Selecting Preservatives for Marine Structural Timber in Herring Spawning Areas

Abstract and project information last updated: 12 March 2013. Project updates are dated below.

A small gold-colored fish is center, with some sea life blurred in the background.

Credit: Courtesy Wikipedia Commons

Wood immersed in saltwater is prone to attack my marine borers, various types of marine invertebrates such as the Pacific Herring (Clupea pallisii) pictured, that can destroy a wood structure in a few years. Alaska researchers are testing the toxicity and effectiveness of preservatives used on marine structure materials to herring eggs.

AUTC
Project
Number
410037
Principal
Investigator
Robert A. Perkins (UAF)
raperkins@alaska.edu
Funding
Agency

US Department of Transportation (RITA)

Alaska Department of Transportation & Public Facilities

Washington State University

University of Alaska Fairbanks

Project
Budget
121778
Start
Date
1 July 2010
Estimated
End Date
30 June 2012

Abstract

Alaska marine harbors use wood for many structures that come in contact with saltwater, including piles, floats, and docks, because it is economical to buy and maintain. However, wood immersed in saltwater is prone to attack by marine borers, various types of marine invertebrates that can destroy a wood structure in only a few years. In Alaska marine waters there are only two wood preservatives currently recommended: ACZA (ammoniacal copper zinc arsenate) and creosote. ACZA is a water-based preservative that leaches copper into the marine environment; copper is toxic to marine invertebrates and other species. Creosote is an oil-based preservative made from coal tar; it leaches a class of hydrocarbon chemicals called polycyclic aromatic hydrocarbons into the water. Some research indicates that copper leaching from ACZA is slight after a year or so, while creosote leaches PAH at a declining rate over time, but is still measurable after many years. Field research with both preservative methods is hampered because harbors are frequently contaminated with many chemicals, so determining how the wood preservatives alone impact marine life over time is difficult. This project will test the toxicity of marine structural materials to herring eggs under a variety of conditions common in Alaska marine waters, focusing on Southeast Alaska; it will also compare the durability of creosote-versus ACZA-treated marine timbers under comparable climatic and service conditions. This research aims to provide relevant information to ADOT&PF to improve its selection of wood structural materials in the marine environment, especially the selection of wood-preserving methods.

Final Report

Selection of Preservatives for Marine Structural Timbers in Herring Spawning Areas
11 Jul 2013

Selection of Preservatives for Marine Structural Timbers in Herring Spawning Areas
Dr. Robert A. Perkins, P.E.
410037.MarineTimbers.Perkins.Final_.pdf

Related Project Activity

11 July 2013

Selection of Preservatives for Marine Structural Timbers in Herring Spawning Areas

by

410037.MarineTimbers.Perkins.Final