1
Urbanization Impacts on Stream Health in Castle Creek Joanie Hilton ‘12 and Susan Cushman Biology Department, Hobart and William Smith Colleges Introduction The physical characteristics and variables of a stream ultimately provide an environmental gradient that influences its function. The River Continuum Concept (RCC), outlined by Vannote et al. (1980), gives a very specific framework as to what a healthy stream should look along this gradient (Figure 1). These authors hypothesize that certain structural and functional characteristics of a stream community should change along the upstream-downstream continuum based on inputs of organic matter and channel dimensions. We interpret this as a null model, but there are many variations to this model that can be tested, including how this model is affected by surrounding landuse. Urbanization is indicated by human growth which leads to the expansion of cities, the changing of landscape, and an increase in impervious surfaces. All of these impacts that come with urbanization are extremely detrimental to a stream system, leading to habitat degradation, poor water quality, and a decrease in riparian buffers and vegetation. Because of this, urbanization can be a disturbance that ultimately affects the RCC. In this study, we hypothesize that downstream in urban areas, we will see degraded habitat, a decrease in water quality, and variations in benthic macroinvertebrate composition compared to a rural area upstream (Figure 2). This study was done on Castle Creek, which is a stream that is located at the North-West Point of Seneca Lake, NY. It originates in agricultural lands before forming a main channel that runs through suburban landuse before flowing through the city of Geneva, NY. Therefore, Castle Creek provides the perfect case study for how land-use affects a stream system’s overall quality. Methods Six different sites were visited, two rural sites, two suburban sites, and two rural sites, at the beginning of a month for three months (February, March, and April). Each time the sites were visited, water quality tests were run (temperature, dissolved oxygen, pH, conductivity) including a chloride test. Also, benthic macro-invertebrate (BMI) sampling was completed, and samples were taken back to the lab to be labeled. After labeling, the BMIs were sorted into pollutant tolerant species, pollutant sensitive species, and functional feeding groups. In March when the sites were visited, two tiles were placed in the stream at each of the six sites to collect algae. In April, whatever algae were present was scraped off into containers and taken to the lab for analysis. During the visits in April as well, a habitat assessment was conducted at each of the six sites. All data was averaged to clearly show trends along the urban- rural gradient. Results Conclusions Overall, our results show that there is much variation on a temporal and spatial scale within water quality measurements, macroinvertebrate composition and habitat variables. In regards to the temporal scale, as predicted, water quality changed throughout the season. Chloride also changed throughout time, indicating variation not only on a temporal scale but on a spatial scale as well with overall increased numbers in the urban areas. BMI composition also varied over time and space, going against predictions made by the RCC. In the functional feeding groups, a decrease of shredders occurred on the urban to rural gradient, which according to the RCC, the opposite should be happening. However, an increase in predators occurred over time, specifically in the rural sites, which was found in Roy et al. (2003). Also, an extreme decrease in pollutant sensitive species over time occurred in urban sites specifically, coincident with Roy et al. (2003) as well. They found that EPT richness is negatively correlated with urban use. Because the water quality was not as healthy downstream, urban landuse could be having a major effect on the BMIs that are present in the stream. Finally, better habitat qualities are seen in the rural areas, such as large amounts of riparian buffer as well as an increase in large woody debris and rootwads, which ultimately provide suitable habitats for particular BMIs. Altogether, these aspects supports our hypothesis that urbanization has detrimental effects on a stream and the components of its environment. References Acknowledgements Figure 6: Average percentages between each site in each area of the functional feeding groups present in Castle Creek from February to April 2012. Collectors dominated the samples in each area over the course of the three months (which were mostly made up of Chironomidae). A steady increase in collectors is seen on the urban to rural gradient. Shredders are more heavily present in the urban sites, and slowly decrease into the rural sites. With the exception of one predator found in the urban sites in March, predators were mostly found upstream, with a larger presence in April in both the suburban and rural sites. Figure 1: The River Continuum Concept as depicted in Vannote et. al., 1980 Figure 2: The effect of urbanization on stream health. As urbanization increases, stream health is predicted to decrease. Table 1: Average Water Quality Measurements for Castle Creek from February to April 2012. Sites were averaged together across categories for each month. Figure 3: EPT (Ephemeroptera, Plecoptera, Trichoptera) richness values for Castle Creek from February to April averaged across sites. The Trichoptera order was more dominant in the month of February, but by April, they were almost absent. This is especially apparent in the urban sites where there were about 18 Trichoptera (all from the family Hydropsychidae) present in February, but in April ,there was only 1. Ephemeroptera also were a dominant order throughout the months at each site, particularly the suburban sites. A bell curve pattern is present for Ephemeroptera in each month across the sites. Plecoptera were mostly present in April, especially in the rural sites, with a few seen in March. 0 5 10 15 20 25 February EPT Abundance Plecoptera Trichoptera Ephemeroptera 0 5 10 15 20 25 March EPT Abundance 0 5 10 15 20 25 April EPT Abundance Urban Suburban Rural Stream Health Urbanization Table 2: Habitat assessment results for Castle Creek in April 2012. For all variables except average velocity and riparian buffer, the numbers represent habitat variable counts. Overall, better habitat qualities are being seen in the rural area, especially the large amount of riparian buffer. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Predator Scraper Collectors Shredders 0.06 0.1 0.14 0.18 Urban Suburban Rural AFOM (g) 45 60 75 90 105 February March April Chloride (parts per million) Urban Suburban Rural Figure 4: Algal biomass measurements were averaged between tiles at each site and then again with each area. A decrease was seen along the urban-rural gradient, with a decrease of 0.1 g from urban to suburban areas. Figure 5: Chloride measurements were averaged within each site for each month. The rural sites overall had significantly lower chloride measurements across each month, however April showed the lowest measurement for each area. Vannote, R. L., G. W. Minshall, K. W. Cummins, J. R. Sedell and C. E. Cushing. 1980. The river continuum concept. Canadian Journal of Fisheries and Aquatic Sciences 37: 130-137. Paul, M. J., and J. L. Meyer. 2001. Streams in an urban landscape. Annual Reviews Ecology System 32: 333-365. Short, T. M., E.M.P. Giddings, H. Zappia, and J. F. Coles. 2005. Urbanization effects on stream habitat characteistics in Boston, Massachusetts; Birmingham, Alabama; and Salt Lake City, Utah. American Fisheries Society Symposium. 47: 317-332. Roy, A. H., A. D. Rosemond, M. J. Paul, D. S. Leigh, and J. B. Wallace. 2003. Stream macroinvertebrate response to catchment urbanization (Georgia, U.S.A). Freshwater Biology. 48: 329-346. I would like to thank Professor Cushman for all her support and dedication, as well as FLI’s Jordan Youngmann. Without these two, this project would not have been able to happen! Thank you! February March April Dissolved Oxygen (mg/L) 16.49 17.54 18.79 Temperature (˚C) 2.01 0.74 6.20 Conductivity (ms/cm 3 ) 0.744 0.814 0.753 pH 7.04 6.37 6.34 Urban Suburban Rural Average Velocity (m/s) 7.75 6.35 9.11 Large Woody Debris 2.5 3.5 5.5 Rootwads 5 7 5.5 Debris Jams 0 2.5 3 Riparian Buffer (m) (L=left, R=right) 0 L 7.5 R 35 L 45 R 50 L 50 R Subunits (Riffles, Pools) 4.5 R 4 R, 5 P 3 R, 3 P

