Benthic Macroinvertebrate Study

Transcription

1 City Of London Environmental and Engineering Services Department Wastewater Treatment Operations Benthic Macroinvertebrate Study Dingman Creek August 2013 Prepared by: Jessica Lompart and Tara McCowan Revised June 2014 by: Miranda Gregorio 1

2 Table of Contents 1.0 Introduction Benthic Macroinvertebrates Water Quality Indicators The Stonefly The Mayfly The Caddisfly Indicator Species Summary Data Analysis Research Materials (Field and Laboratory Work) Method Materials and Apparatus The Eckman Sampler Procedure Field Observations Old Victoria - Site # Highbury - Site # Green Valley Road - Site # Green Lane - Site # White Oak Road - Site # Wonderland Road - Site # Colonel Talbot Road - Site # Lambeth - Site # Additional Statistical Analysis Results Tables and Graphs Water Quality Observations Observations and Conclusions Recommendations Sampling Locations of Dingman Creek Appendix A: Benthic Survey Field Notes Appendix B: Quantitative Data Sheets

3 1.0 Introduction 1.1 Invertebrates Study Overview The Dingman Creek benthic macroinvertebrate study was undertaken by the City of London, Environmental & Engineering Services Department. Benthic sampling is a biological method of studying bottom dwelling aquatic organisms that can determine water quality. The diversity of aquatic species found livings on the creek beds are sampled. The Eckman sampling technique was suited for the slow flow and soft bottom of Dingman Creek and was used to collect the samples for this study. The City of London's primary objective in conducting benthic macroinvertebrates sampling is to quantitatively and qualitatively benchmark aquatic life forms of Dingman Creek. The Hilsenhoff's Family Biotic Index (FBI), Simpson's Index (Si) and Shannon s Diversity Index (H ) were used in the report for data analysis. The results from the data analysis were used to assess the water quality. 3

4 2.0 Benthic Macroinvertebrates 2.1 Definition Benthic macroinvertebrates are small organisms inhabiting the bottom of streams, rivers and lakes. They may roam freely over rocks and organic debris, or live in constructed cases, tubes, or nets attached to rocks during all or part of their life cycle. Macroinvertebrates have no backbone. They are retained on a U.S. standard No. 30 sieve (0.595 mm openings) (Standard Methods for the Examination of Water and Wastewater 22 nd Edition). Included among the macroinvertebrates are nemertea (worms, flatworms), gastropoda (snails), pelecypoda (clams, mussels), plecoptera (stoneflies), ephemeroptera (mayflies), trichoptera (caddisflies) and diptera (flies, mosquito larva, and midges). The composition and density of macroinvertebrate communities in streams, rivers and lakes, are reasonably stable from year to year in undisturbed environments. Seasonal fluctuations associated with life cycle dynamics of individual organisms may result in extreme variations at specific sites within any year. Most aquatic habitats, particularly free flowing waters with acceptable water quality and substrate conditions are able to support diverse macroinvertebrate communities. In this case, a reasonably balanced distribution of families and their genus among the total number of individuals is present. Macroinvertebrate communities respond to changing habitat quality by adjustments in their community structure. Many large rivers with acceptable water quality are dominated by a particular invertebrate. Small changes in their relative numbers may not be indicative of changes in water quality. 4

5 2.2 Environmental Impact Macroinvertebrate communities respond to environmental changes and are useful in assessing the impact of municipal, industrial, and agricultural wastes on water bodies. Changes in macroinvertebrate communities can be caused by organic loading (the increase of organic materials causing low dissolved oxygen levels), substrate alteration, and toxic chemicals. Organic pollution may cause low diversities in macroinvertebrate communities, as more sensitive species die off and tolerant species dominate, or even thrive. Organic pollution results in a decreased number of sensitive invertebrates and an increase in tolerant species. Siltation and toxic chemical pollution may not only reduce, but eliminate the entire macroinvertebrate community from the affected area. Not all cases conform to those described above because conditions may be mediated by other environmental and biological factors. Assessing the impact of a pollution sources generally involves comparison of macroinvertebrate communities, and their habitats at sites influenced by pollution, with those collected from adjacent unaffected sites. Using macroinvertebrates as an indicator is beneficial since they are generally stationary and inhabit areas suitable for their survival. They can also be used to locate a pollution source. This typically involves sampling and analyzing communities and then determining whether the presumed pollution affected community differs from an unaffected one. The basic information required for bottom fauna analyses is an identification and count of the individual organisms. From the data, the communities can be characterized and compared according to community structure, biomass, and diversity. Other water quality indicators such as dissolved oxygen concentration, ph, water depth, algae cover, and sediment type are equally important. 5

6 3.0 Water Quality Indicators 3.1 The Stonefly The stonefly or Plecoptera, are terrestrial insects but are not found very far from running waters. The adults are primitive in structure and have poor flight ability. The emerging nymphs and adults are readily spotted on the stones surrounding the river, thus earning their name. Emergence usually occurs during late winter or early spring. The nymphs are aquatic, but do resemble their adult relatives. The nymphs range in length from 6 to 50 mm and can range in colour from yellow, tan brown or black. The stonefly nymph is sluggish and can usually be found in masses of leaves or under stones in unpolluted streams. In general, they are found only where high levels of oxygen exist. Many stoneflies are carnivores feeding mainly on mayfly nymphs and diptera larvae. The nymph stage lasts one to three years. The stonefly nymph is a major source of food for trout. 3.2 The Mayfly The mayfly or Ephemeroptera, are widely distributed throughout the world. Different types of mayflies may be found in standing or running waters. A dissolved oxygen level of at least 2 to 5 mg/l is needed to support mayfly life. Mayfly eggs are usually deposited on the water surface in clusters. The eggs then sink to the bottom of the river where they stick to rocks. In the Baetis species, the female crawls beneath the water and lays the eggs on the river bottom. After the eggs hatch, the mayfly spends three to six months in the water before emerging as an adult. At this stage the insects are called nymphs. The nymphs are mainly herbivores, feeding on plant material and some animal material. A mayfly nymph can easily be distinguished by its three tails (cerci) and its ten segment abdomen. During the adult stage the male mayflies gather in large swarms. The female mayflies enter the swarm to choose a male partner for breeding. The adult stage usually lasts only three or four days. 6

