Archive of Methods and Results for First Six Years of Study

(Return to Watershed Study)

Archive of Methods First Eight Years of Study

2004

The first phase of the study was completed in the Fall Semester of 2003.  This involved collecting leaves and establishing base-line data for abiotic and biotic factors.   Leaves representative of those in the surrounding woodland were collected from the area adjacent to the stream.  These were added to the experimental segments in phase two.

Phase One Methods

Leaf sampling

Toss the hula hoop over your shoulder.  Identify all the leaves within the hoop using the tree key.   Follow the steps until you arrive at the correct species for the tree.   Repeat the process at a new location.  List the frequency for each species.  Calculate the percent for each species.  Using a rake collect all the leaves within a three meter radius of the center of the hoop.  Scoop the leaves into the leaf bag. 

Water sampling

Abiotic

Collect a clean water sample from the center of each pool.  Follow the directions and determine dissolved oxygen, nitrate, phosphate, and pH.  Use a thermometer to measure the temperature at the center of the pool.  Using a ruler, measure the depth of the pool at the center. 

Biotic

Macroinvertebrate sampling.  Use a D-net to sample the benthic (bottom) habitat.  Place the bottom of the net on the surface of the substrate.  While twisting the net back and forth, force the net upstream for two meters.  Empty the contents of the net into collecting trays.  Rinse the net with clean water until all of the debris is emptied into the trays.  This should be done for all four pools.  Keep the samples separate!  Samples will be returned to the lab for identification.  Carefully search through all leaf and rock debris.  Using forceps or eyedroppers, place specimens in small sample vials with a small amount of clean stream water.  Pour specimens with water into petri dishes or watch glasses and place them on the stage of a dissecting microscope.  Do not disturb the sample and allow all sediment to settle out.  Observe the specimens under the microscope.  Use the appropriate identification key to identify the specimen.

Phase two was completed in the spring of 2004.  Four pools were selected for study.  Two of these pools were control segments and two were experimental segments.  Each segment had a one-by-two meter rectangle designated as the sample area. 

Leaves representative of those in the surrounding woodland were collected from the adjacent woodland in the previous fall.  At the start of the experiment, about one cubic meter of leaves were added to each experimental sample.  None were added to the control samples.  Each sample area was covered with mesh nylon netting secured with plastic stakes.  No leaves were allowed to accumulate on the surface of the netting. 

Phase Two Methods

Abiotic sampling (as in Phase One)

Biotic sampling (as in Phase One)

Preparing the experimental and control segments

Spread one cubic meter of leaves (about 6 pounds dry weight) evenly over each experimental segment.  Carefully, place the one-by-two meter nylon netting over the leaves in about the center of each segment.  Stake the netting down at the corners, along each side, and in the middle.  Place one-by-two meter netting over the two control segments and stake them down as with the experimental segments.

In phase three, about eight weeks later, each site was sampled.  Phosphate and nitrate tests, pH, and dissolved oxygen tests were performed on water samples from each site.  The netting was removed.  A D-net was placed on the substrate and moved upstream for two meters with a jabbing motion and shaking of the net side-to-side to allow water through.  Each scoop was poured into a plastic dish pan.  Invertebrates were identified on site or returned to the lab for further identification.   A stream quality index (SQI) was determined for comparison of different sites.  

Phase Three Methods

Abiotic Sampling (as in Phase One)

Biotic Sampling (as in Phase One)

 

2005

Phase two was completed in the spring of 2005.  Four pools were selected for study.  Two of these pools were control segments and two were experimental segments.  Each segment had a one-by-two meter rectangle designated as the sample area. 

Leaves representative of those in the surrounding woodland were collected from the adjacent woodland in the previous fall.  At the start of the experiment, about one cubic meter of leaves were added to each experimental sample.  None were added to the control samples.  Each sample area was covered with mesh nylon netting secured with plastic stakes.  No leaves were allowed to accumulate on the surface of the netting. 

Phase Two Methods

Abiotic sampling (as in 2004)

Biotic sampling (as in 2004)

Preparing the experimental and control segments (as in 2004)

In phase three, about twelve weeks later (July 2005), each site was sampled.  Phosphate and nitrate tests, pH, and dissolved oxygen tests were performed on water samples from each site.  The netting was removed.  A D-net was placed on the substrate and moved upstream for two meters with a jabbing motion and shaking of the net side-to-side to allow water through.  Each scoop was poured into a plastic dish pan.  Invertebrates were identified on site or returned to the lab for further identification.  A stream quality index (SQI) was determined for comparison of different sites. 

Phase Three Methods

Abiotic sampling (as in 2004)

Biotic sampling (as in 2004)

2006

Biotic and abiotic sampling were done in April 2006.  Leaves collected in Fall 2005 were added to experimental sites #4 and #5.  None were added to control sites #3 and #6.  Following the recommendations of students in 2005, two rockier, upstream sites were added.

