Presentation on theme: "Intro to Macroinvertebrates"— Presentation transcript:
1Intro to Macroinvertebrates Aquatic EcologyDave WernerMATES
2Biological Monitoring Biological monitoring involves collecting, identifying and counting macroinvertebratesThe purpose of biological monitoring is to quickly assess both water and habitat qualityHealthy streams are characterized by abundant and diverse macroinvertebrate populations (however our key places importance on diverse populations)Monitoring involves quarterly sampling by volunteers
3What are Macroinvertebrates? Macros are organisms that lack a backbone and can be seen with the naked eye such as aquatic insects, mollusks and crustaceansThe organisms that we will be sampling for are benthic macroinvertebrates – macros that live in the substrate, or bottom, of a water bodyMacros live in various stream habitats and derive their oxygen from the waterThese organisms are impacted by all the stresses that occur in a stream environment, both man-made and naturally occurring
4Macroinvertebrates as Indicators of Water Quality Not very mobilePresent during ALL stream events (though recent heavy rains can affect results)Relatively easy to catch, view and identifyThey are affected by the physical, chemical and biological conditions of the streamValues may differ upon location
5When and how often?Because aquatic biological communities are relatively stable over time, plan on monitoring:Once every 3 months, season or quarterSame time and locationRecord weather conditions
6Stream HabitatsRiffles - shallow area of a stream in which water flows rapidly over a rocky or gravelly stream bedLeaf packs - decomposing vegetation that is submerged in the waterVegetated margins - area along the edge of water body consisting of overhanging bank vegetationWoody debris - dead or living trees, roots, limbs, or other submerged organic matterSand/rock/gravel streambed - area of stream with coarse substrate
7Stream Types and Sampling Locations Rocky Bottom StreamsGenerally found in Northern NJCharacterized by fast moving water flowing over large rocks and bouldersStream stretch consist of pool/riffle systemMuddy Bottom StreamsFound mostly in Southern NJ and urban environments due to erosion and sedimentationSlow moving water with little or no turbulenceSubstrate is generally composed of fine silt, sand or coarse gravel
8Rocky Bottom Sampling Method 3 Riffle areasSample 2x2 foot area with kick seine net4 Leaf packsTake 20g of leaves
9Sample 3 different habitats using D-frame net Muddy Bottom Sampling MethodSample 3 different habitats using D-frame netVegetative Margins7 scoops (1 square foot)Woody Debris with organic matter4 scoops (1 square foot)Sand/rock/gravel or coarsest area of streambed3 scoops (1 square foot)
10Calculate Your Results To calculate the results of your macroinvertebrate sampling use the forms in the field manualThese forms calculate the water quality rating based on the abundance, and more importantly, the diversity of benthic macroinvertebrates foundPollution Tolerance Index
11After Calculating Your Results… If you find:A variety of macroinvertebrates, lots of each kindLittle variety, with many of each kindA variety of macroinvertebrates, but a few of each kind, or No macroinvertebrates but the stream appears cleanFew macroinvertebrates and the streambed is covered with sedimentYou may have:Healthy streamWater enriched with organic matterToxic pollutionPoor habitat from sedimentation
12Group 1 Taxa Pollution Sensitive Organisms Require High Levels of Dissolved Oxygen Found In Good Quality Water
13STONEFLY NYMPH Measure 1/2 -11/2 inch in length (not including tails) 2 sets of wing padsBranched gills betweenlegs on underside of bodyYellow to brown in colorTwo hair-like tailsTwo claws on each footSuperficially similar to certain flattened mayfly nymphs, however stonefly nymphs always have two tails, prominent antennae, and two claws at the end of each leg.Stoneflies do not tolerant low levels of dissolved oxygen and therefore prefer cold, swift-moving streams. The streamlined, flattened bodies of stonefly nymphs enable them to move about the rocky streambed in rapid currents.Video Clip
14MAYFLY NYMPHSimilar to a stonefly, but with noticeable gills on abdomen and three tails instead of twoVideo ClipGills on abdomenUsually threehair-like tailsOne claw on each footMature larvae measure up to 3/4 inch in length (excluding tails)Two rows of long hairs present on inside of front legs, used for filtering food particles from the water.Slender antennaeMay be minnow like with a vertically oriented head and three tails (as pictured) or may be more flattened with a horizontally oriented head and two tails.
15CADDISFLY NYMPHBuilds distinctive cases made of sticks, rocks, sand, plant material and/or other debrisVideo ClipThree pairs of legsTwo claws at posterior endUp to one inch in lengthAntennae reduced and inconspicuousCurls up slightly (not as tightly as the common net-spinning caddisfly)
16Aquatic Snipe Fly Larva Paired, caterpillar-like prolegsFront of body tapered to a pointTwo pointed tails with feathery hairs at back endMeasure ¼ -1 inches in lengthMostly cylindrical, with the front tapering to a cone-shaped pointBody is pale brown to green colorLarva have a number of mostly paired caterpillar-like prolegsTwo stout, pointed tails with feathery hairs at back end
17WATER PENNY Measures 1/4 inch in length Flat disk-like body Head and legs concealed from above6 legs and branched gills on undersidePrefers cold running waterWater pennies prefer cold, fast-moving streams. Their smooth, flattened bodies enable them to resist the pull of the current. Water pennies are usually found on smooth rocks where they graze on attached algae
18RIFFLE BEETLE Riffle beetles measure approximately 1/16 to 1/4 inch in lengthBody small, usually ovalLegs are longAntennae are usually slenderRiffle beetles walk slowly underwater. They do not swim on the surface.
