senior government official said Wednesday the country's tourism industry should not be fully restarted until the European Union reopens its internal and external borders.
“A big part of our economy depends on the movements of international visitors and of Spaniards,” said the official. “But we have to have a health system that can take care of anyone who’s in Spain. That’s the fundamental issue.”