Biological monitoring #

Category: Watershed 101

Biological monitoring

The plants and animals in and around a waterway are excellent indicators of its health. The more diverse the populations, the better the waterway. If only a few species are present, the stream is most likely unhealthy.

Macro Guide #

Macroinvertebrates are a valuable water quality indicator when evaluating aquatic environments. Biological communities reflect the overall ecological health and integrity of a stream, providing links to the type and amount of pollution impacting a specific aquatic ecosystem. Because macroinvertebrates have limited migration patterns, a sessile mode of life and are well suited for their site specific locations, they are excellent indicators of localized stream health. Assessing biological communities is often a practical, low cost way of evaluating non-point sources of pollution degrading aquatic habitats. When sampling for macroinvertebrates, look in riffle areas (shallow areas,

with an abundance of rocks and oxygenated water to support macroinvertebrate life) and limit your search to the spring and fall. Winter sampling is not representative of the macroinvertebrate communities due to their unavailability. Some macroinvertebrates are more sensitive than others to pollution. A stream that is being impaired by AMD may be indicated by the absence of generally pollution sensitive macros and the dominance of generally pollution tolerant groups.

The EPA’s “Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates, and Fish” is designed to provide basic aquatic life data for water quality management purposes such as problem screening, site ranking, and trend monitoring. This publication is critical resource to all organizations undertaking a stream assessment.

Pollution Sensitivity #

Some organisms are very sensitive to pollution and will only inhabit clean, unpolluted water. Large numbers of these sensitive organisms indicate that the waterway is in good health. Other groups of organism are somewhat tolerant of pollution to very tolerant. As numbers of the pollution tolerant organisms increase and sensitive populations decrease, the health of the stream becomes is more precarious. Healthy streams have a diverse mixture of all groups, pollution sensitive and tolerant.

Pollution sensitive indexes have been developed for many organisms found in and around the waterways: insects, fish, algae, mussels, and bacteria. These indexes allow you to determine the health of the stream by surveying the population of organisms and calculating a Pollution Tolerance Index.

Common Biological Tests #

Biological testing can involve any organism that is a part of the waterway, including bird and mammal interaction. The two most common biological testing methods, however, are the biotic index and fish shocking.

The biotic index uses a pollution sensitive index to determine the health of a waterway from the macro invertebrate population. Macro invertebrates are the insects, molluscs, and worms living in the streams and rivers. They are large enough to be seen with the naked eye. Macro invertebrates may also be referred to as benthic, or bottom dwelling, organisms.

Fish shocking is another method of biological assessment. This method allows you to gain a fairly accurate representation of the fish population size and diversity. A similar pollution sensitive index to that of insects can be used on fish.

Biotic index

Macro invertebrates can be very descriptive of the overall water quality of a waterway, though they cannot pinpoint specific chemical parameters. Benthic (bottom dwelling) organisms: reflect the long-term condition of the stream from a variety of sources, have a high species diversity and are more sensitive to changes in the ecosystem than fish, and live at the bottom of the waterway, where pollution associated problems are often magnified.

Biotic surveys can be conducted in a number of ways. It is best to use a variety of capture methods as the insects have a wide variety of habitats. Many of the macro invertebrates are actually insect larva that bear little resemblance to the adult that many are familiar with. Some prefer to burrow into the sandy bottom of a stream, like midges. Others cling to the bottoms and sides of rocks. Some organisms prefer to live in quiet pools while others live in riffles. Riffles are the areas of water that are relatively fast-moving and flow over and around many rocks.

Macro invertebrate populations will respond readily to pollution of many kinds. It is important to remember this when doing a biotic index. If there are multiple pollution types in a stream, each has its own effect. The macros also respond differently to different types of pollution. Agricultural runoff with result in one kind of population change, acid rain another and AMD still another.