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Urbanization Impacts on Stream Health in Castle Creek

Joanie Hilton ‘12 and Susan Cushman

Biology Department, Hobart and William Smith CollegesIntroduction

The physical characteristics and variables of a stream ultimately provide an environmental gradient that influences its function. The River Continuum Concept (RCC), outlined by Vannote et al. (1980), gives a very specific framework as to what a healthy stream should look along this gradient (Figure 1). These authors hypothesize that certain structural and functional characteristics of a stream community should change along the upstream-downstream continuum based on inputs of organic matter and channel dimensions. We interpret this as a null model, but there are many variations to this model that can be tested, including how this model is affected by surrounding landuse.

Urbanization is indicated by human growth which leads to the expansion of cities, the changing of landscape, and an increase in impervious surfaces. All of these impacts that come with urbanization are extremely detrimental to a stream system, leading to habitat degradation, poor water quality, and a decrease in riparian buffers and vegetation. Because of this, urbanization can be a disturbance that ultimately affects the RCC. In this study, we hypothesize that downstream in urban areas, we will see degraded habitat, a decrease in water quality, and variations in benthic macroinvertebrate composition compared to a rural area upstream (Figure 2).

This study was done on Castle Creek, which is a stream that is located at the North-West Point of Seneca Lake, NY. It originates in agricultural lands before forming a main channel that runs through suburban landuse before flowing through the city of Geneva, NY. Therefore, Castle Creek provides the perfect case study for how land-use affects a stream system’s overall quality.

Methods

Six different sites were visited, two rural sites, two suburban sites, and two rural sites, at the beginning of a month for three months (February, March, and April). Each time the sites were visited, water quality tests were run (temperature, dissolved oxygen, pH, conductivity) including a chloride test. Also, benthic macro-invertebrate (BMI) sampling was completed, and samples were taken back to the lab to be labeled. After labeling, the BMIs were sorted into pollutant tolerant species, pollutant sensitive species, and functional feeding groups. In March when the sites were visited, two tiles were placed in the stream at each of the six sites to collect algae. In April, whatever algae were present was scraped off into containers and taken to the lab for analysis. During the visits in April as well, a habitat assessment was conducted at each of the six sites. All data was averaged to clearly show trends along the urban-rural gradient.

