湖沼學(xué)chapter13MethodofLakeSurveys

1、Introduction to Lake Surveys Basic Water Quality AssessmentUnit 3 Module 8 Part C Lake SamplingDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s2ObjectivesStudents will be able to:explain methods used for collecting water, sediment and aquatic organisms.identify reasons for collecting

2、 water and sediment pare and contrast the characteristics and use of discrete water samplers, integrated water samplers, grab samples and pumps. explain methods used for collecting contaminants and microbes.utilize guidelines to determine the size of the water sample needed to conduct specific analy

3、ses.demonstrate specified labeling techniques.describe the different methods of sediment sampling.categorize aquatic organisms by size.describe procedures used in sampling phytoplankton/algae, periphyton, zooplankton, and benthic pare and contrast direct and indirect quantitative analysis with quali

4、tative analysis used to study phytoplankton.classify periphyton by the substrates they grow pare and contrast quantitative and qualitative analysis used to study periphyton, zooplankton, and benthic invertebrates.describe procedures used in sampling aquatic vegetation.explain the importance of diato

5、ms in determining water quality.Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s3Basic water quality assessmentThese slides focus on learning basic field techniques used by limnologists:Morphometry - estimating critical lake basin measurementsField Profiles - physical and chemical pa

6、rameters measured from top to bottom of the water columnSampling collecting water, sediments, and aquatic organismsDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s4Lake samplingThis module contains information about the basic techniques needed to perform a baseline characterization o

7、f a lake.Learn how to collect water, sediment and aquatic organisms from different habitats.Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s5Lake samplingWater samples collected for: major ionsnutrients chlorophyll-a, phytoplanktontotal suspended solids, turbiditycolor, organic carbo

8、n, biochemical oxygen demand Iron (Fe) and other metals (special case mercury-Hg)organic contaminants (PCBs, PAHs, pesticides, hydrocarbons)bacteria (fecal coliforms, E. coli and other pathogens)Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s6Lake samplingSediment samples collected

9、for: bulk propertiesnutrientscontaminants (heavy metals, organics)organisms paleolimnological studies of lake history (fossil algae, zooplankton, insects, pollen)Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s7Lake samplingAquatic Organisms:PhytoplanktonZooplanktonBenthos and sedime

10、ntAquatic vegetationFish and fish habitat assessmentDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s8Water samplingConventionalAutomated water samplingContaminantsMicrobesHow much to collect ?Sample preservation and storageWhere to sample ?Developed by: E. Ruzycki and R. Axler Update

11、d: 12-14-03 U3-m8c-s9Water sampling conventionalConventional:Discrete water samplersVan Dorn, Kemmerer, Go-flow, Niskin and other closing bottles that collect water samples at discrete depthsIntegrated water samplersTubes that composite water from the surface to a set depthGrab samplesDipping a bott

12、le at the water surfacePumpsCan provide discrete or integrated samplesDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s10Water sampling discrete samplersUses bottles that have external trip mechanisms that close the bottle at depth.Requires a carefully metered or measured, non-stretch

13、ing rope or cablenylon is notorious for stretching over 10%tightly braided cotton or synthetic “non-stretch” sail rigging lines ( 550 oC) glassware to vaporize trace organic chemicalsDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s21Water sampling - contaminantsClean hands/dirty hand

14、s (CH/DH) method should be used for collecting and processing samples vulnerable to trace contamination by metals or trace organic compounds.CH/DH are required when collecting samples to be analyzed for metals (e.g., Hg) and other trace organic contaminants and inorganic elements.Developed by: E. Ru

15、zycki and R. Axler Updated: 12-14-03 U3-m8c-s22Water sampling - microbesSterile technique:Containers must be sterilized by autoclaving or with gas used to kill microbesTake care not to contaminate the container Water samplers should be swabbed with 70 % alcoholDeveloped by: E. Ruzycki and R. Axler U

