CHEMICAL AND BIOLOGICAL RECOVERY OF KILLARNEY PARK, ONTARIO LAKES (1972-2005) FROM HISTORICAL ACIDIFICATION by JUSTIN A. SHEAD 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 September, 2007 Copyright © Justin A. Shead, 2007 i ABSTRACT Forty-five lakes in Killarney Provincial Park and the surrounding area in south- central Ontario, Canada, were sampled for crustacean zooplankton and water chemistry in the summer of 2005. For each of the lakes, we had historic data from peak- acidification in the 1970s and post-acidification periods in 1990 and 2000. Situated among the orthoquartzite ridges of the La Cloche Mountains in and near Killarney Provincial Park, many of these lakes were acidified during the mid-1900s owing to extensive mining and smelting activities in nearby (40-60 km) Sudbury, Ontario. There is large variation in the geochemistry of the soils and the bedrock within the park. As a result, these freshwater lakes have varying degrees of acidification, ranging from being heavily acidified (pH < 4.5) to others that were buffered from the effects of acidic deposition. With over 90% reductions in sulphur dioxide smelter emissions over the past 30 years and the present, many lakes in the Sudbury region are starting to show strong evidence of chemical recovery. Despite significant increases in lake water pH, there is limited evidence of biological recovery. A variety of univariate and multivariate metrics, as well as variation partitioning, were used to examine recovery on a lake-by-lake basis and on a regional scale. Our results revealed only moderate recovery of crustacean zooplankton communities despite improvements in water quality. Some lakes increased in zooplankton richness while others decreased compared to richness during peak acidification. Shifts in community composition from a damaged state toward those typical of circum-neutral lakes were observed for lakes that have chemically recovered. The lack of chemical recovery is believed to be impeding biological recovery of many lakes. Biological resistance and dispersal limitation do not appear to be hindering ii biological recovery. Other stressors such as the invasion by the predatory zooplankton Bythotrephes and climate change may delay biological recovery in the coming years. Future recovery of Killarney Park lakes will require further chemical recovery for biological recovery to become complete. iii CO-AUTHORSHIP This thesis conforms to the Traditional format as outlined in the Department of Biology Guide to Graduate Studies. Manuscripts that are to result from this thesis and their co- authors are listed below. Manuscripts directly from this thesis: Shead, J.A., S.E. Arnott, and A.M. Derry. In preparation for Ecological Applications. Limited biological recovery of Killarney Park Lakes (Ontario) from historical acid deposition despite chemical recovery: 1971-2005. iv ACKNOWLEDGEMNENTS First I would like to thank Shelley Arnott for giving me the opportunity to conduct this research and for allowing an “invasive species” into her lab. I would also like to thank her for her guidance throughout this process. I could not have asked for a better supervisor. Her passion for science and life is inspiring. Thank you to my committee members John Smol, Linda Campbell, and Paul Treitz for taking the time to be part of this process. Many thanks go to the staff at the Freshwater Cooperative Ecology Unit in Sudbury. In particular, Bill Keller, Jocelyne Heneberry, John Gunn, Shannon MacPhee, and Amanda Valois. Without their support this research could not have happened. I also would like to thank the staff at Killarney Park who helped with the logistics and to make this research possible. I cannot say thank you enough to my lab mates for being there for me through thick and thin. Thanks to Angela “A-Train” Strecker for sharing her infinite wisdom with me and having my back through this entire process. To Alison “Big Al” Derry, I too thank you for your endless support and advice throughout this journey. Big thanks go out to other members of Team Arnott - Jessica Forrest, Liz Hatton, Shannon MacPhee, Mike Pedruski, and Leah James for their support and making the lab a fun place to be. I also would like to thank all those that helped me in the field and the lab to whom I cannot say thank you enough. Thank you to my friends for your constant moral support, our “deep” conversations at the Secchi table, and for always being there. To my “French Brother” (a.k.a Le Moine), thank you for everything, you are a true friend. Last but certainly not v least, thank you to Isla for always being there, for sharing your tips as an “old pro”, and for being by my side through the good, the bad and the ugly. Finally, to my family I cannot thank you enough for being the pillar of support that you have been through this process. Thank you for always believing in my abilities and your words of wisdom. Although provinces apart, you have always been there for me. vi TABLE OF CONTENTS ABSTRACT ………………………………………………………………………………i CO-AUTHORSHP.