About twelve weeks later (July 2006), each site was sampled.  Phosphate and nitrate tests, pH, and dissolved oxygen tests were performed on water samples from each site.  The netting was removed.  A D-net was placed on the substrate and moved upstream for two meters with a jabbing motion and shaking of the net side-to-side to allow water through.  Each scoop was poured into a plastic dish pan.  Invertebrates were identified on site or returned to the lab for further identification.  A stream quality index (SQI) was determined for comparison of different sites. 

2007

Biotic and abiotic sampling were done in April 2007.  Leaves collected in Fall 2006 were added to experimental sites #4 and #6.  None were added to control sites #3 and #5. 

About twelve weeks later (July 2007), each site was sampled.  Phosphate and nitrate tests, pH, and dissolved oxygen tests were performed on water samples from each site.  The netting was removed.  A D-net was placed on the substrate and moved upstream for two meters with a jabbing motion and shaking of the net side-to-side to allow water through.  Each scoop was poured into a plastic dish pan.  Invertebrates were identified on site or returned to the lab for further identification.  A stream quality index (SQI) was determined for comparison of different sites.  A reference stream was located upstream of Longview Lake in the Little Blue River basin and sampled in July.

2008

Biotic and abiotic sampling were done in April 2008.  Leaves collected in Fall 2007 were added to experimental sites #4a and #4b.  None were added to control sites #3 and #5. 

About twelve weeks later (July 2008), each site was sampled.  Phosphate and nitrate tests, pH, and dissolved oxygen tests were performed on water samples from each site.  The netting was removed.  A D-net was placed on the substrate and moved upstream for two meters with a jabbing motion and shaking of the net side-to-side to allow water through.  Each scoop was poured into a plastic dish pan.  Invertebrates were identified on site or returned to the lab for further identification.  A stream quality index (SQI) was determined for comparison of different sites.  A reference stream was located upstream of Longview Lake in the Little Blue River basin and sampled in July.

2009

Biotic and abiotic samples were taken in April 2009. Leaves collected in early spring 2009 were added to experimental sites 4 and 5. No leaves were added to controls 2 and 3.

About twelve weeks later (July 2009), each site was sampled. Nitrate and dissolved oxygen tests were performed on water samples from each site using Vernier Lab ProTM sensors. Biotic sampling was done as previously.

2010

Biotic and abiotic samples were taken in April 2010. Leaves were added to experimental pools 3 and 4. None were added to controls 1 and 7. About 12 weeks later in July each site was sampled. Abiotic data were collected as in 2009, but biotic data were collected by sweeping the D-nets with seine nets still in place.

2011

Abiotic and biotic data were taken as usual in April 2011. Leaves were added to experimental pools 2 and 3; none were added to controls 1 and 6. However, abiotic and biotic data were collected four weeks later in May. Abiotic data were collected as in 2009. Seine nets were removed before D-net sweeps were taken.

Archive of Results for First Six Years of Longview Watershed Study

 

2003-2004

Results from phases one, two, and three, with experimental and control sites established in April 2004, are shown in Tables 1-5, including tree leaves, organisms, abiotic characteristics, and nitrate-N levels. 

Table 1.  Percentages of most important tree species found in the woodland surrounding Little Mouse Creek and added to experimental sites in 2004.  No distinction was made between species of elm and oak.

 TREES

Elm

Oak

Hackberry

Locust

Cherry

Hedge

Dogwood

Boxelder

Redbud

Percentage

59.0

11.3

   8.5

   6.4

   4.9

   3.2

    3.0

   1.5

   1.3

A summary of invertebrate organisms collected during 2003-2004 can be seen in Tables 2 and 3.  As can be seen there was no increase in stream quality index in the experimental sites (2 and 3) between April and June when the leaves were in place.  Stream quality index values were higher in the rockier, upstream sites (3 and 4).  There was no increase in numbers of somewhat sensitive organisms in the experimental sites either.  By far the largest numbers were seen in the fall.  This might be due to lower temperatures (Table 4).  Dissolved oxygen levels were fairly high, especially in the spring (Table 5). An unexpected factor was the amount of silt that was accumulated and mostly removed during the period from April to June.  About ten inches of silt was removed from under the net at site 2 and five inches from under site 3.  There was an unusual amount of rain during this period.  This may have adversely affected the number of organisms recovered.

 

Table 2. Organisms collected from watershed test sites 2003-2004.  Sites 2 and 3 were experimentals and sites 1 and 4 controls.  Only organisms taken from the 1X2 meter area under the nets are included in Table 2; however, additional organisms were collected from the general area of the test sites in June. The area near site 1 contained: 3 Hemiptera, 4 adult Coleoptera, 1 Trichoptera, 5 Oligochaeta, 2 Gastropoda and 3 Isopoda. The Hemiptera all belonged to the family Gerridae and the 4 adult Coleoptera were from 3 different families. The area near site 2 had two additional organisms, 1 Hemiptera and 1 Diptera.  The classes Oligochaeta and Gastropoda are considered pollution tolerant while the other groups are considered somewhat sensitive.