16、pdated: 12-14-03 U3-m8c-s23Water sampling microbesGrab samples taken with sterile containers Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s24Sampling how much water do you need?Depends on the parameters to be analyzedChlorophyll and TSS often require the greatest volume ( 1L)Better

17、 to be safe and have too much water rather than too littleOften depends on how productive the system isAlso depends on how practical it is to carry out large volumes of waterDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s25Analyte/ volume tableAnalyteVolume neededchlorophyll500 mLsT

18、SSOften 1 Ltotal phosphorustotal nitrogenanions200 to 500 mLsDissolved nutrients 100mLsTotal and dissolved carbon60 mLs Metals60 mLs color, DOC60 mLsSuggested sample volumesDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s26Lake sampling filling the bottlesRinse containers with a smal

19、l amount of sample, discard, then fill with fresh sampleFill bottles completely to eliminate head space (unless the bottles are going to be frozen immediately)If using cubitainers put the cap on loosely, squeeze out all of the air, then tighten the capLeave space in bottles that are to be frozenDeve

20、loped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s27Lake sampling sample bottlesCubitainers work well for bulk samples that are to be split and processed later in the laboratory.High density polyethylene wide mouth bottles (60 to 1 L volume) work well for most analytes. They freeze well, d

21、ont crack and the wide mouth is easy to fill. Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s28Lake sampling sample labelingAn unlabeled sample may as well just be dumped down the drain.Use good labels not masking tape, etc. Poor labels often fall off when frozen samples are thawed.

22、Use permanent markers NOT ball point pens, pencils in a pinchDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s29A simple sample label with the minimum amount of information neededWOWShagawa Lake 7/26/021m RAW, frozenLake sampling sample labelingOften, much more information may be need

23、ed by the laboratory performing your analyses. You will also need to supply a chain of custody form. Lake sampling sample labelingprojectSite, date, depthSample processing and preservation infoDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s30Sediment sampling/nr/

24、environmental/water.htmDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s31Dredges Commonly used to grab a bottom sediment sample in lakes, estuaries and slower moving riversCollect soft sediments (mud and muck) for sieving out benthic organisms and also obtaining bulk sediment charact

25、eristics Common typesEkmanPetersonPonarQuantitative corersBox corersSediment samplingDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s32Photos of sediment samplersSediment sampling Ekman Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s33Sediment sampling Ekman dredgesm

26、all, light, easy to trigger by messenger (usually)stainless steel usually OK for contaminantsbest for muck, soft mud and silt where a relatively undisturbed sample down to 15 cm or more may be collectedmost common size = 6 inch cube (15 cm)not as good for sand; if sediment is compacted, or if much g

27、ravel, rocks, or large debris is present, the heavier Peterson or Ponar dredge is preferredDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s34Sediment sampling Ekman dredgeThis animation of the Ekman dredge, illustrates the chain of events during use./program_areas

28、/environmental/teach/smprimer/dredges/dredges.htmlDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s35Sample collection photos Sediment sampling Ekman dredgeInto the baggieExtruding (sub-coring)Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s36 humor photoThe jaws are s

29、trong .be careful Sediment sampling Ekman safetyDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s37photosPetersonPSediment sampling Peterson and PonarSediment sampling Peterson and Ponarusually require winches can sample coarser material than the Ekman (small woody debris and gravel)D

30、eveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s38Sediment “quantitative” corervariety of devices to collect undisturbed Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s39Sediment sampling box corersUsed for large lake and oceanographic researchDeveloped by: E. Ruzycki

31、 and R. Axler Updated: 12-14-03 U3-m8c-s40Sampling aquatic organismsLearn how to collect water, sediment and aquatic organisms from different habitats.Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s41Sampling aquatic organisms algaePhytoplankton (float freely in the water)Periphyton

32、 (attached to aquatic vegetation, rocks, wood and other substrates)Benthic algae (grow on the lake bottom/sediments); also sometimes called periphyton .nz/periphyton_/understanding/algae.htmlDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-