7 3.3 The Caddisfly The caddisfly or Trichoptera is a relatively small order of insects widely distributed throughout the world. Adult caddisflies are small, brown or grey moth-like insects and are active mainly at night. Larval caddisflies live only in water. Caddisfly larvae produce special cases that are made of debris fastened by a silk web, this increases their respiration efficiency. Many of the net-spinning species build a fixed retreat or shelter in which the larva lies while food particles are collected from the current by its silken capture net. These retreat-makers are filter feeders and their food includes small fragments of plant and animal material, invertebrate feces and algal cells. Most caddisflies complete one generation each year, passing through five larval stages, a pupal stage, and a winged adult stage. The time required for completion of the actual metamorphosis, i.e. the emergence of adult from the pupal skin, is generally three weeks. 3.4 Indicator Species Summary Stoneflies are found in pristine cold running waters in masses of leaves or under stones. Stoneflies are good indicators of excellent water conditions while mayflies and caddisflies are indicators of good water conditions. In general, stoneflies are found only where high levels of oxygen exist. Mayflies and caddisflies are found in running or standing waters with oxygen levels at least 2 to 5 mg/l. Stoneflies have been found previously in 2010 at the Old Victoria and Highbury locations. Benthic sampling conducted in 2011 and 2012 showed no presence of Stoneflies in any of the sampling locations. 7

8 4.0 Data Analysis 4.1 Hilsenhoff's Family Biotic Index, Simpson s Indices and Shannon s Diversity Index Benthic data was analyzed using Hilsenhoff's Family Biotic Index (FBI), Simpson's Indices of Taxa Richness, Diversity and Evenness and Shannon s Diversity Index. Hilsenhoff's FBI (Hilsenhoff 1988) consists of each taxon being assigned a pollution tolerance value (Table 1). The scale ranges from 0 to 10, with 0 being the least pollution tolerant and 10 being the most tolerant. Taxa found in the sample were used to calculate a weighted FBI value that provides an indication of water quality for each site (see Table 1). To calculate the FBI value, the number of individuals found in each taxon is multiplied by the assigned pollution tolerance value and the sum of these products is then divided by the total number of individuals found in the sample. The FBI rating system was updated in Changes were made to the assigned pollution tolerance values for some taxa. This change means that the 2012 and 2013 FBI data will be comparable to 2011 but will not be comparable to previous years, however; it is a more accurate assessment of water quality. Taxa Diversity measures the richness and abundance of taxa in a community, Taxa Diversity, D, was calculated as: In this equation, S is the total number of taxa found, and Pi is the number of individuals in a specific taxa divided by the total number of individuals in the sample. Taxa Richness is a measure of the number of different taxa present in the sample whereas abundance measures the total number of individuals of that taxa in the sample. A balanced and stable community is represented by a large diversity value approaching unity. Diversity can never be smaller than 1/S, S equaling the total number of taxa found, which occurs when all taxa are equally abundant. Taxa Evenness, E, measures the relative abundance of each taxon amongst the taxa within a sample. Taxa Evenness was calculated as: In this equation, D is the taxa diversity calculated from the above equation and S is the total number of taxa found (richness). Evenness is measured on a scale of 0 to 1; as the 8

9 value approaches 1, the relative abundance of each taxa is evenly distributed representing a good evenness. Taxa evenness approaching 0 is poor, representing a sample dominated by a small number of taxa. Shannon s Diversity Index (H ) is an index used to measure the diversity of the sampled benthic community. It takes into account both richness and evenness of the taxa present. Shannon s diversity, H, was calculated as: H = Pi is the number of individuals in a specific taxa divided by the total number of individuals in the sample. Pi is calculated and multiplied by the natural logarithm of Pi, the product is summed for all taxa and multiplied by negative 1. 9

10 Table 1: Hilsenhoff's Pollution Tolerance Values for Calculating FBI Taxonomic Name Common Names Pollution Tolerance Value Elmidae Riffle Beetle 4 Psephenidae Waterpenny Beetle 4 Gammaridae Scud 4 Helobdella Leech 9 Sphaeriidae Fingernail Clam 7 Corixidae Water Boatman 5 Chironomidae Midge 6 Ceratopogonidae Biting Midge 6 Ephemeroptera Mayfly 4 Oligochaeta Aquatic Worm 8 Nematoda Thread Worm 8 Asellidae Sowbug 8 Prosobranch Gilled Snail 6 Pulmonate Lunged Snail 8 Decapoda Crayfish 6 Chloroperlidae Stone Fly 1 Sialidae Alder Fly 4 Hydropsychidae Caddisfly 4 Tipulidae Crane Fly 3 Simuliidae Black fly 6 Planaria Flatworm 4 Anisoptera Dragonfly 3 Arachnida Water Mites 6 Tabanidae Horsefly/Deerfly 6 Corydalidae Dobsonfly 4 Zygoptera Damselfly 5 Stratiomyidae Soldierfly 7 Hydrometridae Water Measurer 5 Gerridae Water Strider 5 Lepydoptera Pyralid 5 Hydrophilidae Water Scavenger 4 Ephydridae Brine fly 6 Helophorus Beetle 5 Haliplidae Crawling Beetle 5 Dytiscidae Predaceous Diving Beetle 5 Haliplidae Predaceous Water Beetle 5 Dytiscidae Diving Beetle 5 Empididae Dancefly 6 Hydrophilidae Water Scavenger Beetle 5 Athericidae Snipefly 4 10