Functional Ecology #

One way that macro invertebrates can be classified is by using their functional ecology, or food gathering techniques. The basic groups include: scrapers, shredders, collectors and predators. Scrapers usually have very flat, sleek bodies that allow them the easily cling to rocks and scrape off algae for food. Some species of mayflies and stoneflies are scrapers. Shredders are organisms that devour the large particulate matter in the streams, such as dead leaves in the fall. Collectors are usually either filtering collectors or gathering collectors. Filtering collectors usually cling to the rocks, either through suction-cup like appendages or protective structures (cases) that they build and attach to the rock with ‘glue’. Nets or fine hairs are then released into the water to collect whatever food particles are passing by. Gathering collectors usually burrow into the sandy or muddy bottoms of the stream to find food. Collectors always search for fine particulate organic matter. Filtering collectors include caddis flies and black flies while an example of a gathering collector is a midge. The last group, predators, is self-explanatory in their feeding ecology. These insects prey on other macro invertebrates. Dragonfly nymphs are often found in area streams as dominating predators. Expect the number of predators to be the lowest portion of the population, if the predator population was too large, the entire macro invertebrate community would collapse.

For additional information on macroinvertebrates please go to Macroinvertebrate Guide.http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm

Collection Methods #

The four most common means of collecting benthic organisms are: rock washes, kick nets, sediment drags, and leaf packs. It is a good idea to use a combination of these methods to obtain an accurate portrait of the macro invertebrate population. One important thing to remember before doing any data collection is to start downstream first! This prevents contamination of the next sample site by any dirt, sediment or organisms that are stirred up from the first sampling. It is also a good idea to repeat each sampling method 2 to 3 times at each site to ensure an adequate sample is obtained.

Rock washing is by far the simplest method to explain, but can be difficult to do correctly. Be sure to have some basins available to wash the rocks in as well as sample bags if the samples will be taken to a lab for analysis. Try to choose 3 -4 dinner plate sized rocks from a riffle area. Fill the bottom of the basin with stream water and thoroughly scrub each rock, carefully setting them aside when done. Then proceed to find and identify your critters or transfer the water and

critters to bags to return to the lab. If you are taking the samples to a lab, be sure to have everything clearly labeled and identified. DO NOT MIX SAMPLES!

Kick nets are relatively easy to do, but are best done with 2 people. One person holds a D-frame net (so named because the opening is shaped like a D) against the bottom of the stream in a riffle area while the other person stands in front of the net and kicks the rocks in a approximately a 2 square foot area in front of the net for 2 minutes. D-frames have a fine mesh that allows water to travel through while trapping macro invertebrates. The nets can then be rinsed into basins and counted or rinsed into bags and taken to the lab. Be sure to have filters available to sift out sediment, but retain the macro invertebrates.

Sediment drags are similar to kick nets. It is possible to use a d-frame net for this as well. It this procedure, someone scoops into the sediment on the bottom of the stream and rinses it into a basin or bag as before.

Leaf packs are very easy to use, but require much more time. Prepare leaf packs by filling screen mesh bags with leaves, try to use the same kinds as the trees surrounding your stream. Make sure the mesh is large enough for the macros to climb in. Weight each bag with a rock and attach 3 or 4 to a brick or other weight. Place 3 to 4 bricks in various locations at each sample site. Allow the bricks to remain for about a month before collecting them. When collecting them be sure to look carefully, bricks are often moved by strong currents. Bag the leaf packs and take them back to the lab to count and identify the macro invertebrates.

Do not be surprised if the organisms you gather appear different from the adult, this is normal in insect development. Some of the macros go through incomplete metamorphosis so the nymph grows in size, but changes little in appearance. Others undergo complete metamorphosis, in which the larva looks nothing like the developed adult. At times even separate stages in the development of either type of insect can appear quite different. If there are any questions about the identity of a captured microorganism, be sure to make use of the available help from the conservation district or accessible qualified macro inverterbrate identifier.

Be sure to return most of your samples to the stream to prevent population depletion, questionable, interesting or required samples can be removed and kept for further reference.