33、s42Sampling aquatic organisms zooplanktonZooplankton:Crustaceans (Cladocerans, copepods)RotifersProtozoans, ciliatesAquatic insects (e.g., Chaoborus)photo source: North American Benthological Society/see/questions/dp_biosphere/bios_place/dp_bios_place_.au/p

34、ages/research/hatchery-feeds/hfa-01.html/scripts/cf/result2.cfm?mis_index=110Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s43Sampling aquatic organisms - benthosBenthic macroinvertebratesAquatic insects (adults and larvae)LeechesCrayfishMussels, snailshttp:/w

35、ww.usask.ca/biology/skabugs/http:/www.usask.ca/biology/skabugs/http:/www.usask.ca/biology/skabugs/http:/www.usask.ca/biology/skabugs/http:/www.usask.ca/biology/skabugs/Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s44Sampling aquatic organismsAquatic macrophytesSubmergentEmergentFlo

36、atingBacterioplanktonFishPaleolimnology- reconstructing historical biological communitiesAlgae (usually diatoms)ZooplanktonBenthic invertebratesDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s45Sampling aquatic organismsAn alternate way of grouping aquatic organisms:Plankton (open wa

37、ter communities) = phytoplankton and zooplanktonBenthos (bottom communities) = periphyton, benthic macroinvertebrates, aquatic macrophytesFish (organisms that go where they choose)Dead stuff = detritusDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s46Sampling aquatic organisms by siz

38、eMost plankton sampling techniques are size selective (based on mesh size).Phytoplankton range in size from 0.2um to 200 um (from bacteria sized to colonies and filaments easily seen by the human eye).Zooplankton range from single-celled protozoans, 80 um rotifers, to crustaceans and insects (up to

39、millimeters in length)..au/pages/research/hatchery-feeds/hfa-01.htmlDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s47Sampling aquatic organisms by sizeTerminology is often confusingNannoplankton: 80 mFrom Wetzel 2001:picoplankton: 0.2 to 2.0 multraplankton : 2 to 20 mmic

40、roplankton: 20 to 200 m; usually refers to phytoplanktonMacroplankton: 2mm (2000 um) and up to cm in lengthDensities are expressed as:individuals per unit volume (#/L)biomass or weight (mg/L)Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s48 Reference table of sizes rangesFreshwater

41、Plankton Classifications with Suggested Mesh SizesMicron SizePlankton Classification1000Largest zooplankton and icthyoplankton (larval fish)750Larger zooplankton and icthyoplankton600Large zooplankton and icthyoplankton500Small zooplankton and icthyoplankton363Large microcrustacea243Microcrustacea15

42、3Microcrustacea and most rotifers118Small rotifers80Net phytoplankton and net zooplankton63Large nannoplankton and large diatoms10Small nannoplanktonSampling aquatic organisms by sizeDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s49Sampling - algae/phytoplanktonPhytoplankton (float

43、freely in the water)Periphyton (attached to aquatic vegetation, rocks, wood and other substrates)Benthic algae (grow on the lake bottom/sediments); also sometimes called periphyton Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s50Sampling - algae/phytoplanktonI. Goals of analysis1.Q

44、uantitative, direct; biomass, cell density2.Quantitative, but indirect; measuring chlorophyll concentration3.Qualitative; presence/absence, dominanceII. Sampling 1.Methods2.FrequencyDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s51Sampling - algae/phytoplanktonIII. Ancillary informa

45、tionIV. Preservation methods:IV. Counting methods: taxonomic guidescounting chambers, slidesmicroscopesArchivingV. Monitoring for toxic algaeDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s52Phytoplankton I. Goals of analysis1.Quantitative analysis (direct):For monitoring and researc

