The amount of Puget Sound shoreline that falls within Tacoma city boundaries is between 12 and 13 miles. Most of it lies to the south of Commencement Bay, but there is a smaller section on the north side of the bay as well. (These figures exclude the industrial waterways on the Puyallup tide flats.)
The idea for the survey came during a Sustainable Tacoma Commission meeting where the idea of a plastic bag ban was being discussed. The point being debated was whether plastic bags are a significant source of marine pollution in Tacoma; the fact that there was no data to draw from was presented as one of the reasons to delay the decision about a ban.
The Tacoma Shoreline Survey was organized as a project that would transit the entire municipal shoreline, conducting individual surveys at various points along the way. Surveys used a modified NOAA protocol designed for standing-stock surveys (although items were removed as opportunities allowed.) The survey was split into two parts: the first was conducted between Aug. 4-6 and the second took place in late November and early December, after the first major rains of the season.
– There were at least 2 major shoreline cleanups in the weeks leading up to the first pass. The North shore of Commencement Bay (Yowkwala Beach), was cleaned on July 19th in an event organized by Citizens for a Healthy Bay. The section from Salmon Beach to the Boathouse (the entire shoreline of Point Defiance), was the focus of a citizen cleanup organized by Tacoma Metro Parks as part of the CHIPin program on July 26th. Area cleanups were a factor in the followup sessions as well; the Yowkwala Beach followup was actually done as a scheduled beach cleanup, in partnership with the South Sound chapter of the Surfrider Foundation.
– The surveyed shoreline is more than 50% armored. The bulkheads and other armoring methods have greatly affected the beaches below, with the general result being that the beaches are completely flooded by tidal activity virtually every day. (This means that debris is unlikely to accumulate in these areas, although there are other implications with regard to the overall health of the beach environment. Those issues, although important, are not the focus of this project.)
– The second pass of the shoreline survey showed the impact of seasonal changes on total amounts of debris. Almost all categories spiked from their summer numbers and exchanges due to runoff and storms seemed to be significant.
– The accompanying spreadsheet represents the actual results of both passes. The most impacted sections of shoreline were Yowkwala Beach and Thea’s Park, although all sites saw marked increses in accumulation.
– Although different survey areas yielded a variety of debris (both type and quantity), and while some items were found in some areas but not in others, it is interesting to note that each of these transects contained plastic bags.