Kitsap County’s proposal to pave a 2-mile road over the hill in North Kitsap Heritage Park is a bad idea for many biological reasons. The impending loss of high-quality habitat and consequent reduction in biodiversity inherent in the project is unacceptable.
Frogs and salamanders (amphibians) are critically endangered globally and in decline locally. Because most amphibians depend on wetlands for reproduction and larval development, and later depend on uninhibited access to substantial, unspoiled uplands for growth and adult development, the Sound to Olympics trail as envisioned is particularly harmful.
Two categories of effects are especially damaging — Toxicity and Obstruction.
Toxicity
“Thin skin” is an anatomicalreality in larval amphibians, making them especially vulnerable to the toxic effects of:
1. Asphalt. Chemical compoundstoxic to larval amphibiansare released initially from the paving process and perpetually from the effects of maintenance, sunshine, wear, ground fires, age and the nature of the pavement. Recycled asphalt has become stylish and may be particularly harmful as it has been “cooked” twice, creating novel chemical compounds.
2. Rubber tire antioxidants. A compound found in all rubber tires which, when released by abrasion, is known to be toxic to salmon fry, and probably to amphibian larvae.
3. Petroleum products. Inevitably released by construction and maintenance equipment. Directly toxic to gill-breathing amphibian larvae and retards gas exchange at the air/water interface.
4. Synthetic chemical products. Gravel Lok, a synthetic chemical often used to stabilize gravel trails, is toxic. The pesticide Atrazine leads to the feminization of male frogs. Some brands of sunblock and insect repellent are toxic to larval amphibians. Most newly synthesized organic chemicals (thousands per year) are not tested for toxicity to amphibians.
5. Silt. A particular problem for gill-breathing wetland inhabitants, including larval amphibians. A known threat to fish, the effort to isolate silt generated at construction sites, such as Arborwood, with silt fencing only exacerbates the migratory difficulties for reproductive amphibians.
Obstruction
The physical or behavioral inhibition of free, voluntary movement of wildlife within an identifiable ecosystem resulting from:
1. Open skies. A wide, clearcut roadway, such as that proposed for the STO, will retard movement of most small vertebrates, fearful of predation. That includes migrant adult amphibians, which because they live on average only one year, have but one opportunity to make their migratory reproductive journey.
2. Fencing and rock walls. These are barriers required to create low gradient American with Disabilities Act grades in areas of steep slopes. Such barriers are irrational in a park intended to be part of a “wildlife corridor,” negatively impacting coyotes, bobcats, beaver, raccoon, opossum, etc.
3. Roads. A road by a wetland, even if not in contact, acts as a barrier to dispersion of juvenile amphibians, resulting in a reduction of genetic exchange, leading to a decrease in diversity and a decline in population fitness.
These are all biological concerns and when citizens are fully informed become public concerns. We have the rare opportunity here to do something truly beneficial for small species simply by not accepting the notion that paving a natural park is progress.
Thomas Doty is a herpetologist, specializing in the study of reptiles and amphibians. He has a doctorate in biological sciences and is an emeritus professor of biology at Roger Williams University in Bristol, R.I.
