Response of Phytoplankton to Water Quality in The

RESPONSE OF PHYTOPLANKTON TO WATER

QUALITY IN THE CHOWAN RIVER SYSTEM

A. M. Witherspoon, Associate Professor Charles Balducci, Graduate Student Oliver C. Boody, Graduate Student Jimmie Overton, Graduate Student

Department of Botany North Carolina State University Raleigh, North Carolina 27650

The work upon which this publication is based was supported in part by funds provided by the Office of Water Research and Technology, U. S. Department of the Interior, Washington, D.C., through The University of North Carolina Water Resources Research Institute, as authorized under the Water Research and Devel- opment Act of 1978. Additional support was provided by the Department of Natural Resources and Community Development of the State of North Carolina.

Project No. B-091-NC

Agreement No. 14-34-0001-6104

April 1979

TABLE OF CONTENTS (continued)

Page

Phosphorus Chemistry ...... 99 Alkaline Phosphatase Activity ...... 100 Phosphate Uptake Rates and Turnover Times ...... 102 Light ...... 104 Phytoplankton Growth Rates ...... 104 Temperature ...... 110 Die1 Studies ...... 11 0 PHYTOPLANKTON AND BACTERIA ACTIVITY, 1976-1977 ...... 113 Procedure ...... 11 3 Results ...... 11 3 Physical Factors ...... 113 Chemical Parameters ...... 116 Nitrogen ...... 116 Phosphorus ...... 116 N:P...... 120 Carbon...... , ...... 120 Chloride Ion, Chemical Oxygen Demand, and pH ...... 120 Phytoplankton ...... 122 Bacteria ...... , ...... 133 DISCUSSION ...... 135 Dominant Species Importance ...... 136 AlgalBiomass ...... 138 Biomonitor Biomass ...... 139 Phosphate Enrichment ...... 140 LITERATURE CITED ...... 143

APPENDICES...... 145

Appendix A - Biomass at Various Stations Sampled Bimonthly in the Chowan River and Tributaries ...... 145 Appendix B - Temporal and Spacial Location of Species in the Chowan River System, March 1974-March 1975 ...... 147 Appendix C - Dominant Species at Tunis, Colerain, and Edenton . . . . 156 Appendix D - Environmental Data, 1975-1976 ...... 165 Appendix E - Miscellaneous Data - July 1976-April 1977 ...... 170

1. Algal Occurrence ...... , ...... 170 2. Algal Cell Density, Biomass, Cell Carbon, and Species Present. 185 3. Algal Cell Density, Biomass, Cell Carbon, and Species Present by Group ...... 186 4. Algal Species, Cell Degsity, Biomass, and Cell Carbon by Period, Site, and Season ...... 190 5. Chemical and Bacterial Data ...... 203 ACKNOWLEDGMENTS

This study was financed in part by the Office of Water Research and Technology's Matching Grants Program through The University of North Caro- lina Water Resources Research Institute. Additional funds were provided by the Department of Natural Resources and Community Development of the State of North Carolina.

Several people were associated with the project in various ways. Dr. L. A. Whitford provided expert algal identification and general advice on many species. The 1974-75 samples were collected by Mr. Grover Cook and the sampling crew from the Department of Natural Resources and Community Development, the State of North Carolina. Technical support was given by Ms. Cheryl Dicks, phytoplankton enumeration; Ms. Pat Boody, algal assay; Mr. Roger Pearce, data reduction and computer graphing. Dr. William S. Galler aided with data retrieval and Dr. Don W. Hayne critiqued the regression analysis. Typing and table preparation were done by Mrs. Sarah Miller and Mrs. Sandra Perkins of the Botany Department and by the clerical staff of the Water Resources Research Institute.

Several graduate students in the Botany Dcp~rtmentof N. C. State Uni- versity contributed to this report through their graduate studies for the Master's Degree, Botany (phycology): Mr. Charles Balducci, 1975-1976 assay studies on phosphorus uptake kinetics; Mr. Jimmie Overton, 1975-1976 biomonitor biomass study; and Mr. Oliver Boody, 1976-77 phytoplankton-bacteria studies. Full reports of these theses will be filed in the D. H. Hill Library at N. C. State University.

DISCLAIMER STATEMENT

Contents of this publication do not necessarily reflect the views and policies of the Office of Water Research and Technology, U. S. Department of the Interior, nor does mention of trade names or commercial products constitute their endorsement or recommendation for use by the U. S. Government. ABSTRACT

An investigation of seasonal changes in phytoplankton species diversity and biomass, phosphorus uptake kinetics, in-situ and in-vitro algal growth potential and phytoplankton-bacteria interaction in the Chowan River system was conducted from March 1974 through June 1977.

Due primarily to differences in flow patterns, the river is divided into two sections with respect to phytoplankton dominants: (I) the upper, faster- flowing narrow section from its beginning at the confluence of the Nottoway and Blackwater Rivers to the bend in the river some 16 km downstream; and (2) the lower, wider section with very low water flow that extends approximately 64 km from the deep bend in the river to its mouth near Edenton, North Carolina.

The upper river is characterized by seasonal changes in dominants, usually of the flagellated types. Diatoms are omnipresent with fewer blue-green, green, and yellow-green algal types appearing seasonally. The lower river is characterized by filamentous blue-green algae during spring and summer. The slower-moving water in this section promotes longer residence time for nutrients and algae; therefore, it is plagued with seasonal algae blooms. There are five species that may become dominant during the blooms: (1) Anabaena circinalis, (2) Anabaena aegmlis, (3) Anabaena wisconsinense, (4) Anacystis (Microcystis) firma, and (5) Aphanizomenon fzos-ayme (gracile). The blooms are inversely correlated with nitrate and phosphate concentrations in the river. However, substantial levels of biomass are able to persist after P04, NO3, and NH3 concentrations are below detectable levels. Nutrient recycling by bacteria and fungal activity, nitrogen fixation, and algal physiological utilization of organic phosphorus may facilitate this process.

Nitrate was found to be a preferred source of nitrogen by the bloom algae while other algae seemed to prefer ammonia.

Nutrient concentrations in the river (NOj, NH3, PO4) were found to quantitatively support an annual phytoplankton biomass of 0.01 to 30 mg/liter. The higher biomass was found in the lower river during the spring-summer season and in the upper river during the late fall and winter season. Increase in total biomass did not always represent a negative change in water quality. However, poor water quality or late-winter/early-spring increases in nutrient levels subsequently promoted increased biomass by a few species in the lower Chowan, accompanied by a reduction in biomass of other species. This resulted in a rather constant total seasonal biomass even though there may have been a visible bloom on the river. The minimum visible bloom had a mean biomass of 1 mg/l (10~~~/1).

The reduced flow in the lower Chowan increased the "nutrient-algal" residence time thereby increasing the potential for an increased algal standing crop; in addition, engendered warmer water promoted increased bacterial- fungal action releasing recycling nutrients into the system. This gave a competitive advantage to species with morphological or physiological compatibility to the changed ecological conditions. In its present status, Chowan River water quality, without point-source input, is sensitive to the hydrographical and hydrophysical condition of the river. Sound management practices, therefore, must concentrate on the control- lable conditions that potentially could further decrease water quality. LIST OF FIGURES -No. Page 1 The Chowan River drainage basin of northeastern North Carolina and southeastern Virginia ...... 7 2 The Chowan River System in southeastern Virginia and northeastern North Carolina, showing towns and sampling sections for project years 1975-77 ...... 8 3 Diagram showing sampling stations in the Chowan River System . . . . 10

4A Seasonal distribution of algal biomass in the Chowan River, 1974- 1975;StationC-1 ...... 13

4B Seasonal distribution of algal biomass in the Chowan River, 1974- 1975;StationC-2 ...... 14

4C Seasonal distribution of algal biomass in the Chowan River, 1974- 1975; Station C-3 (Winton) ...... - . . . . 15

4D Seasonal distribution of algal biomass in the Chowan River, 1974- 1975; Station C-4 (Tunis) ...... 16

4E Seasonal distribution of algal biomass in the Chowan River, 1974- 1975; Station C-5 (below C. F. Industries) ...... 17

4F Seasonal distribution of algal biomass in the Chowan River, 1974- 1975; Station C-7 ...... 18

4G Seasonal distribution of algal bi.omass in the Chowan River, 1974- 1975;StationC-8 ...... 19

4H Seasonal distribution of algal biomass in the Chowan River, 1974- 1975; Station C-9 (Harrellsville) ...... 20 41 Seasonal distribution of algal biomass in the Chowan River, 1974- 1975; Station C-10 ...... 21 45 Seasonal distribution of algal biomass in the Chowan River, 1974- 1975; Station C-11 (Colerain) ...... 22

4K Seasonal distribution of algal biomass in the Chowan River, 1974- 1975; Station C-16 (Edenhouse) ...... 23 5A Total algal biomass, March 9, 1974 ...... 24 5B Totalalgalbiomass, April23,1974 ...... 25 5C Total algal biomass, May 21, 1974 ...... 26 5D Totalalgalbiomass, June 5,1974...... 27 5E Totalalgalbiomass, June 18, 1974 ...... 28 ..

LIST OF FIGURES (continued)

Page

Total algalbiomass. July 10. 1974 ...... 29 Total algalbiomass. July 11. 1974 ...... 30 Total algal biomass. July 14. 1974 ...... 31 Total algal biomass. August 6. 1974 ...... 32 Total algal biomass. August 30. 1974 ...... 33

Total algal biomass. September 4. 1974 ...... 34 Total algal biomass. September 27. 1974 ...... 35 Total algal biomass. October 1. 1974 ...... 36 Total algal biomass. October 15. 1974 ...... 37 Total algal biomass. November 19. 1974 ...... 38

Total algal bioma.ss, January 21. 1975 ...... 39 Total algal biomass. February 4. 1975 ...... 40 Total algal biomass. February 25. 1975 ...... 41 Total algal biomass. March 11. 1975 ...... 42 Total algal biomass. April 2. 1975 ...... 43

Algal biomass distribution by genera. May 7. 1974 (Station BL-1) ...... Algal biomass distribution by genera. May 7. 1974 (Station N-1) . Algal biomass distribution by genera. July 14. 1974 (StationBL.1) ......

Algal biomass distribution by genera. July 14. 1974 (StationN-1) ...... Algal biomass distribution by genera. July 14. 1974 (Station S-1) ......

Algal biomass distribution by genera. November 19. 1974 (Stations-1) ......

Algal biomass distribution by genera. March 9. 1974 (Station C-1) ...... J LIST OF FIGURES (continued) -No. Page 13 Algal biomass distribution by genera, May 7, 1974 (Station C-1) ...... 48

Algal biomass distribution by genera, May 21, 1974 (StationC-1) ...... 49

Algal biomass distribution by genera, October 15, 1974 (Station C-1) ...... 49

Algal biomass distribution by form, June 18, 1974 (Station M-3) ...... 51

Algal biomass distribution by form, June 18, 1974 (StationC-2) ...... 51

Algal biomass distribution by form, June 18, 1974 (Station C-3) ...... 52

Algal biomass distribution by form, June 18, 1974 (Station C-4) ...... 52

Algal biomass distribution by genera, June 18, 1974 (Station M-3) ...... 53 Algal biomass distribution by genera, July 14, 1974 (StationM-3) ...... 53

Algal biomass distribution by genera, August 6, 1974 (Station M-3) ...... 54

Algal biomass distribution by genera, June 18, 1974 (StationC-2) ...... 54 24 Algal biomass distribution by genera, July 14, 1974 (Station C-2) ...... 55 25 Algal biomass distribution by genera, August 6, 1974 (Station C-2) ...... 55

26 Algal biomass distribution by genera, June 18, 1974 (StationC-3)...... 56

27 Algal biomass distribution by genera, July 14, 1974 (StationC-3) ...... 56

28 Algal biomass distribution by genera, August 6, 1974 (StationC-3) ...... 57

29 Algal biomass distribution by genera, June 18, 1974 (Station C-4) ...... 57 LIST OF FIGURES (continued) -No. Page 3 0 Algal biomass distribution by genera, July 14, 1974 (Station C-4) ...... 58 Algal biomass distribution by genera, August 6, 1974 (Station C-4) ...... 58

Algal biomass distribution by genera, May 21, 1974 (StationC-11) ...... 59 Algal biomass distribution by genera, May 21, 1974 (StationC-12) ...... 59

Algal biomass distribution by genera, May 21, 1974 (StationC-13) ...... 60

Algal biomass distribution by genera, May 21, 1974 (StationC-14) ...... 60

Algal biomass distribution by genera, Hay 21, 1974 (StationC-15) ...... 61

Algal biomass distribution by genera, May 21, 1974 (Station C-16) ...... 61

Monthly average discharge and maximum and minimum daily average discharge for each month at Chowan River near Eure and Chowan Riveratwinton ...... 63

Monthly average discharge and maximum and minimum daily average discharge for each month at Chowan River near Harrellsville and Chowan River near Colerain ...... 64 Monthly average discharge and maximum and minimum daily average discharge for each month at Chowan River near Edenhouse ...... 65 Algal biomass distribution by genera, June 5, 1974, (Station C-16) . 66

Algal biomass distribution by genera, June 18, 1974 (StationC-16) . . . , ...... 66 Algal biomass distribution by genera, July 10, 1974 (Station C-16) ...... 67

Algal biomass distribution by genera, July 11, 1974 station^-1) ...... 67

Algal biomass distribution by genera, July 10, 1974 (StationW-3) ...... 68

Algal biomass distribution by class.=s, June 5, 1974 (StationC-16) ...... 69 LIST OF FIGURES (continued)

-No. Page Algal biomass distribution by classes, June 5, 1974 (StationC-11) ...... 69

Algal biomass distribution by classes, June 5, 1974 (StationC-13) ...... 70

Algal biomass distribution by classes, June 5, 1974 (StationC-14) ...... 70

Algal biomass distribution by classes, June 5, 1974 (StationC-15) ...... 71

Algal biomass distribution by classes, June 5, 1974 (StationC-1) ...... 71

Algal biomass distribution by classes, June 5, 1974 (Station C-3) ...... 72

Algal biomass distribution by classes, June 5, 1974 (StationC-4) ...... 72

Algal biomass distribution by classes, July 10, 1974 (Station C-2) ...... 73

Algal biomass distribution by classes, July 10, 1974 (Station C-3) ...... 73

Algal biomass distribution by classes, July 10, 1974 (StationC-4) ...... 74

Algal biomass distribution by classes, July 10, 1974 (StationC-5) ...... 74

Algal biomass distribution by classes, July 10, 1974 (StationC-6) ...... 75

Algal biomass distribution by classes, July 10, 1974 (StationC-7) ...... 75 Algal biomass distribution by classes, July 10, 1974 (StationC-8) ...... 76

Algal biomass distribution by classes, July 10, 1974 (Station C-9) ...... 76

Total algal biomass, April 23, 1974 ...... 78

Seasonal distribution of surface temperature, pH, and Secchi depth at Edenton and Tunis, 1975-1976 ...... 82 LIST OF FIGURES (continued) -No. Page 65 Precipitation and Chowan River discharge at Winton, Colerain, and Edenton, 1975-1976...... 85 66 Seasonal distribution of ortho-phosphate concentrations as determined at bi-weekly intervals, 1975-1976 ...... 86

6 7 Seasonal distribution of total phosphorus concentrations as determined at bi-weekly intervals, 1975-1976 ...... 87

68 Seasonal distribution of nitrate-nitrogen concentrations as determined at bi-weekly intervals, 1975-1976 ...... 89

69 Seasonal distribution of ammonia-nitrogen concentrations as determined at bi-weekly intervals, 1975-1976 ...... 91

70 Seasonal distribution of total nitrogen concentrations as determined at bi-weekly intervals, 1975-1976 ...... 93

71 Seasonal distribution of algal biomass as determined at bi-weeklyintervals,1975-1976...... 94

72 Bi-weekly determinations of standing crop carbon and biomonitor carbon at Tunis and Edenton, 1975-1976 ...... 97

73 Seasonal distribution of DIP and algal biomass at Winton, Harrellsville, Colerain, and Edenton, 1975-1976 ...... 101

74 Seasonal distribution of temperature, DIP, algal biomass, k~' P-uptake, and C-uptake at Colerain, 1975-1976 ...... I03 75 DIP turnover times at Colerain, 1975-1976 ...... I05 76 DIP turnover times at Edenton, 1975-1976 ...... 106

77 Diel variation of k L' P-uptake, C-uptake, PAR, DIP, and algal biomassat20°C ...... 107

78 Diel variation in DIP turnover time and DIP uptake under light anddarkconditions ...... I08 79

8 0 Diel variation of PAR, DIP, and algal biomass at Colerain, November 1,1975 ...... I12

81 Sample rack for simultaneous measurement of algal primary productivity and bacterial heterotrophic activity ...... I14

82 Mean air temperatures (Murfreesboro and Edenton) and water temperatures (Tunis and Colerain), 1976-1977 ...... 115

xiii LIST OF FIGURES (continued)

-No. Page 83 Average monthly precipitation at Murfreesboro and Edenton, 1976-1977...... 117 84 Total nitrogen (TN) , total organic nitrogen (TON), ammonia nitrogen (NH3-N), and nitrate (NO3-N) at Tunis and Colerain, 1976-1977...... 118

Total phosphorus (TP), total organic phosphorus (TOP), and ortho-phosphate phosphorus (0-P04) at Tunis and Colerain, 1976-1977......

Relationship between total nitrogen and total phosphorus and between inorganic nitrogen and inorganic phosphorus at Tunis and Colerain, 1976-1977 ......

Chloride ion (CI), chemical oxygen demand (COD), and pH at Tunis and Colerain,1976-1977 ......

Total algal cell numbers and total algal biomass at Tunis and Colerain, 1976-1977 ......

Algal cell number composition by group, at Tunis and Colerain, 1976-1977......

Algal biomass composition, by group, at Tunis and Colerain, 1976-1977 ......

Nitrate-nitrogen concentrations at Tunis and Colerain, 1975-1977......

Ammonia-nitrogen concentrations at Tunis and Colerain, 1975-1977...... *

Ortho-phosphate-phosphorus co.ncentrations at Tunis and Cole- rain,1975-1977 ......

Bacterial cell number and biomass at Tunis and Colerain, 1976-1977......

xiv LIST OF TABLES -No. Page 1 Location and identification of sampling stations in the Chowan River System...... 11

Distribution by divisions of the various classes, genera, species, varieties, and forms of phytoplankton located in the Chowan River, 1974-1977 ...... 12

Field measurements of surface water remperature (WT) in Coy pH, and Secchi depth (SDp) in cm, at Tunis and Edenton, 1975-1976 ... 83

Bi-weekly concentrations of total phosphorus (TP), orthophosphates (OP), total nitrogen (TKN), nitrate nitrogen (NO3), and ammonia (NH3) in mg/l, 1975-1976 ...... 88 Bi-weekly algal biomass (mgll), 1975-1976 ....,...... 96

Bi-weekly determinations of standing crop biomass (SCB), standing crop biomass carbon (SCB carbon), biomonitor biomass (BMB), biomonitor carbon (BMB carbon), change in carbon (Acarbon), and bio- monitornet productivity (BNP) ...... 98 Temperature effects (QlO) on P-uptake ...... 110

SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

Summary and Conclusions

The Chowan River Estuary, located in northeastern North Carolina, devel- oped a heavy algal growth that promoted a large fish kill during the summer of 1972.

During the winter of 1974, a research team of federal, State, and university personnel was organized to investigate the water quality conditions of the river.

The objectives of this project were to:

1. determine biomass of phytoplankton as an index of primary productivity of the river,

2. estimate concentration of rate limiting nutrients,

3. determine algal growth potential of river water,

4. supply kinetic data on phytoplankton growth for development of predictive models, and

5. provide ground truth for multispectral photographic studies.

Specific findings were:

1. There are three peaks of relatively high algal growth: (a) the short-lived, late-winter peak; (b) the mid-spring peak; (c) the summer peak that lasts through September to early October.

2. Biomass ranged in the river from 0.01 to 30 mg/l during the period March 1974 through June 1977.

3. Dominant influences on the river discharge were directional wind tides and basin hydrography. River flow is a dominant - influence on nutrient distribution and algal growth.

4. The river is divided into two biotic sections: (a) the upper river usually with adequate nutrients but short residence time for algal-nutrient interaction; and (b) the lower river usually with low flows with long residence time for nutrients and algal interaction.

5. Adequate to high nutrient levels during the winter, spring, and fall coupled with moderate to high algal biomass indicate that nutrient levels during these seasons were adequate to support a high phytoplankton growth when other growth requirements were present. 6. Water temperatures ranged from O°C to 35OC. Algal species, in variable combination, are acclimated to variable temperatures. Light penetration was approximately one meter.

