Clowhom Lake Water Use Plan. Clowhom Lake Wildlife Census. CLOW-WUP-Wildlife. Year 4. Study Period: April 1, 2009 March 31, 2010

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1 Clowhom Lake Water Use Plan Clowhom Lake Wildlife Census CLOW-WUP-Wildlife Year 4 Study Period: April 1, 2009 March 31, 2010 D.J. Bates and G. Ferguson Resource Management Department shíshálh Nation PO Box 740, Sechelt, BC V0N 3A0 March 31,

2 Executive Summary The Clowhom Lake aquatic wildlife monitoring study was developed and initiated in 2006 in a small wetland complex at the north end of the Clowhom reservoir. The wetland complex was selected for its proximity to the reservoir and obvious influence from reservoir level and operation. The monitoring project includes the development of performance measures to track changes in both flora and fauna in the study area and is based on early studies of riparian vegetation development in response to reservoir operation conducted by BC Hydro. In Year 4 (2009/2010) a total of 3-field censuses (April, May and January) were completed. These surveys used the transect pattern established in 2006 with the crew working along the predetermined transects. Data was recorded on a spreadsheet for future inclusion in a database and analysis. This census is the last of the first rotation completing a full calendar year of surveys and resulting in the successful completion of the first 4-years of this project. Issues and challenges in this first rotation have been minor, requiring slight modification to the approach but still providing useful insight into the use of the area. Perhaps the greatest change to the original methodology has been the loss of wetland water level gauging. This will be corrected with the use of reservoir water levels and benchmarked elevations within the wetland, inferring influence of lake operation on the study area. This is not considered a significant deviation or restriction to the outcome. Changes in the water level recording have been proposed for the second rotation. In addition to the reporting of the data in 2009, recommendations have been proposed for the continuation of this study. They include: Collection of new air photos that cover the study area. This is required under the Terms of Reference and must be completed every 5-years. This facilitates an update of the vegetation typing and identification of community change. The start of the second rotation on this 20-yr study. New census months for 2010 will be June, October and February. Re-surveying of transect markers ensuring they are secure and not at risk of loss. Re-establishing a water level recording station in the wetland using a modified approach for the level recording. The proposed approach will include piezometer and depth logger installed within the wetland. 2

3 Table of Contents Page Executive Summary... 2 Table of Contents... 3 List of Figures... 3 List of Tables... 4 List of Appendices Introduction Study Area Methods Wildlife Census Data Analysis Results Vegetation Typing Wildlife Census Wetland Hydrology Discussion Vegetation Typing Wildlife Census Wetland Hydrology Future Recommendations References Appendices List of Figures Figure 1: Location of the Clowhom Lake wetland complex located at the head of the lake

4 List of Tables Page Table I: Amended schedule for the wildlife census conducted on the Clowhom Lake headwater wetland. The column highlighted in yellow is the completed census period in 2009/ Table II: Schedule for the wildlife census proposed for the second rotation of sampling. The column highlighted in yellow is the census periods for the 2010/2011 contract year... 9 List of Appendices Appendix I: Data collected from the April and May 2009 and January The data is entered on a spreadsheet

5 1.0 Introduction In 2009/2010, the shíshálh First Nation and BC Hydro completed the fourth year of a 20- year monitoring program documenting wildlife utilization of a wetland complex. The complex is located at the head of Clowhom Lake and is periodically influenced by reservoir operation that may flood the wetland and its vegetation communities. The monitoring program, implemented as a result of recommendations from the water use planning (WUP) process attempts to quantify and qualify change in the utilization and development of the wetland ecosystem by area wildlife during varying lake management scenarios. The purpose of this report is to present the results of the Year 4 sampling season, which completes a full calendar year of samples, referred to as the first rotation. The report also discusses issues encountered in the first rotation along with challenges and success. Lastly, this report provides recommendations for the next contract year. 2.0 Study Area The study area for the wildlife census remains the same as delineated in 2006 and includes a wetland complex located at the northeastern end of Clowhom Lake (Figure 1). The complex is approximately 500-metres upstream from the lake along the Clowhom River and is back-flooded cyclically from the lake as reservoir storage changes. The wetland is also inundated during spring and fall freshet events in the Clowhom River. The study area measures approximately 40-hectares and is characterized by both deciduous and conifer forest of various ages, patches of shrub layers and a large area consisting of wetland grasses and sedges. This vegetation cover has not been altered in 2009/2010 and the details of the vegetation polygons are summarized in Bates (2008). 3.0 Methods 3.1 Wildlife Census The wildlife census is conducted through the predetermined study area three times a year (Bates et al., 2009; Bates, 2008; Bates, 2007) by a wildlife biologist and technician. The census is completed within 1-2 hours after sunrise and is completed in 1-day. The crew follow transects that were geo-referenced and reported in Bates (2007). The census is conducted mid to late month and is weather dependent. The original Terms of Reference (ToR) (BC Hydro, 2005) called for the completion of the census mid month. This has proved difficult as the timing is more dependent on access to the study area and has on occasion been hampered by extreme weather conditions. The schedule in 2009/2010 was adjusted to ensure each calendar month was surveyed within the studies 5

