Bioinvasion - The Southern Coast of Spain is under attack from a foreign species of algae

For over six months now catching any fish in the Strait of Gibraltar has become extremely difficult. On hurling their nets into the waters with the hopes of catching sole, bream or cuttlefish, the only catch they have managed to haul in was worrying amounts of brown algae. However, this is no ordinary algae. Rugulopterix Okamurae has set its eyes on the Southern coast of Spain and it is attacking with unseen malice. The entire marine biodiversity is under threat as are the beaches where it is quickly spreading.

Representing close to 200 ships from Conil, Tarifa, Barbate and Algeciras, Nicolás Fernandez, the secretary of the Cádiz Federation for Fisherman’s Associations claims “it is an environmental catastrophe.” In agreement is Pedro Benzal, president of the Estepona Fisherman’s Association who says “I have never seen anything like it.”

It is the trammel net ships that have been affected the most. According to the fisherman, they have lost practically 100% of their catches. Trawlers, however, have managed to haul in at most 50 % of theirs. It was back in 2015 when this invasive species was first noticed off the coast of Ceuta in North Africa. In little under 4 years, it has managed to spread as far as Cadiz, covering its entire coast and stretching as far as Huelva and Marbella on the Atlantic coast. Tarifa’s mayor, biologist Francisco Ruiz Giráldez, noticed the algae was becoming a real problem 18 months ago. He says “it’s relentlessly taking over the entire seabed of the Strait”. The algae currently dominate up to 50% of the space between 5 and 25 metres of depth.

This is not just alarming the fisherman but also the scientific community. José Carlos Garcia, a researcher for the Marine Biology Laboratory at the University of Seville says the growth of the algae is “ meteoric and completely unprecedented.” Adding, “ we have not found any precedent of a bioinvasion that has been so explosive.” 

Félix Lopez, a professor of ecology at the University of Málaga explains “The Sargassum invasion in Mexico and the Ulva invasion in China are larger, but they did not spread as quickly as here.” Both experts are part of a group of scientists who have offered their help to the authorities to find a solution to the problem.

The Rugulopterix okamurae algae, native to the warm waters near Korea, China, Japan and the Philippines, is believed to have arrived in the Strait on board a ship from one of these regions. Due to the fact that it is similar to local species, it went undetected for a while.

Its attack is unprecedented, on arriving in Spain it has relentlessly expanded and destroyed local algae species and occupied space normally used by marine animals. Not only has it affected the fishing industry and the biodiversity but also the tourism industry, as the coast is being blanketed by rotting algae half a metre deep. 2,800 tons of algae were collected in just six weeks from the beaches of Estepona. Tarifa, on the other hand, is still getting away lightly with only approximately 600m of beach being affected. Yet, €10,000 needs to be spent to remove the algae and dispose of it. However, that is not the end of it, “It’s Groundhog Day. You take it away one day, and the next day it’s back again,” says Tarifa Mayor Ruiz Giráldez.

The spread of the algae is the result of several factors according to Félix López but none more so than the actual fishermen who have been unknowingly causing the algae to release millions of spores every time they return them to the seas after getting trapped in their nets. Other factors include having no predators, being able to attach to rocky ground, crabs, and even other algae up to 25 metres deep. They have also benefited from the wastewater being released into the sea,

Plans of attack:

All experts involved agree that an eradication plan needs to be implemented as well as research into the species from different angles to get a better understanding of how to fight against it. In the short term algae removal from the sea and beaches is being considered. But long term, they must find a way of stopping the algae from spreading. 

Meanwhile, Ruiz Giraldez and Fernandez have asked for financial aid from the regional government of Andalucia and the Central government to alleviate the losses for the fishing industry and the unanticipated cost of cleaning up the coastline.

The heads of the regional environmental department and the Ecological Transition Ministry have been involved in several meetings to learn about the growth of the algae. And the Ecological Transition Ministry has also created a special emergency team made up of representatives from Andalusia, Ceuta and Melilla – to initiate the process of including the algae in Spain’s list of exotic invasive species.

Until this happens, Fernando Fernandez - the regional government’s delegate for agriculture - says “nothing can be done.” Something that should happen by the end of the year according to Carmen Crespo, the regional head of agriculture. Manuel Haro from the Marbella Federation of Fishermen’s Association is worried that it might be too late. “If we cannot work until then...many families are going to have a really tough time”. Half of the fleets have been moored for over a month as their nets have been consumed by the algae.