RECONSTRUCTING THE TROPHIC HISTORIES (ca. 200 years) OF FOUR LAKES WITHIN THE RIDEAU CANAL SYSTEM, ONTARIO by Francine Forrest A thesis submitted to the Department of Biology in conformity with the requirements for the degree of Master of Science Queen's University Kingston. Ontario. Canada Apd. 2001 copyrightG Francine Forrest. ZOO 1 National Library Bibliothèque nationale l*i of Canada du Canada Acquisitions and Acquisitions et Bibliographic Services services bibliographiques 395 WeUington Street 395, nie Wellington Ottawa ON K1A ON4 Ottawa ON K1A ON4 Canada Canada The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant à la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, disûibute or seil reproduire, prêter, distribuer ou copies of this thesis in microfom, vendre des copies de cette thèse sous paper or electronic formats. la fome de microfiche/film, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyxight in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fiom it Ni la thèse ni des extraits substantiels may be printed or othenvise de celle-ci ne doivent être imprimés reproduced without the author' s ou autrement reproduits sans son permission. autorisation. ABSTRACT Diatom-based paleolimnological techniques were used to track the eutrophication histones (ca. 200 years) of four lakes within the Rideau Canal system. Ontario. Canada. The Rideau Canal watenvay links Kingston and Ottawa and was constructed in 1832 for rnilitary purposes. Recent water quality concems. as well as differing trophic responses to anthropogenic disturbances observed in past paieolimnological studies. prornpted this investigation. Stratigraphical analysis of microfossils and physical sediment characteristics in C OP^ and Ambrosia dated sediment cores, dong with diatom inferred total phosphorus and maximum depth reconstructions. were used to determine the trophic histones in Indian. Big Rideau. Lower Rideau and Otter lakes. Paleoecological information of the dominant diatom taxa that flourished during the pre-settlement penod indicates that these lakes were naturally oligo-mesotrophic. At the estimated time of canal construction, al1 lakes demonstrated an increase in nutrients but their responses varied in magnitude. These difierences were likely related to a number of variables. but surface-area-to-watershed ratio appeared to be one of the more important ones. In additional, the similar trophic response of the control lake (not part of the canal). Otter Lake. illustrated the regional impact of the watershed disturbance (e.g. logging. settlement. mining, agriculture) and minimal impact fiom the canal per se. in more recent years (-1970 to present) there is an increase in less productive planktonic species ( e.g. Cyclotella cornensis and Cyclotella aff. cornta v. unipunctata) observed in dl the study lakes. These recent improvements in water quality are ataibuted to the mitigation of phosphate detergents, improved nutrient retention of developing soils in secondary growth forests and the potential effects of climate warming. Eutrophication patterns determined for the deep lakes were similar to the other deep lake paleolimnological study in the canal. However, the trophic response in the shailow lake. Lower Rideau Lake. is more pronounced at the tirne of canai construction than those demonstrated in previous shallow canal lake studies. This heightened response was attributed to increased nutrient export fiom watershed disturbances within its limestone catchent. Trophic patterns From this shallow lake study suppon the alternative equilibriurn theory. Results fiom this study can now be used to help set realistic mitigation targets for these Iakes. ACKNOWLEDGEMENTS First of dl, 1 would like to thank Dr. John Sm01 for sharing his enthusiasm of paleolimnology and providing tremendous guidance and support throughout my thesis. Special thanks to my cornmittee members for contributing unique perspectives towards this project: Dr. Brian Cumrning for introducing me to the world of multivariate statistics and providing helpfd advice to my statistical and dating questions: Dr. Bob Gilbert for teaching me aspects of physical limnology: Paul Hamilton for sharing with me his knowledge of diatom taxonomy and biodivenity of the Rideau Canal system. Special thanks to John Glew for Mingseveral maps and contributing insightful cornments. Thanks to Don Galloway. Kery McGonogal, and Anne Bendig for their fnendly support and supply of physical and chemicai data on the study lakes. 