19GILLED SNAIL Shell usually opens on right Shell opening covered by a thin plate (operculum)When monitoring, do not count empty shells!
20Group 2 Taxa Somewhat Pollution Tolerant Organisms Require Moderate Levels of Dissolved Oxygen Found In Good or Fair Quality Water
21COMMON NET SPINNING CADDISFLY LARVA Dorsal plates (sclerites) on all three thoracic segmentsBody is caterpillar-like with three pairs of legsBody is strongly curvedBranched gills along underside of bodyBristle-like tuft at the end of the abdomen
22DOBSONFLY & FISHFLY LARVA Paired cotton-like gill tuftsMeasure 3/4 - 4 inches in length.Body is elongate and somewhatflattened.Short inconspicuous antennae.Large pinching jawsAbdomen terminates in two small prolegs, each bearing two claws.Feeds on other aquatic insects.Dobsonflies (hellgrammites) are usually found on the underside of large rocks in cool, slow-moving streams.Handle Dobsonflies (hellgrammites) carefully - larger individuals may deliver a painful pinch!Eight pairs of lateral appendages
23DRAGONFLY LARVA Measures between ½ - 2 inches in length Large eyes, large jaw that covers the underside of headStocky body without tailsMeasures between ½ - 2 inches in lengthTwo pairs of wing padsLarge round or oval abdomenAbdomen terminates in three small pointed structuresPrefers cool, still water. Often found among vegetation and leaf packs or burrowed in sedimentVideo Clip
24DAMSELFLY LARVA Measure ½ - 1 inch in length Large eyes, large jaw that covers the underside of headThree oar-shaped tails (gills)Measure ½ - 1 inch in lengthAbdomen usually much more narrow and slender than that of dragonflies
25CRANEFLY LARVA Measure 1/3-2 inches in length Head is usually pulled back into the front of the bodyFinger-like projections (gills) at back end of bodyMeasure 1/3-2 inches in lengthPlump caterpillar-like segmented bodyMilky green to brown color
26CRAYFISH Measure up to 6 inches in length Resembles a small lobster Large pinchersFive pairs of legsMeasure up to 6 inches in lengthResembles a small lobsterCrayfish are usually active only at night. During the day they hide in burrows or under rocks.Crayfish are omnivorous, eating both plants and animals.
27AQUATIC SOWBUG Measure 5-20 mm in length. Clear whitish to pink in color.Dorsoventrally flattened (top to bottom).Seven pairs of legs, the first two are modified for grasping.Found in shallow freshwater on rocks or detritus.
28SCUD Measure 5-20 mm in length. Clear whitish to pink in color. Laterally flattened (side to side).Found in shallow freshwater springs, streams, lakes and ponds.Most species feed on detritus.Scuds are an important food source for many fishes.
29CLAMS & MUSSELS Clam Mussel Fleshy body enclosed between two clamped shellsIf alive, shells cannot be pried apartWhen monitoring, do not count empty shells
30Group 3 Taxa Pollution Tolerant Organisms Require Low Levels of Dissolved Oxygen Found In Any Quality Water
31Has a distinct head and two small prolegs at the front of the body MIDGEFLY LARVAHas a distinct head and two small prolegs at the front of the bodyMeasure up to 1/2 inch in lengthBody small, cylindrical, and slightly curvedOccasionally deep red in color, otherwise variously coloredTwo small prolegs just posterior to headFrequently found in bottom sediments of lakes, streams, and ponds where they feed on deposited organic materialCh.5 – Bugs of the Underworld DVD
32BLACKFLY LARVA Measure to 1/2 inch in length Head contains fan-like mouth brushesBody is larger at the rear end, similar to a bowling pinMeasure to 1/2 inch in lengthAbdomen terminates in an attachment discBlackfly larva prefer cold running water and are usually found attached by the end of their abdomens to rocks, woody debris, or vegetation in the currents of rivers and streams
33LEECH Measures 1.0 mm to 5.0 cm in length. 34 SegmentsSuckers on both endsMeasures 1.0 mm to 5.0 cm in length.Typically dorsoventrally flattened.Leeches are common in warm protected waters of lakes, ponds, streams, and marshes.Leeches usually avoid light by hiding under rocks or among aquatic vegetation or detritus.Silty substrates are unsuitable for leeches because they cannot attach properly.
34AQUATIC WORM Measure 1-30 mm in length, but sometimes over 100 mm. Clear whitish to pink in color.Body consists of 7 to 500 segments.Segments often have bristles or hairs.Tolerant of low dissolved oxygen concentrations.Found in silty substrates and among debris or detritus in ponds, lakes, streams and rivers.Dense populations of Tubificids can often be found in organically polluted rivers.Approximately 200 species in North America
35LUNGED SNAILS Shell usually opens to the left when pointed end is up Breathes airNo operculumWhen monitoring, do not count empty shells!