11 ( UTRCA Benthic Sampling Data) (2005. R. Fox, Lander University) (2006 Soil & Water Conservation Society of Metro Halifax) (ZEAS 2008) (2010 Soil and Water Conservation Society of Metro Halifax (1993 Melvin. C. Zimmerman, Lycoming College) (2002 Benthic Macroinvertebrates in Freshwater, S.M. Mandaville) ( East Interlake Conservation District Data Report, Winnipeg) (2005 Parvin Branch and Tarkin Branch Watershed Restoration Master Plan, Citizens United) (Storm water Effects Handbook, G. Allen Burton, Jr and Robert E. Pitt Lewis Publishers, 2001-appendix B Benthic Community Assessment) (IDNR division of fish and wildlife lake and river enhancement program)- *The family biotic index list was updated accordingly. Table 2: Evaluation of Water Quality using the Family-Level Biotic Index Family Biotic Index Water Quality Degree of Organic Pollution Excellent Organic pollution unlikely Very Good Possible slight organic pollution Good Some organic pollution probable Fair Fairly substantial pollution likely Fairly Poor Substantial pollution likely Poor Very substantial pollution likely Very Poor Severe organic pollution likely (Hilsenhoff 1988) 11

12 5.0 Research Materials (Field and Laboratory Work) 5.1 Method The initial stages of the project involved planning the order of work to be done and conducting preliminary research. Information was compiled using previous studies prepared by The City of London, MOE, and Upper Thames River Conservation Authority. Research involved becoming familiar with the types of organisms which lived in and on the river and streams to be sampled. The correlation between certain species and water quality was determined using the Internet and other sources provided by professionals in the field. An Eckman sampling method was used in this study since it is recommended for areas with a soft creek bed and no riffles. In order to undertake the inventory of benthic macroinvertebrate samples, a checklist was devised. The criterion included stream width, depth, substrate, water clarity; macrophytes, algae cover, and bank vegetation (see Field Notes for each individual site). 12

13 5.2 Materials and Apparatus 1 Eckman sampler 2 Tweezers 1 Sieve bottom bucket 1 Large Sieve 1 Small Sieve 2 Chest waders 3 Large plastic bottles 2 Squirt bottles (rinsing) 2 White tubs 1 Laboratory sample bottle 1 Portable Dissolved Oxygen meter 1 ph meter 2 Petri dishes 85% ethanol alcohol Glass vials with lids Masking tape Field note templates Thermometer Digital camera 13

14 5.3 The Eckman Sampler An Eckman Sampler, or stream bottom sampler, is designed to collect insects, larva and other aquatic life forms for the purpose of water quality analysis. The Eckman Sampler was used in this study because Dingman Creek has very low water flow, a soft creek bed, with no riffle areas. The sampler was placed on the creek bed with its claws opened and pressed firmly into the sediment. The release catch was depressed, allowing the claws to close. Once the claws closed, the sampler was lifted out of the water and emptied into the screen-bottom bucket for washing. The sample was then rinsed into a large plastic jar and sealed. Sorting, identifying, and preserving the samples took place at the Greenway laboratory on the same day as the samples were collected. If sample sorting could not be done on the day of collection, samples were refrigerated at 4 o C overnight. 14

15 5.4 Procedure A total of 7 locations were sampled across the City of London. Three samples were taken at each site, one near the bridge, one upstream and one downstream of this location. While sites were sometimes chosen near the stream bank, an effort was made to choose sites that would always be submerged, even during dry periods. Invertebrates collected were then counted, placed in individual vials containing ethanol alcohol, identified on a taxonomic level and labeled. 15

16 6.0 Field Observations 6.1 Old Victoria - Site #1 This location was the most easterly of all the Dingman Creek sites, located at Old Victoria Road and Dingman Drive. Agriculture dominated the surrounding land use with corn fields bordering the creek on either side. The riparian vegetation included tall grasses, mature trees, shrubs and herbaceous vegetation. When sampling occurred the creek depth was higher than 2012 levels due to recent rainfall. The creek has a low flow rate at this location and the substrate varied from rocks, gravel, pebbles and twigs. A foamy scum substance was found downstream from the bridge. There was a buffer constructed along either side of the creek due to Old Victoria Bridge being recently rebuilt. A taxa richness of 7 was observed this year, a decrease from 9 in The dominant taxon found in 2013 was caddisfly larvae composing of 40.0% of the total taxa which differs from previous years having dominant taxa of midges. The Family Biotic Index was 5.54 (Fair), an increase from 6.25 (Fairly poor) in Upstream 3-June

