NEW: Annual Report - George Mason University

More documents

Recommendations

Info

Total Suspended Solids (mg/L) 80 70 60 50 40 30 20 10 Station 7 Station 9 Gunston Cove Study - 2003 0 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan 25 Total suspended solids (TSS) is measured by filtering a known amount of water through a fine filter which retains all or virtually all particles in the water. This filter is then dried and the weight of particles on the filter determined by difference. TSS consists of both organic and inorganic particles. During periods of low river and tributary inflow, organic particles such as algae may dominate. During storm flow periods or heavy winds causing resuspension, inorganic particles may dominate. Figure 27. Total Suspended Solids (mg/L). Noman Cole Lab Data. Month tick is at first day of month. Total suspended solids were fairly constant and covered a similar range in the river and cove through most of the year (Figure 27). Values outside a general range of 10-30 mg/L were found in November with about 35 mg/L in the river and nearly 70 mg/L in the cove. Volatile suspended solids were typically greater in the cove than in the river (Figure 28). A seasonal pattern was clear in the cove with higher values in the summer except for the maximum in November. In the river lower levels were observed except in late August when river VSS was slightly higher than in the cove. Volatile Suspended Solids (mg/L) 14 12 10 8 6 4 2 Station 7 Station 9 Gunston Cove Study - 2003 0 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Volatile suspended solids (VAS) is determined by taking the filters used for TSS and then ashing them to combust (volatilize) the organic matter. The organic component is then determined by difference. VSS is a measure of organic solids in a water sample. These organic solids could be bacteria, algae, or detritus. Origins include sewage effluent, algae growth in the water column, or detritus produced within the waterbody or from tributaries. In summer in Gunston Cove a chief source is algal (phytoplankton) growth. Figure 28. Volatile Suspended Solids (mg/L). Noman Cole Lab Data. Month tick is at first day of month.
26 C. Phytoplankton Chlorophyll a, Depth-integrated (ug/L) 100 80 60 40 20 Gunston Cove Study - 2003 Station 7 Station 9 0 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Chlorophyll a is a measure of the amount of algae growing in the water column. These suspended algae are called phytoplankton, meaning “plant wanderers”. In addition to the true algae (greens, diatoms, cryptophytes, etc.) the term phytoplankton includes cyanobacteria (sometimes known as “blue-green” algae. Both depth-integrated and surface chlorophyll values are measured due to the capacity of phytoplankton to aggregate near the surface under certain conditions. Figure 29. Chlorophyll a (ug/L). Depth-integrated. GMU Lab Data. Month tick is at the first day of month. Chlorophyll a exhibited a distinct seasonal pattern in both river and cove and the pattern was quite similar in both depth-integrated (Figure 29) and surface (Figure 30) samples. In the cove chlorophyll levels increased fairly steadily from early April to late August/early September. Two exceptions to this steady increase were low values in late May and in early August. A major decline in chlorophyll a was observed in late September corresponding with the passage of Hurricane Isabel. A recovery was observed in October, but November and December continued the seasonal decline. In the river a distinct peak was observed in late April followed by low chlorophyll a levels in May and June. Values increased in July and reached a distinct peak in late August. Chlorophyll a, Surface (ug/L) 100 80 60 40 20 Gunston Cove Study - 2003 Station 7 Station 9 0 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan In the Gunston Cove, there is very little difference in surface and depth-integrated chlorophyll levels because tidal action keeps the water well-mixed which overcomes any potential surface aggregation by the phytoplankton. Summer chlorophyll a concentrations in excess of 30 ug/L are generally considered characteristic of eutrophic conditions. Figure 30. Chlorophyll a (ug/L). Surface. GMU Lab Data. Month tick is at first day of month.
Page 1 and 2: An Ecological Study of Gunston Cove
Page 3 and 4: ii An Ecological Study of Gunston C
