To comment further on herbicide use at the Maury Island Marine Park, it’s quite unsettling to see the extent of invasive plant infestations on Vashon-Maury Islands.

As a restoration contractor commissioned to use herbicide in various municipal parks, in my opinion, targeted “cut and paint” glyphosate applications (herbicide without surfactants that are harmful to fish and amphibians) are the safest method to address plant invasions. The Department of Fish & Wildlife seems not to worry about glyphosate in groundwater, even applied during fish windows.

The alternative is to manually uproot invasives, which disturbs soil and causes erosion, likely more toxic than herbicide. Vashon soils are tainted by smelter pollution, so it’s even more important to retain soil health as a sponge to filter stormwater — the primary polluter of Puget Sound. Like the grit on your car, ongoing air pollution deposits throughout our landscape. Healthy forests can reduce polluted storm water runoff during winter rains, and homeowners can help by replacing lawns with evergreen vegetation.

Invasive plants prevent natural regeneration of forests, and ivy is strangling trees. A study of Mercer Island forests shows English holly stems are outnumbering new native trees nine to one (for references, see seedrain.org), and another study found that holly is doubling every seven years. David Stokes, PhD, of the University of Washington-Bothell, has said holly “has the potential to become a dominant species in both number of individuals and area covered within a few decades.”

The “seed rain” of holly and ivy are spread by birds and can germinate in complete shade, threatening regional forests and potentially affecting timber, fishing and recreational industries. Knotweed, which requires herbicide for eradication, is extremely detrimental to salmon habitat.

Regardless of public concern or my opinion, it’s the job of government to analyze the science and weigh the risk of herbicide with the risk of invasive neglect.

— Steve Richmond