The Truth about DNA, Water Quality, and Pet Waste What do we know And What should we do?

Transcription

1 The Truth about DNA, Water Quality, and Pet Waste What do we know And What should we do? Ralph Svrjcek Water Quality Program (425)

2 2004: 6 Major Causes of Pollution Listings No. of Listed Segment Temp Bacteria D.O. ph Toxics Nutrients Causes

3 About 80 % of the urban waterbodies in the Lake Washington area have bacterial pollution problems.

4 We start out knowing that there is a problem in specific areas.

5 More research usually shows that the problem is widespread throughout the watershed.

6 How is pet waste like this..

7 Getting to local creeks?

8 Certainly not this way!

9 Who?...will clean up North Creek

10 Pet wastes and other substances are using our stormwater system as a pollution highway.

11 Stormwater system map

12 Creek in dry weather

13 Now add stormwater Yuck!

14 Put backyard photo here Is anything (like pet waste) getting thrown over this backyard wall? How do we prevent that from happening?

15

16 Science On-the-ground observations Social Sciences Traditional Water Quality Monitoring Microbial Source Tracking (DNA?)

17 On-the-ground Observations Locate septic systems & sewer lines. Walk local streams and ditches. Check sewer line crossings and pipe discharge areas for unusual growths, odors. Look for nutrient sources. Check behind fences (out-of-sight, out-of-mind).

18 Social Science What are animals doing? Where do they live? What do they do every day? What do they do for fun? What if they get sick? What pollution-generating behaviors can we change?

19 Water Quality Monitoring Sample streams and pipes for bacteria. Test for soaps, fluorides, chlorine, optical brighteners. Perform Microbial Source Tracking.

20 Microbial Source Tracking (MST) A method to determine the host origin of (fecal) bacteria or viruses in surface water. Concept: Fecal bacteria uniquely adapt to host gut environment so that once identified in host, can be identified in receiving waters.

21 Why do people want to use MST? Regrowth in Sediments Pet Waste Septic Tanks Leaky Sewers Birds Wildlife Alternative to traditional on-the-ground studies. Target limited resources. Confirm a source to give reason to act. Don t know what source is.

22 There are many MST lab techniques DNA Ribotyping Pulsed Field Gel Electrophoresis Rep-Polymerase Chain Reaction Quantitative Polymerase Chain Reaction Antibody Resistance

23 Many different organisms are used Bacterial Groups Escherichia coli (E. coli) Enterococcus Bifidobacterium Bacteroides-Prevotella Protozoan Oocyts Cryptosporidium sp. Viruses Coliphages

24 MST Methods Phenotypic methods: characteristics expressed by the bacterium Production of proteins Carbon utilization profiling Ability to survive special environments Genotypic methods: Presence of DNA/RNA-based material Ability to absorb dye during replication

25 From: Domingo et al Quo vadis source tracking? Towards a strategic framework for environmental monitoring of fecal pollution. Water Research 41 (2007),

26 What is MST?.many options available

27 Concerns over the use of MST Biogeographic stability Temporal variability Environmental factors Quantification not possible? Cost $75-$1,000 per sample

28 Edgewater Creek (2000) Swamp Creek (2000) Woodland Creek (2002) North Creek Bothell (2004) Green- Duwamish Watershed (2006) Thornton Creek, Matthews Beach (2007) Glennwood Source Creek Cat/Feline Dog/Canine Opossum/Rabbit <1 1.0 Raccoon Beaver/Rodent Muskrat/Skunk <1 Squirrel <1 0.4 Deer/Elk 6.6 <1 9.3 Bear/Bobcat/Coyote 1.8 Storm Drain 0.5 Human/Sewage Horse Bovine Chicken 0.7 Avian Waterfowl Goose Gull Duck <1 <1 Multi species 6.6 Unknown Total percentage # of isolates

29 Microbial Source Tracking Summary MST techniques are experimental, it is a good tool but use results with caution. Quantification of sources NOT POSSIBLE yet. Quantification of a single sample possible for certain animals (QPCR). Use only when you have high bacteria counts. Intense and rapidly developing field--current scientific literature should be consulted frequently. No single method can be applied to all types of water systems Lack of consistency among labs at performing these techniques. Beware of false negative results

30 Flowchart showing when Microbial source tracking should be used (for now). From: Domingo et al Quo vadis source tracking? Towards a strategic framework for environmental monitoring of fecal pollution. Water Research 41 (2007),

31 Recommendations Measure water quality. Identify high priority areas Find hot spots Look for obvious sources Tease out difficult problems using chemical methods and MST when appropriate. Perform Illicit discharge detection and elimination. Consult with Ecology and others when designing your monitoring plan. Change public behavior and prevent pollution from occurring.