A Scientist Answers
Three citizens, one a member of the City’s Planning Commission submitted a letter in support of the SMP Update’s buffer widths, dock and bulkhead regulations, claiming that they were the way to protect the ecology of Puget Sound. But, are they correct? Will the additional 25 feet added to buffers in every residential zone, the close to outright prohibition on new docks and the stringent limitations on bulkheads really do anything?
Excerpts from a paper prepared by Don Flora, Ph.D. are shown below. The link provided will allow you to read the whole paper.
“After reading over 3,000 research papers on buffers and related subjects, listing a thousand species of aquatic and marine invertebrates, raising shellfish, doing research on geoducks, examining all 250 miles of South Sound shore via rowboat, doing peer-reviewed analytical work on bulkhead/ecosystem interactions, and looking after various lines of stream research, I was surprised by the Gale et al 2-page presentation. It reveals a singular perspective on the SMA and SMP and their implications for human life next to tidewater.” (Page 1)
“Buffers –- There is a vast literature on the efficacy of buffers. Most research has examined effects of livestock use, row crops, or fallow fields. When adjusted to discharge levels appropriate to residences the extant research shows that buffer widths of 5 feet will almost totally remove the pollutants studied, regardless of slope (the most important variable after application rate), soil type, and stormwater rate and duration. Our city’s consultant suggested 30 feet after looking at studies in which efficacy was reported in terms of percentage reduction, ignoring the actual quantities captured, which were at least 8 times typical residential discharges. This means that the zone 1 buffer vegetated buffer can safely be 5 feet or less in width.”(Page 2)
“Docks Migrating salmon do pause when they approach a ferry dock. About half swim around; there is no evidence that predation results in lower survival among swim-arounds than among swim-throughs. Juvenile salmon tend to congregate under residential docks, not avoid them. I encourage a visit to any narrow dock, including the city’s.” (Page 7)
“Shore protection Contrary to Gale et al, peer-reviewed studies have found near-zero correlation between the density of bulkheads on Bainbridge’s 200 drift cells and ecological functions (tidewater habitat). Those findings are supported by independent research in the San Juans and in the South Sound.” (Page 8)
We encourage you to read the entire paper. It is well worth your time.