7. The algae of the upper Chowan are primarily composed of motile unicells and colonies while those of the lower Cho- wan are primarily dominated by blue-green types. Diatoms are omnipresent temporally and spatially.

8. Low nutrient levels coupled with high algal biomass during the mid-summer indicated that when environmental conditions are favorable algal growth quickly depletes nitrogen and phosphorus; yet, algal growth during this season continues. Nutrient recycling, nitrogen fixation, physiological utilization of organic nitrogen and/or phosphorus in high concentration in the river or a combination of all three processes may be providing these essential nutrients during that period.

9. The lower Chowan is subject to spring-summer pulse blooms. During such blooms, overall river algal biomass of the individual blooming species may be very high. The chief initial cause of the bloom is the high nitrogen concentration received by the river during winter and early spring.

10. The visual blooms are caused by five species of cyanophyceae (blue-green algae), three species of Anabaenu, one of Micro- cystis, and one of Aphanizomenon. The non-visual blooms are combinations of diatoms, in particular MeZosira; and/or dinophyceae, in particular Peridinium.

. River topography, flow, nutrient concentrations, temperature, pH, turbidity, and light penetration are in a critical bal- ance in the lower Chowan, however, not so critical in the upper reaches. Therefore, additional nutrients and/or radi- cal changes in environmental conditions could provoke extensive algal problems. Recommerida t ions

Since it has been shown that low discharge is correlated with algal blooms, we recommend that any management scheme involving this river consider very carefully the potential effect of reduced river discharge on algal growth potential in the lower reaches of the estuary.

Point source discharges should be tightly controlled and monitored to insure that no additional nutrients are added to the river system.

Wastewater discharges by Union Camp should be during fall and winter, coordinated with high basinwide rainfall events to insure optimum flushing.

Other nutrient releases should coincide with the discharge by Union Camp whenever possible, since their discharge greatly reduces light penetration and slightly decreases flushing time.

A total annual nutrient budget (nitrogen and phosphorus) from runoff of all point sources should be determined to give accurate information as to nutrient sources and fluxes in the river system. Care should be taken to insure that analytical methods used for nitrogen and phosphorus determinations reflect the true "state of the art."

In order to develop a better management tool for the river and to under- stand more completely the annual cycle of phytoplankton species and biomass in the river system, the following studies are recommended:

Controlled experiments to determine the nutrient requirements of Anabaena circinaZis, A. wisconsinense, A. aequaZis; Anacystis (also called Microcystis, PoZycystis, and CZathro- cysts) firma; and Aphanizomenon fZas-aquae (gracile).

Characterization of the physiological-ecological operation of the species of Anabaena, Anacystis, and Aphanizomenon to determine changes in the Chowan River that would significantly enhance their growth rate.

Field experiments to determine the seasonal origin of the five species of bloom potential in the lower Chowan River and to assess their potential and real nitrogen fixation contribution to the nitrogen economy of the river.

Characterization of chlorophyll-u changes in the river as a whole with controlled in-situ det.ermination, in particular, on the five species of bloom potential, as a function of seasonal biomass changes.

Assessment of the capacity of these dominant species to con- vert organic phosphorus to usable phosphorus as a phosphorus- nutrient source.

Development of a multiple species submodel of the genera of bloom potential to interface with the current model as a means of improving the model's capability to make realistic nuisance algal growth predictions. g. Determination of a nutrient budget for the river and establish- ment of criteria standards for nitrogen and phosphorus. INTRODUCTION

Background, Scope, and Objectives

Wastewater discharges containing substantial quantities of nitrogen have been indicated as an important factor in water quality problems plaguing the Chowan River in northeastern North Carolina. In 1972 the lower river reached a climactic condition of apparent early eutrophication with a rapid increase in phytoplankton growth that resulted in a massive fish kill which persisted for several weeks.

fl Nutrient loading was considered to originate from industries and townships located along the river and from agricultural practices in the river basin.

This deterioration in water quality motivated a multidisciplinary study of the problem. The ultimate objective of this study was to develop a predictive management model for the Chowan River Estuary.

The Chowan River Plan, as the study was called, included water quality measurements by the Division of Environmental Management and the Virginia Water Control Board, river flow measurements by the U. S. Geological Survey, and a series of projects by university researchers designed to generate biological data specifically needed in the development of a management model. In addition to this study, the biological projects included a study of the uptake, storage, and release of plant growth nutrients from the organs of aquatic macrophytes and a study on the recycling of nitrogen in the lower Chowan.

Proper calibration and verification of a management model require either historical data collected over an extended period of time or current field measurements compatible with the geographical design of the model.

Quality historical data suitable for model verification were virtually non-existent on the Chowan River. Therefore, one primary responsibility of the multidisciplinary team was to supply a diversified set of field data for use in model development.

This report describes qualitative-quantitative phytoplankton species, numbers, and biomass in the Chowan River. During the period March 1974 through March 1975, observations were made on the full reach of the river from the confluence of the Nottoway and Blackwater Rivers to Edenhouse. The period April 1975 through April 1977 covers in detail the lower reach of the river, a distance of approximately 64 kilometers upriver from the Albemarle Sound.

In addition, this report describes phmphate uptake kinetics in the river, a biological monitoring technique, and a temporal and spacial algal bioassay with a laboratory assessment of algal groxth response to potential increased loading of nitrogen and phosphorus into the lower river waters.

This study also facilitated the multidisciplinary concept by supplying phytoplankton data to other researchers on the study team. Description of Area

The Chowan River is formed by the confluence of the Nottoway and the Blackwater Rivers just north of the Virginia-North Carolina line and flows in a southerly direction for approximately 80 km into the Albemarle Sound near Edenton, North Carolina (Figure 1). While the Meherrin and the Wiccacon Rivers are the two main tributaries of the Chowan River in North Carolina, Somerton, Bennetts, and Trotman Creeks are also important. The width of the Chowan varies from a few hundred meters to almost 8 km at Edenton. The cross-sectional area of the river through most of its course far exceeds that necessary to transmit the water that enters it (Jackson, 1968). It is affected by ocean tides throughout its course, which may cause variation in water level of up to 0.3 meters (Jackson, 1968). Strictly speaking, the Chowan is not a river but rather an estuary (Jackson, 1968). The lower reaches of the river often have characteristics of a lake with occasional "reverse flow." The mouth of Albemarle Sound is separated from the Atlantic Ocean by a series of barrier islands which both influence the magnitude of the lunar tide and pre- vent the intrusion of seawater by direct flow into the sound. Thus, the river from its mouth up to its headwaters is a freshwater ecosystem with chloride concentrations less than 50 mg/l under normal conditions. 2 The drainage basin of the Chowan includes some 12,600 km (Figure 1). Much of the river is bound by extensive gum-cypress swamps which are frequently inundated. Numerous small streams and channels within the basin facilitate the exchange of water between the swamps and the estuary (Daniel, 1977). Much of the basin is farmland, containing tobacco, corn, and soybeans as major crops. Several small towns border the river. From a northern to a southerly direction, these include Winton, Tunis, Harrellsville, Colerain, and Edenton (Figure 2). Industries located in the basin are Union Camp near Franklin, Virginia; C. F. Industries at Tunis; perry-wynnls Fish Company at Colerain; and United Piece Dyeworks and the Murray Nixon Fishery near Rockyhock. Recreational and commercial fishing, as well as water skiing and boating, are widespread in this estuary.

The two factors affecting flow rates in the river are wind and tributary inflow. Tributary inflow has the greater influence in the upper Chowan while wind is the primary causative factor in the lower reaches (Daniel, 1977; Jackson, 1968). Thus, direction of flow in the lower Chowan is dependent upon the direction and velocity of the wind. Winds from the northwest blow water downstream, and winds from the southeast blow water upstream. However, wind is a greater factor on flow over a short time frame (hourly, daily). Longer periods (weekly, biweekly) are most influenced by the amount of freshwater inflow, particularly from upland parts of the basin.

Suspended detritus and hu~nicmatter brought in by runoff water or accumulated within the well-mixed river water cause high turbidity and a shallow one percent light level, usually less than one meter. However, the mean depth of the river is only about 1.3 meters.

..a. b, @.I.c..l.'l'.l sun., I I 77'00' SO' 16'40'

Figure 2. The Chowan River System in southeastern Virginia and northeastern North Carolina, showing towns and sampling sections for project years 1975-77.

8 BIOMASS AND CELL NUMBERS, 1974-1975

Procedure

At biweekly intervals from March I974 through April 1975, water samples were collected at 27 stations spread over the entire reach of the Chowan River Estuary and its tributaries (Figure 3, Table 1). Subsequent to April 15, 1975, through May 30, 1977, biweekly samples were taken from three to five stations (Winton, Tunis, Harrellsville, Colerain, ELdenhouse) spread over a 64 km stretch of the lower Chowan River (Figure 2). Specific methods used during the latter years will be described in association with each phase of the study.

For enumeration and identification of phytoplankton, 500 ml samples were taken from the surface waters initiating at the one percent light level and integrated upward through the water column. These samples were immediately fixed with Lugol's solution and returned to the laboratory for counting. A fresh sample was taken by tow, using a 20 mesh plankton net and preserved on ice for subsequent species identification.

Either 25, 50, or 100 ml sub-samples of each sample were allowed to set- tle for 12 hours (or overnight) in especially constructed sedimentation chambers and counted by the method of Utermohl (1958). The chambers were placed on the mechanical stage of an inverted phase contrast compound microscope, and phytoplankton species were identified and counted at 250 and/or 630 x. Enough transects (10 mm x 10 mm) were processed to encounter at least 100 individuals of the major species and at least 20 of the minor or rare species.

Biomass estimates were based on species identification and enumeration. Cell counts were converted to biomass from cell-volume calculations. The volume of each species was determined by approximating the shape of the species with a solid geometric formula. A density of lg/ml was assumed for all species in the conversion from cell volume to biomass.

Concurrently, sub-samples of 500 ml were taken of nitrogen, phosphorus, and carbon for analysis. Concentrations in each sample were determined during the period March 1974 - April 1975 by the State Division of Environmental Man- agement laboratory, Raleigh, N. C. Subsequent to March 1975, water analyses were performed by the Department of Biological and Agricultural Engineering, School of Agriculture and Life Sciences, N. C. State University, Raleigh, N. C.

All Chowan River stations (except the tributaries and C-8 and C-9) downstream from and including C-4 were sampled along transects, with collections made at midstream and halfway between midstream and both shores.

Results

Eight divisions, 9 classes, 142 genera, 373 species, 32 varieties, and 5 forms of algae were found in the Chowan River during the three-year period March 1974 through April 1977 (Table 2).

Table 2

DISTRIBUTION BY DIVISIONS OF THE VARIOUS CLASSES, GENERA, SPECIES, VARIETIES, AND FORMS OF PHYTOPLANKTON LOCATED IN THE CHOWAN RIVER, 1974-1977

Division Classes Genera ( Species Varieties Forms

Chlorophyta 1 Cyanophyta 1 Chrysophyta 1 10 Xan thophy ta 1 6 10 0 5 Bacillariophyta 2 30 8 2 9 3 Euglenophyta 1 4 5 0 2 Phyrrophyta 1 4 4 0 2 Cryp tophyta 1 4 4 0 1

TOTAL 9 1 142 373 32 15

The temporal and spacial patterns of phytoplankton and the fluctuations in water chemistry reflected to varying degrees the cyclical temperature and light regimes imposed on most temperate aquatic habitats; therefore, phytoplankton periodicity in the Chowan River is similar to those in a number of other rivers. As indicated in Figures 4A through 4K, phytoplankton biomass during the period March 1974 - March 1975 demonstrated an early spring peak, a slight decline in early summer, and a higher peak during mid-summer to early fall. Almost exclusively, winter months were low in phytoplankton biomass.

Even though the general overall pattern of seasonal changes in phytoplankton biomass prevailed at every station sampled, the magnitude of biomass was quite diverse (Figure 5A-5T). Comparative samples from just above the confluence of the Nottoway and Blackwater Rivers (Stations N-1 and BL-1) demonstrated a very sluggish late-spring peak followed by an increased mid-summer peak. The late-spring peak was dominated in cell number at Station BL-1 by the blue-green algae Ch.roococcus, with 148 cells/ml and 16 percent of all cells counted. The diatom MeZosira varians with 13 cells/ml represented only 1.5 percent of the total cells present; yet, this species was dominant in biomass with 28 percent of the total (Figure 6). Although Chroococcus had the largest number of cells/ml, it represented only 0.4 percent of the total biomass (biomass less than .5 percent not included).

Figure 4E. Seasonal distribution of algal biomass in the Chowan River, 1974-1975; Station C-5 (below C. F. Industries).

...... In- ...... z ...... a ...... I- U...... m...... U...... I....U...... -I ...... u.

I . -1 I ;;;,;"Ill I llllA.l I Ill -11 I 11IUI I I1I1 nil1 I I I I1 - I1 I1 I I 11 ll ii 11 11 I1 I1 11 I, II 11 It I1 I1 II If II I, II If I1 11 II I1 I1 U I1 I1

...0.. ... I...... L,...... I I I.... I I I I lllllIll OIII Ill Ill1 It I/ I1 I1 11 I1 I! 11 1, 11 I1 I1 11 If 11 11 I1 I, 11 11 11 I! 11 I1 I1 11 H 11 11 01 II I1 It I1 Ill1 +

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...... 0.. ...u..."...... en. .. 1.-...... U...... I(...... -u...... -. N...... b ...... -...... -.. *..U. .+ ...... *...... - a .....W .....J ...I n ..... u .*.a*...... *...... U...... )I. ..l..U...... *er..au .....

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...... G. - ...... u...... *~LLTU3rnW .-...... n . ...u...-...... -...I..*...... U...... II-. . *...-..a ...... U.. -...... U...... e .

...... U... I I 111-1 I I I I I IUI I I IIIIIIIII IIIIIIII "CwzzL~nw I I;

-1 I I I IUI 12 IIIIII- IIIIIl< IIIIIW IIIIIYi IIIIIJ 1111 r IIIII " IIIII I I ICII 111-1 I I I IUI I IIIIIII IIIIIII IIIIIII IIIIIIII IIIIIII 1111l ...I I1 ...... 1 ...... I .....@...... I..... y.. I ..m...... U..... I ...... C...... I ...I...... I e...... I ...... I ...... I...... I. . 11P-1 . .- 11 lUl . .*.. I 1111 ..... I111 D .... Ill.. . I I I ..... I 1 ..... V) I IIIl 111 I1 II " + IIIIIIII I1 1 I 7 I 11 111111 I1 I ,u I I ~'111111 +++... I ...... n . I1 0 11 I I ...... Z ,I 11 I ...... U II 11 ...... q. I It 11 ..... UeN ...... y I .... I ...... C...... U...

... -11 .. lJl 11 IIIIIII I I I I lRl l 1 I111-1 l I I 11 Ill1 1 l I I I I I If11 1111 -11 111 .UII 11. II 11. I1 111 Ill I 111-1 111- I1 I I UIIUZ I 11 11 11 11 - I 1, 11 11 114 I It u I11 IUI IIIIIJ 1111 0 IIIII (1 I I I I I I I ICI I 111-1 I I IILJI I lIlllIl IIIIIII IIIIIII 11111111 Illll~l . 111111 ...... 11

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....-0. .a. C...... -...... Z ..,..a 0 .....W .....J 9.r. 0 008: ..*...... U 0 g 2, ...0.. \Dm+ I..-.. 9 3 ...... m Ill ...... 0 ...... I oooq ...... 999 ...... 9 +hlm3 ...... 0 m*6+ ...... ,...... I I.. *...... C...... I* ....L .... .m I ...u .. e..lr. I ...... 9 .....I..... V) ...... " I ...... -, 1 ...... 3 I ...... s...... *.09.. C + ..... 7 I ...... U...... J I ..,...... *...~...U..... I ...... : I ...... I ...... U ..... ! . * ...... u ...... U... .."'... b9UZT>3'PL ...... -..a ...L,...... Q.. .I..-..

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..aI...... I. . .Z . . J*.I....,...... C...... **********,********Lt MELOSIRA t+*+* ***.* COCCONEIS , It* ***** .** ** . 1.1 **2 1 . . *** * * . . * * * ... $ 0.0048 0.012455 r rLnSTcR [uu ** 27.68% .2.53% * .... 1 * * * . .. * .... 0.031 * lb.3bX 1 * .... . L...... * 1 ...... * NAVICULA * ...... 0.00545 .. .2.88% . *...... 0.0096 1 ....+.. 0.012166 PANOORINA 5.07% ...... 6.42% * 0 ...... * ...... * OTHEl ..il .... *.* ...... *...... * ..... , ...... 0.02912 . 4. ** 15.37% ... * * * ...... 0.03166616.71% Oe006402 * .3.380.006825 ** ** **I PERIDlNIUM ** . .3.60%. * **** ** .. **a TRACHZLOMONAS * *** *** .. ****I ****. ****** ..***. ***.**.***

Figure 6. Algal biomass distribution by genera, May 7, 1974 (Station BL-1).

MELOSIRA*************************** **** **** *** *** ******* * * ** ****** * ** ** 0.C62656 * 36.29% .. * .. .. * GYROSIGMA **** .. * ... *** * * ...... 0.008 .....C . 4 -63%...... *. . .s ... *t* CHROOCOCCUS NAVICULA ...... 3.009295 1 0.0039...... 5.38% * ;...... 2.26% ...... * * ...... * t ...... 0.011659 * * ...... 6.75% * L** ...... * OTHER ...... * ** ...... * .. . . * PERIOINIUM *** ...... * .. . . * * 0.010431. ** .. 6.04% 0.00528 -3.06% * . * 1 *** . . . ** *** .. * * **a.**** .. *** ebb* *****be TRACHELOMON4S SCENEDESMUS **** **.*******.. ***********

Figure 7. Algal biomass distribution by genera, May 7, 1974 (Station N-1). Comparatively, Station N-1 (the Nottoway just above the confluence) was quite similar in species dominance. MeZosira continued to dominate with 36 percent of the total biomass. However, the relative importance of Chroococcus was greater (516 cells/ml, 37 percent of total cells present, and 5.4 percent of total biomass) (Figure 7). Peridiniwn with 17 percent and TracheZomonas with 19 percent of the total biomass represented notable codominance at this station.

While these two confluence-forming stations were similar in dominant species, they were generally quite different qualitatively. N-1 had a greater variety of algae and a higher species diversity than BL-1 (Appendix C). In general, throughout the 1974-75 sampling year, the Nottoway River produced a higher biomass and greater species diversity than did the Blackwater River (Appendix C, Figures 5A-5T).

Total biomass in these two confluence-forming stations ranged from 0.34 and 0.28 mg/l (BL-1 and N-1, respectively) during early spring, 1974, to a high of 10.9 and 7.5 mgll during mid-July 1974 (Appendix A). However, at no time during 1974-75 did their algal biomass seriously challenge that at other stations in the mid to lower reacfies of the river (Figures 5A-5T).

Qualitatively, the BL-1 station featured 26 genera in five different classes. The overall dominant genera in biomass were MeZosira, Peridiniwn, Scenedesmus, Chroococcus, Cryptomonas, and GZoeocystis. While most of the 26 genera had a seasonal succession pattern, MeZosira was perennial, forming a maximum of 46 percent of tfie biomass in mid-July (Figure 8).

Station N-1 continued to be qualitatively similar to Station BL-1 during the summer (Figure 9). However, N-1 seasonally had a larger variety of non- motile unicells and colonies (NMCI and NMUCO) of the class cyanophyta (blue- green algae) (Appendix B) .

Station S-1, which drained Somerton Creek, a small but important tributary of the Chowan, showed high biomass during mid-July and November of 1974, 7.86 and 7.15 mg/l, respectively (Appendix A). Peridiniwn and MeZosira were the dominant genera, having 74 and 19- percent of total biomass during July, and 42 and 21 percent during NovemEer, respectively (Figures LO and 11). Upstream monthly average discharge (cubic ft/sec) in the Chowan proper for these two months was just above the zero level, the lowest during 1974-75 (Daniel, 19771. According to Daniel (1977), tributary water flow was often reduced due to tributary water storage.

Station C-1, the uppermost station in the Chowan River, characteristically had a high biomass throughout July and early August, with an average of 7-9 mg/l, declining to 3.77 mg/l in early September (Appendix A). Late fall and winter months featured a typical low biomass regime, followed by a very weak, early spribg increase. The species composition was uncharacteristic at this station th-oughout tlie year. The Euglenophyte, irracheZomonas, made up 41 percent of the &rch 9, 1974, biomass followed by Melosira, 17 percent, and Peridiniwn 15 percent (Figure 12). Early spring (May 7, 1974) MeZosira and TracheZomonas completely dominated the biomass, with 42 and 34 percent, respectively (Figure 13). On May 21, 1974, Peridiniwn had increased its biomass to 52 percent of the total at this station (Figure 14). Normally, a

Figure 10. Algal biomass distribution by genera, July (Station 5-1).

