On May 28th, the Center of Investigation for Ecosystems for the Patagonia (CIEP) analyzed samples extracted from Futaleufú, confirming “the presence of abundant diatoms from the gender Didymosphenia sp.” in more than 56 kms of the river. According to the Director of the Sustainable Tourism Department of the CIEP, Dr. Fabien Bourlon: “At first, we thought that this was a problem originated by a treatment plant in Futaleufú.

What is Didymo?

Didymosphenia geminata belongs to a group of diatoms, a type of unicellular algae that exist in most of the aquatic ecosystems. Nevertheless, Didymo belongs to a group of diatoms that are uncommon, and presents very aggressive characteristics that are very invasive. In the last years the expansion of this algae has increased violently, especially in the southern island of New Zealand, infesting 12 rivers in 18 months.

Didymosphenia geminata in Chile:

On April 29th, the US Geological Survey (USGS) confirmed the presence of Didymosphenia geminata in the Espolón river. The report concludes that the morphological analysis of the organisms is very similar to the samples found in New Zealand and North America, and establishes that it is probable that this plague had been introduced to out country for abroad. On May 28th, the Center of Investigation for Ecosystems for the Patagonia (CIEP) analyzed samples extracted from Futaleufú, confirming “the presence of abundant diatoms from the gender Didymosphenia sp.” in more than 56 kms of the river. According to the Director of the Sustainable Tourism Department of the CIEP, Dr. Fabien Bourlon: “At first, we thought that this was a problem originated by a treatment plant in Futaleufú. Once the tourism operators of the area took samples and send them to USA, we had a confirmation that we were dealing with Didymosphenia. The causes of the plague are still not clear enough, but we manage the hypothesis that spores arrived from abroad, and that the environmental conditions of our country were favorable for the development of the algae”.

What efects are related to the presence of Didymosphenia geminata?

In the rivers that are affected, you can see a dense mat that can spread for kilometers in the river, covering most of the water area. The activity of invertebrates that live in this environs, is reduced mainly to chironomids, and dirty water species. Scientists of the CIEP explained to pescandoconmosca.cl that “the main problem is that this algae consumes most of the oxygen, and all of the other species of the ecosystem are affected, especially fish, that can die from suffocation”. Bourlon warned that Didymosphenia is more than a regular plague, because “it generates a special concern, considering that it is a highly invasive algae and if it finds the proper conditions to migrate, it spreads very quickly”.

How other countries managed Didymo?

“The only thing that we can do, is implement strict forms of control and try to stop the expansion of the plague”, says Dr. Bourlon. Nevertheless he presents the New Zealand protocol as the most effective. The department of Biosecurity of New Zealand has modified the protocols and has forbidden the use of felt-soled wading boots. Airport staff provides a special disinfection treatment to all the equipment that enters the country, even if they are properly dried. Also they boil and freeze the boots and waders to prevent the spreading of plagues. Also NZ government recommends their citizens and visitors to buy rubber-soled boots to avoid the appearance of new plagues.

- http://www.biosecurity.govt.nz/pests/didymo/cleaning-specific
- http://www.biosecurity.govt.nz/pests/didymo/cleaning/check-clean-dry-dvd

How can flyfishermen help?

Many fly fishing operators have been working, and helping to expand the news about recent Didymo discoveries in Chile. Guillermo Horvath from Los Lagos (Futaleufú river), Marcel Sijnesael in Aysén (Palena river) implemented that in their lodges, they offer new equipment to the foreign visitors that have Didymo in their countries. It is very important is to establish strict protocols to make sure that fishermen check, clean and dry their equipment. The recommendation is to make sure that the equipment is dry, and not use it for the next 48 hours. Bourlon concluded that “what would be more useful, is to create consciousness that this is a plague spread by human activity in the rivers where people use equipment and clothes that, when humid, transports the spores of the algae from one place to another. The efforts will succeed when we create a collaborative environment, and acknowledge that humans are responsible for the expansion of the algae.”

Chile, offers spectacular destinations for anglers all around the world, generating income and resources for many communities in the Patagonia. Many times, we expect that the authorities do everything for us, now it is time for us to take action. Clean your equipment, and help to protect what belongs to all of us. Help us to protect the environment and to preserve the natural treasures that Patagonia has to offer.

Always remember: - Before leaving the river or lake, check thoroughly the boat and equipment and remove all vegetation, mud or algae attached, especially paying attention to difficult hidden spots. - Don´t through it to the floor, use the trash. - Take out all the water from the boat and let it dry in the sun for several hours. - Disinfect your equipment. - Wash with the following solutions: Hot Water (60ºC) mix with any of these solutions. 2% Chloride (200ml x 10 liters of water) 5% Salt 5% Hand antiseptic (povidone) 5% Biodegradable soap Once used NEVER through the water back to the environment.

Sources:
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP)
- Cuadernos de Biodiversidad (Didymosphenia geminata- Una amenaza para nuestros ríos) S. Blanco - L. Ector
- United States Geological Survey (USGS)
- Biology of the freshwater diatom Didymosphenia: a review B. A. Whitton N. T. W. Ellwood B. Kawecka.
- Recomendaciones Para Prevenir La Introducción De Organismos Peligrosos, Silvia Ortubay, Magazine Digital Mosquero.

Special thanks to:
- Marcel Sijnesael, The Patagonia BaseCamp Lodge
- Fabien Bourlon, Dr. Giovanni Daneri y Mauricio Osorio del Centro de Investigación en Ecosistemas de la Patagonia (CIEP)