 

ORGANISMS

NOVEMBER

APRIL

JUNE

 

1

2

3

4

1

2

3

4

1

2

3

4

Oligochaeta   1         1       4 2
Gastropoda 1     2   3 1 1        
Isopoda 35 58

26

36 2 3 4 14     8 14
Amphipoda 29 9 4 19 3 14 5 10   1 2 3
Decapoda   1     1   1 3        
Ostracoda               1        
Coleoptera       1               1
Diptera: midge                       1
Diptera: misc.                   1 1  
Hemiptera                 1 1    
Stream Quality Index 5 7 4 8 6 5 8 9 2 5 6 8

 

Table 3. Stream quality index values for watershed test sites 2003-2004.

SITE NOVEMBER APRIL JUNE
1 control 5 6 2
2 experimental 7 5 5
3 experimental 4 8 6
4 control 8 9 8

 

Table 4.  Values for abiotic measures for sample sites in Little Mouse Creek for three sampling dates in 2003-2004.  Sites 2 and 3 were experimentals and sites 1 and 4 controls.

MEASURE           NOVEMBER                    APRIL                   JUNE
     1    2    3    4     1      2     3     4    1     2     3    4
Temperature

(degrees C)

 7

 

 7

 

10

 

10

 

10

 

10

 

10

 

10

 

14

 

15

 

19

 

19

 

Depth (cm) 30 21 18 17 29 29 20 17 14 15 14 17
PH 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 7.5 7.5 7.0 7.2
Dissolved

Oxygen (ppm)

7.0

 

7.0

 

6.0

 

7.0

 

10.0

 

10.0

 

10.0

 

10.0

 

 7.5

 

 7.3

 

 6.6

 

6.7

 

 

 

Table 5 shows nitrate-N levels (ppm) in Little Mouse Creek from three sampling dates in 2003-2004 for all four sites including two experimental sites with leaves added (sites 2 and 3) and two control sites with no leaves added (sites 1 and 4).  Leaves were in place in the experimental sites between April and June.  Notice that the amount of nitrate decreased in site 2  by 0.1 ppm during the time leaves were in place.  There was a decrease in nitrate in site 3 by 0.5 ppm and in site 4 by 0.2 ppm from April to June.  The day sites 3 and 4 were sampled was rainy and the creek was at a high level, accounting for the very low nitrate levels that day, as well as the uniformity since mixing of water in pools was enhanced.  Nitrate levels in pools were probably too variable to draw firm conclusions here, but the one experimental pool (site 2) did seem to experience a greater reduction in nitrate than the control (site 1).  Dissolved oxygen levels were slightly less in the experimental sites during 2003-2004 (Table 4), possibly indicating more decomposition leading to enhanced denitrification. There was a correlation between dissolved oxygen and nitrate (Pearson product-moment correlation coefficient equal 0.978).  Phosphate levels in the four sampling sites along Little Mouse Creek were all very low, less than 0.2 ppm in 2004.

 

Table 5.  Nitrate-N levels (ppm) in four sampling sites along Little Mouse Creek on three sampling dates in 2003-2004.  Sites 2 and 3 were experimental sites with leaves added between April and June.  Sites 1 and 4 were control sites with no leaves added. 

 

 

DATE

 

       

       1

    

 

        2

 

 

 

        3

 

 

 

       4

 

November

     0.3

     0.4

     0.2

     0.2

April

 

     0.2

 

     0.3

     0.6

     0.3

June

     0.2

     0.2

     0.1

     0.1

 

2004-2005

Phases one through three were mostly a repeat of the previous year except that leaves were left in place twelve weeks instead of eight weeks. Experimental and control sites were established in April 2005.  Tree leaves, organisms, abiotic characteristics, and nitrate levels can be seen in Tables 6-9.  Invertebrate numbers in 2005 (Table 7) once again indicated no increase in stream quality index in experimental sites.  Upstream sites had higher stream quality indices.  When numbers of individuals and number of species were taken into account, there was greater abundance in July.  This corresponds to the emergence of insect larvae with warmer weather.  Since most aquatic insects are capable of flight, they might allow assimilation of nitrogen that is not recycled back into the water, hence permanent removal.

Table 9 shows nitrate-N levels for sites in 2005.  The experimental sites saw less increase (site 2) or a decrease (site 3) between April and July compared to the control groups.  Once again, this was consistent with lower oxygen levels in July in the experimental sites (Table 8), indicating that denitrification may have occurred in these sites due to decomposition of the added leaves.   Pearson product-moment correlation coefficient (r) between oxygen and nitrate concentration was 0.944 (0.95 required for 5% significance level).

