USDA Forest Service General Technical Report PNW-22 1974 Effects of Log Dumping and Rafting on the Marine Environment of Southeast Alaska Bruce C. Pease ABSTRACT The extent of water-dependent log handling and storage facilities in southeast Alaska is summarized, along with the available literature on the environmental impact of these facilities. Field studies were conducted at 16 sites and correlated with laboratory studies of leaching rates and toxicity of the four major wood species harvestedin southeast Alaska. Signif- icant effects on water quality are believed to occur only under unique conditions and were observed at only 2 of the 16 study sites. Bark deposits with a high demand for oxygen were observed at all active and abandoned log dumping sites. The abundance of benthic infauna was noticeably reduced in bark covered areas and intertidal raft storage areas. The laboratory studies demonstrated that oxygen demanding organic compounds rapidly leach from logs in water, but precipitate in salt water. The wood leachates are toxic to pink salmon fry in the laboratory but probably have little effect on fish in the natural environment. Further studies are needed to further quantify the environmental impact of water-oriented log handling practices. Keywords: Logging rafts, fish management, water quality. This work was sponsored by the Forest Service, U. S, Department of Agriculture Grant No. FS-PNW-Gr 88 and prepared by the FISHERIES RESEARCH INSTITUTE College of Fisheries, University of Washington, Seattle. Mention of companies or products by name does not imply endorsement by the U. S. Department of Agriculture. USDA FOREST SERVICE General Technical Report PNW-22 EFFECTS OF LOG DUMPING AND RAFTING ON THE MARINE ENVIRONMENT OF SOUTHEAST ALASKA Final Report for Period July 1, 1972 - August 30, 1973 by Bruce C. Pease FISHERIES RESEARCH INSTITUTE College of Fisheries University of Washington Seattle, Washington 98195 PACIFIC NORTHWEST FOREST AND RANGE EXPERIMENT STATION Robert E. Buchan, Director Portland, Oregon Forest Service U. S. Department of Agriculture TABLE OF CONTENTS Page INTRODUCTION ............................ 1 Background .......................... 1 ScopeoftheProblem ..................... 4 Project Objectives ...................... 5 METHODS AND MATERIALS ....................... 6 Fieldstudies ......................... 6 Study Sites and Sampling Stations ............ 6 WaterQuality ...................... 10 Benthic Communities ................... 19 Laboratory Studies ...................... 20 Leaching Rate Experiment ................. 20 Bioassay Study ...................... 22 RESULTS .............................. 25 Fieldstudies ......................... 25 WaterQuality ...................... 25 Benthic Deposits ..................... 32 Benthic Communities ................... 36 Laboratory Studies ...................... 41 Leaching Rate Study ................... 41 Bioassay Study ....................... 46 Log Barging versus Log Raft Towing . 49 DISCUSSION ............................. 52 SUMMARY .............................. 54 RECOMMENDATIONS .......................... 56 REFERENCES ............................. 57 LIST OF FIGURES Figure Page 1 Study sites in Southeast Alaska .............. 2 2 Active log dump at Thorne Bay ............... 3 3 Intertidal raft storage at Fish Bay ............ 3 4 Thorne Bay sampling stations ............... 11 5 Rodman Bay sampling stations ............... 12 6 Katlian Bay sampling stations ............... 13 7 Herring Cove and Bear Cove sampling stations ....... 14 8 Eagle River and Mud Bay sampling stations ......... 15 9 Nakwasina Sound and Starrigavan Bay sampling stations ... 16 10 Hanus Bay and Fish Bay sampling stations ......... 17 11 Sediment sample BOD's (run 8/1/72 to 8/4/72) .................. 33 12 Sediment sample BOD's (run 8/14/72 to 8/16/72) ................. 34 13 COD leaching rates of test log sections .......... 45 14 Total leachate leaching rates of log sections ....... 47 15 Threshold toxicity concentrations from pink salmon fry bioassay ................. 50 LIST OF TABLES Table Page 1 Site abbreviations and classifications ........... 7 2 Log dumping activity at study sites ............ 8 3 Log rafting activity at study sites ............ 9 4 Size of pink salmon fry used in the bioassay study ..... 23 5 Quality of dilution water used in the bioassay study .... 24 6 Salinity (ppt) of water samples collected atallstudysites ..................... 26 7 Temperature (C) of water samples collected atallstudysites ..................... 27 8 Dissolved oxygen (ppm) of water samples collected at all study sites ................ 29 9 Oxygen saturation (%)of water samples collected at all study sites ................ 