Results

Conclusions

Overall, our results show that there is much variation on a temporal and spatial scale within water quality measurements, macroinvertebrate composition and habitat variables. In regards to the temporal scale, as predicted, water quality changed throughout the season. Chloride also changed throughout time, indicating variation not only on a temporal scale but on a spatial scale as well with overall increased numbers in the urban areas. BMI composition also varied over time and space, going against predictions made by the RCC. In the functional feeding groups, a decrease of shredders occurred on the urban to rural gradient, which according to the RCC, the opposite should be happening. However, an increase in predators occurred over time, specifically in the rural sites, which was found in Roy et al. (2003). Also, an extreme decrease in pollutant sensitive species over time occurred in urban sites specifically, coincident with Roy et al. (2003) as well. They found that EPT richness is negatively correlated with urban use. Because the water quality was not as healthy downstream, urban landuse could be having a major effect on the BMIs that are present in the stream. Finally, better habitat qualities are seen in the rural areas, such as large amounts of riparian buffer as well as an increase in large woody debris and rootwads, which ultimately provide suitable habitats for particular BMIs. Altogether, these aspects supports our hypothesis that urbanization has detrimental effects on a stream and the components of its environment.

References

Acknowledgements

Figure 6: Average percentages between each site in each area of the functional feeding groups present in Castle Creek from February to April 2012. Collectors dominated the samples in each area over the course of the three months (which were mostly made up of Chironomidae). A steady increase in collectors is seen on the urban to rural gradient. Shredders are more heavily present in the urban sites, and slowly decrease into the rural sites. With the exception of one predator found in the urban sites in March, predators were mostly found upstream, with a larger presence in April in both the suburban and rural sites.

Figure 1: The River Continuum Concept as depicted in Vannote et. al., 1980

Figure 2: The effect of urbanization on stream health. As urbanization increases, stream health is predicted to decrease.

Table 1: Average Water Quality Measurements for Castle Creek from February to April 2012. Sites were averaged together across categories for each month.

Figure 3: EPT (Ephemeroptera, Plecoptera, Trichoptera) richness values for Castle Creek from February to April averaged across sites. The Trichoptera order was more dominant in the month of February, but by April, they were almost absent. This is especially apparent in the urban sites where there were about 18 Trichoptera (all from the family Hydropsychidae) present in February, but in April ,there was only 1. Ephemeroptera also were a dominant order throughout the months at each site, particularly the suburban sites. A bell curve pattern is present for Ephemeroptera in each month across the sites. Plecoptera were mostly present in April, especially in the rural sites, with a few seen in March.

0

5

10

15

20

25

Fe

br

ua

ry

EP

T A

bu

nd

an

ce Plecoptera

Trichoptera

Ephemeroptera

0

5

10

15

20

25

Ma

rc

h E

PT

Ab

un

da

nc

e

0

5

10

15

20

25

Ap

ril E

PT A

bu

nd

an

ce

Urban Suburban RuralStr

eam

Healt

h

Urbanization

Table 2: Habitat assessment results for Castle Creek in April 2012. For all variables except average velocity and riparian buffer, the numbers represent habitat variable counts. Overall, better habitat qualities are being seen in the rural area, especially the large amount of riparian buffer.

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Predator

Scraper

Collectors

Shredders

0.06

0.1

0.14

0.18

Urban Suburban Rural

AFO

M (

g)

45

60

75

90

105

February March April

Ch

lori

de (

part

s p

er

millio

n)

Urban

Suburban

Rural

Figure 4: Algal biomass measurements were averaged between tiles at each site and then again with each area. A decrease was seen along the urban-rural gradient, with a decrease of 0.1 g from urban to suburban areas.

Figure 5: Chloride measurements were averaged within each site for each month. The rural sites overall had significantly lower chloride measurements across each month, however April showed the lowest measurement for each area.

Vannote, R. L., G. W. Minshall, K. W. Cummins, J. R. Sedell and C. E. Cushing. 1980. The river continuum concept. Canadian Journal of Fisheries and Aquatic Sciences 37: 130-137. Paul, M. J., and J. L. Meyer. 2001. Streams in an urban landscape. Annual Reviews Ecology System 32: 333-365.Short, T. M., E.M.P. Giddings, H. Zappia, and J. F. Coles. 2005. Urbanization effects on stream habitat characteistics in Boston, Massachusetts; Birmingham, Alabama; and Salt Lake City, Utah. American Fisheries Society Symposium. 47: 317-332. Roy, A. H., A. D. Rosemond, M. J. Paul, D. S. Leigh, and J. B. Wallace. 2003. Stream macroinvertebrate response to catchment urbanization (Georgia,

U.S.A). Freshwater Biology. 48: 329-346.

I would like to thank Professor Cushman for all her support and dedication, as well as FLI’s Jordan Youngmann. Without these two, this project would not have been able to happen! Thank you!

February March April

Dissolved

Oxygen (mg/L)

16.49 17.54 18.79

Temperature (˚C) 2.01 0.74 6.20

Conductivity

(ms/cm3)

0.744 0.814 0.753

pH 7.04 6.37 6.34

Urban Suburban Rural

Average

Velocity (m/s)

7.75 6.35 9.11

Large Woody

Debris

2.5 3.5 5.5

Rootwads 5 7 5.5

Debris Jams 0 2.5 3

Riparian Buffer

(m)

(L=left, R=right)

0 L

7.5 R

35 L

45 R

50 L

50 R

Subunits

(Riffles, Pools)

4.5 R 4 R, 5 P 3 R, 3 P