6 . Figure 1: Location of the Clowhom Lake wetland complex located at the head of the lake.. 6

7 4-yr rotation. The schedule and adjusted census months is provided in Table I. Review of the data occurs in Year 5 as per the original project ToR. As in previous years the census begins at the designated start of the transect (T1) and the crew walks the predetermined route noting time and wildlife sign(s). Data is recorded in the field then transcribed onto a spreadsheet. Table I: Amended schedule for the wildlife census conducted on the Clowhom Lake headwater wetland. The column highlighted in yellow is the completed census period in 2009/2010. Year Census period 1 (2006/07) 2 (2007/08) 3 (2008) 4 (2009/10) 1 June July August April 2 October November September May 3 February March December January 3.2 Data Analysis Data are entered into a spreadsheet for future analysis. The format remains the same each consecutive year using the format reported in Bates (2007). All data will be collated as a time series in order to analyze for temporal trends in species diversity. Wildlife surveys were originally supplemented with vegetation data defining community types and structure (Bates, 2008). This data will also be applied to the 2009 data and facilitate comparison of species diversity to vegetation community structure for the 12 calendar month period. 4.0 Results 4.1 Vegetation Typing Vegetation typing remained unchanged in The vegetation classifications are based on the earlier air photo and ground-truthing reported in Bates (2008). 4.2 Wildlife Census The wildlife census was conducted three times in the 2009/2010 field season. The first census was on April 25, followed on May and lastly on January The census data is recorded on a spreadsheet for each sample date and is included in Appendix IV. 7

8 4.3 Wetland Hydrology The stage recording of water levels in the wetland has proven ineffective. In 2007 the first of 2 pressure transducers were installed in the wetland complex. Extreme low water and freezing conditions have resulted in the loss of both transducers with the first in late 2007 and second in late In 2008, stage recorders were added to the littoral lake-monitoring program at the north end of the lake. Recorded level values coupled with reservoir level/discharge and river discharge will be used to estimate inundation of the wetland. This data will be compiled in Discussion 5.1 Vegetation Typing Vegetation typing was required only once during the first census rotation and was completed using air photos collected on July 21, 2006 (Bates, 2007). Typed vegetation was ground-truthed in the spring of 2007 and polygon size and composition along transects reported (Bates, 2008). An updated typing of vegetation is scheduled to occur in This new vegetation survey will require new air photos to be collected mid July. When these new air photos are available, the study area will be vegetation typed and ground-truthed to compare with the original polygons along the study transects. This process is consistent with the ToR and will provide an updated description of the vegetation communities in the study area. 5.2 Wildlife Census Data presented in this report represents the final year of a four-year wildlife census cycle referred to as a rotation. In each of the years, a completed series of three censuses were conducted at varying months. The exact dates and month completed changed slightly from the original proposed schedule in the ToR but has had no bearing on the final outcome. The purpose of the staggered timing in this study was to ensure a calendar year was completed in a cost effective manner. This was achieved by spreading the sampling and sample intensity out over a longer period of time. The current schedule, presented in Table I has provided a complete year of observations. The completion of the first rotation of the wildlife census has proven successful. The most important component of this study success has been the involvement of field staff with exceptional observational skills. Much of the data collection relies on wildlife sounds and observed use, noting changes or altered habitat(s) to infer use. This emphasizes the importance and skills of the ground crews. While the original ToR called for trained biologists to complete the survey the pairing of a skilled biologist and technician has achieved excellent results and allowed skill building among the technical 8