30 10 Total leachate as ppm FDE in water samples collected from stations at TR and HR ............ 31 11 Sediment composition at study sites from observations made along the SCUBA transects ........ 35 12 Organisms observed along SCUBA transects atstudysites ....................... 37 13 Abundance of benthic infauna in the van Veen samples from all sites ................... 40 14 Organisms collected in the van Veen grab samples at selected study sites .............. 42 15 pH of the log sections in the leaching rate study ..... 48 16 Summary of threshold toxicity concentrations from pink salmon fry bioassay .................. 51 INTRODUCTION Background Southeast Alaska is basically a system of islands convoluted with numerous bays and estuaries (Fig. 1). Because of the water-oriented g 0 raphy and lack of roads, most commercially harvested timber in Southeast Alaska is stored and transported on its marine waters. The water-dependent log handling and storage facilities in Southeast Alaska are of four types (State of Alaska, 1971): 1) Sale area dumping sites 2) Sale area raft collecting and storage sites 3) Winter raft storage sites 4) Mill storage and sorting sites Logs are introduced into the water at the sale area dumping sites by a variety of methods. Usually, they are bundled with steel bands while still on the logging truck, then lifted and lowered into the water with an A-frame crane (Fig. 2). In some logging operations the log bundles are slid or skidded into the water; in others individual logs are either lifted, slid, or skidded into the water and bundled there. The log bundles are then collected into rafts of approximately 70 ft by 550 ft and 300 to 600 thousand board feet (bd ft). The rafts remain at the sale area raft collecting and storage sites until they are towed to either the mill storage and sorting sites or the winter raft storage sites. The mill storage and sorting areas are usually in deep water located near the processing mills. Here logs are kept for only a short time, as they are usually processed soon after arriving. The winter stor- age sites are often intertidal areas near the heads of estuaries. Here the log bundles ground at low tide and receive freshwater from inland streams (Fig. 3). Logs kept at the winter storage sites are usually in excess of the demand from summertime processing at the mills and are drawn upon gradually during the winter and spring. Intertidal areas are chosen for extended log storage because grounding at low tide and the relatively low salinities minimize infestation by marine wood-boring organisms, known as "teredos" (Bankia setacea). Most logs in Southeast Alaska are handled and stored at 1 RODMAN BAY 2 HANUS BAY 3 FISH BAY 4 EAGLE RIVER 5 MUD BAY 6 NAKWASINA BAY 7 KATLIAN BAY 8 STARRIGAVAN BAY 9 HERRING COVE 10 BEAR COVE 11 THORNE BAY Figure 1. Study sites in Southeast Alaska. 3 Figure 2. Active log dump at Thorne Bay. Figure 3. Intertidal raft storage at Fish Bay. 4 the heads of bays and estuaries for protection from teredos and from stormy weather . Scope of the Pmblem Approximately 60 individual logging companies operate within Southeast Alaska (State of Alaska, 1971). They supply timber to two large pulp mills and approximately 18 smaller saw mills in Southeast Alaska. In 1970, they harvested 560 million bd ft of timber, 70% of which was hemlock (Tsuga hetero- phytla), 25% spruce (Picea sitchensis), and 5% red and yellow cedar (Thw*a pzicata and Chamaecypds nootkatensis) (State of Alaska, 1971). A total of 650 acres (approximately 1 sq mi) of water was used for the storage and han- dling of that timber. Since some of the logging companies move their opera- tions to new areas each year, a large area of water has been used for log handling and storage in Southeast Alaska, The literature on the effects of log dumping and rafting on the marine environment of Southeast Alaska is very scanty, In 1970, investigators from the Auke Bay Biological Laboratory of the National Marine Fisheries Service described the extent and impact of bark debris at one active dumping site, three abandoned dumping sites, an active raft storage area, and two control areas (U.S. Fish and Wildlife Service, 1970). SCUBA divers made subjective observations on the amounts of bark, wood debris, and other debris on the bottom, as well as the relative numbers and types of large benthic organisms in the area. Drastic depletion of benthic organisms was observed at three dumping sites, along with thick beds of bark and organic debris, and scattered steel bands and cables, A less used dumping site had an insignificant amount of debris and appeared to have a normal population of benthic organisms. At the active raft storage area the benthos was apparently unaffected except directly under the rafts, where shading had apparently inhibited