1 also appreciated the help of several local residents and township staff for maps and historical information. Thanks to everyone at P.E.A.R.L. for providing a fiiendly and exciting environment to work in. Saioni -chats and cooking treats. Rene - general stress management and banter, Kim - maintainhg a high music standard in the lab. Petra - sharing her excitement of limnology, Neil - keeping the atmosphere light. Andrew - super editing skills. Tammy - helpf'ui thesis guidance, Kat - safe lab tips. Robeno - happy dancer. Dan - cornputer support, Dixits - fiiendly Binford advisors, Kate - nats wiz, Sudharma - field help, Chloë - helpfid cornments. 1 would also like to thank Euan for taxonomy and mode1 advice. Special thanks to those of you for editing, and discussions on dating. shallow lakes, diatorn taxonomy, climate change. eutrophication and stats. Finally, 1 would like to thank my family and fnends away from Kingston for providing encouragement and perspective while 1 was absorbed in this masters program. I would especiaily like to thank Cam for his loving support and sense of humor throughout this learning experience. Thanks everyone! TABLE OF CONTENTS ABSTRACT ACKNOWLEDGEMENTS LIST OF TABLES LIST OF FIGURES LIST OF AIBBREVIATIONS CHAPTER 1: INTRODUCTION AND LITEkU7JRE REVIEW Eutrophication Paleoiimnology and Lake Eutrophication Diatoms and Eutrophication Diatoms and Mulitvariate Statistics SE Ontario Total Phosphorus Mode1 Eutrophication in the Rideau System Past and Present Watershed Disturbances Previous Paleolimnological Studies Purpose and Objectives CHAPTER 2: SITE DESCRIPTIONS Cataraqui Watershed Indian Lake Rideau Watershed Big Rideau Lake Lower Rideau Lake Otter Lake CHAPTER 3: MATERIALS AND METHODS Field work Physicd Sediment Characteristics Sediment Chronology Micro fossil Preparation and Andysis Statistical Andysis TABLE OF CONTENTS (cont'd) CHAPTER 4: RESULTS AND DISCUSSION Core Chronologies Sedimentary Characteristics Ordinations Reconstructions Microfossil and Trophic Inferences Indian Lake Big Rideau Lake Lower Rideau Lake (shallow) O~terLake (control) Ordinations of Smdy Lakes CHAPTER 5: GENERAL DISCUSSION AND CONCLUSIONS Lake Cornparisons Pre-disturbance conditions Historical anthropogenic disturbance Recent Trophic State Inferences Alternative Equilibriurn Theory Mode1 Evaluations Total Phosphorus Mode1 Maximum Depth Reconstructions Conclusions LITERATURE CITED APPENDIX A: Histoncal Secchi and chlorophyll a data APPENDIX B: Species code list for tilia and ordination diagrams APPENDIX C: Relative abundance of diatom taxa (12%) found in study lakes APPENDIX D: Relationship between % planktonics and inferred maximum depth APPENDM E: Relationship between log excess OP^ activity and cumulative mass VITA LIST OF TABLES DaRe Table 1. Physical and chemical charactenstics of the study lakes. 18 LIST OF FIGURES wx Figure 1.1. Map of southeastem Ontario showing location of the study 7 lakes and geology of the area. Figure 3.1. Bathymetfic map of lndian Lake, Ontario. 16 Figure 2.2. Bathymetric map of Big Rideau Lake. Ontario. 25 Figure 2.3. Bathymetric map of Lower Rideau Lake. Ontario. 30 Figure 2.4. Bathymetric map of Otter Lake. Ontario. 58 Figure 4.1. OP^ activity and sedimentary color profiles for the 5 1 Indian Lake sediment core. Figure 4.1. Diatom reconstructions and model evaluations for Indian Lake. 5 J Figure 4.3. The correlation between DCA axis one sarnple scores and 56 inferred variables. Figure 4.1. Dominat diatom taxa, % organics and cyst:diatom profiles for 57 Indian Lake. Figure 4.5. Physical sediment characteristics for Indian Lake. 59 Figure 4.6. "'~b activity. Ambrosia and sedimentary color changes for the 63 Big Rideau Lake sediment core. Figure 4.7. Correlations between DCA avis one sarnple scores and TP 65 and MZ inferences for the Big Rideau Lake sediment core. Figure 4.8. Diatom reconstructions and model evaluations for Big Rideau 66 Lake. Figure 4.9. Dominant diatom taxa % organics and cystdiatom profiles for 68 Big Rideau Lake. Figure 4.10. Physical sediment charactenstics for Big Rideau Lake. 70 Figure 4.1 1. "Opb activity, Ambrosia and sedimentary color changes for the 73 Lower Rideau Lake sediment core. LIST OF FIGURES (con't) page Figure 4.12. Diatom reconstructions and mode1 evaluations for Lower Rideau Lake (piston core). Figure 4.13. Diatom reconstmctions and mode1 evaluations for Lower Rideau Lake (short core). Figure 4.14. Correlations between DCA aisone sarnples scores and TP and MZ inferences in the short and piston cores fiom Lower Rideau Lake. Figure 4.15. Dominant diatom taxa % organics and cystdiatom profiles for Lower Rideau Lake (piston core). Figure 4.16. Physical sediment profiles for Lower Rideau Lake (piston core). Figure 4.17. Physical sediment profiles for Lower Rideau Lake (short core). Figure 4.18. Dominant