 

Table 6.  Percentages of most important tree species found in the woodland surrounding Little Mouse Creek based on leaves collected in fall 2004 and added to experimental sites in April 2005.  No distinction was made between species of elm and oak.

 TREES

Elm

Oak

Hackberry

Locust

Cherry

Hedge

Dogwood

Boxelder

Redbud

Percentage

28

 3

   59

    

   10

   

    1

  

   

 

Table 7.  Organisms collected from watershed test sites during 2005.  Sites 2 and 3 were experimentals and sites 1 and 4 controls.  Only specimens taken from the 1X2 meter sample area included in Table 7. Additionally, near site 1 in April were found predaceous diving beetle larvae, snails, and earthworms.  A cricket frog was found near site 2.  In July near site 1 were found a damselfly nymph, hemiptera larva, diptera larvae, water striders, a bristle worm, and water flea.  Near site 2 water striders, diptera larvae, copepods, nematodes, and oligochaetes.  Near site 3 diptera larva, isopods, crayfish, water flea, copepods, and nematodes.  Near site 4 diptera larvae, water strider, copepods, crayfish, and oligochaetes.  Nematoda are considered pollution tolerant.  Megaloptera and Ephemeroptera are considered to be pollution sensitive.  All others are somewhat sensitive.

 

ORGANISMS

APRIL

JULY

 

 

1

2

3

4

1

2

3

4

1

2

3

4

Nematoda             7          
Oligochaeta               2        
Gastropoda             1 2        
Isopoda 5 17

7

5   69 1 62        
Amphipoda 95 64 62 98   1   1        
Decapoda           1   1        
Other Crustacea             4 1        
Coleoptera         3     1        
Diptera: midge         1 5 3 7        
Diptera: misc.         1 4 19 13        
Hemiptera               6        
Megaloptera         1              
Odonata           1 2 4        
Ephemeroptera               3        
Stream Quality Index  4  4  4  4 7 10 10 21        

Table 8.  Values for abiotic measures for sample sites in Little Mouse Creek for sampling dates in 2005.

MEASURE           APRIL       JULY                              
     1    2    3    4   1  2  3  4    1     2     3    4
Temperature

(degrees C)

 10

 

 10

 

10

 

11

 

22

 

22 23 23  

 

 

 

 

 

 

 

Depth (cm) 32 25 18 18 28 25 16 12        
PH 7.8 8.0 7.5 8.0 8.0 8.0 8.0 8.0        
Dissolved

Oxygen (ppm)

>9.0

 

9.0

 

9.0

 

>9.0

 

6.4   

 

6.0 6.0 7.6       

 

       

 

       

 

      

 

 

Table 9.  Nitrate-N levels (ppm) in four sampling sites along Little Mouse Creek in 2005.  Sites 2 and 3 were experimental sites with leaves added between April and July.  Sites 1 and 4 were control sites with no leaves added.  Phosphate levels in the four sampling sites along Little Mouse Creek were all very low,  generally 0.1 ppm or less in 2005.

 

 

DATE

 

       

       1

    

 

        2

 

 

 

        3

 

 

 

       4

 

April

     0.30

     0.40

     0.40

     0.30

July

 

     0.40

 

    0.41

    0.37

    0.50

 

 

 

 

 

2005-2006

Results for the 2005-2006 study are given in Tables 10-13. Experimentals show greater abundance of organisms in July than controls (Table 11). Nitrate-N data (Table 13) were inconclusive.

Table 10.  Percentages of most important tree species found in the woodland surrounding Little Mouse Creek based on leaves collected in fall 2005 and added to experimental sites in April 2006.  No distinction was made between species of elm and oak.

 TREES

Elm

Oak

Hackberry

Locust

Cherry

Hedge

Dogwood

Boxelder

Redbud

Percentage

6

 3

   89

    

    2

   

    

  

   

Table 11.  Organisms collected from watershed test sites during 2006.  Sites 4 and 5 were experimentals and sites 3 and 6 controls.  Only specimens taken from the 1X2 meter sample area included in Table 11.  A planarian was also found in site #4 but was unclassified.  Nematoda, Oligochaeata, Gastropoda, and Chironomidae are considered pollution tolerant.  All others are somewhat sensitive, except Megaloptera and Ephemeroptera which are pollution senstive.  Organisms found outside the 1X2 meter sample area but in the vicinity included damselfly nymphs and water striders near pool 3; and dragonfly nymphs, water striders, beetle larvae, and tadpoles near pool 4.