...... MELOSlRA ****a*** **** *.** ****** *** . * * I** . ** ***** .. .. * * .. 1.1303 .. ** CUYPT')YUL.(AS * 21.27% .. . * *** * .. * * . * .0.30029 . .... +* * 5.651 .. ..a * ** ...... * ASTCRnCOCCUS' e. ... * ..... 0 3849 1 ...... 7.24% * * .....*...... * ..... 0.2 19843 * 8 4.14% ...... * OTHER t ...... *** ...... * ** .... 0.504b4 ."...... 9.50% * * ** ... .. * * * m0.2432... . SYNEDUA * ..4.58% .e *** 6.1~0.12831 * *** .3.532.41%...... *** ****** . . *. ***I .. ... *** **** .....** SURlRELLI **** . .., **** *********** *.*******.* SPHAERJCYSTIS t SCENEDES+US

Figure 11. Algal biomass distribution by genera, November 19, 1974 (Station 5-1). NAV * * ... . ** ..a. 0.0313bJ . .. ** 16.65% * .0.0039 . *. * 2.07% .0.00854 .. CLOSTERIV4 8 . . . 4.55X.s PERlOlNlUY * ... . * . . .. *** + ... .. e. 0.016 * 0.02912 . ... 4.50% * * 15.47% ...... * ...... * .. ...*a * ASTEWIYYELLA ..a .. 3.007118 3.82% a ...... 0.002561...... as... ..1.36%...... OTHER

Figure 12. Algal biomass distribution by genera, March 9, 1974 (Station C-1).

*** ***** .. * * EUDORIN4 .. .. *** ** ...... * . ma. * CHQJOCOCCVS * 0.003493.. , ...... 2.82%...... *. ..0.004297 n.. a ** ..... 3.46%... * ...... *** ASTERIONFLLA * ...... 0.0371Rj * ...... 5.79% ...... * ...... 4.... * ...... 0.010393 ...... a. 37% * *... 0.004532 ...... * * J,.bSX...... a ... OTHER PANDORINA ...... * ...... a *** *. . * * * * * *** *** ****** ***. ******** *** *** **a* ***********, ***********I.** TRACHELOYCNhS Figure 13. Algal biomass distribution by genera, May 7, 1974 (Station C-1). MELOSIRA ***** ...... ****+ ***** .** PANOORINA *. *t+ **** ...... *** ** C3ELA9TRUM I*...... **** ** ...... **** * .0.02;677 0.09516 * ** C .3.13%...... 10.78% ...... * * ...... ASTERIONELLA * ...... e.4 0006371 * * .. 7.21% * ...... * * * ...... * .I. * ... 0.092811 * .. 10.51% * .... . * OTHER .. * * .. ... * * ...... ** ** * **** **** * PER IDINIUW ** *** * ***** *** ***** ***** *** ******I*************

Figure 14. Algal biomass distribution by genera May 21, 1974 (Station C-1).

+****...... *** ***** *** * * *** * * *** MELOSIAA * ***** * * ** *** *** * .. **** * * * . * * * * .. .. .0.15;4;;'.*'. 49HANOCAPSA * ...... 2.41% , * ...... *..*.*..*. 0.195082 * * ...... 3.02% OTHCR * .... 0.20;;;; ....*.f . 3.10% ..... * TRACHELOMONAS * 4 40294 ..... 68.23% * * * * * * WICAOCYSTIS ** * * * ** ***** * * * *** ** ***** *** ***** ***** *** ********** ********** Figure 15. Algal biomass distribution by genera, October 15, 1974 (Station C-1). winter-spring genus, Peridiniwn maintained dominance along with MeZosira throughout the summer and well into the fall. This pattern was interrupted when Microcystis became responsible for 68 percent of the biomass on October 15, 1974 (Figure 15).

Stations M-3, located 92 m upstream of the mouth of the Meherrin River (MR), C-2, located 92 m downstream from the mouth of the MR, C-3, located at U. S. Highway 13 at Winton, and C-4, located at Tunis (Figures 2 and 3) were not appreciably different in phytoplankton biomass from early fall to late spring. Fall-winter biomass ranged downward in Sep tember 1974 from 7.91 mg/l at C-2 to 0.13 mg/l at C-3 during January 1975 (Appendix A). Summer conditions, however, expressed a notable difference between biomass at M-3 and the three Chowan stations, C-2, C-3, and C-4 (Appendix A), A maximum biomass of 14.75 mg/l was seen on June 18, 1974, at b[-3. This represented an order of magnitude higher in phytoplankton organic matter than any of the three Chowan stations. This trend continued throughout the summer. Species composition in these four stations was composed largely of motile unicells or motile colonies \ (MUC, MCO) (Figures 16, 17, 18, and 19). Peridiniwn, TracheZomonas, C~yptomonas, Pandorina, Ceratium, and MeZosira were the principal genera, with Peridiniwn having the highest biomass in time and space at M-3 (58 percent) (Figures 20, 21, and 22). MeZosira at Station C-2 (Figures 23, 24, and 25), TracheZomonas at C-3 (Figures 26, 27, and 281, and Peridinim at Station C-4 (Figures 29, 30, and 31), temporally represented all other dominants from these stations.

Biomass concentrations and species composition began to notably change at Station C-5 approximately 92 meters downstream from C. F. Industries and continued through Station 16 at Edenhouse. The change was temporal and spacial, beginning in early March 1974 and continuing throughout the project year (Figures 5A-5T).

There was a slight temporal increase in biomass at each station from C-5 through C-9 (Figures 4D-4H) from early March through early May. However, on May 21, B74, Stations C-10 through C-14, the principal sites that encompass the Colerain area, had a mean biomass of 12.62 mg/l (Appendix A). This constituted a visual algal bloom that lasted for several days. The dominant species during the bloom were MeZosira with a total relative biomass at Stations C-11 of 66 percent, C-12 - 76 percent, C-13 - 44 percent, and C-14 - 61 percent (Figures 32-35). Microcystis represented only 2 percent of the total biomass at C-11, 3 percent at C-12, 10 percent at C-13, and 14 percent at C-14; and Anabaena made up less than 3 percent of the total biomass at any station. Yet, even though the magnitude of biomass for Microcystis and Anubaena was small, these two species gave an alarming visual blue-green appearance to the surface waters.

Stations C-15 and C-16 reversed the temporal and spacial increase in biomass during the May 21 bloom with only 1.59 mg/l at C-15 (Appendix A) and 6.91 mg/l at C-16. At Station C-15, 22 percent of the total biomass was attributed to Microcystis with Anabaena, MeZosira, and Scenedesmus each having approximately 11 to 13 percent (Figure 361, whereas more than 90 percent of the biomass at Station C-16 was divided between MeZosira, 38 percent, and Pseudokephryon, 54 percent (Figure 37).

I LEGEND F = Flagellates MCO = Motile Colonies MUC = Motile Unicells E1MCO - Non-Motile Colonies NMUC = Non-Motile Unicelle

FORM ~i~u're18. Algal biomass distribution by form, June 18, 1974 (Station C-3). ***** I ***** a********* ***** *a*** ***** ***** ***** O9 ***** ***** ***** I**** ***** ***** ***** ***** **a** b**t* **+** **tat ***** ***** ***** LEGEND *a*** ***** ***** Ow'" ***** a**** ****a F Flagellates i ***** ***** ****a ***** ***** ***** MCO Motile Colonies ***** ***** MUC Motile Unicells I**** ***** *I)*** ***** ***** NMCO - Non-Motile Colonies ***** ***** LC*** ***** *** ** NMUC - Non-Motile Unicelle **a** ***** ***** ********** ***** ***** *****I**** ***** ***** *a*** ***** ***** ***a* ***** ***** ***** *I*** ***** O*' i ******+*** ***** *********)I ***** ***** ***** Oo3 i a********* ***** ********** *********a ********I* ***** O** ***** **a** ****a i *I*** ***** ***** ***** ***** *****I**** ...... ***.* ***** **I** F MUC NMCO FORM Figure 19. Algal biomass distribution by form, June 18, 1974 (Station C-4). CERATIUM *****......

***** ********** ********** PERIDINIUM * Figure 20. Algal biomass distribution by genera, June 18, (Station M-3).

...... * ...... 0.927814 ...... a * 0.62375 ...... 9.33% ** * * ...... I * 6.27% ...... * * OTHER YSTlS ...... * * **** ...... 0.6411 . . . 0.901036 '" * .. .. 6.45% .. . . . 9.06% a* * * ** 0.764120.;43;0.5046;:. ..a* ** e * *** .. 7.68% 2.45% 5.07% . * WACUS *** .. ... *** ,. . . .. * * **a. . . *** ** T~~CHELOMONAS *I**

Figure 21. Algal biomass distribution by genera, July 14, 1974 (Station M-3)...... **** **** **** t..

Figure 22. Algal biomass distribution by genera, August 6, 1974 (Station M-3).

GC\:t::!::ZL*****. t.*,, EUDOR INA ***** . ***** *** *. 2 DACTVLUCOCCO'US ** , *** *. * .. ,, *** ** .. .. ** *** MELOSIRA *+** .0.03496 . .. ** ** . 5.57% .0.034286. 5.47% . 0.018114. . ** ** APHAYOTHECE .2.89% ** 0.122562 ... * 19 -54% a* . . b ..*a...... 0.O99R93 14.33% * ...... * .... * * ...... * * ...... , nu...... *...... 0.01Rb73 DTHEl * ...... 2.99% * * ...... * 0.11 0074 .. * 17.55% .. * ** MXCRCCYSTIS ** *** * .. . * * 0.198744 ** * .. 31.68% ***** * ** .... *** ** ** **. ****** ******** ***** **.**++*** t *******+** PLEO'~RINA

Figure 23. Algal biomass distribution by genera, June 18, 1974 (Station C-2). COELASTRUH *************..****. . .******* **** ****a*** .... . * ** *** ****** . . ** *** . . ** * * * . ANAHAENP ** 0.149389 *+ * 2 -35% * * . . * . . * . . 1.47505 Z * . 23.21% *+ * . . * * ** . . * * .. : * .. * * * * ...... * ...... * ...... 0.441945 * * 6.95% ** ...... ** * 3.98130 ...... OTtiER ** 62.65% .. s.9.135624. * ... 2.132 ...... *0.17162.. ... MELOSIRA * 2.70% * ** * ...... * SCENEDESHUS * * * .. * +* ** PEDIASTRUM *** *. . ****** ** **** *** * * ******** ******* ************ *********** Figure 24. Algal biomass,distribution by genera, July 14, 1974 (Station C-2).

* ** OTHER

** ..* ****** ** * *** .1 ** * ***I**** *** **** ******* TRACHELOYONAS ************ *****;:**** Figure 25. Algal biomass distribution by genera, August 6, 1974 (Station C-2). LLUEOCYSTI S HFLOSIRA **** )+***. .ll*b***tL***I.,+ **** **** .** +.*1 , *** ** CRY Ml~Ctitirrl; **" r4* ... .. * * I.9 *

...... a ...... a*..* * 't4LAWYJOI(OMLS * ...... O.OV5913 ...... 2.94% * * ...... * +. * I ...... 0.25281 * * ...... 7.49% t * ...... * OTHER ** ...... * e 0.19032 .... I* 1e6744 .. 5.6aX *. . *+* 49.62% .. . . 1 .. * ** . * b* IRbCHFLIIWlNAS * * ....* PERIDINIUM ** ** z (r * * Or***** *** **** ******* **** *********** *********** Figure 20 Algal biomass distribution by genera June 18, 1974 (Station C-3).

WLLLI~~HI ...... *** tee** ******** ** .** CYANn4nM4S ** .. *** + ** . * * ...... ** c 3.00758 .... 26.451 ... +* 0.29918. e2.63Y ** *. ...* ...... *** ANAl34EN4 MICROCYST1 S ** ...... * .. ... 1.536Tb * *...... 13.51% * ...... * ...... * PERlDlNlUY * 1.10656 .. + * 9.73% ...... * .....a,. 1.15576 ...... I0.16X ...0.310348.* . * *...... a*, .. * * OTHFR ...... *** SPHLEROCYSTtS* *...... ** .....** +* 3.51625 * ** 30.92% bet * * ** *** ** *** ** *** I****...... ***** TR4CHELOMONA5 Figure 27. Algal biomass distribution by genera, July 14, 1974 (Station C-3). PERIOINIUM SCENEOESHUS **************+*+~**b ****I.. **I** ****. . I** *** SVNE3RA * * a ** ... *** * * ** * .. ** * *0.09;3~9 0.53.L)72 .. L* L *. 12.943 16.63% ** ...... *** * ... 0.24568 .. .. ** UELOSIRA * .. .. 7.583 . .. *** * ...... * I . .. 0,324783 I. LO. 02%

Figure 28. Algal biomass distribution by genera, August 6, 1974 (Station C-3).

**a 0.910945 **)! 1. 29.6111 + MEAL SYOPEDIA * .. L * .. .* * * .. *...... * *... 0.17073;* .. .. * 5.32% 0 s e -.. . ..00121081 ..a ....* * ...... * CHLOPELLA * ...... * ...... 0. L87Oi! * 0.363244 ...... 5.82% * 11.31X ...... * ...... 0.19521 1 * * ...... h. on): ...... *...... OTHT?

Figure 29. Algal biomass distribution by genera, June 18, 1974 (Station C-4)...... **I* **** *a** **. **a* .*** ****** . ** ** *** .. * * **** .. ** . + MELOSIHA * * .. I * ** * e 0.3617?8 * PER lOlNtUM . 14.46% * ** .. ** 3.35062 .. 56.151 ...... * * .... 0.150260 * ANARAENOPSI S * 2.52% a * ...... + * * ...... * a*... * ** ..... * ...... 0.82251413.78X * ** ... ** * ...... ** ... . * * OTHER ** ...... * * a. . 0.371195 0.1680.2432.. 6.22% .. ** ** 2.82Xb.001 .. * *** . .. .. ** *** . ** .. ******* . .. *** *+5* , TRACHELO4ON4S ***a ******.**** *.*********. . *** SCENEOESYUS SURIRELLA

Figure 30. Algal biomass distribution by genera, July 14, 1974 (Station C-4).

**** **$*C*O*$***+*t*Z*L,LI ****MCLOSIRA .** *** *** MICROCYSTIS*** *** .. * *.* .. ** ** PEOIASTRUM +:** 0.. . .. ** .. 0.381713 b r* . 25.0411 **. .0.055037 * SCENEOESMUS ** e.8 .3.61¶.* * t* 0.062201 ...*...... 4.00% . . UICTYOSPHAERIUM 9.. ... * * **...... a ...... 0.060796...... CRYPTO'IONIS ** .. .3.99X ...... 0.031037. * ...... a 2.09% * 1 ...... 0.01256 ...... * ...... 2.791.. .. ANKI STROOGSWUS * ...... 0.040658 * * ...... 2.671 * ...... * * ...... t a 0.304 ...... 0.130031 *** 19.941 ...... 8.53% +** STAURASTRUM * * ...... OTHER .. .-0.039593 * + .. 2.60% * ** ...... * ** ...... * .. .. WESTELLA * * .. 0.37576 *.* 24.65% * *** .. ** * **.*** . * *I** *** **** *** a*** **** *e********* *********** TRACHELOMONAI, Figure 31. Algal biomass'distribution by genera, August 6, 1974 (Station C-4).

5 8 ...... **** OTHEQ . . I. .. ** . 0.357504 * * . . i).2093.94% ., 0.198130.56786$2.31%. 2.19% 6.27% .... a. .. .t . . ** **a +* I. *** .- .- .- LL*--- ..a. . ..**** TRACHELUYONAs **.****.** *********+ SCENEDESMUS MICROCYSTIS * PERIDINIUM

Figure 32. Algal biomass distribution by genera, May (Station C-11).

MELOSI RA

'HER

.. ..*** (I SCENEDESMUS

Figure 33. Algal biomass distribution by genera, May 21, (Station C-12).

Even though the May 21 bloom only slightly affected Stations C-15 and C-16, by June 5, 1974, phytoplankton biomass at C-16 had reached 30.99 mg/l, the highest at any station during the March 1974 - March 1975 project year (Figure 3D, L4ppendix A).

The high biomass seen at C-16 during early June 1974 gradually decreased as river discharge increased, By mid-August biomass had decreased to 6.53 mg/l and continued to decline with increased water flow to a low of 1.37 mg/l on August 30 (Figures 38, 39,'and 40; Appendix A).

Merismopedia, a colonial blue-green alga, constituted 38 percent of the total biomass at C-16 during the peak growth of June 5, 1974. A number of small spore-like balls that were unidentifiable made up 26 percent of the biomass (Figure 41) during early June. Micrccystis became dominant, constituting 28 percent of the biomass during mid-June, giving way to Anubaenu and Peridiniwn during mid-July (Figures 42-43).

As can be seen on Figure 5D, upper Cf.owan stations had extremely low concentrations of biomass while there were increased concentrations within the downstream sites. Biomass ranged from 1.1 to 30.9 mg/l on June 5, 1974.

Tributary activity up and down the river had parallel algal biomass to that in the Chowan River proper. Quantitatively, tributary biomass often exceeded, temporally, that of local stations in the Chowan (Figures 5A-5T). The Wiccacon River was the most prolific, featuring a maximum biomass of 20 mg/l during the peak growing season (Appendix A). Two species of blue-green algae, Anabaena and Microcystis, dominated Stations W-3 and T-1 during the mid-summer season. Together, they contri.buted 57 percent of the biomass followed by another blue-green species, Merismopedia, with a biomass of 11 percent (Figure 44), or dominated by it with a biomass of 41 percent (Figure 45).

Careful consideration of the species composition indicated a strong blue- green dominance during the critical growth season in the lower Chowan River. The 30.99 mg/l biomass seen at C-16 on June 5, 1974, was clearly dominated by the non-motile class, Cyanophyceal (Figure 46). Dominance by Cyanophycael also closely parallels 0th-er classes at the Colerain and upper Edenhouse Stations C-11 - C-15 (Figures 47-50). In the upper Chowan on this day, where water flow was greater, dominance was controlled by the motile class Dino- phyceae (Figures 51-53J. Euglenophyceae, another motile group, and several motile species of Chlorophyceae closely followed in class dominance. The June 5, 1974, algal response was typical of up-river, down-river species, genera, and classes of algae, depending on yearly season. However, during mid- summer when water flow is reduced (Daniel, 1977), up-river biomass class dominance shifts toward conditions exemplifying those down river (Figures 54-61).

In general, all stations in the study area reflected a moderate to high biomass during the 1974-75 project year. There were similarities among the upper Chowan River Stations C-1 - C-6; the intermediate Stations C-7 - C-9; Colerain Stations C-10 - C-13; and the lower Stations C-14 - C-16 (Figure 62). However, following a rainfall event (Figure 63), biomass was evenly distributed throughout the river with tfie exception of its lowest reach, Stations C-11 - C-16. Note that biomass at tliese stations was two to threefold higher than at any other &$n Chowan station or tributary. Daily discharge for the days immediately preceding April 23 had a negative value for Colerain (Stations C-11 - C-14) and Edenhouse (Stations C-15 - C-16) (Daniel, 1977). Figure 38. Monthly average discharge and maximum and minimum daIly average discharge for each month at Chowan River near Eure and Chowan River a t Winton, C 11[1111111, 11111111111111111111111 02053523 Chowon Rivrr nr

Mox~mum aally ovrrogr dischorgr for roch month , 30,000 I. I'\

- Minimum doily o orgr for roch month77 10,000' ' ' ' -' Ill I1111111111 WJ D LL 60,000 I I I I I I , , , I~IIIIIII ' I I 0 b265;6;3 hnvr r 6 Colrroin, N. C. 50,000 A Droinogr orro 4835 mi2 - z f I 40,000. w', :$ 2 g 30,000 h 5:- 20,000 0 v \ I\' I I\ 0 I 0 10,000 - - 0 I - 0 0 1, 0 OO6 0 0. OO0O a 0 0 0 A z / 4 W :l0,000 I ' Illllllllll 11111111111 saP 0JFMAMJJASONDJFMAMJ JASONOJFMAMJJ ASOND 3 I 1974 1 1975 I 1976 I (Courtesy of Dr. Charles Danie 2, USGS)

Figure 39. Monthly average discharge and maximum and minimum daily average discharge for each month at Chowan River near Harrellsville and Chowan River near Colerain. E 60,000 Edenhouse , N. C. 50,000 Drainage area 4885 mi2

40,000

30,000

20,000

10,000

Minimum daily overagr discharge for oath month llllI111111 201000~t11'1~'~~~'~~1~1aa11111 DJFMAMJJASONDJFMAMJ JASONDJFMAMJ JASOND I 1974 1975 1976 (Courtesy of Dr. Charles Daniel, USGS) -

Figure 40. Monthly average discharge and maximum and minimum daily average discharge for each month at Chowan River near Edenhouse.

