Benthic Macroinvertebrate Ecology & Identification. Susan F. Cushman Hobart & William Smith Colleges Geneva, NY

Transcription

1 Benthic Macroinvertebrate Ecology & Identification Susan F. Cushman Hobart & William Smith Colleges Geneva, NY

2 Outline I. Reason to study, definition, identifying characteristics II. Sampling protocol III. Identification of major groups IV. Tier 2 analysis V. Stream habitat for macroinvertebrates VI. Aquatic food webs

3 Outline I. Reason to study, definition, identifying characteristics II. Sampling protocol III. Identification of major groups IV. Tier 2 analysis V. Stream habitat for macroinvertebrates VI. Aquatic food webs

4 Why Macroinvertebrates? Provide an integrated picture of stream chemistry (water quality), physical habitat, and environmental change Easy to collect and identify to determine potential impact Inexpensive equipment Assessment models are easy to understand Great activity to get kids involved with!

5 Definition A macroinvertebrate is the term used for invertebrate fauna that can be captured by a 500- m net or sieve. This includes arthropods (insects, mites, scuds and crayfish), molluscs (snails, limpets, mussels and clams), annelids (segmented worms), nematodes (roundworms), and platyhelminthes (flatworms). (Hauer and Resh, Methods in Stream Ecology, Academic Press, San Diego, CA.)

6 BMI Lifecycles Larval aquatic forms Spend most of their juvenile life underwater Live multiple years in water Incomplete Metamorphosis Complete Metamorphosis

7 Basic Anatomy

8 Outline I. Reason to study, definition, identifying characteristics II. Sampling protocol III. Identification of major groups IV. Tier 2 analysis V. Stream habitat for macroinvertebrates VI. Aquatic food webs

9 Macroinvertebrate Protocol Take one benthic sample per visit Disturb debris along diagonal transect for 5 mins Place contents of net in pan for inspection

10 D- net sampling

11 Outline I. Reason to study, definition, identifying characteristics II. Sampling protocol III. Identification of major groups IV. Tier 2 analysis V. Stream habitat for macroinvertebrates VI. Aquatic food webs

12 Major Group Analysis

13 Tier 2 Major Group Major Group: Ephemeroptera Common name: Mayflies

14 Tier 2 Major Group Major Group: Plecoptera Common name: Stoneflies

15 Tier 2 Major Group Major Group: Trichoptera Common name: Caddisflies

16 Tier 2 Major Group Major Group: Diptera - Chironomidae Common name: Midges

17 Tier 2 Major Group Major Group: Coleoptera Common name: Beetles

18 Tier 2 Major Group Major Group: Oligochaeta Common name: Aquatic worms

19 Biotic Index Analysis

20 Tier 2 Biotic Index Net spinning Caddisflies Non - Net spinning Caddisflies 7 10

21 Tier Two Biotic Index Major Group: Megaloptera Common name: Dobsonfly

22 Tier Two Biotic Index Major Group: Coleoptera Minor Group: Elmidae Common name: Riffle Beetle

23 Tier Two Biotic Index Major Group: Coleoptera Minor Group: Psephenidae Common name: Water Penny Beetle

24 Tier Two Biotic Index Major Group: Coleoptera Common name: Other

25 Tier Two Biotic Index Major Group: Diptera Minor Group: Tipulidae Common name: Crane Fly

26 Tier Two Biotic Index Major Group: Gastropoda Common name: Gilled Snail Major Group: Gastropoda Common name: Lunged Snail

27 Tier Two Biotic Index Major Group: Amphipoda Common name: Scud

28 Tier Two Biotic Index Major Group: Megaloptera Common name: Alderfly

29 Tier Two Biotic Index Major Group: Odonata Common name: Damselfy Dragonfly

30 Tier Two Biotic Index Major Group: Diptera Minor Group: Simuliidae Common name: Black Fly

31 Tier Two Biotic Index Major Group: Isopoda Common name: Sow Bug

32 Outline I. Reason to study, definition, identifying characteristics II. Sampling protocol III. Identification of major groups IV. Tier 2 analysis - PMA V. Stream habitat for macroinvertebrates VI. Aquatic food webs

33 PMA

34 PMA % 0% 28% 19% 6% 3% 3%

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37 Outline I. Reason to study, definition, identifying characteristics II. Sampling protocol III. Identification of major groups IV. Tier 2 analysis V. Stream habitat for macroinvertebrates VI. Aquatic food webs

38 Hierarchical classification of stream habitats

39 Habitat Complexity Habitat is made more complex by: Organic matter Large woody debris Rootwads Leaf packs/debris jams Channel morphology Geologic formations Forces of erosion (undercutting) Slope of the stream Pools, riffles, runs, glides Landscape influences Slope of the land adjacent to stream Landuse near the stream Low extent of upstream environmental impacts

40 Large woody debris - Non- living logs that are found near, hanging over, or in the stream channel

41 Rootwads - Living trees that line the streambank, which provide streambank stability and habitat for fish and macroinvertebrates

42 Undercut and eroded banks Undercut banks are stabilized by roots and provide habitat for fish and macroinvertebrates, while eroded banks have exposed, bare soil that are susceptible to future erosion from storm events and will release sediment into the stream channel.

43 Pool/Riffle System -Depth -Sediment size -Flow rate

44 BMI Habitat Preferred habitat varies Lithophilous taxa: stony substrates Ex. Water penny (Psephenidae) Sammophilous taxa: sandy substrate Ex. Tube- building caddisflies (hydropsychidae) Burrowing taxa: Ex. Amelytidae mayflies Xylophilous taxa: wood dwelling Ex. Some beetle larvae Phytophilous taxa: aquatic plants Ex. Rhyacophila caddisflies (free- living)

45 Outline I. Reason to study, definition, identifying characteristics II. Sampling protocol III. Identification of major groups IV. Tier 2 analysis V. Stream habitat for macroinvertebrates VI. Aquatic food webs

46 Invertebrate consumers Feeding Role Shredders Suspension Filter Collector Deposit Gatherer Grazer Predator Food Resources, Examples Non- woody CPOM, leaves, fungi, microbiota Trichoptera, plecoptera, crustacea FPOM, bacteria, sloghed periphyton Net spinning trich, simuliidae (diptera), ephemeroptera FPOM, bacteria Ephemeroptera, chironomidae (diptera) Periphyton, diatoms, biofilms Many ephem, trich; some diptera, coleoptera Animal prey Odonata, megaloptera, some Plec, Trich, Dip, Colep

47 Vertebrate inhabitants of stream ecosystems Leopard Frog No. two lined salamander No. Water snake Box Turtle Green Frog

48 Stream fish: minnows, sunfish, suckers, sculpins Blacknose Dace Bluegill Sunfish Rosyside Dace Green Sunfish Mottled Sculpin Creek Chub White Sucker

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