46、h purposesRequires a high level of expertiseThe cost ($250/sample) and time involved are usually too high for a typical water quality assessmentTypically surface water (0 m) or a 0-2 m composite is collected for long-term monitoring (because noxious scums of blue-greens collect in surface water; sit

47、e of water contact recreation)Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s53Phytoplankton I. Goals of analysis2.Quantitative analysis (indirect):such as chlorophyll concentration, provide an excellent index of the total amount of phytoplankton, but not what species are actually p

48、resent. A cost-effective strategy for many long-term monitoring efforts is to combine chlorophyll data with periodic qualitative community structure estimates.Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s54Phytoplankton I. Goals of analysis3.Qualitative analysisYields presence/abs

49、ence information Costs less to analyzeStill requires taxonomic expertise but goals of analysis are often different than quantitative (i.e., ID to genus level is often enough) or even to Class (blue-greens, diatoms, greens etc.)Collected as a whole water sample or by plankton netDeveloped by: E. Ruzy

50、cki and R. Axler Updated: 12-14-03 U3-m8c-s55Phytoplankton II. Sampling1.MethodsWhole water; integrated or grab sampleNets: mesh size appropriate to analysis goals10 um mesh will capture most phytoplankton; clogs easily howeverBlue-green algal scum can often be sampled by dipping a sample bottle but

51、 is effected by: time of daywind conditionsDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s56Phytoplankton II. SamplingImages of phytoplankton samplersIntegrated (whole water) sampler Van Dorn (whole water) sampler Plankton net/nr/environmental/Developed by: E. Ru

52、zycki and R. Axler Updated: 12-14-03 U3-m8c-s57Phytoplankton II. Sampling2.FrequencyWeekly to bi-weekly sampling is necessary to capture the seasonal dynamics of phytoplankton and to quantify abundance and biomass.Monthly may be adequate to provide an overall picture of the changes occurring in the

53、ice-free growing season when water quality criteria are usually most critical. Developed by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s58Phytoplankton III. Ancillary informationChlorophyllThe most common estimator of algal biomass Ideally best to have both chlorophyll and algal community ide

54、ntificationMore sophisticated techniques are becoming more available for major algal groups via detailed pigment analysisOther important dataNote any unusual odors when samplingSecchi depth and nutrients, silicaTemperature, DO, and light profilesDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-0

55、3 U3-m8c-s59Phytoplankton IV. Sample preservationLugols IodineStore in airtight glass containerStore in darkness (light sensitive)Stains starch a dark color which is useful for identifying green algaAdd enough to make 1% solution ( 0.5 mL to 50 mL sample yields the color of a fine brandy)Developed b

56、y: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s60Phytoplankton IV. Sample preservationOther preservatives:acid formalin solution (FAA) GluteraldehydeThese are known or suspected carcinogens and OSHA and state regulations for the workplace should be checked before useLong-term archiving may pro

57、ve useful to identify trends in species composition or even changes in morphologyDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s61Sampling - periphytonPeriphyton (attached to aquatic vegetation, rocks, wood and other substrates)Benthic algae (grow on the lake bottom/sediments); also

58、 sometimes called periphyton Photo source: Tahoe Research Group, U California-DavisDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-03 U3-m8c-s62Sampling - periphytonPeriphyton are algae attached to solid substrates; bottom sediment, rocks, twigs, beer cans, VW Beetles These benthic algae are cl

59、assified by the substrates that they grow on:Epilithic- on rock or other non-living substrateEpiphytic- on plantsEpizoic- on the surface of an animalEpipelic- on soft organic or silty sedimentsEpisammonic- on sandEpirefusic- on garbage in the lakeDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-

60、03 U3-m8c-s63Periphyton - samplingI.Goals of analysis1.Quantitative:biomass, chlorophyll (standing crop) per unit area, species ID, AFDW, organic matter2.Qualitativepresence/absence, relative abundance, dominanceII.Sampling methodsIII.PreservationDeveloped by: E. Ruzycki and R. Axler Updated: 12-14-