** **** ***********ll **** LC** .8*** ***NCLOSIRA ***a *** LC** ..* 888 . ** a58 8 *** . , .. ** .. * 8 8, . .I ,0474 .. MERISYOPEDIA 4.90% .. . L ANABAENI. ** .. * * . .. . * * ... 3.25813 . 8 1 . 15.23% * . . 1 . . ... 8 * . . 8 8 ..... 8* ...... 8 ...... 8 ...... 1.45497 8 6.80X ...... OTHER ** ...... 0.50464- .. * * + ...... 2.36X ...** ...... 0.769001...... 3.59% ** ...... 0.5021 29 ...... SYNEDRA ** .. 2.35X.a .. .. 1.6511 . .... 8 8 7.72% ** .. 3.35062 **.a .... SCENEOESYUS .* 15.66X .. 888 .. ** 8.8 *** .. ***..a ~~~RMIDIuY wlCROCYSTIS - eta *.** **** *..*** ***** 8 *********** PERlOlNIUM

Figure 45. Algal biomass distribution by genera, July 10, 1974 (Station W-3). CLASS Figure 46. Algal biomass distribution by classes, June 5, 1974 (Station C-16).

-.- ***** ***** ***** ***** ****c~ ***** ***** I **-****I* ***** ***** ***** ***** I*CILLA CKOROP CRYPTOP CYANOPH EUGLENO CLASS Figure 47, Algal l!homass distribution by classes, June 5, 1974 (Station c-11).

CLASS

Figure 56. Algal biomass distribution by classes, July 10, 1974 (Station C-4).

*****I**** ***** ***** ****I***** ****a I**** ***** *I*** a**** ***** ***** ***** a********* ***** . ******I*** ***** *a*** ***** ***** ***** *****a**** *****a**** ***** ********** *a******** ***** ****a ***** ***** ***** *a*** **I** *+Lee ***** ***** ***** ****I ****I ***** ***** ***** ***** ***** ***** I**** **I** ***** **LC* ***** ***** .______-__--_-_-~------.------***** ***** ***** I**** ***** BACILLI CHLOROP CRVPTOP CVANOPH EUGLENO CLASS Figure 57. Algal biomass distribution by classes, July 10, 1974 (Station C-5). CVANOPH

CLASS

Figure 58. Algal biomass distribution by classes, July 10, 1974 (Station C-6).

***** ***** **I** " i ***a* ***** " ***** i I**** ***** I**** lo ***** A i ***a* ***** B 'j ***** ***** *****a**** ***** 'i *** ** ** * ** **a** *+++* ********a* ***** 'i ***a* ***** ***** I**** ***** ***** ***** **a** ***** ***** ***** ***** ***** ------_&______i BACILLA CHLOROP CRVPTOP CVANOPH OINOPHV EU CL EN0 CLASS

Figure 59. Algal biomass distribution by classes, July 10, 1974 (Station C-7). CLASS

Figure 60, Algal biomass distribution by classes, July 10, 1974 (Station C-8).

Figure 61, Algal biomass distribution by classes, July 10, 1974 (Station C-9). -----*------*----N---"*---"~""""*~""-*"--- xxxlrE2," wxuxx-xx xxxuxUxXx Xx%xxxxxx h x*x*uxxx N ~X~*XXXXWoWZx03~w %XXXXXX 03 %XXXXXX X*XXV)XX m XXX-XXX XY*UXX I XXXX* 0 EXoo;oo~o LD 0 0000000 h 0 0 oonoo 0800-oooooouoo g 03 0 0000 Nm 000 0-mm * O0m88YS8 h mmammmm \4 * I.. $XIXI%%' Y 8t8C;mm, E 08 I \-I mmm 000" :: .n XXJ a +**,***+* UO 0 11 YHU-I, ; .rl :Iltlv:i , C" . .'UUUIIU# * UIIIIUH n 11 IIU +** I1 ::xx+:+ 2 XXXXX x ~o0oox: 0 000 0 0 rl 00 m 0 x"a"me I xx.. + a 0. + 11 mum dN IIO.. !UX 0 I x .00 rl

I+X +

+ + 1, 11 11 11 11 + I! . . I! 11 I1 11 ;; ; 11 I1 ;; ; H I1 . 1111 Ill1 ...... ; I IL..:::", == .U ....I...... ul ...... - ...... Q... "...... u...:::: .I-f ...... -...... :. 2:::::. [ I... ..: ...... ::::z:.::.; - ...... U ...(U

BIOMASS BIOMONITORED, 1975-1976

Procedure

An adjustment in the experimental design was undertaken with the initia- tion of the 1975-1976 project year. The total number of sampling sites was reduced from 29 (1974-75) to a maximum of five. Within these stations, depending upon the investigation undertaken, two to five sites were sampled b iwee kly .

The decision to use five sampling stations was based on both economic and scientific reasoning. The river was shown, by 1974 data, to be divided into two areas: (1) the upper Chowan, represented by Stations C-3 and C-4, and (2) the lower Chowan, represented by Stations C-9, C-11, and C-16. Stations C-3 and C-4 were above C. F. Industries at Winton and Tunis, respectively, and C-9, C-11, and C-16 were located with increasing distances downriver below the plant.

Monthly average discharge past the three downstream stations was very similar (Daniel, 1977). However, inflow from the Meherrin River (MR), 4.1 km above Station C-3 at Winton, had a tremendous impact on discharge in the upper Chowan. The MR drains an area of 2600 km2, or 33 percent of the total Chowan basin (Daniel, 1977). The upper river stations (C-3 and C-4) thus represented the highest flow area of the Chowan while the lower river stations (C-9, C-11, and C-16) represented the slower-flowing or less-discharge area.

Biomonitor - Biomass Determinators

Along with a continuing assessment of chemical, environmental, biological factors, this phase of the study examined the extent to which phytoplankton, if caused to remain in space, would quantitatively change temporally. Stations were selected at Tunis (C-4), Colerain (C-11), and Edenhouse (C-16); and the biomonitor (Schlichting, 1974) was utilized to carry out biweekly in situ investigations .

Due to similarities in physical data collected at Stations C-11 and C-16 and incomplete biomonitor data for Station 6-11 (due to vandalism), biomonitor findings are reported only for Station C-16 (Edenhouse) and Station C-4 (Tunis). Discharge, nutrient, and algal biomass data are reported for all three locations.

Investigations with the biomonitor involved in situ incubation of the standing crop of algae in the river for a two-week period, following which the crop was harvested and biomass determined.

Incubation included inoculation of the biomonitor with known amounts of natural populations of phytoplankton. This sample was sealed in the biornonitor, which was a 500 ml plexiglass cylinder with a 0.45 micron membrane filter on each end. A foam filter disc was on the exterior side of the filter as a pro- tective measure. This apparatus was suspended at 0.3 m depth by means of a harness and ' snap swivel to minimize shading effect. The organisms contained within the biomonitor were allowed to grow for a two-week period, at which time they were collected and replaced. The collected water was transferred to a Nalgene (1 liter) ample bottle, and fdve 100 ml increments of distilled water were used to rinse the biomonitor and create a 1:l dilution of the sample. A "rubber policeman" was used to remove organisms that adhered to the sides and to the filter.

An aliquot of the 1:1 dilution of organisms was transferred to a settling chamber and prepared for enumeration by the Utermohl method (1958). Cell. numbers and cell volumes were used to calculate biomass in mglliter. Strathmann's (1967) method as modified by Campbell (3973) was used to calculate the amount of carbon contained within a given volume of diatom biomass (0.11 picograms of carbon/$). The carbon content of other algae was assumed to be 40 percent of the total biomass. The amount of carbon in the biomass used to inoculate the biomonitor was subtracted from the amount harvested 'o determine the change in carbon (A carbon) during the incubation period. The L?; carbon divided by the number of days of incubation equalled the daily rate of increase, the "Biomoni- tor Net Productivity" (BNPJ.

Light Attenuation

Light attenuation was measured by a uni'directional (Fred Schueler - model 29) submarine photometer . Tlie pro6e was lowered in 0.1 m increments and incident light was recorded in foot candles. 'Prom these readfngs the one percent light level was calculated and recorded. An extfnction coefficient was calculated using tlie formula IZ ~~z-~~wliere the light intensity or irradiance (Iz), at depth (z) is a functson of 2ntensl"ty at tlie surface (TO] to the log base of the negative extinct2on coeff fc3ent (ny at tlie depth (Iz) in meters.

Secchi disc transparency was -measured l5TweeZly at Edenton and Tunis using a weighted disc, 2Q cm in dTameter, wi'th wlii'te and black quarters. It was lowered on tkTe shade and sun si'des of a platform until it disappeared from sight, then raised untfl it reappeared, The poiht of reappearance was recorded as Secchi depth.

Temper a ture

Water and air temperatures were determined w2th a standard mercury ther- mometer (Scientific Products) havfng a range of -10 to +llO°C. Preliminary experiments revealed homogenous temperatures throughout the water column; thus, only surf ace water temperatures were measured in this study.

Water Samples

Surface water samples were integrated over a 0.3 m depth using a La Motte JT-1 Water Sampler. Subsamples were removed for pH determinations, organism and biomass determinations, and nutrient analyses.

Nutrients

Nutrient concentrations were determined by the Biological and Agricultural Engineering Department at N. C. State University, using a Technicon Auto Analyzer. Samples were kept in a dark, ice-filled chest until transferred to the laboratory where they were placed in a freezer. Each sample was removed from the freezer and thawed at room temperature in a dark box immediately (3 hrs.) before determinations were made.

Total nitrogen and ammonia-nitrogen concentrations were determined by a modification of M. E. Gales' (1975) method. Nitrate-nitrogen concentrations were determined by a modification of Technicon Industr~alMethod No. 100-70W. Total phosphorus and ortho-phosphate concentrations were determined by a modification of Technicon Industrial Method No. 329-74W.

Samples were placed on ice in a dark chest for transport to a local lab (Tunis) where hydrogen ion concentrations were determined electrometrically by using a Fisher Acumet Model 230 pH/iun meter. Periodic field pH readings were obtained and compared to those of transpor ted samples.

Results

Temperature and pH

Maximum and minimum temperatures throughout the river during the period of the study were 28.5 and 4Y00C, respectively. The greatest daily range was 5.S°C (23.0-28.5OC) on July 19 (Figure 64, Table 3). The cooler waters were found at Tunis, while the warmer waters were at Edenton. As in the 1974-75 study, there was less than a 1°C change in temperature in a 2- to 3-meter vertical water column.

The river reached its maximum temperature in July 1975 and remained between 28.0 and 28.5OC throughout August with a slight decline in mid- September. Throughout October, November, and December, temperatures continued to decline. The minimum temperature (4'C) was reached during mid-January 1976 (Figure 64, Table 3) .

In late January 1976, waters began to warm, and by late February reached an unseasonable 13OC. Water temperature reached 19.5"C at Tunis during mid- March, then decreased to 17'~by late March. Cooler waters continued to pre- vail during early April (Table 3).

Maximum and minimum pH readings in the river during the study were 7.4 at Edenton in November and 6.2 at Tunis in July (Figure 64). The pH varied very little throughout the study, remaining in the near-neutral range.

Light Attenuation

Secchi disc and photometer readings revealed rapid attenuation of light in the water column. Although there were variations in time and space, no major, unexpected seasonal trend in light diminution was seen.

The smallest Secchi depth recorded was 38 cm at Tunis near the end of July (Figure 64, Table 3). Field notes revealed rapid currents and heavy siltation at that time. This depth increased to 100 cm by the end of August at this station. --,oog- U

e= temperature

Figure 64. Seasonal distribution of surface temperature, pH, and Secclri depth at Edenton and Tunis, 1975-1976. Table 3

FIELD MEASUREMENTS OF SURFACE WATER TEMPERATURE (WT) IN cQ, pH, AND SECCHI DEPTH (SDp) IN cR1 AT TUNIS AND EDENTON, 1975-1976 - Tunis - I Edenton SDp Date - WT pH 1. - SDp WT I pH 1 I I

The greatest Secchi depth (120 cm) was recorded at Tunis during early December, but most periods showed Secchi depths of only 40-80 cm.

Extinction measurements of light with a unidirectional photometer corrob- orated Secchi disc recordings of shallow light penetration. Extinction coefficients at Tunis ranged from 2.11 during September to 7.59 during December.

Precipitation and Flow

Daily discharge estimates were determined from U. S. Geological Survey data. Stations nearest those of this study were located at Winton, Colerain, and Edenhouse. A mean was calculated in 3-day intervals and plotted to express discharge graphically (Figure 65).

Precipitation was measured daily, totaled twice monthly, and graphically illustrated (Figure 65) . Major peaks in flow occurred in July, late September, early January, and early February preceded by high amounts of rainfall (Figure 65). Changes in flow and degree of peaks varied from one site to another. Flow was more sporadic at Edenton and Colerain than at Winton and frequently reversed at the two lower stations.

Nutrients

Phosphorus. Measurements of phosphorus included ortho-phosphates (0-P) and total phosphorus (TP) (Figures 66 and 67, Table 4) . Ortho-phosphates represented that fraction of phosphorus readily utilizable by algae.

Total phosphorus concentrations were relatively high in the Chowan River. On a seasonal basis, they remained higher at Tunis (Station 4) than downriver at Colerain and Edenton (Stations C-11 and C-16). All samples taken at Tunis except those taken during mid-February had total phosphorus concentrations greater than 0.10 mg/l. A maximum total phosphorus concentration of 1.4 mg/l was recorded on September 13 at Colerain (C-11) and a minimum of 0 .O5 mg/l was found on August 10 at this station.

The exceptionally high peak found at Colerain on September 13 was also found at Tunis and Edenton. Total phosphorus on that day varied from 0.58 mg/l at Tunis to 1.45 mg/l at Colerain. Ortho-phosphate contributed 72 percent of the total phosphorus measured on Septemlier 13 at Tunis, 94 percent at Colerain, and 91 percent at Edenton.

With the exception of the high September peak, ortho-phosphate concentrations remained in a range of 0.02-0.05 mg/l at Colerain and Edenton from early July to early December (Figure 66, Table 4). Winter increases peaked at Cole- rain on January 3 (0.13 mg/l) , and at Edenton on January 31 (0 .l8 mg/l) . These high concentrations had declined to 0.03 mg/L by mid-February. Concentrations climbed gradually in March 1976 at Colerain and Edenton to 0.08 and 0.09 mg/l, respectively. Extreme phosphorus changes were not seen at Tunis during the early spring 1976, but concentrations remained high (0.08-0.16 mg/l) from December through April.

Nitrogen. The concentrations of total nitrogen (TKN), nitrate-nitrogen (NOg), and ammonia-nitrogen (NH31 were determined in mg/l (Figures 68 and 69 Table 3).

Nitrate levels ranged from just below the levels of analytical detection to 0.12 mg/l at all sampling stations from July to October 10, 1975 (Figure 68, Table 4). An increase in nitrate concentration at Edenton was noted on October 10 (0.28 mg/l) . Full peaks were revealed at Tunis (0.23 mg/l) on November 8, at Colerain (0.50 mg/l) on November 22, and at Edenton (0.28 mg/l) on October 10. December concentrations were relatively low at Tunis (0.03- 0.07 mg/l) as opposed to 0.26 mg/l to 0.42 mg/l at Colerain and Edenton during that month. Concentrations were high (0.23-0.51 mg/l) for the entire sampled MONTHS

Figure 65. Precipitation and Chowan River discharge at Winton, Colerain, and Edenton, 1975-1976.

*cfs = cubic feet per second Figure 66. Seasonal distribution of drtho-phosphate concentrations as determined at bi-weekly intervals, 1975-1976. EDENTON

I I J I A 'S'O'f,' D J ' F M A MONTHS

Figure 67. Seasonal distribution of total phosphorus concentrations as determined at bi-weekly intervals, 1975-1976.

Figure 68. Seasonal distribution of nitrate-nitrogen concentrations as determined at bi-weekly intervals, 1975-1976. area in January but dropped to about 0.20 mg/l in mid-February. Nitrate gradually increased in March at the twoLwer sites, then dropped to as low as 0.03 mg/l by late April at Tunis.

The minimum ammonia readings extended below detectable levels at Edenton, Colerain, and Tunis on several dates, and a maximum of 0.50 mg/l of ammonia occurred at Edenton on January 31 (Figure 69, Table 4). A small peak of 0.13 mg/l was found in July at Tunis, but was not reflected downriver. Ammonia levels remained from below detectable levels to 0.06 mg/l through October. Winter increases were evident from December until February with peaks of 0.25, 0.20, and 0.50 mg/l, respectively, in the downstream sequence. Rapid decreases of ammonia occurred throughout the river in early February with Edenton showing the most drastic decrease (0.50 to 0.07 mg/l) between January 31 and February 14. Ammonia levels ascended sporadically after this date, but the highest level recorded was 0.14 mg/l during the spring.

Total nitrogen concentrations revealed numerous fluctuations throughout the study (Figure 70). The maximum concentration was found in late August at Tunis (1.41 mg/l). Other major peaks in total nitrogen were noted in August at Colerain (1.39 mg/l), mid-September at Colerain and Edenton (1.25 - 1.38 mg/l), and late February at Colerain and Tunis (1.16 - 1.27 mg/l).

Significant decreases in nitrogen concentrations were seen throughout the river during mid-August, late September, and mid-February. A minimum concentration of 0.23 mg/l occurred at Colerain in early January.

Dominant Species

Dominant species were determined for each site from the total species list on a bi-weekly basis, In this report, dominant species were those that represented highest biomass at a given time and at a given site, The biomass of these species and the percentage of total biomass were calculated and recorded (Appendix C).

The highest biomass of any one species during this study was 15.6 mg/l of Peridiniwn sp. on August 30 at Colerain. Peridiniwn sp. dominated algal biomass in the late summer and early fall throughout the river. It represented 14.5 to 67.1 percent of the biomass at all locations during August 1975. Peridiniwn sp. represented 31.3 percent of algal biomass at Tunis in mid- September and 43.5 percent at Edenton in mid-October. Biomass levels of Peridiniwn sp. were low during the winter or not found at all, but were high (0.85 mg/l) in the early spring. It should be noted that higher than normal precipitation and river discbarge characterized the 1975-1976 project year.

MeZosira ituZica var. tennuissima dominated the algal biomass at Colerain and Edenton during late fall and winter. It represented 34.4 percent and 32.9 percent of the biomass in early December at Colerain and Edenton, respectively, M. itaZica var. tennuissim represented 28.2 percent of algal biomass at Cole- rain and 49.3 percent at Edenton in early January. Similar results were found in the lower reaches of the river in late January, February, and early March (Appendix C). The highest levels of biomass recorded for M, itaZica var. tennuissima (9.2 mg/l) composed 80.8 percent of the algal biomass at Edenton on April 11. TUN l s

EDENTON

Figure 69 Seasonal distribution of amo~~ia-nitrogennnttn determined at bi-weekly inter-rals, 1975-1976. Several classes of algae competed for chief dominance during the study. The Cyanophyceae (blue-greens) (Phormidim sp., Microcystis aZruginosa, Merismopedia convoZuta, Rhaphidiopsis cwlvatu) were dominant in the middle and late summer.

Diatoms, other than M. itaZica var, tennuissima, that exhibited dominance included : Eunotia sp. , Neidim sp ., MeZosira varians, Amphora sp . , Surire ZZa sp., and Synedra uZm. The diatoms were most prevalent during the winter months, but some species of diatoms were omnipresent. Synedra ulna composed 73 percent of total algal biomass (1.52 mg/l) in mid-July (Appendix C).

Two classes, Crypotophyceae and Euglenophyceae, were again dominant at Tunis most frequently; Cryptomonas erosa and Cryptomonas ovata were found in dominance sporadically at Tunis throughout the study. TracheZomonus sp. was an important genus in September at Tunis. It represented almost 40.0 percent of total biomass.

The Chlorophyceae expressed dominance (CZosterim sp., Stawlastm sp., Carteria sp., ChZamydomonas sp., and Peniwn ZibeZZuZa) less often than the above classes. ChZamydomonas sp. was the only representative of this class that exhibited chief dominance on a given sampling date. ChZamydomonas sp. represented 22.3 percent of algal biomass (0.02 mg/l) in early January (Appendix C).

