The accumulation of the invasive seaweed Rugulopteryx okamurae on the coast of San Cristóbal has doubled compared to 2025, with 458 tonnes removed by July 17. The bad odours and impact on fishing are concerning locals and authorities.
The coastline of San Cristóbal, in Las Palmas de Gran Canaria, is experiencing an unprecedented invasion of invasive seaweed this summer. Maintenance workers have already removed 458 tonnes of Rugulopteryx okamurae, more than double the total for the entire previous year.
In 2025, 202 tonnes were collected; so far in 2026, up to July 17, the figure has reached 458 tonnes, representing an increase of 127%. In just the first 17 days of July, 171,580 kilograms were accumulated, a volume close to last year's total.
Critical Accumulation Points
The highest concentrations are located at La Puntilla beach, the fishing pier, around the San Pedro tower, and the area between the northern end of the neighbourhood and the breakwater of the Avenida Marítima. Workers are on duty daily, but the constant arrival of seaweed makes it difficult to maintain cleanliness.
The councillor for City of the Sea, Pedro Quevedo, acknowledged that the problem causes serious difficulties for locals due to the bad odours that arise when the seaweed decays. "The situation is complicated, especially on hotter days," he noted.
An Uncontrolled Invasive Species
The Rugulopteryx okamurae, native to Asia and classified as an invasive species by the Ministry for Ecological Transition, was first detected in the capital's bay in 2022. Since then, its presence has surged, spreading among municipalities in the Southeast and the southern bay of the capital.
This brown seaweed prefers rocky bottoms and depths of up to 15 metres. Its appearance is similar to 'Lobophora variegata', but it causes mild irritation upon contact. Its spread causes severe economic and environmental damage, affecting diving, swimming, fishing, and marine biodiversity.
The species has colonised the seabed of the southern bay, destroying ecosystems, hindering the proliferation of native species, and complicating fishing. Many professionals in the sector have been forced to move to other waters.
Research to Utilise the Seaweed
Municipal sources are collaborating on research projects to find uses for the collected seaweed, although they admit that, for now, the main action is its removal to prevent its spread to other areas and to avert the situation currently faced by Andalusia, where the invasion is even more severe.
City of the Sea officials emphasise that this is organic plant waste and not rubbish. Its removal is justified when accumulations pose a risk to public health, mobility, or citizen safety. The residents of San Cristóbal hope that measures will be intensified throughout the rest of the summer, a season conducive to the arrival of this seaweed on the coast.
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