17 Downstream 3-June-2013 Bridge 3-June

18 Family Biotic Index Taxa Richness Old Victoria Taxa Richness Year Old Victoria Family Biotic Index Year 18

19 6.2 Highbury - Site #2 This site is located at the intersection of Highbury Avenue at Dingman Drive. The area is primarily agricultural with a few residences including a cattle farm located on the eastern side of Highbury Avenue. The creek bed was rich in organic matter, mud, tree roots and sand. Algae were located along the banks of the creek and attached to some large boulders. Submergent macrophytes in the creek consisted of seaweed as well as emergent macrophytes such as grasses and reeds. In the late summer months the creek became overgrown with macrophytes. The water clarity at this sampling location was moderate. The taxa richness this year was found to be 17, an increase from 2012 having a value of 12. The dominant taxon for 2013 was midge larvae representing 40.2% of the total taxa which differs from 2012 which had a dominant taxon of aquatic worms. The FBI value was calculated as 7.56 (Very Poor) a decrease from the 2013 rating of 7.26 (Poor). Upstream 5-June

20 Downstream 5-June-2013 Bridge 5-June

21 Family Biotic Index Taxa Richness Highbury Taxa Richness Year Highbury Family Boitic Index Year 21

22 6.3 Green Valley Road - Site #3 This site is located off of Green Valley Road. An industrial area is present to the north where an open storm sewer drains south into Dingman Creek. The creek is surrounded by various vegetation including trees, shrubs and tall grasses. Algae were observed on some rocks and floating on top of the water. A beaver dam was located downstream of the outfall causing the upstream water depth to increase. Benthic sampling at this site did not occur this year due to increased water levels upstream from the beaver dam. The water clarity was observed to be cloudy and poor upstream and relatively clear downstream this difference may have been due to the difference in water depth. Upstream 6-June

23 Downstream 6-June-2013 Beaver Dam 6-June

24 6.4 Green Lane - Site #4 This site is located on a private road owned by Orgaworld. This road allows access to its recycling depot, BFI, and the Orgaworld composting plant. The closed Westminster PCP is located on the North side of the site. The surrounding creek land use is primarily agriculture. There are two large and one small storm sewer discharges upstream. The substrate consisted of large rocks, clay, sand, silt and tree roots (downstream). The water clarity was poor and the riparian vegetation consisted of tall grasses, trees, shrubs and herbaceous vegetation. The taxa richness this year was 12, a decrease from 14 in The dominant taxa this year was aquatic worms, similar to 2012, consisting of 50.0% of the sampled benthic community. The FBI was 7.06 (Poor) similar in water quality of 7.02 (poor) in Shannon s diversity index (H ) was 0.57 a decrease from 0.67 in Upstream 6-Jun

25 Downstream 6-Jun-2013 Bridge 6-Jun

26 Family Biotic Index Taxa Richness Green Lane Taxa Richness, Year Green Lane Family Biotic Index, Year 26

27 6.5 White Oak Road - Site #5 This site is located at the corner of White Oak Road and Dingman Drive. Similarly to the other sampling sites located along Dingman Creek, the surrounding land use is agricultural. A storm sewer outlet was located upstream. The riparian vegetation upstream consisted of tall grasses and herbaceous vegetation whereas mature trees and shrubs were predominating downstream. The substrate was mainly silty sand with pebbles, a few rocks, and very muddy under the bridge, clay and organic matter was observed upstream. The creek was swollen and water clarity was very poor due to a recent rainstorm, no shallow areas were visible and some algae was present on banks. The taxa richness was 14, an increase from 13 in As was the case last year, the dominant taxa were fingernail clams representing % of the sampled benthic macroinvertebrate community. The FBI was 7.26 (Very Poor) a decrease in water quality from 7.13 (Poor) in Upstream 11-Jun

28 Downstream 11-Jun-2013 Bridge 11-Jun

29 Family Biotic Index Number of Species Found White Oak Taxa Richness, Year White Oak Family Biotic Index Year 29

30 6.6 Wonderland Road - Site #6 This site is one of the additions in 2004 to assess water quality between the White Oak Road and Lambeth site. Located on Wonderland Rd. S just north of the 402 overpass, there is a large farm that runs along the creek from White Oak Road to this site. In the past there has been a decrease in the water quality at the sampling site, however; since 2008 there has been an increase in the taxa diversity showing that the quality of the water has been improving except for the slight decrease in The creek at this location is surrounded by agricultural fields and a few residences. A sewage odour was present downstream, and the riparian vegetation included some tall grasses with mature trees and the water clarity was poor. The creek substrate consisted of tree branches, gravel, mud and organic matter. The taxa richness this year was 17, an increase from 15 in Consistent with the past 3 consecutive years, aquatic worm was the dominant taxon representing 40.62% of the sampled benthic community. The calculated FBI was 6.84 (Poor) an increase in quality from last year, 7.41 (Very Poor). Upstream12-Jun

31 Downstream 12-Jun-2013 Bridge 12-Jun

32 Family Biotic Index Taxa Richness Wonderland Taxa Richness, Year Wonderland Family Biotic Index, Year 32

33 6.7 Colonel Talbot Road - Site #7 This site has been monitored since 2004 and is downstream from the Wonderland Road sampling site. Greenhills Golf Course is directly east and residences are located to the west. The storm outlet that was observed last year was not visible due to high water levels; the stream was very swollen and water clarity was poor due to a recent intense rain event. Large trees, shrubs, tall grasses and herbaceous vegetation along the banks were submerged. The taxa richness was found to be increasing since This year there was a decrease of taxa richness to 12, from 18 in Similarly to previous year s sampling, aquatic worms were the dominant taxa making up 83.95% of the samples. The calculated FBI was 7.51 (Very Poor) a decrease in quality from last year s value of 7.47 (Fairly Poor). Upstream 17-Jun

