Ecological Impacts of Water Use and Changes in Levels and Flows A Literature Review Prepared For: The Great Lakes Commission June 13, 2002 Prepared By: Limno-Tech, Inc. (LTI) Michel Slivitzky A Literature Review On Ecological Impacts June 13, 2002 PREFACE This literature review was prepared for the Great Lakes Commission as a component of an ongoing project, Development of a Water Resources Decision Support System for the Great Lakes/St. Lawrence System. The project is sponsored by the Great Lakes Protection Fund. Financial support was also provided by Environment Canada. Limno-Tech, Inc. and Michel Slivitzky i A Literature Review On Ecological Impacts June 13, 2002 EXECUTIVE SUMMARY The Great Lakes Commission is currently developing the framework for a decision support system that will provide the data, information and process required to ensure timely and well-informed public policy decisions concerning the use and management of ground and surface water in the Great Lakes Basin. The Great Lakes Protection Fund is supporting this effort, which is titled: Development of a Water Resources Decision Support System for the Great Lakes/St. Lawrence System. Project Element Four addresses the compilation of an inventory of information on ecological impacts of current and prospective water use. One Element Four task involves a literature review that may be used to contribute to a better understanding of ecological impacts (Great Lakes Commission, 2000). The thrust of this literature review was to compile the body of research relevant to the identification and quantification of ecological impacts that might arise from water withdrawals/diversions in the Great Lakes Basin. Because this topic really encompasses the entire body of knowledge on the effect of physical, chemical, and biological conditions in a freshwater ecosystem on its structure and function, we had to be reasonably selective in the inclusion of literature in this document. Also, in an effort to organize the included literature in a logical and understandable way, we have grouped the literature in four broad categories: 1) effects on physical/chemical habitat; 2) effects on populations and/or communities; 3) ecosystem effects; and 4) synoptic modeling studies. There were also a number of large, focused studies that have or are making significant contributions to these four categories. We have dealt with each of these studies individually. Both the published and the “gray literature” (i.e. the numerous provincial, state and federal, and private sector publications) were searched. More than 260 documents were reviewed and summarized. Our review indicates that while there have been a great many studies that are relevant to assessment of ecological impacts of water withdrawals/diversions, most of these studies have been site-specific and descriptive in nature. Often they test a hypothesis that there is or is not a significant response of the system, but do not collect sufficient information for quantitative analysis of the deterministic, cause-effect relationships that underpin the empirical observations. It is really only with this critical process understanding that we can generalize the findings, through synthesis and model development, to the various types of ecosystems that exist in the Great Lakes Basin. A quote from Hardy (1998) in regard to stream habitat modeling is especially relevant to this point; he says that the future of habitat modeling “remains an abstraction, in that integration of all the pieces has yet to be accomplished, field validation remains unproven, availability of an integrated analysis framework (i.e., computer software system) is not yet available, and a clear framework for selection and application of specific tools has not been developed.” Meyer et al. (1999) reaches a similar conclusion. He points out that: “We are limited by availability of both data and models. More extensive data sets and better models are needed linking hydrologic regime with ecosystem processes (productivity, Limno-Tech, Inc. and Michel Slivitzky ii A Literature Review On Ecological Impacts June 13, 2002 nutrient dynamics, food web interactions), with ecological interactions (predation, species invasion), and with water quality.” In view of these observations, we strongly recommend that future funding for research and development in this area be directed at “data mining” for both qualitative and quantitative stress-response relationships in this subject area. There should also be a concerted effort to synthesize and model the quantitative relationships between water withdrawals/diversions in various types of Great Lakes ecosystems (large lakes, inland lakes, streams and rivers, groundwaters) and potential ecological impacts of those water uses. This synthesis and modeling effort is essential if we are to truly deal with the assessment and management of cumulative impacts from multiple withdrawals within a given watershed and the cumulative impacts of multiple watersheds on one of the Great Lakes or the St. Lawrence River. Another technical issue that demands an integrative approach is the confounding effects of multiple stressors acting in concert to produce a series of ecological responses; these confounding conditions make it difficult to isolate the hydrological ecological cause-effect relationships. Also, there are the issues related to time and space scales in making cause-effect assessments. Often, the time and space scales of the hydrologic/hydraulic stressors are very different than those for the ecological manifestation of those stressors. We have already seen that changes in flows or levels can be classified in three categories: 1) changes in mean values – annual or seasonal; 2) changes in frequency and amplitude of extremes – floods and droughts; and 3) changes in seasonal timing of levels or flows. Each of these categories of stressor may have its own time and space scale for a given system, and each may elicit a different ecological response with a different time lag (many years in some cases) and spatial extent. Any field or experimental characterization of cause-effect relationships should be done in the context of both stressor and response endpoint time and space scales. Given the state of our understanding and the state of our data base on this issue, it makes sense to consider adopting an adaptive management approach in making and following up on water withdrawal decisions. Several authors, including Persat (1991) and Walters (1997), have pointed to the above multi-scale issues and data/understanding limitations as arguments for using an adaptive management approach. Limno-Tech, Inc. and Michel Slivitzky iii A Literature Review On Ecological Impacts June 13, 2002 CONTENTS EXECUTIVE SUMMARY ..........................................................................................II 1. INTRODUCTION .................................................................................................... 1 1.1 BACKGROUND .............................................................................................. 1 1.2 OBJECTIVES................................................................................................... 2 2. APPROACH ............................................................................................................. 4 2.1 LITERATURE REVIEW METHODS AND SOURCES ................................ 4 2.1.1 PUBLISHED LITERATURE REVIEW ............................................................. 4 2.1.2 GRAY LITERATURE REVIEW ..................................................................... 5 2.2 DESCRIPTION OF CATEGORIES................................................................. 6 2.2.1 EFFECTS ON PHYSICAL HABITAT .............................................................. 7 2.2.2 EFFECTS ON POPULATIONS AND/OR COMMUNITIES................................... 7 2.2.3 ECOSYSTEM EFFECTS................................................................................ 7 2.2.4 SYNOPTIC MODELING STUDIES ................................................................. 8 2.3 SPECIAL FOCUSED STUDIES...................................................................... 8 3. DESCRIPTIVE INVENTORY OF LITERATURE................................................. 9 3.1 EFFECTS ON PHYSICAL HABITAT............................................................ 9 3.2 EFFECTS ON POPULATIONS AND/OR COMMUNITY STRUCTURE.. 16 3.2.1 EFFECTS ON FLORA................................................................................. 16 3.2.2 EFFECTS ON FAUNA ................................................................................ 18 3.3 ECOSYSTEM EFFECTS ............................................................................... 23 3.3.1 WETLANDS ECOLOGY............................................................................. 24 3.3.2 STREAM ECOLOGY AND ECOLOGICAL ASSESSMENT ............................... 25 3.4 SYNOPTIC MODELING STUDIES ............................................................. 38 4. SPECIAL FOCUSED STUDIES............................................................................ 46 4.1 INTERNATIONAL JOINT COMMISSION ................................................. 46 4.1.1 EROSION ................................................................................................. 47 4.1.2 FISHERIES AND WILDLIFE ....................................................................... 47 4.1.3 WETLANDS ............................................................................................. 48 4.1.4 WATER QUALITY