Publication Summary

Port Angeles Harbor, Washington has been listed as an impaired water body under the 1998 Clean Water Act 303(d) for not meeting water quality standards for dissolved oxygen. The Washington State Department of Ecology wants to determine the extent to which water quality problems are due to wood waste accumulation. Science Applications International Corporation, under contract to Ecology, conducted a survey to map the extent of wood waste on the harbor bottom and assess the biological impact due to its accumulation.

Port Angeles Harbor, Washington has been listed as an impaired water body under the 1998 Clean Water Act 303(d) for not meeting water quality standards for dissolved oxygen. The Washington State Department of Ecology wants to determine the extent to which water quality problems are due to wood waste accumulation. Science Applications International Corporation, under contract to Ecology, conducted a survey to map the extent of wood waste on the harbor bottom and assess the biological impact due to its accumulation.

The study was designed to address the following objectives: 1. Map the horizontal extent of wood waste accumulations 2. Measure the thickness of the accumulations 3. Describe the wood waste encountered 4. Measure the depth of the apparent redox potential discontinuity (RPD) 5. Identify areas with potential for high sediment oxygen demand (SOD) 6. Evaluate the health of the benthic macroinvertebrate community

The survey was conducted in subtidal portions of Port Angeles Harbor (west of the end of Ediz Hook; 123º 24'W Longitude) using sediment vertical profile photography, sediment plan-view photography, and towed underwater video.

The following is a summary of the major findings of this study:

1. Wood waste covers approximately 25 percent (500 acres) of the bottom of Port Angeles Harbor, primarily in nearshore log booming areas.

2. Five types of wood waste were identified on the bottom of Port Angeles Harbor: Logs or large wood pieces, small wood and/or bark chips (wood chips), very fine wood particles and/or fibers (wood pulp), trace to sparse wood pulp/chips mixed within the sediment column, and sparse, scattered wood pieces on top of the sediment surface

3. Abundant wood debris including logs and large bark/wood fragments was observed in the active and historical log booming grounds. Large piles of recently deposited logs were observed in the active log booming grounds along the northern portion of the harbor. Size and abundance of wood debris decreased offshore from the booming grounds.

4. A layer of wood pulp covering approximately 35 acres is buried under 6 to 8 cm of ambient silt in the western central harbor. The layer represents an estimated volume of 9,500 cubic yards of wood pulp (wet-volume).

5. Shallow apparent redox (RPD) depths in Port Angeles Harbor were associated with active and historical log booming grounds and indicate organic overloading. Stations with very shallow to non-existent apparent redox depths were observed close to shore near the Daishowa facility, the public log dump grounds, the booming grounds near K-Ply, and the former ITT Rayonier grounds.

6. Accumulation of fine wood waste (pulp) has contributed to apparent high sediment oxygen demand (SOD) conditions in the western harbor near the Daishowa and M&R Timber facilities, the public log dump, the booming grounds near K-Ply, and the former ITT Rayonier grounds. Bacterial mats, which indicate organic loading and low dissolved oxygen conditions, were also observed at four stations in the western harbor.

7. Organism-Sediment Index (OSI) values in the central harbor were between +7 and +11 indicating healthy benthic infaunal communities. Stressed or disturbed communities (OSI values less than +6 were generally observed in the log booming grounds.

8. Degraded benthic habitat (OSI less than zero) was observed in near shore areas of the western harbor (stations 8, 12, 40, 43, and 95). Such habitat is of little value to fish.

9. The presence of sparse, scattered wood debris on the sediment surface (offshore of the log booming areas) appears to have minimal impact on the health of the benthic community and provides habitat for epibenthic organisms (e.g., shrimp, crabs, fish).