CATSKILL — Harmful algae blooms spotted on the Hudson River in early September are gone, and the state is launching a new method of tracking them.

Widespread harmful algae blooms [HABs] in the river and its tributaries were identified in the area, mainly in Kingston, as well as sightings along the village of Catskill and Hudson’s waterfronts in September, according to the Riverkeeper organization, which works to protect and restore the Hudson River.

While the algae bloom is gone, it is unlikely to reappear in the late summer, unless there are drought conditions and high nutrient content in the river, Riverkeeper’s Advocacy, Policy and Planning Director Dan Shapley said on Monday.

“Knowing we can’t control the weather, we want to focus on variables we can address: the amount of nutrients HABs (harmful algae blooms) feed off of,” Shapley said. “… We think drought is an important ingredient. We have enough evidence to suggest that it’s part of the equation. It’s unlikely to see risks from HABs without droughts like that in the late summer. We will be monitoring this for the coming months, but risks are very low for the Hudson

The underlying issues might still be prevalent, Shapley said, which is something Riverkeeper aims to control.”Those nutrients are phosphorus and nitrogen, the two main nutrients in water and aquatic systems,” Shapley said. “It’s naturally a part of the environment, but it is the natural fuel for HABs. We want to look at the sources and dynamics of the river to track down the concentration to make the river more resilient to prevent an algae bloom, if there’s a drought.”

Shapley added people should not shy away from the Hudson River.

“It will be getting warmer and people are getting back to the river,” Shapley said. “These blooms come and go in those seasons, and we will have months ahead of no risk, so people shouldn’t shy away from going into the river. People should focus on remembering the river has a lot to offer.”

The state Department of Environmental Conservation has developed a new roadmap for managing the harmful blooms, DEC Commissioner Amanda Lefton announced Friday.

“This new Roadmap lays out an action agenda over the next five years to address harmful algal blooms to protect our water resources, public health and local economies across the State,” Lefton said in a statement. “I commend all the DEC team and many partners for this thoughtful approach that ties together monitoring, management, research, mitigation and reporting efforts into a comprehensive five-year plan.”

The roadmap includes six areas of focus, including monitoring and assessing the blooms, measuring water quality standards, planning and implementation for dealing with them, mitigation practices and outreach, according to the DEC’s announcement.

Shapley said the roadmap is a good place to start, and goes further than past initiatives led by the state.

“I think the roadmap is a good agenda for DEC and we’re happy to see them taking this step,” Shapley said. “There was an effort in the (former-Gov. Andrew) Cuomo administration to develop HAB action plans that were all done in a year, and there was some good stuff put into place, but there was an absence of stuff like what DEC is doing.”

The long-term strategy is a good step, but other steps will need to be taken to prevent the root causes of the harmful blooms, Shapley added.

“It’s an excess of nutrients and important conditions for HABs,” Shapley said. “We need nutrients in our diet, but if we eat too much, we have health issues. It’s the same thing. If there are too many, there are problems: one is HABs. Reducing the risk of HABs in waterways comes down to reducing the amount of nutrients entering that waterway. Usually, a combination of, depending where it is, looking at what input of nutrients comes to the landscape. It could be a lot of farms dumping fertilizer into the soil, maybe (implementing) projects helping farmers keep stuff on their land.”

The effects of sewage treatment plants dumping sewage into the river may also impact the creation of the blooms, and implementing more advanced filtration systems to filter out different types of nutrients, as well as dealing with stormwater runoff, may decrease the development of HABs, Shapley added.