Biomass

Maximum and minimum phytoplankton biomass measurements during the period of study were 34.9 mg/l at Colerain (late August) and 0.08 mg/l at Tunis (early January), respectively (Figure 71, Table 5). The biomass reflected a seasonal trend with a gradual decrease during the winter months. During late August, Tunis was substantially lower in biomass than Edenton and Colerain.

High phytoplankton volumes occurred in July at Edenton (11.9 mg/l; 9.2 mg/l) and Colerain (19.5 mg/l and 19.9 mg!l) and relatively high biomass at Tunis (6.72 mg/l; 2.09 mg/l) that month. Biomass dipped in mid-August at Colerain and Edenton but peaked throughout the study area by August 30. Dur- ing September both Edenton and Colerain had high biomass while biomass at Tunis was steadily decreasing. Relatively high levels of biomass at all three stations continued through the fall with minor fluctuations in November (Table 5).

A decreasing biomass trend was observed throughout the river beginning in November and continuing through mid-February. Edenton and Tunis have slight biomass increases in mid-January; and Colerain began its spring biomass increase in early February. Minimums during the winter were 0.08 mg/l (early January) at Tunis, 0.36 mg/l (mid-January at Colerain, and 0.47 mg/l (early February) at Edenton.

Biomass increased with time and space in the downstream sequence from mid-February until April. By mid-April aigal biomass at Tunis had reached 1.43 mg/l, while algal biomass at Edenton had reached 11.4 mg/l. By mid-May, even though biomass did not show an outstanding increase, the Colerain station was in bloom. The Anabaena-Microcys2::is bloom persisted throughout June. i.,... -+- ---+- ---- t---+-- ' ; -.- - $- - -- - t--+ J A s '0 N D 4 F M MONTHS A

Figure 70. Seasonal distribution of total nitrogen concentrations as determined at bi-weekly intervals, 1975-1976. j 93 Figure 71. Seasonal distribution of algal biomass as determined at bi-weekly intervals, 1975-1976. are recorded for only Tunis and Edenton (Table 6). SCB carbon was the amount (mg/l) found in the river sample and used as an inoculum for the biomonitor. BMB carbon was that amount contained in the biomonitor after a two-week incubation period. BMB and SCB were converted to carbon. The difference in BMB and SCB was recorded as the change in carbon (A carbon). The A carbon divided by the number of days of incubation yielded "Biomonitor Net Productivity" (RNP) .

The maximum BMB carbon (14,836 pg~/l)was collected on March 13, 1976, at Edenton following 13 days of in situ phytoplankton growth with an initial concentration of (133 pgC/1). Minimum BMB carbon recorded (282 vgC/l) was collected in early December at Tunis.

High amounts of BMB carbon were also found during July (6,163 pgC/l) and mid-August (10,411 pgC/l) at Tunis.

BMB carbon decreased steadily in October, November, and edrly December. There was a peak (5,7112 jlgC/S) in late December at Edenton. A decrease in BMB carbon was noted during January and early February; but in late February and early March extremely high levels, 11,032 and 14,836 ugC/l, were measured at Tunis and Edenton, respectively.

The "Biomonitor Net Productivity" was at a maximum (1,131 pgC/l/day) in late February and early March at Edenton. The minimum (18 pgC/l/day) was recorded for Tunis during late November (Table 6). Table 5

BI-WEEKLY ALGAL BIOhASS (mall), 1975-1976 - Edenton Colerain Tunis Date b comas_ _-- s biomass biomass- 71 7/75 11.9 19.5 6.7; - -7/19/75 9.2 19.9 2.09 81 2/75 19.4 19.0 4.46 __ 8/16/75 5.85 7.53 7.65 8130175 17.9 35.9 18.3 9/13/75 10.1 8.33 3.55 -- 0.36 9/27/75 7.33 - .- 8.21 ------10/10/75 12.8 2.40 0.693 10/25/75 13.0 3.83 0.408 - 111 8/75 6.05 7.29 2.6b 11/22/75 4.67 3.25 0.215 121 6/75 6.27 1.20 0.206 12/17/75 5.20 1.97 0.266 11 3/76 1.32 0.676 0.0813 1/17/76 3.00 0.357 0.366 6.33 0.364 0.103 2/14/76 0.47 0.970 0.0837 2/28/76 1.21 3.42 0.282 3/13/76 2.37 2.38 0.557 3/28/76 3.32 1.49 1.11 4/11/76 11.4 3.40 1.43 -

Biomoni tor

Carbon equivalents for concentrations of biomass were determined by tlw method of Strathmann (1967) as modified by Campbell (1973). These wexe reprr- sented graphically as "standing crop biomass" (SCB) and "biomonitor biomass (BMB) (Figure 72) for Edenton and Tunis sampling sites. The BMB represented biweekly in situ growth of SCB. The graph (Figure 72) illustrates tht! change in phytoplankton growth from the date of inoculation (t to the succcedinp harvest (t2). Destruction of the membrane filter prevented measurement of BMB carbon on several sampling dates for the Golerain site; therefore, these data

Table 6

BI-WEEKLY DETERMINATIONS OF STANDING CROP BIOMASS (SCB), STANDING CROP BIOMASS CARBON (SCB CARBON). BIOMONITOR BIOMASS (BMB), BIOMONITOR CARBON (BMB CARBON), CHANGE IN CARBON (A CARBON) , AND BIOMONITOR NET PRODUCTIVITY (BNP) PHOSPHATE UPTAKE KIFIETICS, 1975-1976

Procedc re

Four carefully selected sites along 64 km of the Chowan River were sampled biweekly during the project year July 1975 - June 1976. The sites selected exemplified different hydrologicsl patterns and/or areas that were historically notorious for algal blooms. Beginning in the upper reach of the Chowan River, the sites were: (1) C-3 (Winton); (2) C-9 (Harrellsville); (3) C-11 (Colerain); and (4) C-16 (Edenton) (Figures 2 and 3).

Phosphorus-32 uptake (P-uptake) by particles retained on 0.45 micron membrane filters was measured as a first step in determining how phosphorus cycles affect phytoplankton growth within the river. Tests were conducted to measure the influence of water temperature, solar radiation, and phosphorus concentrations on P-uptake by these particles. At the same time primary production by carbon-14 uptake (C-uptake) was measured. Also, several die1 studies of P-uptake and an analysis of alkaline phosphatase activity during an Anabaena sp. bloom were conducted. All kinetic tests were performed in thermally controlled outdoor water baths at a field laboratory located at Winton, N. C. Dissolved inorganic phosphorus (DIP), dissolved organic phosphorus (DOP) , particulate phosphorus (PP) concentrations and algal biomass were simultaneously measured biweekly at the four stations.

Results

Phosphorus Chemistry

Sampling over one year provided sufficient time to detect seasonal cycles in'the distribution of the various phosphorus species. An understanding of the seasonal cycle provided a scale of reference for interpreting short-term fluctuations of DIP abundance from instantaneous wet chemistry measurements. Sampling over 64 km of river provided the spacial gradient necessary to detect heterogeneous rates of chemical and biological conversions of phosphorus.

Amounts and fluxes of each phosphorus species (DIP, UOP, and PP) were determined in order to obtain an understanding of the entire phosphorus cycle. The relative quantitative importance of DIP can be determined if the D1P:DOP:PP stoichiometric ratio remains stable through time or if a phosphorus budget can be formed to estimate total quantities of DIP, DOPy and PP coming into and leaving the system within a defined time period. In both cases insufficient information was available to make conclusive statements of the relative quantitative importance of all phosphorus species, but sufficient information was collected to make conclusive statements of the DIP role and clear statements of the DOP and PP roles.

DIP concentrations varied as much from one location to another on the same day as within any one location throughout the entire year (Figure 73). The range encompassed the limits of detectability for the soluble reactive phosphorus (SRP) test, 0.03 - 5.0 - M (x-0.851 My sc=1.02, n=132). A measure of precision, the mean coefficient of variation (C.V.) among all replicates was 5.0 percent. An upstream-downstream gradient was not evident in winter DIP concentrations. There was a gradient during the summer and fall, however, of high DIP from the upstream location, Winton, to the lowest downstream location, Edenhouse. The summer-fall gradient of DIP concentrations most likely integrated over many biological and chemical mechanisms removing DIP form and returning DIP to the waters. DIP was inversely correlated to phytoplankton biomass, a relationship which progressively tightened from spring through fall and along a downstream gradient. Also, sedimentation with clay, precipitation as iron phosphate, adsorption to benthic sediments, and uptake by sediment biota were likely mechanisms removing DIP from a column of water moving 65 km from Winton to Edenhouse. These mechanisms were likely for several reasons. First, flow rates decreased downstream (Figure 65). This was due partly because the cross-sectional area of the river basin increased more rapidly than increased volume flow from the remaining watershed. Reduced flow promotes quick settling out of suspended particles (Whitton, 1975). Second, river residence times during the summer were 50t days (Stanley, 1975); therefore, the column of water was in contact with the sediments long enough for the adsorption and uptake by sediment biota mechanisms to have had a marked influence on the concentrations of DIP in the water column. Furthermore, the ratio of the volume of a column of water moving from Winton to Edenhouse to the benthic surface area it encountered is low. If flow were constant and the sediment structure and associated biota were homogeneous between upstream and downstream locations, then the influence of the benthos alone would have accounted for an approximately exponential decrease of DIP from the moving column of water .

DOP concentrations changed little through time and space. DOP concentrations averaged 0.58 M (sd=0.305, n=129) at all locations throughout the year (Appendix D). Variations from the mean were correlated directly with increasing algal biomass and inversely with rapid flushing of the river. DOP was at times 5 to 10 times more abundant than DIP (Appendix D).

PP concentrations (1976 data only) ranged from 0.36 - 4.27 M (x=1.24, sd=0.69, n=68). The mean annual concentration varied relatively little between locations (Appendix D) .

The ordinate intercept of the PP to phytoplankton carbon correlation indicated high levels (0.86 M) of non-algal particulate phosphorus in the Chowan. Since this river drains agricultural lands and low-lying swamps, the non-algal PP forms probably were suspended clay and detrital material. Phytoplankton biomass concentrations were low upstream and higher downstream, and PP concentrations changed relatively little between locations; however, high PP concentrations at Winton were coincident with periods of high flow (Daniel, 1977), and flow was greatest during the winter; large quantities of non-algal PP entered the system during the winter (Appendix D).

Alkaline Phosphatase Activity

The relative importance of the phosphomonoesterase enzyme (PME) as a source of metabolic phosphorus for phytoplankton may be significant during the late stages of formation and maintenance of a bloom when DIP has been depleted or in oligotrophic waters where DIP is ordinarily scarce, PME hydrolyzes phosphomonoesters (PME) such as adenosine-monophosphate and glucose-6-phosphate. Figure 73. seasonal distribution of DIP and algal biomass at Winton, Harrollsville, Colerain, and Edenhouse, 1975-1976. Both marine and freshwater phytoplankton are capable of synthesizing this enzyme (Kuenzler and Perras, 1965). An assay was run for the presence of alkaline phosphatase activity in non-filtered river water during an Anabaena circinaZis bloom to determine the possibility of DIP regeneration mechanism for the Chowan waters. Bacterial contribution to this enzyme activity was assumed to be minimal.

A rapid rate (9.95 um P/pgC/hr) of enzyme activity was detected. It is possible then for phytoplankton in these waters to increase in size and numbers while growing on an alternate phosphorus source when DIP is scarce. Rate is not a quantitative estimate of phosphorus used by the algae in the river, however. The alkaline phosphatase activity gave evidence only of the enzyme activity. It gave no proof or naturally occurring PME hydrolysis or any assurance of ester-P incorporation in phytoplankton tissue; yet, aquatic ecologists have observed an absence of DIP during blooms of phytoplankton. DOP is a plentiful, alternate source of phosphorus for phytoplankton; DOP was high in concentration throughout this project year (Appendix D).

Phosphate Uptake Rates and Turnover Times

Rates of DIP-32 uptake were measured by time series analysis to under- stand the underlying mechanisms controlling change and to determine the relative importance of this phosphorus species to the phosphorus cycle. P-uptake either approaches isotopic equilibrium rapidly and is detectable within the short time interval of the kinetic test or it approaches isotopic equilibrium slowly, and the relatively slow rate of uptake is not detectable within the short time interval of the test. Slow P-uptake relative to the time scale of the existing experiments perhaps is important to the phosphorus cycle of the system when a large fraction of the actively growing phytoplankton community is mediating the reactions. By inference from low C:P uptake ratios (Figure 771, however, complete P-uptake by phytoplankton in these kinetic studies occurred exclusively within the short time scale.

Rates of P-uptake ranged throughout the year from a winter low of 0.01 ~M/hrto a summer high of 0.1 pM/hr (Figure 74). There were no detectable differences between locations. A trend was observed from high P-uptake during the summer to low P-uptake during the winter with marked short-term variations. For example, rates of P-uptake changed by 0.06 pM/hr over one two-week period during the summer at the Colerain location (Figure 74). Furthermore, rates of P-uptake changed by 0.05 pM/hr over a 24-hour period during the fall at this same location. Phytoplankton biomass and cell P-nutrition coupled with environmental variables probably governed P-uptake change within the river. An experimental approach was chosen, therefore, to determine how water temperature, photosynthetic light intensity, and DIP concentrations affect rates of P-uptake change in whole river water samples.

Uptake rates provide information on the rates of appearance of phosphate in phytoplankton cells whereas the turnover time provides information on how rapidly the DIP concentrations change. Turnover time is the time required for the particles on the filter to remove all of the DIP from the water, assuming a constant rate of input to the DIP pool. It is calculated as the reciprocal of the rate constant for P-uptake. Turncver times at Colerain and Edenton exhibited a generally sinusoidal pattern over the yearly cycle. Turnover times were as low as one hour during the summer and as high as 105 and 95 Figure 74. Seasonal distribution of temperature, DIP, algal biomass k P-uptake, and at Calerain, 1975-1976. L , C-uptske hours, respectively, during the winter (Figures 75 and 76). The yearly pattern of DIP turnover was directly correlated with simultaneous changes in water temperature (Figure 74) and solar radiation, phosphate concentrations, and algal biomass (Figure 77).

Light

We were unable to resolve quantitatively changes in P-uptake due exclusively to photosynthetic light intensity. P-uptake was nearly as rapid in dark pyrex reagent bottles as in clear bottles exposed to ambient light intensities (Figures 77, 78, and 79).

Phytoplankton Growth Rates

Using the DIP-32 uptake measurements, growth rates were determined for phytoplankton phosphorus in the Chowan River. The exponential growth rates were calculated from the equation:

where (p) is the growth rate of the phytoplankton phosphorus in doubling time, (In2) is the logarithm to the base 2, (t) is time in days, (P) is phytoplankton phosphorus in pg-at, and (AP) is new phytoplankton phosphorus. Phytoplankton phosphorus was derived by regression procsdures with phytoplankton wet-weight biomass, while new phytoplankton phosphorus was determined from the kinetic measurements.

Growth rates (doubling cells), ranged from 106 during the summer (1975) to 0.486 during the winter (1976). Rapid phytoplankton growth rates during the summer correlated with low flow rates (residence time = 5M- days) and relatively low DIP concentrations. Summer phytoplankton biomass, although variable, was sustained above 10 times the winter levels. Since the fastest growth rates co-occurred with the largest phytoplankton populations at a time of year when inflow of DIP was lowest, other sources of DIP evidently supported phytoplankton growth. Regeneration mechanisms are the most probable sources. Benthic regeneration of DIP from winter-deposited PP was likely of greatest quantitative importance. Pelagic regeneration mechanisms can be important sources of DIP also. Hydrolysis of DOP by phosphatase enzymes and excretion of DIP by zooplankton probably were periodically important mechanisms regenerating DIP within the water column as was shown with the PME test during the Anabaem bloom.

Summer phytoplankton growth rates exceeded the exponential rate of population loss due to outflow; therefore, phytoplankton accumulated in the system. High biomass was observed (15 mg/l); yet, phytoplankton did not appear (1975- 76) in the abundance expected from their measured growth rates. Various sources of phytoplankton death such as zooplankton grazing, cell autolysis, and sedimentation, along with outflow, probably were important mechanisms limiting the continued build-up of phytoplankton biomass in the river. ~~nths

Figure 75. DIP turnover times at Colerain, 1975-1976. Months

Figure 76. DIP turnover times at Edenton, 1975-1976. Figure 77. Die1 variation of kL9 P-uptake, C-uptake, PAR, DIP, and algal biomass at 20°C.

HARRELSVILLE 28 JULY 75 I

Figure 79. Light effects on P-uptake. Temperature

Although rates of P-uptake in natural waters have been reported in the literature, the effect of temperature on this transfer has not be quantitatively determined. The choice was made, therefore, to test how temperature affects P-uptake.

Phosphate uptake was temperature dependent. Temperature coefficients (QlO) for P-uptake (integrated values for diel studies) ranged from 1.1 to 3.74 (~~1.92)within the range of the annual river water temperature (Table 7). When P-uptake is normalized for heterogeneous microbial distribution and the major effects of co-varying physico-chemical factors are determined, P-uptake with the river is predicted to change directly with temperature-depth profiles of the water column, river mile, and time of year. Except during brief periods of low flow and absence of wind, temperature profiles of the Chowan River water column were isothermic. Temperature effects on P-uptake, therefore, were uniform with depth. Variations of water temperature with river mile were observed, but the magnitudes were low. Thus, there was no consistent percep- tible temperature effect on P-uptake between locations on the same day. River water temperature graphically exhibited a sinusoidal seasonal pattern increasing fromawinter low of 5OC to a summer high of 30°C (Figure 64). Hence, on the basis of water temperature alone, rates of P-uptake varied seasonally from 5 to 10 fold.

Table 7

TENPEFUTURE EFFECTS (QlO) ON P-UPTAKE

Location Ql~Ql0 DIP Light Algal Biomass Date (A/C) (&'A) PM u~/m/sec mg/liter

A = ambient river temperature; H = ambient + 10°C: C = ambient - 10°C.

Die1 Studies

Tests were conducted to determine the occurrence of diel periodicity in P-uptake mediated, in part, by changes in photosynthetic light intensity. Sampling over a 24-hour interval provided a sufficient time scale to detect trends in P-uptake which otherwise would not be apparent from an instantaneous measurement. Measurements from this type of study integrate over short-term loosely coupled cause-and-effect relatiorships. Integrated measurements of light intensity and P-uptake enable co-occurring patterns to be resolved.

A sinusoidal pattern of P-uptake was detected in the diel studies in waters relatively rich in DIP (i.e., in phosphorus sufficient cells) but did not detect a pattern in waters relatively low in DIP (i.e., in phosphorus deficient ce:Lls) (Figures 77 and 78). Evidently, P-uptake changed directly with changes in light intensity when the cells were P-sufficient, when the cells were growth limited by some other factor. In addition, there was a depressed sinusoidal pattern of P-uptake through a simultaneous 24-hour dark bottle field study. The size of the postulated intracellular carbonaceous pool was linked, therefore, to the magnitude and duration of net primary production (NPP). Possibly, a natural phytoplankton community briefly maintains P-uptake regardless of its immediate light experience by respiring intermediate products of photosynthesis.

In one diel study, rates of P-uptake integrated over the 24-hour interval showed that the phytoplankton removed 0.69 pM DIP from the river water. The net DIP concentration change in the river was small; therefore, DIP apparently was regenerated. Transfer of DIP from the sediment was quantitatively the most likely mechanism balancing pelagic P-uptake. Because the mean depth of the river is 4.5 meters and a large fraction of the river surface area is in contact with the benthic area, DIP released from the benthos was perhaps con- centrated in the overlying waters. Indeed, the net effect of pelagic P-uptake and benthic regeneration of DIP was a dynamic equilibrium concentration of DIP in the water column (Figure 80). TIME OF DAY

Figure 80. Die1 variation of PAR, DIP, and algal biomass at Colerain, November 1, 1975. PHYTOPLANKTON AND BACTERIA ACTIVITY, 1976-1977

Procedure

A diurnal summer biweekly and a "winter-fall" monthly sampling regime was designed to measure relative activities of radioactive carbon uptake by populations of phytoplankton and bacteria simultaneously by the methods of Schindler, et az. (1974) and Hobbie and Crawford (1969). Modifications were made in the in situ incubation process by designing a 125 ml multi-bottled plastic holding rack (Figure 81) with side arms for phytoplankton incubation and bottom holders for bacteria runs.

Bacteria enumeration was accomplished by the method of Francisco et az., (1973) as modified by Daley and Hobbie (1975) and Hobbie et aZ., (1977) using the acridine orange ipiflourescent technique.

