Adirondack heritage-strain brook trout and round whitefish have been restored to more than 50 ponds, he noted.
Strides in environmental education - for both children and adults - have also been achieved, he said.
Since 1990, "Summit Stewards" have worked the Adirondack High Peaks, educating visitors about the rare alpine ecosystem that is found on only 16 of the highest peaks in the state.
Grannis said it was important to raise environmental awareness in youth - and prompting their interest in the outdoors has been an important objective for DEC. More than 100,000 children have participated in the Junior Naturalist Program during its 14-year history at DEC campgrounds, he said, and hundreds annually attend DEC environmental education camps.
Grannis also cited the substantial reduction of pollution in the Hudson River. The number of waterways classified as severely damaged by pollution have declined 88 percent, he said.
The commissioner noted other examples of environmental progress in the state including the cleanup of nearly 1,800 polluted sites.
Grannis also cited the comeback of Bald Eagles and Peregrine Falcons, severely threatened decades ago, but now enjoying record-high populations.
Grannis was joined by Fund for Lake George Executive Director Peter Bauer, Lake George Association Director Walter Lender, Adirondack Council President Brian Houseal and Open Space Institute President Joseph Martens - all of whom offered their views on achievements in cleaning up and protecting the environment.
Grannis said efforts must continue in protecting the environment, noting particularly his concerns over greenhouse gases and global warming. He said that as a member of the state's Climate Action Council, he and others will be planning how to reduce carbon dioxide emissions in New York State by 80 percent as of 2050.
"There is plenty of work to do across the state and many new issues to address - from climate change to invasive species," he said. "If we are to continue making progress, we'll need the same amount of passion and dedication as those first Earth Day marchers had - It's time to re-dedicate ourselves to taking the next step."