34 Downstream 17-Jun-2013 Bridge 17-Jun

35 Family Biotic Index Taxa Richness Colonel Talbot Taxa Richness, Year Colonel Talbot Family Biotic Index, Year 35

36 6.8 Lambeth - Site #8 This is the most westerly site and is located where Highway 2 crosses Dingman Creek in Lambeth. In 2009, due to high water levels and difficulty sampling at Lambeth, insufficient biota was obtained in the first sample; so the second sample was taken at Kilbourne Rd., just west of Colonel Talbot Rd in Lambeth. Since 2010, the sampling has been conducted at the Lambeth site located on Longwoods Road; and high water levels due to recent heavy rainfall were observed in The surrounding land use consists of Lambeth Centennial park located to the north, residential to the east and agricultural lands to the west. The taxa richness was 13, a decrease from 19 in 2012, with aquatic worms, similar to 2012, dominating % of the sampled benthic community. The calculated FBI was 7.15 (Poor) a decrease in quality from 6.89 (Poor) in Upstream 19-June

37 Downstream 19-June-2013 Bridge 19-June

38 Family Biotic Index Taxa Richness Lambeth Taxa Richness, Year Lambeth Family Biotic Index, Year 38

39 7.0 Additional Statistical Analysis The Pollution Tolerance Index, Taxa Richness, Simpson s Indices for diversity, evenness, Hilsenhoff s Family Biotic Index and Shannon s Diversity Index are indices used in the following table. Table 3: Data Analysis Results Site Taxa Richness Taxa Diversity Taxa Evenness FBI Shannon s Diversity H 1. Old Victoria Rd (F) Highbury Ave (VP) Green Valley Rd. Not Sampled Not Sampled Not Sampled Not Sampled Not Sampled 4. Green Lane (P) White Oak Rd (VP) Wonderland Rd (P) Colonel Talbot Rd (VP) Lambeth (VP) *P = Poor, FP = Fairly Poor, F = Fair, G = Good, E = Excellent Taxa richness measures the number of different taxa found in the sample. Highbury Avenue and Wonderland Road had the highest taxa richness with 17, followed by White Oak Road having 14 taxa representing the sample. Old Victoria had the lowest taxa richness with only 7 taxa present. High diversity values are an indication of a balanced and stable benthic community. Stable benthic communities are represented by a large number of taxa present in similar numbers. Highbury Avenue had the highest diversity value of all sampled sites of 3.75, while the site with the lowest diversity value of 1.41 was Colonel Talbot, which was dominated by aquatic worms (83.95%) and Midges (3.68%). Both taxa are tolerant of pollution, indicating an unstable benthic community. Evenness measures how abundance is divided among all taxa present in the sample, an even community is represented by taxa present in equal proportions whereas uneven communities are dominated by one or few taxa. Old Victoria Road had the greatest taxa evenness and Colonel Talbot had the lowest evenness. White Oak, Colonel Talbot and Lambeth all had relatively low taxa evenness, and although the dominant taxa at White Oak was fingernail clams, there was also a high number of aquatic worms present causing a low taxa evenness. At Colonel Talbot and Lambeth, at least half of the sampled benthic community was dominated by a single species. Due to the formula used to calculate evenness, samples with very low taxa richness and had one taxon dominating the sample may indicate an acceptable evenness value, while the sample is still very uneven. 39

40 The Family Biotic Index results indicate that the site with the best water quality was Old Victoria, similarly to the 2012, with a value of 5.54 and a Fair water quality rating. The site with the lowest water quality was Highbury Avenue with a FBI value of 7.56 and a Very Poor water quality rating. Overall, 4 out of 7 sites (Highbury, White Oak, Colonel Talbot and Lambeth) scored very poor. Green Lane, and Wonderland, scored a water quality rating of poor. Compared to last year, all but two sites family biotic index ratings have increased indicating a decrease in water quality, except for Old Victoria and Wonderland. Rainfall in 2012 was about 30 % below average and rainfall in 2013 based on the first six months was 1,136 mm annual average equivalent. The 2013 rainfall was about 30% above average. There would be a significant difference in runoff between 2012 and At the Green Lane, Wonderland, Colonel Talbot and Lambeth sampling locations the dominant taxa of the sampled benthic community was aquatic worms, which are very pollution tolerant. Midges, also pollution tolerant taxa were the dominant taxa at Highbury and Fingernail Clams also a pollution tolerant species was the dominant taxa at White Oak. Shannon s diversity index (H ) is a measure that describes how diverse the benthic community is and also how the abundance of the taxa are distributed among all of the taxa in the community. High H represents a more diverse community with a proportional distribution of taxa. The site with the highest index was Wonderland with a value of The site with the lowest index value was Colonel Talbot with a value of Shannon s diversity index values are also consistent with Simpson s diversity and evenness results. Overall, as the water quality decreases, the number of individuals of pollution tolerant taxa increase, the ratios between the different types of taxa increases and pollution tolerant taxa become more prevalent. 40