 

ORGANISMS

APRIL

JULY

 

 

3

4

5

6

3

4

5

6

3

4

5

6

Nematoda     1         1        
Oligochaeta         2 12 6 12        
Gastropoda             3 2        
Isopoda 1 15

2

17 6 7 16 5        
Amphipoda 15 25    1 2 8 20 2        
Decapoda           1            
Other Crustacea         1     4        
Coleoptera        1     5          
Diptera: midge         11 1   1        
Arachnida           1            
Hemiptera               1        
Megaloptera           1            
Odonata           1            
Ephemeroptera             1          
Stream Quality Index  4  4  3  6 8 15 11 12        

Table 12.  Values for abiotic measures for sample sites in Little Mouse Creek for sampling dates in 2006.  Sites 4 and 5 were experimentals and sites 3 and 6 controls.

MEASURE           APRIL       JULY                              
     3    4    5    6   3  4  5  6    3     4     5    6
Temperature

(degrees C)

 11

 

 10.5

 

16

 

15

 

20

 

19.5 18 19  

 

 

 

 

 

 

 

Depth (cm) 21 20 15 16 16 9 14 13.5        
PH 7.8 7.5 8.0 8.0 7.5 7.5 7.5 7.3        
Dissolved

Oxygen (ppm)

10

 

7.0

 

6.5

 

9.0

 

6.75

 

12.25 7.0 9.0       

 

       

 

       

 

      

 

Table 13.  Nitrate-N levels (ppm) in four sampling sites along Little Mouse Creek in 2006.  Sites 4 and 5 were experimental sites with leaves added between April and July.  Sites 3 and 6 were control sites with no leaves added. Phosphate levels in the four sampling sites along Little Mouse Creek were all very low, all zero except 0.3 ppm  in site 5 and 0.1 ppm in site 6 in July.

 

 

DATE

 

       

       3

    

 

        4

 

 

 

        5

 

 

 

       6

 

April

     0.40

     0.30

     0.50

     0.40

July

 

     0.35  

 

     0.50

     0.40

     0.50

 

2006-2007

Data for the 2006-2007 study arre located in Tables 14-16. Nitrate-N data (Table 16) are inconclusive. A less-disturbed but similar-sized reference stream was located elsewhere in the Little Blue River Basin. Unfortunately, on the day it was sampled, rains and flooding made the data of little value in comparison to the Longview stream.

Table 14.  Percentages of most important tree species found in the woodland surrounding Little Mouse Creek based on leaves collected in fall 2006 and added to experimental sites in April 2007.  No distinction was made between species of elm and oak.

 TREES

Elm

Oak

Hackberry

Willow

Cherry

Hedge

Sycamore

Boxelder

Redbud

Percentage

6.6

 

   70.4

   14.9 

    6.5

   

    1.6

  

   

 

Table15.  Organisms collected from watershed test sites during 2007.  Sites 4 and 6 were experimentals and sites 3 and 5 controls.  Only specimens taken from the 1X2 meter sample area included in Table 15.   Nematoda, Oligochaeata, Gastropoda, and Chironomidae are considered pollution tolerant.  All others are somewhat sensitive, except Megaloptera and Ephemeroptera which are pollution senstive.  Additionally, near site 3 in April were found 1 Diptera larva, 2 Gastropoda, and 1 isopod.  In July, the riffle area downstream from site 3 had 3 Coleoptera and 3 Isopoda; the riffle downstream from site 4 had 1 Coleoptera, 1 Oligochaeta, 1 Gastropoda, and 12 Isopoda; the riffle downstream from site 5 had 1 Hemiptera, 2 Coleoptera, 1 Gastropoda, and 1 Isopoda; the riffle downstream from site 6 had 2 Coleoptera, 2 Diptera, 8 Oligochaeta, and 5 Isopoda.

 

ORGANISMS

APRIL

JULY

 

 

3

4

5

6

3

4

5

6

3

4

5

6

Nematoda               1        
Oligochaeta 1 1       2            
Gastropoda                        
Isopoda 8 8

16

2   11 12          
Amphipoda 3 3 9  41   4 7          
Decapoda 1 1   1                
Other Crustacea           1            
Coleoptera           1            
Diptera           5   2        
Arachnida                        
Hemiptera                        
Megaloptera                        
Odonata                        
Ephemeroptera                        
Stream Quality Index 7 6 4 6 1 8 4 2        

Table 16.  Values for abiotic measures for sample sites in Little Mouse Creek for sampling dates in 2007.   Sites 4 and 6 were experimentals and sites 3 and 5 controls.   Dissolved oxygen levels in April were not reliable, probably due to old reagent.