Macroinvertebrates: all messed up see pdfs

The next group is http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm moderately sensitive or (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm)g (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm)anisms (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm). (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm)

Hi (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm)g (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm)h Sensitivity (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm) http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm Moderate Sensitivity (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm) http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG3.htm Low Sensitivity (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG3.htm)

For general information and descriptions of macro invertebrates view or download http://amrclearinghouse.org/Sub/WATERmonitoring/MacrosBack.pdf What are Macros? (http://amrclearinghouse.org/Sub/WATERmonitoring/MacrosBack.pdf)

Identification and classification manuals are available. For a listing of various sources please go to http://amrclearinghouse.org/Sub/WATERmonitoring/Resources.htm Resources (http://amrclearinghouse.org/Sub/WATERmonitoring/Resources.htm).

Fish shocking

It is debatable which reflects long term pollution trends better – fish or insects. A combination of both surveys can be very valuable and enlightening.

Fish shocking is used to gather a fair representation of the diversity of the fish population. In this method, electrical current is run through the water, momentarily stunning the fish which are then swept up in nets. the photograph on the overview page illustrates a group employing fish shocking.

The electrodes are attached to a large backpack which holds an electrical generator. The current follows through the water between the two hand-held electrodes. The number of people required to conduct a successful fish-shocking is determined by the size of the waterway. The must be enough people to follow along behind the electrodes to capture the shocked fish in nets as well as people carrying water-filled buckets. The buckets are used to deposit fish into while the fish shocking takes place. Most fish recover quickly from the shock and can be returned to the stream after counting with no ill effects.

The distance covered as well as the length of time should be recorded during a fish shocking. It is important to have trained professionals conduct or assist in this type of assessment to make sure that the equipment is operated safely and correctly with no harm coming to either fish or humans.

Fish shocking

It is debatable which reflects long term pollution trends better – fish or insects. A combination of both surveys can be very valuable and enlightening.

Fish shocking is used to gather a fair representation of the diversity of the fish population. In this method, electrical current is run through the water, momentarily stunning the fish which are then swept up in nets. the photograph on the overview page illustrates a group employing fish shocking.

The electrodes are attached to a large backpack which holds an electrical generator. The current follows through the water between the two hand-held electrodes. The number of people required to conduct a successful fish-shocking is determined by the size of the waterway. The must be enough people to follow along behind the electrodes to capture the shocked fish in nets as well as people carrying water-filled buckets. The buckets are used to deposit fish into while the fish shocking takes place. Most fish recover quickly from the shock and can be returned to the stream after counting with no ill effects.

The distance covered as well as the length of time should be recorded during a fish shocking. It is important to have trained professionals conduct or assist in this type of assessment to make sure that the equipment is operated safely and correctly with no harm coming to either fish or humans.

Common fish guide (pics needed)

The following pictures are examples of fish commonly found in streams and creeks in Pennsylvania. Fish shocking is a good way to capture and examine the fish in the watershed.

Black-nosed Dace

Sunfish #

Sunfish come in many sizes and colors, but basically the same shape. Many common sunfish, such as the Bluegill and Pumpkin seed have brightly colored earflaps beside their gills. Most sunfish inhabit quiet, weedy ponds or mud-bottom streams. Some are also found in rocky bottom streams.

Sucker #

Suckers are

Brook Trout #

Brook trout like cool, clear waters in lakes and large streams. Normally, these fish are found in more turbulent areas, such as riffles.

Johnny Darter #

The Johnny darter belongs to the perch family of fishes. They are commonly found on the bottom of streams. They settle to the bottom and dart forward occasionally. Darters are extremely sensitive to pollution and will only inhabit clean water.

The above information taken from A Guide to Common Freshwater Animals part of the Environmental Education Leaflet Series #6 published by the Commonwealth of Pennsylvania, Department of Environmental Resources, Office of Resource Management and Bureau of State Parks.

Descriptions of the fish can be found in Reader’s Digest North American Wildlife.

The Pennsylvania Fish and Boat Commission hosts an online guide to Pennsylvania Fishes. http://sites.state.pa.us/PA_Exec/Fish_Boat/pafish/gal1.htm l

Sources/Links (as provided in the source text):

• http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm
• http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm
• http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG3.htm
• http://amrclearinghouse.org/Sub/WATERmonitoring/MacrosBack.pdf
• http://amrclearinghouse.org/Sub/WATERmonitoring/Resources.htm
• http://sites.state.pa.us/PA_Exec/Fish_Boat/pafish/gal1.htm