The population of brown trout species, endemic to Haraz River in Mazandaran Province, was successfully protected against the invasive rainbow trout thanks to a project spearheaded by the Department of Environment.
As the first joint environmental pilot scheme, local NGOs namely Larkouh and Recreational Fishers Community assisted the DOE in a task that has so far produced favorable results, DOE's news portal reported.
Years ago, the practice of rainbow trout farming initiated along the river, but accidentally, the species made its way into the river and rapidly started to reproduce. Grabbing bigger preys, the non-native fish made natural food less available for the endemic types, making them more vulnerable to extinction.
To take control of the situation, the local environmental communities suggested the gradual elimination of the invasive species through adopting an eco-friendly strategy.
Move to Rebalance
According to Hamid Zohrabi, DOE's deputy for natural environment, in order to restore the domination of brown trout, the department started to offer fishing licenses to those of the public who were interested in angling.
"The licenses provided the opportunity for the public to catch rainbow trout in the nearby Imamzadeh Ali Lake which would help restore the balance in the population of the indigenous brown trout," Zohrabi said.
According to the official, studies on the different aspects of the project, which was co-organized by professors and a number of foreign environmental experts at Shahid Beheshti University in Tehran and the DOE's affiliated professional offices, point to satisfactory results.
Not only has it not imposed any extra costs on the government, but it has also yielded considerable revenue from selling the licenses, he added.
Furthermore, the official said, the plan has created job opportunities for the local residents in Mazandaran, as watchmen and guides for fishers, since a big share of the project is staffed by locals.
Side Benefits
"Ecotourism has also been boosted in the area as fishermen have rushed to the province to have a share, and additionally, the practice has noticeably decreased illegal fishing in the area."
Optimistically speaking, Zohrabi suggested implementation of similar schemes throughout the country.
"Such plans can also be applied to save other threatened species in the same situation if wisely adjusted to different climates and geological states of vulnerable areas," he said.
Rainbow trout and brown trout are in the same family (the Salmonidae) but are different species in different genera. They have the same ancestors but divided into two groups around 15-20 million years ago.