9 staff. It is anticipated that the crew will remain the same for the second rotation of this project. Techniques and methodology will also remain unchanged. There has been some discussion regarding increasing the length and/or number of surveyed transects. This will be discussed with the field crew prior to the first census of the next rotation scheduled for June The scheduled census dates have been set for the second rotation. This schedule is presented in Table II with the methodology remaining the same as previous years. Crews will attempt to begin the census survey in the third week of each target month starting within 1-2 hours after sunrise. The monthly timing varies slightly from the ToR but remains consistent with weather-influenced changes in the first rotation. Table II: Schedule for the wildlife census proposed for the second rotation of sampling. The column highlighted in yellow is the census periods for the 2010/2011 contract year. Year (Rotation 2) (2010/11) (2011/12) (2012/13) 1 June July August September 2 October November December January 3 February March April May Census Number 4 (2013/14) 5.3 Wetland Hydrology The recording of direct water inundation of the study area has proven difficult. The loss of stage recorders during extreme low water periods in the winter resulted in a loss of two Global Water WL transducers. These transducer failures were a result of freezing of the units, which caused the loss of the data collection opportunity. As a result of transducer failures, lake levels recorded by BC Hydro and benchmarked elevations will be used to infer inundation at survey times for the first rotation. This evaluation of wetland flooding is a change to the original ToR. Water level in the wetland was to be used with lake level and upstream river discharge to develop an understanding of the extent of flooding that occurs in the wetlands. This original planned approach is practical but a change in data logging equipment is required and implemented for the second rotation. In addition to the existing information on reservoir levels it is proposed two new approaches to understanding and monitoring wetland water level be considered. The first is to install a new style of transducer (Onset ) in a piezometer installed within the wetland. This new installation will be conducted in June/July 2010 when the area is accessible. The second proposed change would be the development of a detailed topographic survey of the wetland complex using LIDAR imagery. The topographic data 9

10 would be tied into known elevation benchmarks and the flooding of the wetland modeled from reservoir levels and river discharge. The use of LIDAR will require discussions with BC Hydro. The issue of wetland water levels is not considered problematic. Automated data collection is frequently un-reliable without the injection of large costs and equipment. It is expected that predictions and modeling will be available using detailed data provided through reservoir and river records coupled with new direct stage recording within the wetland. It is anticipated that any future improvements to monitoring of the wetland water level can and should be used to develop and understand water inundation in the first rotation ( ) of this monitoring study. In conclusion, the 2009 sample season has proven successful with the culmination of a full calendar year cycle for the wildlife census. The components of the wildlife usemonitoring program have yielded data within the wetland complex and identified polygons. Minor issues hampering water level data collection has been met with an opportunity to explore alternate methodologies and will ultimately address the procedures and study hypotheses proposed in the original ToR. 6.0 Future Recommendations The first rotation of the wildlife use monitoring has been successfully completed. The establishment of study transects and vegetation typing has remained unchanged through the 4-year period with only minor alteration to the methodology originally proposed in the ToR (BC Hydro, 2005). In order to continue the success of this program there are required and recommended activities in These include: 1. A series of updated air photos that cover the study area is required. The ToR identified the requirement for new air photos every 5-years. This new flight line must be completed in the summer (July) of Once completed, a review and re-typing of vegetation polygons followed by vegetation ground-truthing will be undertaken. Again, these activities are consistent with the original study methodology (BC Hydro, 2005) 2. The start of the second rotation on this 20-yr study. The new census dates will initially follow the months proposed in Table II. Timing of the census will remain unchanged. 3. The re-survey of transect markers to ensure they are secure and not at risk of loss. Transects are geo-referenced and coordinates will be re-visited. This is not identified under the ToR but deemed essential to ensure future crews can locate the transect markers allowing for comparative sampling. 4. Re-establishment of a water level recording station in the wetland using different designs for the level recording. This new approach should be a piezometer or 10

11 well installed within the wetland. Ideally in an area that does not dry reducing the risk of transducer freezing. It is also recommended that a different style of transducer be deployed. It is anticipated that this costs will be within the current operating budget for the project. 5. It is recommended that the use of wetland topography be used to model water influence and estimate flooding of the study areas. This may be achieved through the use of LIDAR imagery and development of contour/elevation models. 7.0 References Bates, D.J Clowhom Lake Water Use Plan Clowhom Lake wildlife census Year 2. Resource Management Department, shíshálh Nation, Sechelt, BC. Bates, D.J Clowhom Lake Water Use Plan Clowhom Lake wildlife census Year 1. Resource Management Department, shíshálh Nation, Sechelt, BC. Bates, D.J., Staats, M. and Ferguson, G Clowhom Lake Water Use Plan Clowhom Lake wildlife census Year 3. Resource Management Department, shíshálh Nation, Sechelt, BC. BC Hydro, Clowhom Lake Water Use Plan-Monitoring Program Terms of Reference. BC Hydro, Burnaby, BC. 11

12 Appendices Appendix I: Data collected from the April and May 2009 and January The data is entered on a spreadsheet. 12

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