Environment

Bulkheads do threaten

A letter in Saturday’s paper came to the conclusion that bulkheads do not threaten the health of Puget Sound. Substantial information is available on the effects of bulkheads. Bulkheads can interrupt inputs of soils from the land to the sea by forming an impervious barrier between the two. This interruption of fine material inputs can substantively alter nearshore habitat, including loss of fine-grained beaches important to spawning fish and other marine wildlife.

Bulkheads can increase wave-reflective force, increasing erosion of nearby beaches and properties. Shoreline armoring can reduce or eliminate upper intertidal habitat, and recent research from the University of Washington has shown that armoring can have effects including reducing woody debris and increasing beach surface temperatures which can stress spawning fish and invertebrates.

Potential effects of bulkheads can be reduced by good planning and site design, and by placement above mean higher high water. (But keep in mind that with climate change what is planned above the high-tide line may not remain that way!). The fact that bulkheads are regulated at both the state and federal level is testimony to concern for not only their safety but also their environmental impacts.

Mr. Sethney’s letter opines that “moderate levels of impacts shouldn’t cause concern.” Looking at an individual bulkhead, it may be hard to understand why there should be concern. However, about 50 percent of Bainbridge’s shorelines – more than 25 of our 50-plus shoreline miles – are armored; that level of armoring moves us beyond individual actions to cumulative impacts. As a parallel example, think of the effects our cars have on Puget Sound’s water quality: each of us driving contributes minute amounts of oil, plastics and heavy metals to the Sound, an arguably small effect in isolation, but the cumulative effects are massive.

It is extremely important that we think not only in terms of our individual actions, but on their cumulative impacts for the health of the Sound.

DEBORAH RUDNICK, Ph.D, Ecologist

COBI Environmental Technical Advisory Committee member