The upper river site at Tunis (C-4) and the lower river site at Colerain (C-11) were chosen to represent the two distinct geo-hydrological sections of the river (upper river, rapid flow; and lower river, slow flow). Diurnal winter sampling and incubations were done every two hours while those during spring, summer, and fall were done every four hours.

Other parameters measured were light intensity, water temperature, alkalinity, pH, chloride, total organic carbon (TOC), total phosphorus, ortho- phosphate-phosphorus, total nitrogen, ammonia-nitrogen, and nitrate-nitrogen.

Results

Physical Factors

Climatological data were supplied by the National Oceanic and Atmospheric Administration (NOAA). NOAA recording stations at Murfreesboro and Edenton were 20 km and 26 km from Tunis and Colerain, respectively. Monthly average temperature (Figure 82) was below normal at Edenton for the first eight months of the project. A comparison of normal air temperature at Murfreesboro was not presented in NOAA data. Air temperatures were consistently lower at Murfrees- boro than they were at Edenton. These stations are 75 km apart. The highesi air temperatures were recorded in July 1976, 24.7'~ in Murfreesboro and 25.7 C at Edenton. As expected, lowesE temperatures were recorded in January 1977, -1.6'~ at Murfreesboro and 0.11 C at Edenton. This was apparently the coldest winter in current history. The river was frozen to the Highway 13 bridge at Edenhouse and from shoreline to shoreline, making it impassable to navigational traffic for three weeks in late January and early February. Air temperatures in the spring were higher than normal at Edenton.

Water temperature at the two sampling stations followed patterns similar to air temperature (Figure 82). These data were collected for each sample period during each incubation period. Mean daily temperature at Tunis ranged from 29'~ (July 20, 1976) to O.OOc (January 14, 1977). The January sample . .

TOP VIEW

END VIEW

Figure 81. Sample rack for simultaneous measurement of algal primary productivity and bacterial heterotrophic activity.

114 MUZFREES3GZO - D EDENTON- A

Figure 82. Mean air temperature (Murfreesboro and Edenton) and water temperature (Tunis and Colerain), 1976-1977. period was four days before freeze-up of the river. Differences between stations were generally not greater than 3°C. Water temperatures were nearly as great in April (20°C) as they were during the first sample period in July (21'~).

Average monthly precipitation (Figure 83) was also abstracted from NOAA data. Precipitation at Edenton was less tnan normal for five months during the sampling period. The lack of precipitstion resulted in a drought condition during these months. Precipitation gas sporadic with 2- to 5-week. periods of zero precipitation or only trace amount; of precipitation. A comparison between the two recording stations also indicated a sporadic nature of precipitation difference with the greater amount falling on the slower flowing section of the river at Edenton.

Chemical Paran~eters

Water san~plesfor analysis of chemical constituents were collected in conjunction with each incubation period. With very few exceptions, concentrations of chemical species did not fluctuate significantly at either station throughout the 24-hour period. Therefore, values in the following sections reflect means for that chemical during each sampling period at each station. For ease of reporting, the two biweekly July and August sample periods will become "July I," "July 11," "August I," and "August I1 ."

Nitrogen. TOTN did not indicate any seasonality (Figure 84). The range of TOTN was 87.8 pg-atm/l (163.16 ug-atm1.L in March, 75.36 pg-atm/l in October) at Colerain, and 107.07 pg-atm/l (164.33 pg-atm/l in March, 57.26 ug-atm/l in November) at Tunis. Concentrations of TOTN were not significantly different between stations throughout the project. However, fluctuation of the various nitrogen species was evident. Total organic nitrogen (TON) was the largest fraction of TOTN at both statlons; the concentrations of TON were greater at Colerain than at Tunis. A patrern following optimum algal growth seasons was evident at Colerain where TON was greatest from July through October with a decrease from November to April. A similar pattern for TON was not found at Tunis where fluctuations occurred more randomly. There was one period, November to January, where the decrease in TON at Tunis was similar to that at Colerain. This decrease occurred during the time frame that Union Camp discharged "black liquor" pulp wastes.

Ammonia-nitrogen (NH3-N) at Colerain was in greatest concentration from July to October, rapidly decreased from October through December, and remained relatively low through April. Increase of nitrate/nitrite-nitrogen (NO3-N) occurred during the periods of decreasing NH3-N concentration. N03-N concentration was lowest in October (0.12 pg-atm/l) .

Concentrations of NH3-N at Tunis were generally lower than those found at Colerain. As a component of the TOTN spectrum, NH3-N was not an important species here. N03-N was higher at Tunis than at Colerain during the summer and fall (Figure 84).

Phosphorus. Whereas there was some similarity of patterns between nitrogen species between stations, there was a general inverse trend in phosphorus concentrations found at these stations (Figure 85). The range for total phosphorus (TP) at Colerain was 6.94 pg-atm/l, peaking in February (10.27 pg-atm/l) with a low in October (3.33 pg-atm/l). TP concentrations at Tunis had a range 83. Average monthly precipitation at Murf reeaboro and EdentolL, 1976-1977. Eigur~84. ~otalnitrogen . (TN), total organic nitrogen (TOIN) r mmonia nitrogen (NHg-N), and nitrate (NO3-N) at Tunis and oler rain, .1976-1977'. Figure 85. Total phosphorus (TI'), total organic phosphorus (TOP), and ortho-phosphate phosphorus (0-PO) at Tunis and Colerain, 1976-1977. of 4.66 ~g-atm/l (October, 7.85 pg-atm/l, to July 11, 3.19 pg-atmll). During most sampling periods, total organic phosphorus (TOP) was the major phosphorus species at both stations. The major exceptions were October at Tunis when ortho-phosphate-phospi~orus (0-PO4) comprised 81.5 percent of TP and December 1976 when 0-PO4 was 59.8 percent of TP at both stations. Fluctuations in 0-PO4 were less erratic at Colerain than at Tunis. The concentration of 0-POL, at Colerain was 1.2 pg-atm/l or less through November 1976. Tunis, however, had large fluctuations in 0-PO4 on a sampling-period-to-sampling- period basis. Only the February 1977 to April 1977 sampling frame had con- tinuity of a trend. Both stations indicated similar increases in 0-PO4 concentrations between the November 1976 to December 1976 period, coinciding with Union Camp ' s discharging. -P Ratios of N are presented in Figure 86. Total N:P at Tunis ranged from 21.69 in late August to 4.5 in October. There was considerable fluctuation in N:P at Tunis from July I through Clctober. A steady increase was observed from October through January 1975. A nearly 3x increase occurred between Febru,sry and March with a sharp decline in April. Total N:P at Cole- rain did not exhibit as much variation frcm sampling period to sampling period (from a low of 3.83 in February to a high of 15.11 in March). A general decline in total N:P occurred from August I1 through February. The pattern of increase and decrease in N:P for February, March, and April at Cole- rain closely followed the pattern found at Tunis. Mean N:P for the ten months was 10.23 (S.D.=3.26) at Colerain and 10.73 (S.D.=6.38) at Tunis. Based on this relationship, neither site is significantly different from the other. However, the variance over the same time frame is nearly 2x greater at Tunis than at Colerain. This result indicated the potential for larger fluxes in either N or P at Tunis than was exhibited at Colerain.

Two major peaks in inorganic N:P at Tunis during July I1 and August 11 were similar to peaks in total N:P. The magnitude of the peaks was a result of nearly 2x decreases in inorganic P and 2x or greater increases in inorganic N. Inorganic I:P was lowest in October (0.53), but a steady increase was observed through April. Only one major peak was observed at Colerain. August I had the highest ratio (8.9) for the 10-month period. A comparison of total N:P and inorganic N:P at both sites indicates that during most sampling periods, the organic fractions have the greatest effect on total N:P. This statement lends support to an earlier one concerning fluxes in N or P and the relative potential for these increases to occur at Tunis.

Carbon. As with nitrogen and phosphorus, the total organic fraction of total carbon (TC) was greater than inorganic fractions. Total Organic Carbon (TOC) closely followed some peaks in 0-PO4 at both Tunis and Colerain. Total Inorganic Carbon (TIC) was low at both stations and was indicative of "soft water" systems of the region. The range for TIC at Colerain was 51.53 pg-atm/l (48.47 pg-atm/l August I1 to 100 pg-atmll, January) and 62.62 pg-atm/l (34.67 ug-atm/l, August I1 to 97.29 ug-atm/l, July 11) at Tunis. Yearly means for TIC were 73.94 pg-atm/l (S.D.nl5.6) at Colerain and 59.66 pg-atm/l (S.D.= 19.0) at Tunis (Figure 86) .

Chloride Ion, Chemical Oxygen Demand, and pH. Chloride ion (C) concentrations were lower at Tunis. than at Colerain for 8 of the 11 sampling periods* (Figure 87). C at Tunis was relatively stable from July I through November Figure 86. Relationship between total nitrogen and total phosphorus and between inorganic nitrogen and inorganic phosphorus at Tunis and Colerain, 1976-1977. (Z = 6.18/mg/l, S.D. = .40). Between November and December, C increased from 6.05 mg/l to 38.23 mg/l and maintained high concentrations until March-April , when the concentration decreased to about ehe mean of the first six periods. , This increase in C at Tunis coincides with the flow of wastes discharged by Union Camp. C at Colerain was higher than at Tunis for all periods other than during the Union Camp discharge. In January 1977, the effect of this discharge on C was also detected at Colerain. The ixrease was greater than during summer months (Z = 12.26 mg/l, S.D. = 2.66); nowever, C concentrations during this period (high of 27.57 mg/l) were not as great as in October when C was 38.32 mg/l.

Chemical Oxygen Demand (COD) was esseatially identical at both stations (Figure 87). Major increases in COD were in October and in December through April coincident with the Union Camp discharge.

Hydrogen ion concentration, pH, was not appreciably different between the two stations (Figure 87). Mean pH at Tunis was 7.09 (S.D. = .33) and 7.07 (S.D. = .21) at Colerain. There was an inzrease in pH at Tunis during both August sampling periods; another gradual increase occurred between October and February. Fluctuations of pH at Colerain were not indicative of any pattern.

Phytoplankton

Quantitative and qualitative assessment of algal populations'yielded distinct differences between Tunis and Colerain. Throughout the project, algal density was consistently lower at Tunis than at Colerain (Figure 88). Total algal cells at Tunis ranged from 1.25 x lo3 cells/ml in January 1977 to 1.90 x lo4 cells/ml during August I, whereas total algal cells at Colerain ranged from 2.17 x lo3 cells/ml in December 1976 to 5.92 x lo4 cells/ml during August 11. Algal populations followed seasonal trends at both stations. Although algal cell density was always greater at Colerain than at Tunis, algal biomass was greater at Tunis during the August I, October, December, and April sampling periods. Biomass at Tunis ranged from 0.81 mg/l in January to 32.72 mg/l during August I. Algal biomass at Colerain ranged from 1.45 mg/l in December to 22.30 mg/l during August 11; also, biomass was nearly this high during July I when it was 21.72 mg/l (Figure 88).

A total of 232 taxa and 7 unidentified categories were classified throughout the project. Appendix E contains a listing of occurrence for all taxa; dominant species (highest percentage cell number) and co-dominant species (comprising 10 percent or greater total cell number) are indicated. Of this total, 44.4 percent of the taxa were represented at both sites, although not necessarily at the same time. The number of taxa present at Tunis during each period ranged from 30 to 54 (f = 45, S .D. = 7) . Taxa present at Colerain ranged from 38 to 72 (R = 51, S.D. = 10).

Seasonal fluctuations in algal taxa were nearly as great as from period to period (Appendix E). At Colerain, the seasonal complement of algae ranged from 70 taxa in the fall to 109 taxa in winter. The range at Tunis was from 68 taxa in the spring to 93 in summer. There was a greater number of taxa present at Tunis than at Colerain during summer and fall. e I I I I I I I I I J I JII A I A1 I 0 N' 0 J F M A 1976 1977

Figure 87. Chloride ion (CI), chemical oxygen demand (COD), and pH at Tunis and Colerain, 1976-1977.

123 Figure 88. Total algal cell numbers and total algal biomass at Tunis and Colerain, 1976-1977.

124 Two major peaks in cell density occurred at Colerain during JII and A11 (Figure 88). Phormidiwn angustissimwn, a blue-green alga, was the dominant species (56.62 percent) during the first peak. No species met the co-idominance criteria stated earlier; however, CycZoteZZa sp. (9.87 percent) and M~Zosira granuZatu var. ungustissim (6.58 percent), both diatoms, were important in the population. The second peak, which w2.s nearly twice as great as the July I1 peak, was mainly comprised of two blue-greens, OsciZ Zatoria geminata (48.22 percent) and Raphidiopsis curvata ( 10.82 percent). Ankistrodesilnus faZcatus var. spiriZZifomis (9.5 percent), a green alga, and Phomidium angustissimwn (8.53 percent) were also present among the 44 taxa represented. After August I1 algal density decreased tic a winter minimum (2.17 x lo3 cells/ml) in December. The dominant and co-dominant species during a four-month period beginning in November were all diatoms. AreZosira granuZata var. angustissima (MGA) was dominant in December (17.93 percent) and February (12.99 percent, and co-dominant in November (13.43 percent) and January (12.25 percent) . MeZosira distans was dominant in January (13.57 percent) and co-dominant in December (12.36 percent) and February (12.68 percent). SkeZetonema potomos was dominant in November (24.52 percent) and co-dominant in December (11.41 percent). A brief surge of Synura petersonii (23.42 percent), a chrysophyte, occurred in March with MGA (16.64 percent) co-dominant. In April, dominance shifted back to diatoms with MGA (36.00 percent) and SkeZetonem potomos (17.38 percent).

Diatoms were dominant 9 out of 11 periods at Tunis. Of those 9, NGA was dominant 7 periods, reaching a maximum dominance of 59.3 percent during a bloom on August I. CycZoteZZa gZomerata was the dominant species on July I1 (15.4 peroent) and in February (12.5 percent). C. gzomerata was co-dominant on July I (11.06 percent) and made an important contribution on August I1 (7.05 percent) and in December (7.89 percent). hodo om on as minuta, a cryptomonad, was an important constituent of the population during fall, winter, and spring. R. minuta was co-dominant in October (14.04 percent), November (20.13 percent), January (15.55 percent), and important in March (8.66 percent). During April, over 44 percent of the algal density was comprised of highly motile, flagellated algae, having R. minuta dominant (15.16 percent with Cryptomonas erosa var. reftern, a cryptomonad, (14.58 percent) and Synura uveZZa, a chrysophyte, (14.35 percent) as co-dominants. MGA was also a co-dominant with 11.02 percent. The only other period not dominated by diatoms was January. During this period P. angustissirnwn was dominant with 24.73 percent, and R. minuta (13.07 percent) and MGA were co-dominant.

Algal taxa were grouped into seven groups which closely approximate class relationships. For the purpose of this report, certain taxa were grouped together due to morphological similarity. The seven groups are as follows:

B = Blue-Greens, Class Cyanophyceae C = Chrysophytes, Classes Chrysophyceae and Xanthophyceae D = Diatoms, Class Bacillariophyceae E = Euglenophytes, Class Euglenophyceae F = Flagellates, Class Haptophyceae, Cryptomonadaceae and Cryptochrysidaceae G = Greens, Class Chlorophyceae P = Dinoflagellates, Class Dinophyceae.

When Chowan River algae are fractionated into these groups, a cleaner interpretation of the collective effect of a given tendency within a class can be seen (Figures 89 and 90). For example, at the Colerain site during July through November 1976 approximately 40 percent of the cell numbers were of the blue-green algal types, over 90 percent of which are either filamentous or colonial types. The diatoms were nearly 50 percent of the remaining cell numbers. Although boch groups were present throughout most of the project, blue-greens (B) dominated from JI through October, and diatoms were a considerable factor for the remainder of sampling. Chrysophytes (C) were relatively non-existent prior to December; however, their population began to expand in the next three months and declined in April. Euglenophytes (E) were not present at all, and dinoflagellates (P) were present only from Janu- ary through April.

As in earlier examples, Tunis was again distinctly different from Cole- rain. The Tunis site (Figure 91) showed a clear dominance by diatoms throughout the year. The notorious blue-green algae seen at the Colerain site made up only 10 percent of the cell numbers at Tunis and were mostly of the uni- cell and colonial types. Flagellates in general and the flagella-bearing members of the green algae (F) made up a substantial amount of the cells at Tunis. Chrysophyceae (C) and Dinophyceae (P) at this site were few in cell number, but the cells generally had a large biovolume.

When a comparison is made between cell numbers and biomass at these two stations, it is shown at Colerain the percentage of Chrysophyceae biomass increased during the winter months while the percent of diatoms slightly decreased (Figure 90). The summer, early fall blue-green algae, class Cyano- phyceae, remained fairly constant, drastically decreasing, however, during the late fall and winter months with an early spring return. The flagellates and Dinophyceae (P), though small in number, expressed themselves considerably greater as biomass than as cell number.

If consideration is given to all motile species at the Tunis site (Figure go), class Chrysophyceae, Chlorophyceae, Euglenophyceae, Dinophyceae, and the collective group of flagellates make up approximately 50 percent of the biomass. More than 85 percent of the species of these classes have motility.

An overall assessment of Chowan River phytoplankton response to water quality can be deduced from the nutrient data collected from July 1975 to January 1977 (Figure g1). This period encompassed a spring bloom in 1976. Nitrate-nitrogen at both Tunis and Colerain varied throughout the year. The higher the biomass, the lower the nitrate-nitrogen. During the bloom, a period of high biomass, nitrate-nitrogen was just above the limit of detection at both stations, and at Colerain this condition persisted until early Novem- ber. Initially, a buildup of biomass started at Tunis during late April; however, it was short lived and was reflected in a quick recovery of NO3-N in early June. The situation was similar for ammonia nitrogen (NH3-N) (Figure 92). However, the conditions for this nitrogen species were never as drastic as for NO3-N.

That the composition of two species of Anabasnu and one of Microcystis that promoted the bloom did not prefer NH3-N over NO3N is indicated by the NH3-N consistency. Ammonia response was similar at Tunis and Colerain. How- ever, it can be seen in Figure 92 that ammonia declined in late May. This Figure 89. Algal cell number composition by group, at Tunis and Colerain, 1976-1977.

127 B-G , \

TUNIS

I 8 I *1 JII Al All 0 N J F n MI O 1977

Figure 90. Algal biomass composition, by group, at Tunis and Colerain, 1976-1977. Figure 91. Nitrate-nitragen concentrations at Tunis and Colerain, 1975-1977. Figure 92. Ammonia-nitrogen concentrations at Tunis and Calerain, 1975-1977. Figure 93. Ortho-phosphate-phosphorus concentrations at Tunis and Colerain, 1975-1977. Bacterial cell number

Bacterial biomass

Figure 94. Bacterial cell number and biomass at Tunis and Colerain, 1976-1977. corresponded well with the flagella.te buildup during this period. These algae usually preferentially take up ammonia over nitrate-nitrogen (Whitford, 1969).

Ortho-phosphate-phosphorus during the bloom remained moderate at the Tunis site while it varied inversely with biomass at Colerain (Figure 93). The early abundance of 0-PO4 in the river and the large number of high biomass species at Tunis probably allowed luxury consumption.

Bacteria

Bacterial populations at Tunis and Colerain followed similar trends with only a few points of deviation (Figure 94). Three major peaks in occurrence were observed throughout the study period. The first peak was during August I when cell numbers were 4.71 x lo9 cells11 and 4.42 x lo9 cells11 at Colerain and Tunis, respectively. This peak was followed by a graduate decline through November. In December, the second peak occurred with 3.61 x lo9 cells11 and 3.59 x 10' cells/l at Colerain and Tunis. The increase in cells during Decem- ber could possibly be related to the presence of Union camp's waste discharge and the buildup of N and P species. A drastic decrease in cell numbers was found in February. As stated earlier, this sample was taken just four days prior to river freeze over. In fact, thin sheet ice was forming on surface waters in evening hours at both stations during this sample period. Tempera- ture stress may have led to bacteria cell numbers being as low as 4.08 x lo6 cells11 at Colerain and 5.27 x lo6 cells/l at Tunis. Cell numbers in subsequent months increased to the highest values found during the entire project (1-33 x lo1O cells/l at Colerain and 9.52 x lo9 cells/l at Tunis during April).

The curve for bacterial biomass followed the same trends as did cell numbers (Figure 94). The highest biomass was during April with 0.68 mg/l at Colerain and 0.49 mg/l at Tunis. Biomass was lowest in February, 0.00021 mg/l and 0.00027 mg/l at Colerain and Tunis, respectively.

Peak values for cellular carbon occurred in April (Figure 94). Total cell carbon at Colerain was 4.50 pg-atm/l, whereas total cell carbon at Tunis was 3.23 ug-atm/l. In February, cell carbon was as low as 0.0018 ug-atm/l and 0.00014 pg-atm/l at Tunis and Colerain.

