Lake Waban: Water Quality. Shoot the Messenger: Phytoplankton are both indicators and causes of poor water quality

Transcription

1 Lake Waban: Water Quality Shoot the Messenger: Phytoplankton are both indicators and causes of poor water quality

2 Lake Waban: Water Quality Eutrophic 1994: Pavla Zakova Cultural Eutrophication Carlson TSI: >50

3 Excess phosphorus among major water pollutants Inorganic chemicals Organic chemicals Sediment Radioactive materials Thermal pollution Infectious agents Oxygen-demanding wastes Plant nutrients: water soluble compounds containing nitrate, phosphate, and ammonium ions Human sources: sewage, manure, and runoff of agricultural and urban fertilizers Source: Revenga et al. 2000

4 Original/Actual Design Original: Tracing the phosphorus pollution to primary sources Fertilizers Algal blooms in Lake Waban Curtail the use of fertilizers Actual determine Lake Waban s water quality preventative measures Wellesley College could take

5 Total Phosphorus Source: Zakova 1994

6 Phytoplankton microscopic, photosynthetic plants and some species of bacteria. Green Algae, Diatoms, Euglenoids Cyanobacteria

7 Algal Blooms overabundance of nutrients. Eutrophication Blooms Phosphate levels of mg/l of water will trigger a bloom Life: Block sunlight, kill plants Death Deplete DO

8 Algal Blooms Source:

9 Cyanobacteria: Oscillatoria second most tolerant of organic pollution Thrive in the phosphate-rich lake waters Phosphorus limit growth limit

10 Oscillatoria

11 Green Algae: Spirogyra Grassy odor Source:

12 Spirogyra Source:

13 Diatoms: Navicula, Tabellaria, and Fragilaria Clean: low populations of many different species of diatoms. Polluted: the variety of diatoms decreases; pollution tolerant types increases Tabellaria: taste and odor Fragilaria Navicula: among most pollutant tolerant

14 Tabellaria Source:

15 Fragilaria Source:

16 Navicula Source:

17 Euglenoids: Euglena the most tolerant genus of organic pollution.

18 Protozoan: Paramecium

19 Indicators of Water quality Clean Water Surirella Pinnularia Ulothrix Navicula Cladophora Polluted Water Chlorella Spirogyra Anabaena Oscillatoria Chlamydomonas Nitzschia Euglena Taste and Odor Peridinium Ceratium Anacystis Volvox Tabellaria

20 Algal Genus Pollution Index (Palmer 1969) Genus Index Genus Index Anacystis 1 Micractinium 1 Ankistrodesmus 2 Navicula 3 Chlamydomonas 4 Nitzschia 3 Chlorella 3 Oscillatoria 5 Closterium 1 Pandorina 1 Cyclotella 1 Phacus 2 Euglena 5 Phormidium 1 Gomphonema 1 Scenedesmus 4 Lepocinclis 1 Stigeoclonium 2 Melosira 1 Syndra 2

21 Characteristics Determining Water Quality Characteristic Heavily Polluted Moderately Polluted Slightly Polluted Clean Water Water Condition Brown, possibly with scum and froth Brownish, possibly with scum or film May be nearly clear or slightly muddied Fairly Clear Protozoans Euglena, Amoeba Amoeba Paramecium, Euglena Stentor, Paramecium, Euglena Few Euglena, but not many ciliates Algae and Cyanobacteria Oscillatoria and possibly Melosira Oscillatoria and Spirogyra Pandorina Oedogonium and Navicula Diversity Index Source: Moody et al. 1985

22 Solutions? Biomanipulation: Zooplankton Prevention + Monitoring!

23 Cladocera Bosmina Source:

24 Cladocera Daphnia Source:

25 Copepods Source:

26 Zooplankton: Indicative of Water Quality At 20% grazing rate, zooplankton reduce phytoplankton populations by 75% Rapid decline in the phytoplankton population was accompanied by a resurgence of rotifers and of Cladocera, followed by another small resurgence of copepods in October. Source: Geismar 2001

27 Biomanipulation: Daphnia filter feeder, but Oscillatoria clogs its filtering apparatus Urban light pollution affects vertical migration of Daphnia

28 Prevention Zakova: Limestone berm: Long-term monitoring of the phosphorus, chlorophyll a levels of the lake Patrick Willoughby: To my recollection there has been no follow up regarding the recommendations in the report you are referring to These may be able to be added but I would need associated cost information before a decision is made.

29 Case Study: King County Major Lakes Monitoring Program Water Quality Monitoring on Lake Washington Algal Blooms/Phytoplankton Zooplankton Phosphorus Concentrations ake.htm

30 My Stella model