41 8.0 Results Tables and Graphs 8.1 Quantitative Results Taxa (Common Name) Taxa (Scientific Name) Site 1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 7 Site 8 Riffle Beetle Elmidae Riffle Beetle Larvae Elmidae Water Penny Beetle Psephenidae Scud Gammaridae Leech Helobdella Fingernail Clam Shaeriidae Water Boatman Corixidae Midge Larvae Chironomidae Midge Pupa Chironomidae Midge Chironomidae Mayfly Nymph Ephemeroptera Aquatic Worm Oligochaeta Biting Midge Larvae Ceratopogonidae Biting Midge Pupae Ceratopogonidae Sowbug Asellidae Gilled Snail Prosobranch Lunged Snail Pulmonate Crayfish Decapoda Crayfish Larvae Decapoda Stone Fly Nymph Chloroperlidae Alderfly Larvae Sialidae Pyralid Caterpillar Lepydoptera Caddisfly Larvae Hydroptilldae Cranefly Larvae Tipuidae Beetle Helophorus Deer Fly/Horse Fly Tabanidae Larvae Deer Fly/Horse Fly Tabanidae Pupae Black Fly Larvae Simuliidae Black Fly Pupae Simuliidae Flatworm Planaria Dragonfly Nymph Anisoptera Damselfly Nymph Zygoptera Diving Beetle Haliplidae Diving Beetle Larvae Haliplidae Water Strider Gerridae Water Mite Arachnidae

42 Taxa (Common Name) Taxa (Scientific Name) Site 1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 7 Site 8 Dobsonfly Larvae Corydalidae Soldierfly Larvae Stratiomyidae Crawling Beetle Haliplidae Crawling Beetle Haliplidae larvae Water Beetle Haliplidae Dancefly Larvae Empididae Total Number of Individuals:

43 Family Biotic Index Number of Species Found 8.2 Taxa Richness 18 Dingman Creek Taxa Richness, Old Victoria Highbury Green Lane White Oak Wonderland Colonel Talbot Lambeth Sampling Site 8.3 Family Biotic Index Dingman Creek Family Biotic Index, Old Victoria Highbury Green Lane White Oak Wonderland Colonel Talbot Lambeth Sampling Site 43

44 Shannon's Diversity Index 8.4 Shannon s Diversity Index Dingman Creek Shannon's Diversity Index, Old Victoria Highbury Green Lane White Oak Wonderland Colonel Talbot Lambeth Sampling Site 44

45 9.0 Water Quality Observations Table 4: Water Quality Observations Site Dissolved Oxygen ph Temperature ( C) (mg/l) 1. Old Victoria Highbury Green Valley Not sampled due to high water levels caused by a beaver dam Not sampled due to high water levels caused by a beaver dam 4. Green Lane White Oak Wonderland Colonel Talbot Lambeth Not sampled due to high water levels caused by a beaver dam 45

46 10.0 Observations and Conclusions A diverse and proportionally distributed benthic macroinvertebrate community is an indicator of a balanced and stable community. Higher diversity indicates that the aquatic environment is suitable for many different types of macroinvertebrate communities. As the water quality decreases the taxa diversity decreases because more pollution tolerant taxa become present and pollution intolerant taxa disappear. Macrophytes present in the creek can provide habitat and nutrients for benthic macroinvertebrates. Dense plant growth was present at the Highbury, White Oak and Wonderland sampling locations. The plant growth is also indicative of higher nutrient loadings, which may have been due to run-off from agricultural fields that are in close proximity to the creek at these sites. The dissolved oxygen levels of Dingman Creek ranged from 7.39 mg/l at the Colonel Talbot site to 9.24 mg/l at the Lambeth site. There were slight variations in ph across all sampling locations ranging from 7.02 at Highbury and White Oak and 7.91 at Lambeth. Old Victoria had the coldest temperature of 7.0 o C while the Colonel Talbot site had the warmest temperature of 22.0 o C. Lower water temperatures compared to last year and high water levels, especially at Colonel Talbot and Lambeth were due to a large amount of precipitation this sampling season. The annual rainfall in 2012 was 660mm with an average of 970 mm for the past 27 years. The rainfall for the first 6 months of 2013 was an average of 1,136 mm Comparison Dingman Creek Taxa Richness: The taxa richness decreased for 4 sampled sites compared to 2012 with the greatest decrease occurring at the Colonel Talbot and Lambeth site. Decreasing taxa diversity indicates an overall decline in creek water quality. Conversely, the Highbury Ave site had the greatest decrease in 2012 where as in 2013 it had the greatest increase in taxa richness. The taxa richness increased from 12 in 2012 to 17 observed in Dingman Creek Family Biotic Index: Compared to the 2012 FBI ratings, most of the sites had an increase in the FBI values (decrease in quality) with the exception of Highbury and Wonderland which improved from 6.25 to 5.54 and 7.41 to 6.83, respectively. Overall, the FBI results indicate a decrease in creek health. 46

47 10.2 Overview Water pollution can reduce the number of macroinvertebrate species present, since the aquatic environment can only sustain pollution tolerant species and sensitive species tend to disappear. The Hilsenhoff Family Biotic Index is formulated on the basis that different organism s degree in pollution tolerance differs. For example, gill breathing Stonefly, Mayfly and Caddisfly taxa are only able to survive where there is an abundant amount of dissolved oxygen. These species are intolerant of pollution because their sole oxygen requirements come from the water. Other macroinvertebrates that can survive at low dissolved oxygen concentrations can breathe atmospheric oxygen or have respiratory adaptations that allow them to capture low amounts of dissolved oxygen from the waters. Due to different respiration methods of benthic macroinvertebrates the pollution tolerance values for each family are ranked by their dissolved oxygen requirements and response to organic pollution. When organic pollution is present the biochemical oxygen demand is high due to the decomposition of the organic matter which requires oxygen. Using the FBI can provide a rapid evaluation of water quality without the requirement of being able to identify organisms at the genus or species level. The FBI uses an average pollution tolerance score for a family instead of difference in species. = Additional quantitative and qualitative information should also be collected for the interpretation of the creek health such as species diversity, physical and chemical water parameters. 47