……….……….…….……..………………………………...…..…iii ACKNOWLEDGMENTS……......…………………………………………………..…iv TABLE OF CONTENTS……….………...………………………………………….…vi LIST OF TABLES…...……………….……………….………………………………..vii LIST OF FIGURES……..…………………………………………………………..…viii CHAPTER 1: GENERAL INTRODUCTION AND LITERATURE REVIEW.........1 Crustacean Zooplankton as Biological Indicator Species………..………………..1 History of Acidification…...…..……….……….…….…….…………………… .1 Effects of Acidification…...…….…………………………………………………2 a) Chemical…………………………………………..……………………3 b) Biological………..………………………….…….........………………3 Recovery……………….…...…..…………………………………………………4 Chemical Recovery……………..…………………………………………………6 Biological Recovery……....…….…………………………………………………7 Recovery Barriers…….......…….…………………………………………………7 Thesis Objectives……........….….……………………………………………….10 CHAPTER 2: METHODS ………………..……………………….…………………13 Study Site……………………………………..……….…….……….…………..13 Sampling Design…..……………..…………….….…………………………… .13 Lake Categories.……………………………………..…..………………………17 Statistical Analyses………..…………………………………………..…………17 CHAPTER 3: RESULTS……….…………………………………….………………23 Potential Drivers of Biological Recovery…..………………………………..… .29 Evaluation of Spatial and Environmental Factors….……………..….………….30 CHAPTER 4: DISCUSSION….……..…………………………….…………………57 Chemical Recovery……………..………………………………………………57 Biological Recovery…….......….………………………………………………58 Barriers to Biological Recovery………………..………………………………61 Implications…………………………………….………………………………69 SUMMARY…………………...…………………………………….…………………73 LITERATURE CITED…………………………………………….…………………76 APPENDICIES…………...…….……………………...…….……….….……………86 vii LIST OF TABLES Chapter 2 TABLE 1. Selected physical characteristics of the 45 Killarney Park study lakes. Lake surface areas from Sprules (1975). Zmax = lake maximum depth, Secchi = secchi disk transparency.……………………………………………………………..…33 TABLE 2. Selected chemical and biological characteristics of the 45 Killarney Park study lakes. Lake water sampled as 5 m tube composite samples during July and August of 2005. Lake status defined as described in methods; acid = pH always < 6, recovered = pH increased from < 6 to > 6, circum-neutral = pH always > 6. Cond = Conductivity. TP = average total phosphorus from two samples taken at the same time. DOC = dissolved organic carbon, Ca = calcium, chl. a = chlorophyll a. Bytho and Fish = presence/absence of Bythotrephes and Fish respectively, 0 = absence, 1 = presence. Fish data from Snucins and Gunn (1998)………….. ……………………………………………………………..…35 Chapter 3 TABLE 3. Spearman's rank correlation coefficients (ρ) of year of study with recovery metrics in the 45 studied Killarney lakes in the three different lake categories. Evar = evenness. Lake ….……………………………………………………..…37 TABLE 4. Species names associated with ordination species code names. Arranged in alphabetical order of ordination code..………………………………………..…39 TABLE 5. Multiple regression of 1972 crustacean zooplankton species richness, diversity, evenness, and total abundance with predictor variables in all study lakes (n = 45). Predictor variables include pH, maximum depth, elevation, and total phosphorus. AIC = Akaike's Information Criterion, TP = total phosphorus....…40 TABLE 6. Multiple regression of 2005 crustacean zooplankton species richness, diversity, evenness, and total abundance with predictor variables in all study lakes (n = 45). Predictor variables include pH, maximum depth, elevation, and total phosphorus, dissolved organic carbon, and change in pH (measured as change in H+ concentration). AIC = Akaike's Information Criterion, TP = total phosphorus……...……………………………………………………………..…41 viii LIST OF FIGURES Chapter 1 FIGURE 1. SO2 emissions from the Sudbury, Ontario, area smelters (from Keller et al. 2007)……………………….….……………………………………………..12 Chapter 2 FIGURE 1. Killarney Park, Ontario, Canada. Shaded and black filled lakes indicate the lakes sampled within Killarney Park. Lakes Evangeline, La Cloche, Frood, and Charlton are located outside the park and therefore not shown on the map. Black lakes indicate previously observed presence of Bythotrephes. Shaded lakes have no previous Bythotrephes observations…………………………..42 Chapter 3 FIGURE 2. Linear regression between H+ concentration in 1972 (i.e., acidity) and chemical recovery (the change in H+ concentration between 1972 and 2005) for 45 Killarney Park lakes classified into three lake groups based on water quality improvements. Regressions are significant