By Francesca Krempa
New York State won’t stock brook trout in 13 unnamed ponds throughout the Adirondack Park in 2020 and 2021 so biologists can study the resilience of wild fish swimming in those waters.
After tracking improvements in water quality – specifically acid/base chemistries and contaminants – the department determined the populations of brook trout that already inhabit these select waterways have the potential to reproduce naturally and will be surveyed in 2022 to see if they do so.
While this is promising news for both the iconic species, it doesn’t guarantee their success.
Acidity in many lakes and streams is improving but not fully resolved, Paul Smith’s College natural science professor Curt Stager said. That could contribute to rebounding brook trout, he said, though the park’s warming climate is another threat.
“Eventually temperature is going to be a problem,” Stager said.
It’s no secret the Adirondacks have had a long and complicated history with water quality. The park infamously suffered severe acid rain damage during the 1960s, when fallout from fossil fuels devastated lakes, streams and rivers in the region and decimated aquatic life – especially brook trout. It wasn’t until amendments were made to the Clean Air Act in 1990 that smokestack regulations started to protect the waters.
Jordan Ross, president of Trout Power, a brook trout conservation group in the Adirondacks, explains that clean water isn’t necessarily determined by its clarity, but by the species that live in it. Trout Power’s team is fueled by anglers-turned-citizen-scientists who work closely with the Department of Environmental Conservation to track genetic strains of brook trout around the park. Their team recognizes that when fauna doesn’t exist in the waters it’s supposed to, it’s a red flag.
“The fish that live in (these waterways) are essentially a bio-indicator,” Ross said. “If you’re going to go and catch wild, native brook trout in a stream, and they exist – that in and of itself is an indicator of a healthy ecosystem.”
With water quality improving, suspending stocking is good news for the current fish that live in these ponds.
“If you have a wild population that’s doing well and reproducing, it should be left alone,” said Spencer Bruce, an ecologist who researches aquatic population genetics at the University at Albany. Bruce also works with Trout Power to study the different strains of brook trout throughout the park. Decades of stocking and subsequent breeding with native fish have led to hundreds of hybrid variations.
If the brook trout in these ponds are native strains, halting stocking gives brook trout a chance to avoid a loss of genetic diversity. It also gives the native fish a chance to avoid parasites or diseases that could come from hatchery fish.
“If it is a native population, they’re probably uniquely adapted,” Bruce said. “You don’t want to mix stock-fish with those fish.”
While tracking water quality and suspending stocking are steps in the right direction for ensuring the success of brook trout in these 13 ponds, the fish still have a slew of other ecological factors to contend with over the next two years.
Brendan Wiltse, an ecologist who oversees water quality research and monitoring programs for the Ausable River Association, says there are three primary threats to the survival of brook trout in any environment: non-native and invasive species, habitat fragmentation and rising water temperatures.
Non-native species, specifically brown and rainbow trout, compete with brook trout for access to cool water and food resources. Although the DEC plans to monitor what other fish live in these ponds, the presence of rainbow and brown trout could hinder the likelihood of the brook trout’s survival.
Habitat fragmentation is another battle the fish have to face. Wiltse explains that the natural range of brook trout in the Adirondacks has contracted over time, as man-made culverts and dams prohibit fish from traveling to safely spawn or access colder tributaries.
In the Ausable watershed alone, Wiltse and his team have assessed hundreds of culverts for fish passage, ranking them for their severity and working to replace the ones that seriously impede migration. He mentions that if the ponds have similar engineered structures, this could affect brook trout.
“In the summertime when it gets warm and a fish wants to move … the fish can’t make it up into that culvert and then swim through it to find that cool water,” he said.
Finding that cool water is key, albeit increasingly difficult, in the face of global warming. Like Stager mentioned, rising water temperatures pose the biggest threat to brook trout. The little fish thrive in cold, well-oxygenated water and are extremely sensitive to even the slightest of temperature changes. Unfortunately, climate change is inevitably warming the park’s waterways – presumably these ponds are no exception.
“We should be excited about their recovery, but the next battle for these fish is going to be climate change,” Wiltse said. “That’s going to be the next step in making sure that these fish that are now recovering from acid rain, or the ones that have been here all along, stay here in the long run as our planet warms.”
All three of these challenges have one common denominator: humans. Like acid rain, people are responsible for stocking non-native species that continue to displace the brook trout, as they are for building culverts and contributing to climate change.
Advocates and scientists are hopeful that people recognize their part in brook trout conservation moving forward and, in the case of revitalizing populations in these 13 ponds, will support the comeback.
Currently, the DEC does not intend to promote the names of the specific ponds to avoid disruption in angling habits in hopes of protecting the integrity of data collection.
But conservationists, like Ross at Trout Power, believe that educating the public and telling the story of the fish’s tumultuous journey back to health in the Adirondacks can help them see their role in the trout’s success. Even anglers – who Ross argues are largely more interested in trout conservation than just “reaping the fish’s bounty” – see their value as more than a commodity. Whether it’s through signage at the ponds or outreach, he said, these sentiments need to be communicated to the public.
“You’re not going to change people’s actions without telling a story,” Ross said. “It really comes down to what people will do that will affect the future.”
CORRECTION: This story has been altered to delete a partial quote that mistakenly attributed loss of genetic diversity to inbreeding.