48 11.0 Recommendations 1) Effort should be made to ensure that all individual specimens collected are included in the FBI and to ensure proper representation of the sample collected, and increase accuracy. 2) Sampling should continue to take place at the same time each year. This eliminates certain fluctuations in species numbers as metamorphism may occur at different times of the year for different organisms. 3) Sampling should be held off on days which follow greater than average precipitation events as the normal creek width will be difficult to determine and the banks will be flooded. The water levels will also become higher than average and pose difficulty for sampling the middle of the creek. 4) To improve consistency and to avoid further inconsistencies between samples, an effort should be made to collect samples of consistent size using the Eckman sampler. Also, if possible samples should be taken near the same location each year to eliminate variations in sample substrate that may have an effect on the families of macroinvertebrates collected. 5) Ongoing studies should be conducted due to fluctuating water quality from year to year. 48

49 Table 5: Dingman Creek Indices: Taxa Richness Year Old Victoria Highbury Green Valley Green Lane White Oak Wonderland Colonel Talbot Lambeth Not Sampled due to high water levels Not Sampled due to high water levels

50 Table 6: Dingman Creek Indices: Family Biotic Index Year Old Victoria Highbury Green Valley Green Lane White Oak Wonderland Colonel Talbot Lambeth Not Determined Not Determined

51 12.0 Sampling Locations of Dingman Creek 51

52 Appendix A: Benthic Survey Field Notes Benthic Survey Field Notes: Station 1 Date: June 3, 2013 Station: 1 Body of Water: Dingman Location: Old Victoria Sampling Equipment: Eckamn Other Samples: DO, ph Comments: Riparian growth: silver maple, crab apple and willow. Old Victoria bridge re-done; therefore, buffer on either side of the creek to prevent cement contamination. Buffer made up of cloth, hay bale, wire fence and posts. Site Characteristics Stream Width: 1-2m Depth: 0.5m Substrate: rock, mud, pebbles, gravel and twigs Water Clarity: good Odour: None Macrophytes: Reeds and Tall grass Algae: some attached to rocks Bank Vegetation: tall grass, trees, shrubs, herbaceous vegetation Land Use: Agriculture; corn fields Water Temperature: 14.1C General: DO 8.44mg/L; ph

53 Map 53

54 Bio Survey Card: Station 1 Sampling Date: June 3, 2013 Station: 1 Survey Type: Benthic Location: Dingman Creek Description of Station: Old Victoria Collection Method: Eckman General Group U/S Bridge D/S Total Caddisfly Larva Gilled Snail Midge Larvae Fingernail Clam Segmented Worm Midge Pupae Aquatic Worm Riffle Beetle Adult Total FBI: Fair 54

55 Benthic Survey Field Notes: Station 2 Date: June 5, 2013 Station: 2 Body of Water: Dingman Location: Highbury Sampling Equipment: Eckman Other Samples: DO, ph Comments: Lots of vegetation on creek bed. Site Characteristics Stream Width: 4m Depth: 0.05m Substrate: sand, silt, weed, organic matter, mud and tree rootss Water Clarity: poor Odour: None Macrophytes: grasses, seaweed and herbaceous vegetation Algae: some attached to rocks and along creek bank Bank Vegetation: tall grass and trees; willows and ash Land Use: Agriculture Water Temperature: 14.8C General: DO 8.28mg/L; ph

56 Map 56

57 Bio Survey Card: Station 2 Sampling Date: June 5, 2013 Station: 2 Survey Type: Benthic Location: Dingman Creek Description of Station: Highbury Collection Method: Eckman General Group U/S Bridge D/S Total Midge Midge Pupae Aquatic worm Fingernail Clam Gilled Snail Lunged Snail Black Fly Larvae Damselfly nymph Riffle Beetle Larvae Scud Riffle Beetle (adult) Leech Sow bug Caddisfly May fly Nymph Dragonfly nymph Horsefly Larvae Total FBI: 7.56 Very Poor 57

58 Benthic Survey Field Notes: Station 3 Date: June 6, 2013 Station: 3 Body of Water: Dingman Location: Green Valley Road Sampling Equipment: Eckman Other Samples: DO, ph Comments: Beaver dam downstream of outfall, stream depth too great to sample Site Characteristics Stream Width: N/A Depth: N/A Substrate: Water Clarity: Odour: Macrophytes: Algae: some on rocks and mud Bank Vegetation: tall grasses, trees and shrubs Land Use: stormwater retention ditch Water Temperature: General: 58

59 Map 59

60 Benthic Survey Field Notes: Station 4 Date: June 6, 2013 Station: 4 Body of Water: Dingman Location: Green lane Sampling Equipment: Eckman Other Samples: DO, ph Comments: Storm sewer discharge upstream (2 large, 1 small) Site Characteristics Stream Width: 3m Depth: 0.48m Substrate: rocks, clay, sand, silt, gravel, boulders Water Clarity: poor Odour: decomposing organic matter Macrophytes: weeds Algae: some attached to rocks and along bottom of creek Bank Vegetation: tall grass, trees, shrubs, wildflowers and weeds Land Use: Agriculture Water Temperature: 14.5 C General: DO 8.42mg/L; ph