Page 5 and 6: iv were collected on three sample d
Page 7 and 8: vi We recommend that: 1. Long term
Page 9 and 10: 2 INTRODUCTION This section reports
Page 11 and 12: 4 Table 1 Sampling Dates and Weathe
Page 13 and 14: 6 immediately with formalin to a co
Page 15 and 16: 8 subsample of known volume and res
Page 17 and 18: 10 A. Climate and Hydrological Fact
Page 19 and 20: 12 B. Physico-chemical Parameters:
Page 21 and 22: 14 Dissolved Oxygen (mg/L) 16 14 12
Page 23 and 24: 16 pH, NC Lab 9.5 9.0 8.5 8.0 7.5 7
Page 25 and 26: 18 Secchi Depth (m) 1.2 1.0 0.8 0.6
Page 27 and 28: 20 Ammonia Nitrogen (mg/L) 0.30 0.2
Page 29 and 30: 22 Organic Nitrogen (mg/L) 1.2 1.0
Page 31: 24 N/P Ratio (by mass) 60 50 40 30
Page 35 and 36: 28 Figure 32. Phytoplankton Density
Page 37 and 38: 30 The dominant cyanobacteria on a
Page 39 and 40: 32 Total phytoplankton biovolume ca
Page 41 and 42: 34 Melosira Figure 44. Phytoplankto
Page 43 and 44: 36 Bosmina Density by Station (#/L)
Page 45 and 46: 38 Moina Density by Station (#/m 3
Page 47 and 48: 40 Diaptomus Density by Station (#/
Page 49 and 50: 42 E. Ichthoplankton Larval fishes
Page 51 and 52: 44 Clupeid Larvae (#/10m 3 ) 50 40
Page 53 and 54: 46 Table 4 Adult and Juvenile Fish
Page 55 and 56: 48 The abundance of each species in
Page 57 and 58: 50 Average Number of Fish per Trawl
Page 63 and 64: 56 Average Fish per Seine 600 500 4
Page 65 and 66: 58 Macrobenthos (#/m 2 ) 500 400 30
Page 67 and 68: 60 Total phosphorus levels were fai
Page 69 and 70: 62 Table 10 Correlation and Linear
Page 71 and 72: 64 Water Temperature (oC) 35 30 25
Page 73 and 74: 66 Chloride (mg/L) 350 300 250 200
Page 75 and 76: 68 Dissolved Oxygen (% saturation)
Page 77 and 78: 70 Light Attenuation Coefficient (m
Page 79 and 80: 72 Lab pH, GMU 11 10 9 8 7 Station
Page 81 and 82: 74 Total Alkalinity (mg/L CaCO3), G
Page 83 and 84:
76 Biochemical Oxygen Demand (mg/L)
Page 85 and 86:
78 Volatile Suspended Solids (mg/L)
Page 87 and 88:
80 Soluble Reactive Phosphorus (mg/
Page 89 and 90:
82 Un-ionized Ammonia Nitrogen (mg/
Page 91 and 92:
84 Nitrite Nitrogen (mg/L) 0.100 0.
Page 93 and 94:
86 Nitrogen:Phosphorus Ratio 70 60
Page 95 and 96:
88 Chlorophyll a, Surface (ug/L) 10
Page 97 and 98:
90 PBmax (ug C/ug Chl a/hr) 30 25 2
Page 99 and 100:
92 D. Zooplankton Trends: 1990-2003
Page 101 and 102:
94 Brachionus (#/L) 1000.0 100.0 10
Page 103 and 104:
96 Filinia (#/L) 1000.0 100.0 10.0
Page 105 and 106:
98 Polyarthra (#/L) 1000.0 100.0 10
Page 107 and 108:
100 Diaphanosoma (#/m3) 100000.00 1
Page 109 and 110:
102 Chydorid Cladocera (#/m3) 1000.
Page 111 and 112:
104 Copepod Nauplii (#/L) 1000.0 10
Page 113 and 114:
106 Clupeid Larvae (#/10m3) 1000.0
Page 115 and 116:
108 Atherinid Larvae (#/10m3) 10.00
Page 117 and 118:
110 F. Adult and Juvenile Fish Tren
Page 119 and 120:
112 Table 14 Mean catch of adult an
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
118 Mean Catch Per Trawl 50 40 30 2
Page 127 and 128:
120 Mean Catch Per Trawl 8 6 4 2 Tr
Page 129 and 130:
122 Mean Catch Per Trawl 120 100 80
Page 131 and 132:
124 Mean Catch Per Trawl 16 14 12 1
Page 133 and 134:
126 Seines The mean annual catch pe
Page 135 and 136:
128 Table 19 The number of seines i
Page 137 and 138:
130 Mean Catch Per Seine 300 250 20
Page 139 and 140:
132 Mean Catch Per Seine 250 200 15
Page 141 and 142:
134 G. Benthos Trends Oligochaetes
Page 143 and 144:
136 Amphipods (#/m2) 16 12 8 4 Stat
Page 145 and 146:
138 Corbicula (#/m2) 40 30 20 10 St
Page 147 and 148:
140 Table 21 Summary of Important T
Page 149 and 150:
142 observed through 1995. This has
Page 151 and 152:
144 being filled. A dredged channel
Page 153 and 154:
146 Anadromous Fish Survey Pohick,
Page 155 and 156:
148 sized fishes were seen, an atte
Page 157 and 158:
150 Table 3. Fish eggs and larvae c
Page 159 and 160:
152 Total 7 11 237 13 2 64 119 (2.3
Page 161 and 162:
154 Table 7. Adult anadromous and s
Page 163 and 164:
156 Table 8. Summary of alewife spa
Page 165 and 166:
158 Spawning information on gizzard
Page 167 and 168:
160 The information that pertains t
Page 169 and 170:
162 lower reaches of Pohick Creek i
Page 171 and 172:
164 Table 13. Catches of adult clup
Page 173 and 174:
Appendix A Phytoplankton Species Di
show all

NEW: Annual Report - George Mason University

Create successful ePaper yourself

Delete template?

Save as template?