MEASURE           APRIL       JULY                              
     3    4    5    6   3  4  5  6    3     4     5    6
Temperature

(degrees C)

 14

 

 15

 

14

 

15

 

17

 

17 17 20  

 

 

 

 

 

 

 

Depth (cm) 20 15 11 16 18 10.5 10 14        
PH 8.1 8.0 8.0 7.9 7.8 7.8 7.3 7.3        
Dissolved

Oxygen (ppm)

14

 

 

 

14

 

14

 

5.9

 

5.45 4.5 4.1       

 

       

 

       

 

      

 

Nitrate-N

(ppm)

.4 .6 .6 .6 .4 .5 .4 .5        

2007-2008

Tree leaves collected in fall 2007 included almost 90% hackberry and were similar in composition to previous collections. A new pool developed between old pools 3 and 4, so that the new pool is designated 4a and old 4 is now 4b. Biotic data are shown in Table 17 and abiotic data in Table 18. In July the experimental site 4a that was sampled had more total organisms than the control sites; but, unfortunately, experimental site 4b was destroyed by flooding prior to the sampling date. Nitrate-N decreased from April to July, with the greatest decline in experimental 4b, having a lower value in July than control site 3 next to it, although the lowest reading was in control site 5, which, however, was also very low in April. Table 19 shows results for the reference stream that was sampled on July 1, 2008. Few organisms were collected in the two meter sweep with the net.

Table 17.  Organisms collected from watershed test sites during 2008.  Sites 4a and 4b were experimentals and sites 3 and 5 controls.  Only specimens taken from the 1X2 meter sample area included in Table 17. Additionally, in April, near site 3 were found midge larvae, an adult mosquito, checkered beetle, and a cricket frog. Near site 4a were found an earthworm, leaf beetle, broad-shouldered water strider, and snails. Near site 4b were found water striders, isopods, and a snail. Near site 5 were found a water strider and a cockroach nymph.  In July were found in the vicinity of site 3 hemiptera, oligochaeta, gastropoda, isopoda, and amphipoda. Near site 4a were found hemiptera, oligochaeta, gastropoda, and isopoda. The net for experimental site 4b was washed away so that no sampling was done in July. Near site 5 were found hemiptera, oligochaeta, and isopoda. Nematoda are considered pollution tolerant.  Megaloptera and Ephemeroptera are considered to be pollution sensitive.  All others are somewhat sensitive.

 

ORGANISMS

APRIL

JULY

 

 

3

4a

4b

5

3

4a

4b

5

3

4a

4b

5

Nematoda   2       9            
Oligochaeta               5        
Gastropoda           1            
Isopoda   3

4

2 42 81   41        
Amphipoda 5 1 1     4   9        
Decapoda                        
Other Crustacea                        
Coleoptera                        
Diptera: midge 9 7 1   7              
Diptera: misc.         1              
Hemiptera                        
Odonata                        
Nematomorpha 1                      
Turbellaria   1                    
Stream Quality Index 5 7 5 2 4 11   8        

Table 18.  Values for abiotic measures for sample sites in Little Mouse Creek for sampling dates in 2008.   Sites 4a and 4b were experimentals and sites 3 and 5 controls. The net for experimental site 4b was washed away so no sampling was done in July. 

MEASURE           APRIL       JULY                              
     3    4a    4b    5   3  4a  4b  5    3     4a     4b    5
Temperature

(degrees C)

 14

 

 11

 

13.5

 

11

 

20

 

20   18  

 

 

 

 

 

 

 

Depth (cm) 24 16 20.5 16 16.5 12   7        
PH 8.4 8.2 7.1 8.0 7.45 7.7   6.9        
Dissolved

Oxygen (ppm)

6.4

 

7.4

 

5.9

 

5.4

 

7.0

 

6.9   5.7       

 

       

 

       

 

      

 

Nitrate-N

(ppm)

8.5 8.9 2.9 2.0 2.8 2.6   1.7        

Table 19. Results of sampling of a reference stream upstream from the Longview watershed in a less disturbed site. Only hemiptera, diptera larva, copepods, and nematodes were caught in the two meter sweep of the D net. Fewer organisms were found in the reference stream than in the Longview watershed somewhat surprisingly, since it seemed to be in a less polluted watershed. However, silt was a definite problem in the reference stream, with visibility less than 10 cm deep, and very little flow. Nitrate-N in the less disturbed reference watershed was distinctly less than in the Longview watershed as expected.

MEASURE    
   REFERENCE STREAM
Temperature

(degrees C)

 23 

Depth (cm) 14
PH 7.6
Dissolved

Oxygen (ppm)

6.0

 

Nitrate-N

(ppm)

0.3

2009

Tree leaves were collected in January 2009, consisting of about 81% hackberry, 8% cherry, 5% elm, and others less than 5%. Pools were renumbered so that previous pool 3 became 2 and previous 4a became 3. Pools 4 and 5 were new. Pools 1 and 6 were not selected from the random draw. Biotic and abiotic data from April and July are shown in tables 20 and 21 below.