DISCUSSION

A comprehensive phytoplankton study of a water system as diverse as the Chowan River encompasses numerous physical, chemical, and biological variables. The relative importance of each of these variables to the overall system requires careful determinations. Once gathered, these determinations must be weighed carefully in assessing the role of each parameter in phytoplankton dynamics. The strong interrelationships of these variables lend themselves to a cumulative discussion of events in chronological order with respect to phytoplankton growth.

The Chowan River is a eutrophic estuary containing high levels of inorganic nutrients. Basin morphology, flow rates, breadth, surface area., extent to shoreline, and mean slope all change considerably in the more than 80 km of the river investigated. Levels of phytoplankton productivity along this distance range from moderate above Tunis (C-4) to extremely high below Tunis and at Colerain (C-11) and Edenton (C-16). Phytoplankton species and productivity rates vary with seasonal changes in light, temperature, available nutrients, and several other environmental factors investigated in this study.

The growth season of project year 1974-1975 witnessed high precipitation and high flows over the entire reach of the river. In contrast, during the 1975-1976 year and part of the 1976-1977 year, the river system was subjected to infrequent precipitation, heavy evaporation, and very little flow or inflow. In addition, the upper Chowan River did not express an algal bloom throughout the three-year study. The physical structure of that section of the river usually promotes high flow (Jackson, 1968; Daniel, 1977). The lower Chowan, where the river is wider and sluggish, has persistently been plagued with a variety of algal blooms. Therefore, given the river in its present state, flow (discharge) is perhaps the most important factor in controlling water quality. Not only does the lack of rapid flow in the lower Chowan increase resistance time of algae and nutrients, thus promoting algal growth potential, but certain algal species that are initiated in the upper Chowan are swept downriver into the lower low-flow area. They are then able to aggregate and grow, thus compounding the already omnipresent species. Characteristically, these species are of the buoyant type which floats readily at the mercy of the flowing water. Class Cyanophyceae (blue-green algae) typifies this group. The histogram series figures clearly illustrate the compoundment of blue- green algae on the lower reaches of the river.

Not only is the rate of biomass change in this system important but also the species composition that makes up the standing crop of algae.

During the project period, March 1974 - June 1977, the highest water quality was observed during the period March 1974 - March 1975. The concept of "water quality" is a relative one for the Chowan River, as it is for most other North Carolina aquatic systems. To be exact, it would necessitate historical data initiated during the virgin years of the river basin and closely paralleling the evolution of western civilization. Obviously, no such data exist. Therefore, when we speak of "water quality," our frame of reference is quite limited. However, it is possible to assess water quality over several years as an exercise in long-term monitoring. Such a general comparison of the Chowan River since March 1974 suggests a decrease in water quality. The March 1974 - March 1975 project year was uneventful with respect to an algal bloom. The March 1975 - March 1976 year had a May 1975 obvious bloom of Ambaem and an early potential with Peridiniwn. 1976-1977 was likewise.

It appears that hydrological and environmental conditions are as important to algal growth and water quality as the present pattern and quantity of nutrient loading is.

Dominant Species Importance

Changes in species present and their importance to total biomass reflected compatible growth conditions for certain species and their ability to dominate algal biomass. The river's compatibility for growth of individual species varied with seasonal changes in temperature and light as well as with less pre- dictable environmental changes, such as flow, nutrient concentrations, etc.

Low light conditions in the river followed heavy rains and increased turbidity in July 1975. Synedra ulna adapted to these conditions very well near Tunis where it dominated the algal biomass (73 percent of total). This species has been found in all seasons in eastern North Carolina. It seems to be favored by low light and highly turbid conditions (Whitford and Schumaker, 1969). Unlike many diatoms, Synedra ulna grows well in warm temperatures (Whitford, personal comment). This compares favorably with the 26-30°C temperature regime under which it proliferated in the Chowan River during this year.

Peridiniwn was important throughout the river during the late summer and early fall 1975. During late August, this Dinoflagellate totally dominated with an extremely high peak in biomass. An explanation of the complete dominance demonstrated by this species during late August may be a function of the change in nutrient conditions during late July and early August corresponding to a change in discharge.

This high peak correlated with a small fish kill (May 1975 Field Notes) in the lower Chowan. Some species of Peridinim have been cited as toxin forming (Stewart, ed . , 1974 ) . Peridiniwn triqueretrwn has dominated algal blooms in the Pamlico River, North Carolina (Hobbie, 1971). This nutrient- requiring winter species has been found in abundance during fish kills, but there has not been proof that toxins emitted by the organism initiated such kills. Hobbie (1971) suggested night-time respiration rates increased tre- mendously with large biomasses thereby depleting oxygen levels which could also cause fish kills. The observation of fish kills that correlated with the pro- liferation of Peridinim sp, could have been an expression of one of the before-stated conditions.

The genus MeZosira occurred throughout the river during all of each project year. Like many diatoms, it expressed a high degree of ecological amplitude. MeZosira ituZica var. tennussima was especially importact. It ranked as one of the top three species in biomass on 16 of 20 1975-76 sampling dates at Colerain, and 15 of 20 dates at Edenton. The dominance of this species during winter was clearly seen the previous year, 1974-75. It has been found in North Carolina in abundance in cold nutrient-rich waters during low- light conditions (Whitford and Schumaker, 1969). Hutchinson (1957) lists this genus as an indication of eutrophic conditions. High nutrient concentrations and light attenuation by particulate matter give an ecological advantage to this genus and could account for its successful growth in the Chowan River.

Plankton in the class Cryptophyceae (Cryp.lromonas erosa, C. obovata, C ouata, Ochroomonas sp.) were the most important algae at Tunis on a seasonal basis. These unicellular flagellates competed well with other phytoplankton in the faster flowing waters containing considerable amounts of particulate matter. Their flagella supply motility which allow them to maintain themselves in an optimum light regime. This was a tremendous advantage over non- motile unicells or filaments which were at the mercy of the currents. The low-light conditions at Tunis were also advantageous to this class which has been cited as preferring low-light intensities (Whitford and Schumaker, 1969). Low light may stimulate autotrophic growth in some species in the Cryptophyceae (Stewart, ed., 1974). The environmental conditions at and above Tunis and the adaptive morphology of the Cryptophyceae complement each other.

Algae in class Cyanophyceae have displayed an ability to grow rapidly during warm weather and low-light conditions in eutrophic waters. Aphanizom- inon flos-aquae formed a surface bloom in the Chowan River through rapid reproduction and coagulation of its featherly like colonies (Campbell, 1972). Mic12ocystis sp. has dominated the biomass on several occasions in the past two years. Anabaena was found in bloom conditions in May of 1976 and 1977. The preference of lacustrine waters by blue-greens was exhibited by the greater accumulation of those algae at Colerain and Edenton than the faster flowing water at Tunis. The high winter nutrient conditions expressed at Colerain were a function of longer residence time and slower moving waters. These conditions are perhaps the chief culprit for obnoxious blue-green algal growth when temperatures and light increase in the spring.

Cyanophytas have many features adapted to survival in a competitive environment (Allen, 1966). High surface-to-volume ratios increase buoyancy and allow greater chance of nutrient uptake. Greater buoyancy can be gained by gelatinous sheaths or gas vacuoles, allowing the alga to float to the upper waters and out-compete other phytoplankton for light (Wetzel, 1975). However, these are only advantages in slow-moving or stagnated waters. Phycobilin pigments (phycoerythrin and phycocyanin) contained in thyllakoids are advantageous in reception of photosynthetically active light (Lang, 1968), permit- ting blue-green to utilize a variety of light waves by absorption through a variety of pigment systems. Such absorbed energy is transferred by resonance to chlorophyll-a.

Heterocysts found in some blue-greens have been shown to be a site of nitrogen fixation (Fogg, 1965), thereby giving them an advantage in low nitrogen conditions brought on by high algal biomass or washout due to high flows. Such adaptive features in the Cyanophyceae make them most likely to be the vectors of an undesirable spring or summer bloom in the Chowan River.

Species diversity was found to be fairly high (approximately 30 species/ sample) during the study. Individual species dominated algal biomass under very defined environmental conditions. Synedra ulna (July), Peridinim sp. (August), and MeZosira italics var. tennuissima (winter) exhibited this ability

, primarily in the upper Chowan during 1975. During late spring following the MeZosira winter growth pattern, a surface bloom of Anabaenu occurred (1976 and 1977) in the lower Chowan.

Algal Biomass

The river supported only a moderate algal biomass upstream but a very high- standing crop near Colerain and Edenton. Biomass decreased below 1.0 mg/l only twice during the 1974-75 study near Edenton. Differences on a seasonal basis varied, but the difference due to space was attributed to basin morphology.

The steeper gradient in basin morphology above Tunis and the narrowness of the river allowed a larger volume of water through a smaller area than further downriver. This morphology-increased flow rate, in turn, disallowed a high accumulation of algae. Surface waters are constantly moving and bottom waters do not receive light enough for photosynthesis (Reid, 1961; Hynes, 1972). This factor could very well be responsible for the low biomass in surface waters at and above Tunis.

Seasonal biomass changes were inextricably linked to changes in temperature, light penetration, discharge, and nutrients. The biomass changes in the Chowan followed a distinct periodicity with a seasonal pattern of high levels in summer, maxima in spring and fall, and minima in the winter. This seasonality was attributed to the normal temperature curve and changes in incident light received by surface waters. Nutrient concentrations had an inverse relationship with biomass. As biomass increased, nutrients decreased due to assimilation and retention of nutrients by phytoplankton.

Deviations from this seasonal curve were many and often severe. The sharp decreases in biomass in July 1975 followed heavy rains. These rains increased discharge which lowered temperature and increased particulate matter, which in turn inhibited light penetration and prevented algal growth.

The late August 1975 biomass peak was the result of warm temperatures, low rates of discharge, higher nutrient concentrations, and better light penetration.

The extremely high peak of phosphorus concentrations found in the lower Chowan during mid-September 1975 followed substantial rains in early Sept- ember. Many corn crops were harvested in late August and early September. Allochthonous inputs of nutrients with runoff may have caused the increases.

The 1976 winter biomass curve followed a pattern that has been reported extensively (Wetzel, 1975; Hutchinson, 1957). It decreased readily with winter temperature and light conditions. The increase in ortho-phosphates during this period was due to lack of growth by phytoplankton. The inverse * relationship of nitrate concentrations versus algal biomass was clearly observed.

The effect of high light intensities and warming waters on biomass was reflected during February 1976 when unseasonal growth occurred. Increased productivity in February initiated an early spring increase in biomass that was delayed in March by less favorable conditions. The spring increase resumed in April with sharp increases in biomass and declines in nutrient levels that had accumulated during the winter. These changes showed that when low light and low temperatures prevailed, productivity decreased and nutrient levels increased. With more optimum environmental conditions, the nutrient levels declined due to increased productivity.

Biomonitor Biomass

Use of standing crop biomass to inoculate the biomonitor allowed investigation of growth and transport (or lack of it) of algae that were present in the river at a given site. While seasonal variations were similar to those in standing crop biomass, the biomonitors reacted more rapidly to the optimum conditions that caused prolific growth of phytoplankton in the spring of 1976. This technique had not been employed in previous ecological investigations using natural populations as an inoculum; therefore, comparisons were unavail- able. The biomonitor readings revealed the river's capability to support an algal bloom in the spring of 1976, Wlth warm temperatures, high light, and substantial concentrations of nutrients, algae grew at rates of over 1131 ugC/l/day in the biomonitor at Edenton (early spring 1976).

Evidence that flow rates and basin morphology limited algal growth in the upper Chowan was also provided by use of the biomonitor. Phytoplankton in biomonitors at Tunis were capable of increases as great as or greater than those at Edenton despite higher productivity rates in the river at the latter station.

Light, nutrient concentrations, pH, and temperature measur'ements were very similar at Edenton and Tunis. The biomonitors at both sites allowed diurnal cycling of all of these factors, yet did not allow the organisms to flow downstream, clearly indicating that more rapid flow and less retention time of water were factors limiting buildup of biomass and subsequent high levels of productivity at and above Tunis (C-1 - C-4). The lesser flow increased retention time. Thus, the larger surface area, shallow of water, and occasional reverse flow at Colerain and Edenton, allowed greater algal productivity,

The biomonitor biomass fluctuated with varying growth conditions. The August productivity maximum correlated well with extremely high biomonitor biomass recorded at Tunis. Phytoplankton capabilities for rapid growth were revealed in February when prolific phytoplankton increases occurred in association with increased temperatures, indicating that nutrient levels present in the river at that time would allow exponential increases in algal biomass given proper environmental conditions. The extremely high spring biomass increases, resulting in an Anubaena bloom at Colerain (May 1976), verified this finding. These results are indicative of the relative capability of the biomonitor in assessing the potential of surface waters to promote an algal bloom.

Changes in both standing crop biomass and biomonitor biomass showed inverse relationships with nitrogen concentrations throughout the study. Total nitrogen concentrations were relatively high in the river (0.6-1.4 mg/l), but did not reveal the inverse correlition with biomass as was seen with nitrate-nitrogen concentrations. Winter nitrate levels (0.5 mg/l) were above those recommended by Baumann et aZ., (1973) for avoiding detrimental effects of nitrosenous compounds upon aquatic life. Results from this study, including increases in standing crop and biomonitor biomass as well as results from algal assay procedures with Chowan River water, indicated that nitrogen and/or phosphorus additions were likely to incite increased algal growth and undesirable levels of biomass in the lower Chowan during late spring and summer. Addition to winter river water did not produce bloom levels of biomass above river con- trols.

The Chowan River thus is a nutrient-rich water that is presently in a very productive state. While present water quality conditions may not be detrimental to fishes and other aquatic life, additional nutrient loading from agriculture, domestic wastes, and/or industry, accompanied with optimum environmental conditions (high light, high temperatures, lacustrine water) will certainly promote catastrophic algal blooms in the lower reaches of the Chowan River.

Phosphate Enrichment

Application of P-uptake rates determined from natural mixed populations is contingent upon the mixed populations kinetically responding as a single species. P-uptake by single species of phytoplankton in culture is shown by physiologists to kinetically respond as a single enzyme reaction. Individual phytoplankton species mediating phosphate uptake, like enzymes, are characterized by the kinetic constants K and Vm. Indeed, phytoplankton can be concep- tually approached as kinetic analogs to enzymes. Multiple enzymes catalyzing the same reaction exhibit mixed order reaction kinetics according to Michaelis- Menten kinetic theory. In the same way, heterogeneous populations of phytoplankton, each species identified by separate K and Vm values, are expected to exhibit mixed order reaction kinetics. Predictive ability of mixed population growth as a function of limiting nutrient concentration is dependent upon single order reaction kinetics of the mixed population, Yet, there are few reports which validate applying Michaelis-Menten kinetic theory to mixed natural populations. A test of this question as a necessary prerequisite for applying tracer kinetics to natural mixed phytoplankton populations in the Chowan River was undertaken.

A hyperbolic relationship of P-uptake to DIP concentrations similar to the Michaelis-Menten expression describing the kinetics of a single enzyme substrate reaction was seen in several experiments. This is given by the equation : DIP = '* Kt + DIP where (V) is the velocity of P-uptake in pM/hr, (Vm) is the maximum velocity of P-uptake, (DIP) is the concentration of dissolved inorganic phosphorus in pM, and (K called the apparent half saturation constant for DIP transport, t ), is the DIP concentration at Vm/2. Reciprocal plots from three independent tests, including one during an Anubaenu bloom, were linear indicating apparent single order reaction kinetics. Hence, P-uptake of the mixed phytoplankton populations responded kinetically as a single species population.

For P-limited phytoplankton in steady-state growth, every increment of P-uptake results in an increment of growth. Providing the phytoplankton were growing at steady state during the short time interval of the kinetic tests 50 percent of the maximum growth rates occurred within 1 Kt, or 0.15 pM DIP, under the existing light and temperature conditions. Furthermore, 90 percent of the growth rates occurred within 10 Kt or 1.6 uM DIP. The hyperbolic mathematical relationship of the data indicates that many of the phytoplankton growth rates were controlled by very low DIP concentrations and were controlled progressively less by increasingly higher concentrations. Observations indicate that this relationship has implications for eutrophication studies.

Solving eutrophication problems requires ability to predict biological and chemical changes in natural waters associated with nutrient additions or nutrient decreases. A nutrient is defined as a "limiting nutrient" when it is not present in sufficient quantities, relative to the abundance of other minerals, for continued growth of the biota. Slight quantitative changes in a limiting nutrient will promote a greater response from an organism than the same magnitude of change for the nutrient when it is non-limiting. While increasing the concentration of a limiting nutrient will to a point increase the quantity of phytoplankton cells, eutrophication problems are not necessarily related to the instantaneous size of phytoplankton populations. For example, a small phytoplankton community doubling once a day can process as much phosphorus within a day as a large community doubling once every five days, and can modify existing oxygen and nutrient depth profiles more rapidly than the larger but slower growing community. From this perspective, eutrophication problems are viewed as consequences of the rapid rates of phytoplankton growth and subsequent phytoplankton decay.

Briefly, what is important for reducing the effects of phosphate loading in eutrophic waters is determined from the ratio DIP:Kt. Specifically, an effective reduction of phytoplankton growth rates will begin when the DIP:Kt ratio approaches one, and strong phosphate limitation to phytoplankton growth rates will occur at ratios of one to zero.

On the basis of these criteria, the phytoplankton in the lower Chowan River were P-sufficient from late fall through early spring. This is because concentrations of DIP were sufficiently high to promote maximum phytoplankton growth under the existing temperature and light conditions. Yet, episodes of P-limitation occurred during periods of low flow. Reduction in flow then would, at first glance, seem an adequate mechanism for controlling phytoplankton growth. However, low flow also increases residence time. Such an increase in residence time enables other biological mechanisms, in particular, nutrient recycling and nitrogen fixation, to activate, thus giving continuous growth potential to algae present in the system.

During the spring of 1976 in the lower Chowan, an algal bloom persisted 21 days during a period when both usable nitrogen and phosphorus were below detectable levels chemically. In contrast, only sustained growth (remaining at a given concentration ) of phytoplankton occurred dur.ing the summer (1975) and was maintained through the fall in the lower 25 km of the river. This was because DIP frequently was present in insufficient quantities to promote maximum phytoplankton growth at the existing nutrient levels and temperature and light conditions; the ratio DIP:Kt frequently approached unity; and because river flows, due to high precipitation, reduced residence time of both nutrients and algal species.

It is expected that the Chowan River will continue to have frequent seasonal blooms for some time to come. The extent of these blooms will depend upon seasonal precipitation and river discharge; that is, if no additional nutrients are added to the present state. Any sustained drought will reduce flow due to reduced inflow, nutrient concentrations due to evaporation, and promote a longer residence time for nutrients, algae, and nutrient recycling in the river. Because different algal physiological growth strategies are expressed under variable environmental conditions, different species combinations and diversities will emerge from time to time in this river. However, in the lower Chowan from the Colerain area to the mouth of the river at Edenton, Class Cyanophyceae in general and Anabaena, Aphanizominon, and Micro- cystis in particular will be the algae species most likely to cause problems.

Uncertainty as to the source of river nutrients still exists. Therefore, it cannot be determined if the upper Chowan will become subject to algal blooms in the near future. Certainly, adequate nutrients are periodically present, and almost uniform environmental conditions are imposed on the entire river. However, the hydrographic profile of this section of the river, along with width, slope, and tributary inflow, promotes usually high river flows with a periodicity that would seem to work against nutrient-algae residence time. Therefore, it is not expected that this section of the river will bloom under normal existing conditions.

Tributary activity could be a problem source in the future. These bodies of water receive runoff from farmlands and from 'koint-sources" along their banks. Under heavy rains, they receive and transport large quantities of nutrients. However, these are greatly diluted before they reach the waters of the main Chowan. Tributaries also receive and transport large quantities of sediment, detritus, and other particulate matter which increase the turbidity of the water, preventing light penetration during transport and thus preventing algal growth. However, tributary storage following heavy rains and settling of particulate matter could generate conditions that would promote heavy algal activity. Much of t6e tributary potential will depend upon the control of 11point-source" input of nutrients. LITERATURE CITED

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Stanley, D. N15 Uptake Studies on Chowan River, Personal Communication, May 1975. Strathmann, R. R. "Estimating the Organic., Carbon Content of Phytoplankton from Cell Volume or Plasma Volume," Limnol. and Oceanogr., 12:411-418, 1967,

Utermohl, H. "Zur Vervollkimmung der Quantiative Phytoplankton Mehtodki," Mitt. Int. Verein. Limnol., 9:l-38, 1958.

