Wetland Monitoring in Cranberry Marsh Through the Durham Region Coastal Wetland Monitoring Project

Transcription

1 Wetland Monitoring in Cranberry Marsh Through the Durham Region Coastal Wetland Monitoring Project Greg Grabas Canadian Wildlife Service Environment Canada

2 Durham Region Coastal Wetlands Great wetlands High impacts A lot of monitoring Different methods 2

3 Durham Region Coastal Wetland Monitoring Project Bring together monitoring agencies and stakeholders Implement standardized methods Long term project Results easily understood by scientific and nonscientific interests 3

4 Proposal and Background Report (February 2001) Defined the need for the project Recommendations to the Implementation Committee (April 2001) Existing methods Expert advice Methodology Handbook I (March 2002) Data Quality Field Season (2002) Field Logistics Methodology Technical Reports Handbook II Fact (May Books 2003) Field Season ( )

5 Two Facets to Monitoring Physical Adjacent and watershed land use/veg. cover Sediment and water quality Water levels Bathymetry Sediment and nutrient loading (DEMs) 5

6 Biological Submerged aquatic vegetation Aquatic macroinvertebrates Fish Cranberry Amphibian (frogs and toads) Breeding birds 6

7 Index of Biotic Integrity Find attributes of the biotic community that respond to disturbance (e.g., species richness, abundance of marsh obligate species) Combine attributes and report out of 100 Higher scores indicate higher community biotic integrity 7

8 Additional Sites for Comparison 8

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11 Cranberry Marsh m 11

12 Cranberry Marsh m 12

13 Water Quality is Degraded Water Quality Index Excellent Very Good Good Moderately Degraded Very Degraded Highly Degraded Chow-Fraser (2007) WQI combines: Temp, Turbidity, Conductivity and ph Drawdown Year 13

14 Sediment Quality is Excellent Site Cranberry Marsh Lynde Creek Marsh Corbett Creek Marsh Virtual absence of threat or impairment; conditions very close to natural levels (Canadian Council of Ministers of the Environment 1999) 14

15 Aquatic Macroinvertebrate Community is Average but decreasing? 100 Excellent Index of Biotic Integrity Very Good Good Fair Poor Drawdown Year 15

16 SAV Community Not so good Excellent Index of Biotic Integrity Very Good 60 Good 40 Fair 20 Poor? Drawdown Year 16

17 Amphibian Community Rebounding? 100 Excellent 80 Index of Biotic Integrity Very Good Good Fair Poor Drawdown Year 17

18 Birds Improved 100 Excellent Index of Biotic Integrity Very Good Good Fair Poor Drawdown Year 18

19 Cranberry Marsh m 19

20 Cranberry Marsh m 20

21 Why have we not seen greatly increased biotic community condition? Not sure what pre-water level management conditions existed Bird community doing well increase in emergent vegetation = increase nesting, fledging habitat SAV, Macroinvertebrate, and Amphibian communities may still be affected by adverse conditions Unlikely to be sediment related 21

22 Water levels are decreasing 76.2 Level IGLD Mar 09-May 28-Jun 17-Aug 06-Oct 25-Nov Date 22

23 Temperature follows seasonal patterns Temperature (C) Temp 2003 Temp 2004 Temp 2005 Temp 2006 Temp Mar 09-May 28-Jun 17-Aug 06-Oct 25-Nov Date 23

24 Temperature increasing with lower water levels Temperature (C) Mar 09-May 28-Jun 17-Aug 06-Oct 25-Nov Date 24

25 Water Quality Index may be influenced by wetland water levels Water Quality Index Excellent Very Good Good Moderately Degraded Very Degraded Highly Degraded Chow-Fraser (2007) WQI combines: Temp, Turbidity, Conductivity, and ph Year 25

26 Water Quality Index may be influenced by wetland water levels Water levels reduced: less rain + warm summers Water loss through evaporation (incl. transpiration) Less water: Warms faster increases water temp May concentrate dissolved ions increases conductivity May decrease ph and affect turbidity For organisms existing in the water column, this may not be good 26

27 Loss of water = Loss of Aquatic Habitat SAV, Macroinvertebrate, and Amphibian (larval) communities all need water to survive Submerged Aquatic Vegetation Tadpole Macroinvertebrate 27

28 Bathy Cranberry Marsh DEM 75.5m or +1.35m asl Barrier- Protected System 74.98m or +0.78m asl 28

29 More of the marsh is mud flats Level IGLD Mar 09-May 28-Jun 17-Aug 06-Oct 25-Nov Date 29

30 Conclusions Re-established vegetation has allowed the breeding bird community to flourish Species occupying the water column are likely still experiencing adverse conditions water level related Low water levels are not due to management but instead a result of recent climate Sustained low water conditions would have occurred despite management Recommend: Post drawdown status quo Continue monitoring to support management decisions 30

31 Support Gratefully Acknowledged From: Central Lake Ontario Conservation Authority Toronto and Region Conservation Authority Ganaraska Region Conservation Authority Ontario Ministry of Natural Resources Environment Canada Ontario Canadian Wildlife Service Ecosystem Health Division Great Lakes Sustainability Fund Bird Studies Canada Michigan State University University of Toronto University of Windsor Regional Municipality of Durham Ontario Power Generation 31

32 Questions 32