61 Map 61

62 Bio Survey Card: Station 4 Sampling Date: June 6, 2013 Station: 4 Survey Type: Benthic Location: Dingman Creek Description of Station: Green lane Collection Method: Eckman General Group U/S Bridge D/S Total Leech Aquatic worm Midge Caddisfly Fingernail Clam Riffle Beetle Larva Sow bug Gilled Snail Lunged Snail Horsefly Larvae Blackfly Pupae Dancefly Larvae Total FBI: Poor 62

63 Benthic Survey Field Notes: Station 5 Date: June 11, 2013 Station: 5 Body of Water: Dingman Location: White Oak Road Sampling Equipment: Eckman Other Samples: DO, ph Comments: Storm sewer outlet upstream; water quality very poor and water is greater in depth due to a recent rainstorm Site Characteristics Stream Width: 7.6m Depth: 0.85m Substrate: Silty, small pebbles, gravel, a few rocks, clay and organic matter mostly u/s and bridge. Very muddy under bridge Water Clarity: very poor Odour: none Macrophytes: seaweed Algae: algae on edge of banks Bank Vegetation: tall grass, trees, shrubs, and weeds Land Use: Agriculture Water Temperature: 16.5 C General: DO 7.41mg/L; ph

64 Map 64

65 Bio Survey Card: Station 5 Sampling Date: June 11, 2013 Station: 5 Survey Type: Benthic Location: Dingman Creek Description of Station: White Oak Road Collection Method: Eckman General Group U/S Bridge D/S Total Fingernail Clam Midge Riffle Beetle Larvae Aquatic Worm Blackfly Larvae Blackfly Pupae Gilled Snail Leech Mayfly Nymph Flat worm Crayfish Caddisfly Sow Bug Total FBI: 7.26 Very poor 65

66 Benthic Survey Field Notes: Station 6 Date: June 12, 2013 Station: 6 Body of Water: Dingman Location: Wonderland Sampling Equipment: Eckman Other Samples: DO, ph Comments: Sewage odour downstream Site Characteristics Stream Width: 4.5m Depth: 0.5m Substrate: Clay, pebbles, small gravel, silt, big rocks under bridge, a lot of tree branches on bottom, mostly muddy organic matter Water Clarity: poor Odour: sewage odour Macrophytes: seaweed Algae: algae on rocks Bank Vegetation: Mature trees, herbaceous vegetation, wild flowers and some tall grasses Land Use: Agriculture, residential Water Temperature: 17.8 C General: DO 7.80mg/L; ph

67 Map 67

68 Bio Survey Card: Station 6 Sampling Date: June 12, 2013 Station: 6 Survey Type: Benthic Location: Dingman Creek Description of Station: Wonderland Collection Method: Eckman General Group U/S Bridge D/S Total Mayfly Caddisfly Midge Larvae Midge Pupae Aquatic Worm Fingernail Clam Lunged Snail Gilled Snail Riffle Beetle Larvae Riffle beetle adult Water Penny Leech Dragonfly Nymph Damselfly Nymph Sow bug Scud Horsefly Total FBI: Poor 68

69 Benthic Survey Field Notes: Station 7 Date: June 17, 2013 Station: 7 Body of Water: Dingman Location: Colonel Talbot Sampling Equipment: Eckman Other Samples: DO, ph Comments: Sewage Groundwater outlet u/s. Storm outlet d/s found previous 2012 benthic sampling year was not visible due to high water levels. Very high water levels and creek width due to few days of rain fall. Site Characteristics Stream Width: 15m Depth: 1.25m Substrate: Organic matter, sand and silt upstream, mud on bank and under bridge. Tree branches along bank. Water Clarity: very poor Odour: D/S and U/S sweage smell Macrophytes: seaweed u/s Algae: Not visible due to high water levels and very poor water clarity Bank Vegetation: Mature trees u/s; maple, willow. Shrubs, tall grasses and herbaceous vegetation. Land Use: East: Golf Course, West: Private Water Temperature: 22.0 C General: DO 7.39mg/L; ph

70 Map 70

71 Bio Survey Card: Station 7 Sampling Date: June 17, 2013 Station: 7 Survey Type: Benthic Location: Dingman Creek Description of Station: Colonel Talbot Collection Method: Eckman General Group U/S Bridge D/S Total Aquatic Worm Horsefly Larvae Gilled Snail Lunged Snail Midge Larvae Sow Bug Mayfly Water Boatman Pyralid Biting Midge Horsefly Pupae Riffle Beetle Larvae Total FBI: 7.51 very poor 71

72 Benthic Survey Field Notes: Station 8 Date: June 19, 2013 Station: 8 Body of Water: Dingman Location: Lambeth Sampling Equipment: Eckman Other Samples: DO, ph Comments: High water levels due to previous days of rain fall. Broken storm sewer upstream. Oily substance found downstream from bridge as well as a sewage odor. Site Characteristics Stream Width: 7.5m Depth: 1.15m Substrate: Rocky, weeds, clay, sand and tree branches Water Clarity: very poor Odour: sweage smell Macrophytes: Some seaweed but most not visible due to high water levels and poor water clarity Algae: on rocks Bank Vegetation: Trees, grass, shrubs, herbaceous vegetation. Many Manitoba Maples Land Use: Agricultural, residential, Public Park Water Temperature: 19.3 C General: DO 9.24mg/L; ph

73 Map 73