SHOREZONE DEVELOPMENT LITERATURE REVIEW - INTRO|
Effects of Shorezone Development - Final Report
A Summary of the Effects of Bulkheads, Piers, and Other Artificial Structures and Shorezone Development on ESA-listed Salmonids in Lakes
13 July 2000
This report is a product of a literature review initiated to determine our state-of-knowledge about the impacts of lakeshore development on salmonids, in the context of the Endangered Species Act (ESA).
There is much uncertainty surrounding the impacts of various shorezone structures and activities on salmonids within lakes in the Tri-County area (King, Pierce and Snohomish Counties, WA). Identifying the level of current knowledge, areas of uncertainty, and future research needs could provide a more consistent review and evaluation of shoreline development proposals, and decrease potential impacts to threatened salmon populations if the information is utilized in the course of permit review and assimilated into regulations.
This review was initiated by the City of Bellevue, WA, to provide a digest, a library of pertinent literature, and an annotated bibliography in the form of a Microsoft Access database, detailing the potential impacts of lakeshore development on ESA-listed species. The review is primarily focused on Lake Washington and Lake Sammamish, but most of the information should be applicable for other lakes within the Tri-County area that have threatened salmonid species. Review products will be utilized by decision-makers at the local through federal levels of government to assist in the creation of guidelines and policies related to lakeshore development.
It should be emphasized that, due to time constraints, this "review" is not an exhaustive compendium of all available resources, but rather a measured digest of what was readily accessible in the time allowed. Collection was directed at literature that related directly to shorezone structures and activities in cold, freshwater lakes, but pertinent literature on warmwater, riverine, and marine systems was also included. Despite time constraints, over 350 literature sources were collected and examined, and the salient points from those sources were incorporated into this digest. Primary searches targeted all relevant electronic databases, followed by secondary searches of the references sections of pertinent literature collected during primary searches.
Literature collected includes peer-reviewed journal articles, theses/dissertations, books, and technical documents. The literature collected for the review constitutes the majority of available relevant documents, with only the most inaccessible documents omitted. In addition, personal communications with respected local scientists were included where pertinent, current research was not yet published.
Shoreline development may seem innocuous to most people. The average property owner on Lakes Washington and Sammamish has no intention of harming salmonids when they propose to build a pier or bulkhead or otherwise modify their shoreline. The property owner's intention is often to reduce erosion, to develop a tidy shoreline, and/or to improve water access. Thus, it is initially important to define which structures and activities are being analyzed for impacts, and to identify how they may affect ESA-listed species. In Lakes Washington and Sammamish, shoreline development activities and structures that have a federal nexus (i.e., if a federal agency funds, constructs, or permits the proposed project) and are thus subjected to review under the ESA, include those activities/structures that require a U.S. Army Corps of Engineers (USACE) permit.
Specifically, USACE permits are required for the construction, replacement, or repair of piers, docks, boat canopies, boathouses, and shoreline armoring structures (i.e., bulkheads). Adverse impacts on listed species can result from construction or maintenance activities, or from the existence of the structure. Proposed projects having a federal nexus are analyzed for potential impacts at a variety of levels.
Under the ESA, "take," means any potential adverse effects to a listed species that can occur as a direct result of a proposed project, or as an indirect or interrelated result. Direct impacts to a listed species could occur from water quality impacts during construction, or result from increased opportunities for predation from the presence of a new pier. Such a take would be a direct effect. Indirect effects are less obvious. The reduction in water quality that might occur from a fuel spillage during boat fueling at a new residential pier would be an indirect effect. If the pier had not been constructed, the fuel spill would not have occurred.
The following are some specific potential impacts of shorezone structures and activities that have beenidentified through discussions between The Watershed Company and the U.S. Fish and WildlifeService (USFWS) and National Marine Fisheries Service (NMFS) (collectively called the Services)during 1999 and 2000 as part of the Biological Assessment (BA) process of Section 7 of the ESA. TheServices are concerned about potential adverse impacts of shorezone development on juvenile andadult chinook and coho salmon, and bull trout. Despite the Services concern for these ongoing impacts, they can only act on those concerns when an application for a project requiring a federal permit (or with some other federal nexus) is proposed.
While the focus of this report is on salmonid species that are listed or considered for listing under the ESA, shorezone development could have the same potential impacts on many other native fish within Tri-County-area lakes. The listing or proposed listing of chinook and coho salmon, and bull trout under the ESA indicates that these species face serious threats to their perpetuation within the region. Such threats are likely being faced by other salmonids as well. Thus, in most cases it would be appropriate to consider all salmonids, and perhaps native non-salmonids, as the subjects of the following discussion of impacts.
The potential impacts identified above of docks and bulkheads provided the focus for the review. For discussion purposes, the above list of impacts has been condensed into six categories: chemical contaminants associated with piers, docks, and bulkheads; disruption of natural physical processes; effects on predation and prey refuge habitat; effects on productivity; effects on migration; and recreation and construction activities.
The following is a summary of the information contained within the collected literature. The summary will begin with a discussion of the salmonid species that are present in the lakes of the Tri-County area, and are listed, or candidates for listing under the ESA. Second will be a discussion of pertinent research regarding the potential impacts. Finally, the summary will conclude with recommendations for best management practices (BMPs), mitigation options, and further study.