 

  Table 20. Organisms taken from 1 X 2 m sample sites during 2009. Experimental pools were sites 4 and 5. Controls were sites 2 and 3. During April organisms were also collected outside sample areas near site 2--amphipods, isopods, earthworm, and crane fly larvae; near site 3--odonata nymph, crane fly larvae, isopods, and amphipods; near site 4--crane fly larvae, earthworms, snail, isopods, and amphipods; and near site 5--amphipods, isopods, and earthworm. During July organisms were also near site 2--water strider, crayfish, and oligochaetes; near site 5--water striders, oligochaetes, isopods, and arachnids; near site 4--fisher spider and isopods; and near site 5--damselfly nymph, gilled snail, and isopods.

 

ORGANISMS

APRIL

JULY

 

 

2

3

4

5

2

3

4

5

2

3

4

5

Nematoda                        
Oligochaeta         1                
Gastropoda                        
Isopoda   10

6

  9   1 1          
Amphipoda 2   4   4   3 1   1          
Decapoda 1       1              
Arachnida         4 1   1        
Coleoptera                        
Diptera: midge 2 5     2     1          
Diptera: misc.         2              
Hemiptera         7 2 5          
Odonata                        
Collembola         1 1 2          
Turbellaria   1                    
Stream Quality Index 5 7 4 6 11 8 9 2        

Table 21. Abiotic measures for 1 X 2 m sample areas in April and July 2009. Measurements were taken from the deepest area of pools. Sites 4 and 5 were experimental pools. Sites 2 and 3 were controls. Dissolved oxygen and nitrate-N were determined by Vernier Lab Pro sensor probes.

MEASURE           APRIL       JULY                              
     2    3    4    5   2  3  4  5    2     3     4    5
Temperature

(degrees C)

 14

 

 12

 

14

 

13

 

23

 

23 24 23  

 

 

 

 

 

 

 

Depth (cm) 26 12 20 10 22 6 9 10        
PH 7.5 7.6 7.8 7.3 7.4 8.0 7.4 7.8        
Dissolved

Oxygen (ppm)

7.4

 

8.5

 

7.9

 

7.1

 

6.6

 

5.3 4.4 6.0       

 

       

 

       

 

      

 

Nitrate-N

(ppm)

1.4 4.0 2.9 0.9 1.1 0.9 1.5 1.1        

 

2010

Phases One and Two

Biotic and abiotic samples were taken in April 2010 as in Phase two above. Leaves collected in early spring 2010 were added to experimental sites 3 and 4 with about three pounds dry weight added to each. No leaves were added to control sites 1 and 7.

                                                                                                 

Results

 

2010

Tree leaves were collected on January 30, 2010. Leaves were 59% hackberry, 32 % sycamore, 6% cherry, 2% dogwood, and 1% elm. Pools number 1 and 7 were controls, and pools number 3 and 4 were experimentals. About three pounds dry weight of leaves were added to each experimental site in April. (Previous use of about six pounds of leaves created large humps under the net which accumulated silt.)

 

Table 22. Organisms collected in 1 X 2 meter sample areas in 2010. Pools 3 and 4 were experimentals, and pools 1 and 7 were controls. Low numbers in July are probably attributable to doing D-net sweeps before removing seine nets. For April, in the riffles near pool #1 were also found crayfish (1), amphipods (3), isopods (4), crane fly larvae (2), snails (16), and earthworms (1); near pool 3 water striders (4), midge larvae (1), crane fly larvae (1), and snail eggs; near pool #4 earthworms (13) and water beetle (1); and near pool #7 snail eggs, earthworms (3), isopods (6), amphipods (1), crayfish (3), water striders (2), and crane fly larvae (1). For July, in the riffles near pool #1 were found Hemiptera (1), Chironomidae (1), Isopoda (9), Amphipoda (1), Collembola (1), and Arachnida (1); near pool #3 were found Hemiptera (3), Chironomidae (2), Tupulidae (1), Gastropoda (1), Isopoda (7), and Arachnida (1); near pool #4 were found Hemiptera (3), Chironomidae (1), Isopoda (14), and Arachnida (3); and near pool #7 were found Plecoptera (1), Hemiptera (6), Oligochaeta (3), Gastropoda (2), Isopoda (2), and Arachnida (1). Data were collected again in November and are included in the table below. Also, outside pool #3 were found Amphipoda and Isopoda. Outside pool #4 were found Amphipoda, Isopoda, and Gastropoda.

 

ORGANISMS

APRIL

JULY

NOVEMBER

Pool

1

3

4

7

1

3

4

7

1

3

4

7

Nematoda                        
Oligochaeta   1                    
Gastropoda   4 21                  
Isopoda    

9

  1 1 1 2   1    
Amphipoda 1   10   27   1       6 4 12 9
Decapoda 1     1                
Arachnida     1                  
Coleoptera                        
Diptera: midge 1 7 2   1 1              
Diptera: misc.     4                  
Hemiptera                        
Odonata         1     1        
Collembola         1              
Turbellaria                        
Stream Quality Index 5 6 10 3 8 2 2 4 2 4 2 2

 

Table 23. Abiotic measures for 1 X 2 m sample areas in April, July, and November 2010. Measurements were taken from the deepest area of pools. Sites 3 and 4 were experimental pools. Sites 1 and 7 were controls. Dissolved oxygen and nitrate-N were determined by Vernier Lab Pro sensor probes.

MEASURE           APRIL       JULY                               NOVEMBER
Pool    1    3    4    7   1  3  4  7    1     3     4    7
Temperature

(degrees C)

 12 

 12

 

15

 

12

 

22

 

23 22 24 9

 

9

 

14

 

14

 

Depth (cm) 33 15 30 11 20 16 19 17 7 23 13.5 10
PH 8.2 7.6 7.4 7.3 7.4 7.7 7.2 7.6     6.8 7.3
Dissolved

Oxygen (ppm)

7.2

 

8.6

 

11.5

 

6.8

 

5.0

 

4.8 5.1 4.9   7.4

 

  7.4

 

4.6

 

5.4  

 

Nitrate-N

(ppm)

2.8 4.4 5.0 2.6 3.8 2.9 2.1 2.3 1.0 1.0 1.4 1.2

 

2011

Over 85 percent of the leaves were hackberry that were collected in December 2010, dried to 12 pounds total, and added in 2011. The number of organisms was higher in the controls both in April and May, and also increased more in the controls compared to experimentals. Averages of dissolved oxygen and nitrate-N were higher in experimentals than controls for both April and May. However, nitrate-N actually increased from April to May in the controls while decreasing in the experimentals. Leaves in the experimentals were expected to decrease nitrate-N due to assimilation and denitrification of nitrate by bacteria.

Table 24. Organisms in experimental pools 2 and 3 (leaves added) and control pools 1 and 6 (no leaves added) in 2011. No organisms were recorded for D-net sweep of pool 3 in April. In the riffle below pool 1 were found Isopoda, Amphipoda, Decapoda, Diptera, Oligochaeta, and Gastropoda. In the riffle below pool 2 were found Chironomid and other Diptera larva, Hemiptera, and Isopoda. In the riffle below pool 3 were found Chironomid and Coleoptera larvae, Hemiptera, Amphipoda, Isopoda, Oligochaeta, and Gastropoda. In the riffle below pool 6 were found Isopoda, Amphipoda, and Diptera larva. In May, near Pool 2, Amphipoda, Isopoda, Diptera, Chironomidae, and Oligochaeta were observed in riffles; near pool 6, Hemiptera, Chironomidae, Amphipoda, and Isopoda were observed; near pool 3, Amphipoda, Decapoda, Hemiptera, Oligochaeta, and Gasropoda; near pool 1, Isopoda, Decapoda, and Gastropoda.  Organisms found near pool 2 in November were Gastropoda, Isopoda, Amphipoda, Hemiptera, and Diptera larva.

 

ORGANISMS

APRIL

MAY

NOVEMBER

Pool

1

2

3

6

1

2

3

6

1

2

3

6

Nematoda                        
Oligochaeta 1                      
Gastropoda                        
Isopoda 2  1

 

  4 16 2 9 27        
Amphipoda 4  2     2 34 3 27 5        
Decapoda             1          
Arachnida                        
Coleoptera                        
Diptera: midge         1   1          
Diptera: misc.                        
Hemiptera                        
Odonata                        
Collembola                        
Turbellaria                        
Stream Quality Index 5 4   4 5 4 7 4        

Table 25. Abiotic measures for 1 X 2 m sample areas in April, May, and November 2011. Measurements were taken from the deepest area of pools. Sites 2 and 3 were experimental pools. Sites 1 and 6 were controls. Dissolved oxygen and nitrate-N were determined by Vernier Lab Pro sensor probes.

            APRIL       MAY                               NOVEMBER
Pool    1    2    3 MEASURE   1  2  3  6    1     2     3    6
Temperature

(degrees C)

 16 

 11

 

12

 

14

 

19

 

16 16 15  

 

   9

 

 

 

 

Depth (cm) 30 31 20 38 26 23 13 23        
PH 7.5 7.1 6.9 7.8 7.7 7.7 7.8 7.5     7.2    
Dissolved

Oxygen (ppm)

9.8

 

10.7

 

8.7

 

6.9

 

5.5

 

5.8 5.2 4.3  

 

  5.9

 

 

 

  

 

Nitrate-N

(ppm)

2.9 3.7 4.9 0.6 3.9 3.7 4.1 2.7     1.6    

Return to Longview Watershed Study