Wetzel, R. G. Limnology, W. B. Saunders, Comp., Philadelphia, PA, 1975.

Whitford, L. A. and G. J. Schumaker. A Manual of the Freshwater Algae in North Carolina, Technical Bulletin No. 188, North Carolina Agricultural Expermiment Station, Raleigh, NC, 1969.

Whitton, B. A. River Ecology, California Press, 1975.

APPENDIX A. (continued)

Date of Sampl e cl3 C14 Cl5 C16 N 1 BL 1 S 1 M3 W3 B2 T 1

Mar. 9-74 0.21 0.50 0.35 A 0.09 A 0.14 A 0.31 1.31 0.15

May 7-74 6.99 6.44 5.33 0.28 0.34 1.92 0.27 1.10 A t

May 21-74 3.60 6.71 1.59 6.91 A 2.63 A A ;k

June 5-74 10.68 15.47 22.41 31.00 1.71 J( 1.44 12.08 10.07 A A

June18-74 4.36 12.46 13.95 11.99 3.67 A 1.60 14.75 10.04 9.66 9.89 July 10-74 7.35 12.32 0.23 13.59 7.48 10.97 7.86 12.42 21.69 24.91 18.90 I-' .P O, July11-74 11.89 5.32 6.48 6.52 2.65 8.14 4.39 7.94 18.23 20.68 14.67 July 14-74 19.62 21.96 19.89 6.87 12.26 1.65 4.94 14.49 15.04 22.10

/ Aug. 30-74 0.89 1.15 2.03 1.37 0.22 A 0.37 A 0.16 0.19 Sept.4-74 6.89 7.02 5.02 7.40 2.20 0.76 5.83 1.66 3.99 3.98 4.31 sept27-74 13.82 6.61 8.61 10.89 6.25 3.79 2.12 5.17 0.40 9.69 8.44

oct. 1-74 6.41 6.28 5.54 3.50 A 1.71 2.11 3.83 1.15 1.75

~ov.19-74 11.64 10.20 4.99 6.66 0.28 0.41 7.15 3.27 .L 7.12 7.41

Jan.21-75 0.35 0.94 0.02 A 0.06 0.14 0.12 0.20 0.07 Feb. 4-75 0.24 0.18 0.39 0.16 0.11 0.20 0.17 0.19 0.34 0.15

Mar. 11-75 0.96 1.21 1.31 1 .96 0.16 0.16 0.17 0.37 0.28 0.43 0.70 * Samples not taken

1-16 = Chowan River Sites; BL = Blackwater River; 3 = Bennetts Creek; M = Meherrin River; T = Trotman Creek; ?.J = ';?iccacozxiver; N = ~~~L~vhayKT tt- .-.. D-.--~~l~er; S = Somerton Creek APPENDIX B (continued)

1-16 = Chowan River Sites; BL = Blackwater River; B = Bennetts Creek; M = Meherrin River; T = Trotman Creek; W = Wiccacon River; N = Nottoway River; S = S~nertonCreek

Biomass Percent Species Class Date 0 Total

18.2 Synedra ulna BAC ILLA 1223000 BACILLA 1174080 17.5 Mezosira varians 16.6 Peridiniwn sp. DINOPHY 1113840

73.0 Synedra ulna BACILLA 1524710 MeZosira italics BACILLA 169941 8.1 v. t ennui s sima 9.5 MeZosira granulata BACILLA 199025 v. angustissima

Crypotomonas erosa CRYPTOP 1369830 Peridinium sp . DINOPHY 1113840 Cryptomonas ovata CRYPTOP 862215

Peridiniwn sp . DINOPHY 1110200 Synedra ulna BACILLA 1012600 MeZosira granulata BACILLA 626750 V. angustissima

Peridiniwn sp. DINOPHY 12248600 Carteria sp. CHLOROP 459000 Melosira italica BACILLA 271395 V. t ennuis sima

Peridiniwn sp. DINOPHY MeZosira varians BACILLA Cryptomonas erosa CRYPTOP

EUGLENO .Trache Zemonas s ectabi Zis ~racheZemonas sf. E~~~~~~ Cryptomonas erosa CRYPTOP

10/10/75 Strobomonas sp. EUGLENO Cryptomonas erosa CRYPTOP Cryptomonas ovata CRYPTOP APPENDIX C. (continued)

Date Species Class Biomass Percent - (u3> Total

10/25/75 Osci Z Zatoria sp . CYANOPH 68580 C~yptomonasovata CRYPTOP 65800 C~yptomonaserosa CRYPTOP 39200

11/8/75 C~yptomonas ovata CRYPTOP 768450 Cqjptomonas erosa CRYPTOP 589400 Me Zosira varians BACILLA 3 008 00

11/22/75 Cqjpiornonas ovata CRYPTOP 32900 Fm.wtuZa sp. BAC ILLA 25000 Cryptomonas erosa CRYPTOP 23100

12/6/75 Neidiwn sp. BACILLA 43200 Cryptomonas obovata CRYPTOP 2 7 000 MeZosira itaZica BACILLA 11285 v. tennuissima

12/17/75 Neidiwn sp. BACILLA 11 04 00 Synwa uveZ Za CHRY SOP 43710 MeZosira varians BACILLA 16000

1/3/76 ChZamydomonas sp . CHLOROP 17325 Synedra ulna BACILLA 16600 Cryptomonas erosa CRYPTOP 9800

1/17/76 Cryptomonas erosa CRYPTOP 72100 Peniwn ZibeZZuZZa CHLOROP 47000 CZosteriwn sp . CHLOROP 47000

1/31/76 SurireZZa sp. BACILLA 16000 Cryptomonas erosa CRYPTOP 10500 Synedra ulna BACILLA 8300

2/14/76 Microcystis CYANOPH 12618 MeZosira itaZica BACILLA 7770 V. tennuissima Cryptomonas ero sa CRYPTOP 63 00

2/28/76 Pmidiniwn DINOPHY 91000 Cryptomonas erosa CRYPTOP 67200 Cryptomonas ovata CRYPTOP 44650

157

- - APPENDIX C. (continued) Percent Date Species Class Biomass - - A2-L Total

30.7 sp DINOPHY 3/13/76 Peridinium . 9.1 Ochxomonas sociata CHRY SOP Cryptomonas erosa CRYPTOP 8.2

13.4 3/28/76 MeZosira varians BAC ILLA CRYPTOP 13.8 Cryptomonas ovata 10.0 Cryptomonas erosa CRYPTOP

22.0 4/11/76 Synura sp. CHRY SOPH CRYPTOP 16.0 Cryptomonas erosa 11.5 Cryptomonas ovata CRYPTOP APPENDIX C. (continued) Colerain Date Species Class Biomass Percent - -- (u3> Total

8/2/75 Peridiniwn SP. DINOPHY St;robomonas SP. EUGLENO Me Zosira itaZica BACILLA v* tennuisima

8/16/75 Peridiniwn sp. DINOPHY Microcystis sp . CYANOPH MeZosira itazica BAC ILLA v . tennuissima

8130176 Peridiniwn sp. DINOPHY Phacus Zongicauda EUGLENO Phormidiwn sp . CYANOPH

9/13/75 Phormidim SP. CYANOPH Me Zosira itaZica BAC ILLA v. tennuissima CZosteriwn sp. CHLOROP

9/27/75 Phormidiwn sp. CYANOPH TracheZemonas robusta EUGLENO MeZosira itazica BAC ILLA v. tennuissima

10/10/75 Cryptomonas ovata CRYPTOP Merismopedia convoZuta CYANOPH MeZosira itazica BACILLA v. tennuissima

10/25/75 MeZosira italica BACILLA v. tennuissima CZosteriwn sp . CHLOROP Cryptomonas sp. CRYPTOP

11/8/75 MeZosira itazica BACILLA V. tennuissima Peridiniwn sp , DINOPHY FrustuZia sp . BACILLA APPENDIX C. (continued)

Date Species Class Biomass Percent 0 Total 1

934250 28.7 11/22/75 MeZosira itazica BACILLA v . tennuissima CZosterium sp. CHLOROP 470000 14.4 Cryptomonas dbovata CRYPTOPH 423000 13.0

415325 34.4 12/6/75 MeZosipa itazica BACILLA v . tennuissima Cryptomonas ovata CRYPTOP 220900 11.2 MeZosira granuZata BACILLA 117000 6.0 v. angustissima

855400 43.3 12/17/75 Peridinium sp DINOPHY MeZosira itaZica BACILLA 242165 12.3 v . tennuissima Cryptomonas ovata CRYPTOP 220900 11.2

28.2 1/3/76 MeZosira itazica BACILLA 190365 v. tennuissima 22.0 spw BACILLA 148800 Neidium 7.1 Cocconeis SP. BACILLA 48000

39.5 1/17/76 Eunotia sp. BACILLA 141000 MeZosira itazica BAC ILLA 68450 19.2 v. tennuissima 12.0 Synura uve Z Za CHRY SOP 43710

BACILLA 91200 25.0 1/31/76 Pinnu Zaria 11.4 MeZosira itaZica BACILLA 41625 v. tennuissima 10.7 Cryptomonas erosa CRYPTOP 39200

207570 21.4 2/14/76 MeZosira itazica BACILLA v. tennuissima 11.9 FrustuZia SP BACILLA 115000 BACILLA 110400 11.4 Neidium SP* 11.1 MeZosira itaZica BACILLA 108100

CRYPTOP 851200 24.9 2/28/76 Cryptomonas erosa 13.2 spa BACILLA 451200 Neidiwn 12.8 Cryptomonas ovata CRYPTOP 439450 Cryptomonas erosa CRYPTOP 327600 9.6 v . ref Zexa APPENDIX C. (continued)

Date Species Class Biomass Percent - 0 Total

Me Zosira itaZica BACILLA v.. tennuissima Strobomonas sp. EUGLENO Asterione Z Za formosa BAC ILLA

Ueidiwn sp. BAC ILLA Synura sp. CHRY SOP Cryptomonas erosa CRYPTOP

Me Zosira ita Zica BACILLA v. tennuissima Strobomonas sp. EUGLENO MeZosira distans BACILLA v . aZpigena APPENDIX C. (continued) Edenton

Date Species Class Biomass Percent - Total

7/7/75 Peridiniwn sp. DINOPHY Microcystis sp. CYANOPH MeZosira itaZica BACILLA v. tennuissima

7/19/75 Microcystis sp. CYANOPH Raphidiopsis curvata CYANOPH Phormidium spa CYANOPH

8/2/75 Peridinium sp . DINOPHY Me Zosira italica BACILLA v. tennuissima Microcystis sp. CYANOPH

8/16/75 Peridiniwn sp . DINOPHY Microcystis sp. CYANOPH Cyanomonas amemkana CRYPTOP

8/30/75 Peridiniwn sp DINOPHY Cryptomonas ovata CRYPTOP Euglena sp. EUGLENO

9/13/75 Peridiniwn sp . DINOPHY Rbpa Zodia sp. BACILLA Me Zosira itaZica BACILLA v. tennuissima

9/27/75 Phormidiwn sp. CYANOPH Rhopa Zodia sp . BAC ILLA MeZosira itazica BACILLA v . tennuissima

10/10/75 Peridiniwn sp . DINOPHY Synedra sp. BACILLA Cryp tomonas ova ta CRYPTOP

10/25/75 Cryptomonas ovata CRYPTOP Cryptomonas erosa CRYPTOP MeZosira italica BACILLA v. tennuissima APPENDIX C. (continued)

Date Species Class Biomass Percent L2.L Total

11/8/95 Me Zosira itaZica BACILLA v. tennuissima ~eridiniwnsp . DINOPHY Amphora sp . BACILLA

11/22/75 MsZosira itaZica BACILLA v. tennuissima Staurastrum sp. CHLOROP C.ryptomonas erosa CRYPTOP

12/6/75 MeZosira italica BACILLA v. tennuissima Coe Zosphaeriwn sp . CYANOPH Strobomonas SP. EUGLENO

12/ 17/ 75 Me Zosira itaZica BACILLA v- tennuissima Cryptomonas ovata CRYPTOP Me Zosira granuZata BACILLA v. angustissima

1/3/76 idezosira itaZica BACILLA v. tennuissima Cryptomonas ovata CRYPTOP Cryptomonas erosa CRYPTOP

1/17/76 MeZosira itazica BACILLA v. tennuissima Amphora sp. BACILLA Fragi laria sP . BACILLA

1/3 1/ 76 Me Zosira varians BACILLA Me Zosira itaZica BACILLA v. tennuissima Cryptomonas ovata CRYPTOP

2/14/76 Amphora sp. BACILLA Me Zosira itaZica BACILLA v- tennuissima Cocconeis SP BACILLA APPENDIX C. (continued)

Date Species Class Riomass Percent (~3) Total - P

2/28/76 MeZosira itaZica BACILLA v. tennuissima Cryptomonas ovata CRYPTOP Cryptomonas erosa CRYPTOP

3/13/76 Me Zosira itaZica BACILLA v. tennuissima Synedra ulna BACILLA Mg Zosira distans BACILLA v . a Zpigena

3/28/76 Pmidinim sp. DINOPHY Me Zosira varians BACILLA C~yptomonasovata CRYPTOP

4/11/76 Me losira italica BACILLA v. tennuissima Ochromonas sp . CHRY SOP Trache Zemonas sp . EUGLENO APPENDIX D. Environmental Data

1975 - 1976

Abbreviations and Units

W = Winton

H = Harrellsville

C = Colerain

E = Edenton

PP = Particulate Phosphorus (pM)

DOP = Dissolved Organic Phosphorus (pM)

DIP = Dissolved Inorganic Phosphorus (pM)

TEMP = River Water Temperature (OC)

ALK = Alkalinity (mg ~/1) -1 L.A. = Light Attenuation Coefficient (m )

I = Daily Insolation (Langleys/~ay) APPENDIX D (continued)

Date Station DOP DIP TEMP ALK L.A. ---- - 61575 W 0.148 1.238 25.7 4.47 3.22 H 0.431 0.605 26.8 5.10 -- C 0.259 0.110 - - 5.74 - - E 0.574 0.107 25.6 4.15 2.81

62575 W -- 2.650 27.5 7.22 1.36 H 0.403 0.617 27.5 8.38 -- C 0.503 0.053 26.0 7.44 - - E 0.698 0.345 26.5 7.15 --

70875 C -- 0.078 25.5 -- --

71475 W 2.199 5.063 25.5 4.57 - - H -- 3.180 25.5 5.95 - - C 0.049 0.281 25.5 5.89 6.44 E 1.739 0.471 25.5 4.49 - -

72875 W 0.337 0.998 27.5 10.16 - - H 0.459 0.900 26.0 7.21 4.89 C 0.446 0.660 25.5 5.32 5.05 E 0.539 0.110 24.5 9.23 - -

81075 W 0.626 0.251 28.0 4.81 2.66 H 1.044 0.066 28.4 4.50 - - C 0.402 0.085 28.3 2.29 2.30 E 0.852 0.094 28.1 1.99 - -

83175 W 0.138 0.850 29.0 7.26 3.00 H 0.487 0.245 29.0 7.71 3.00 C 0.467 0.071 28.0 4.03 3.22 E 0.268 0.133 27.5 5.03 3.22

91475 W 0.270 3.146 24.0 3.47 2.81 H 0.388 0.939 24.5 3.61 3.40 C 0.552 0.153 24.0 5.22 - - E 0.542 0.055 24 .O 3.91 --

92875 W 0.538 1.702 21.8 2.43 3.69 H 0,706 1.474 22.8 2.97 - - C 0.400 0.160 23.0 4.05 - - E 0.461 0.080 23.5 3.51 3.44

101275 W 0.202 1.238 - - 4.69 4.60 H 0.346 0.932 - - 3.35 - - C 0.358 0.514 20 2.68 - - E 0.526 0.359 20 3.02 4 .I3

102575 W 1.261 1.389 18.0 4.51 2.90 H 0.947 0.912 19.2 4.17 3.22 C 0.684 0.315 20.2 2.43 3.79 E 0.656 0.338 19.5 2.59 --

166 APPENDIX D (continued)

7 Date Station PP DOP DIP -TEMP 110275 0.544 17.0 0.649 17.0 0.363 17.0 0.409 17.0 0.455 17.0 0.496 17.0 0.544 17.0 0.503 17.0

111675 3.290 13.0 2.630 14.0 0.432 14.0 0.281 --

112875 0.953 11.5

122175 APPENDIX D (continued)

Date Station DOP DIP -TEMP ALK 41076 0.918 0.914 14.0 5.53 0.419 1.698 14.0 5.37 0.519 0.631 14.0 4.74 0.539 0.297 14.0 4.74

42576 0.555 0.242 20.0 4.81 0.553 0.516 20.0 4.81 0.528 0.219 20.0 4.81 0.512 0.235 20.0 4.66 0.497 0.487 20.0 4.51 0.542 0.215 20.0 ------20.0 - - 0.548 0.155 20.0 -- 0.476 0.429 20.0 - - 0.418 0.580 20.0 -- 0.457 0.416 20.0 - - 0.429 0.269 20.0 - - 0.456 0.269 20.0 4.81

50976 0.462 0.165 18 5.10 0.506 0.311 18 5.10 0.493 0.466 18 5.10 0.527 0.201 18 4.81 0.565 0.247 18 - - 0.534 0.233 18 -- 0.460 0.233 18 -- 0.575 0.119 18 - - 0.568 0.130 18 5.10

51576 0.203 4.030 21.5 6.23 0.607 0.178 21.5 5.64 0.429 0.213 21.5 5.89 0.471 0.050 21.5 5.92

52376 0.774 0.062 22.0 4.96

52976 0.459 2.728 21.5 7.58 0.659 0.359 21.5 6.95 0.694 0.100 21.5 5.71 0.470 0.366 21.5 5.71

60676 0.696 0.071 20 4.96 0.776 0 .lo7 20 4.96 0.760 0.159 20 4.96 0.783 0.254 20 4.21 0.806 0.254 20 -- 0.853 0.057 20 - - 0.773 0.082 20 - - 0.778 0.073 20 - - 0.892 0.224 20 4.21

168

I APPENDIX D (continued)

Date / Statior PP DO P DIP TEMP I pH ALK L.A. I APPENDIX E.1. Algal Occurrence

SITEJJAAONDJFMA

Achnanthes def lexa

A. 1. var. rostrata

A. sp. C ++++ ++++++ 'T + +++++++++

Actinastrum hantzchii var. fluviatile C + + + T + +

Agmenellum quadriduplicatum

Amphora ovalis

A. sp.

Anabaena aequalis

A. circinalis

A. flos-aquae

A. spirilliformis

A. variabilis

Anacystis cyanae

A. incerta

A. marina

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ** = dominant (i.e. highest percentage number of species) 1 170 APPENDIX E .I. (continued)

SPECIES SITEJJAAONDJFMA

Anacystis thermalis

Ankistrodesmus convolutus

A. f. var. spirilliformis

A. fusiformis

A. nanoselene

A. setigerus

Aphanizomenon flos-aquae

Arthrodesmus subulatus

Asterionella formosa

Bicosoeca multiannulata

Capartogramrna crucicula

Carteria globosa

C, sp.

Centric diatoms

Ceracium hirdjnella

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ;? * = dominant (i.e. highest percentage number of species) APPENDIX E.1. (continued)

SPECIES SITEJJAAONDJFMA

Characium falcatum

C. limneticum

Chl.amydomonas botrys

C. fenestrata

C. globosa

C. gloegama

C. gloeopara

C. sp.

Chlorella sp.

Chlorogonium spirale

Chroomonas coerulea

C. reflexa

Chrysamoeba radians

Chrysochromulina sp.

Closteriopsis longissima

Closterium acerosum

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ** = dominailt (i.e. highest percentage number of species) APPENDIX E.1. (continued)

SPb.C LES SITEJJAAONDJFMA

Cocc ochloris aeruginosa

Coccornonas orbicularis

Cocconeis sp.

Coelastrum angustare var. armatum

C. microporurn

Cosmarium abbreviatum

C. regnelli

C. subrenif orme

C. sp.

Cosmocladium saxonicum

Crucigenia apiculata

C. fenestrata

C. quadrata

C. rectangularis

C. tetrapedia

Cryptomonas erosa

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ** = dominant (i.e. highest percentage number of species) APPENDIX E. 1. (continued)

SPECIES SITE

C. e. var. reflexa C T

C. obovata C T

C. ovata C T

C. phaseolus C T

Cyclotella bodanica C T

C. comta C T

C. glomerata C T

C . meneghiniana C T

C. stelligera C T

C. sp. C T

Cymbella tumida C T

C. ventricosa C T

C. sp. C T

Dactylothece confluens C T

Dendromonas cryptostylis C T

D. sp. C T

+ = denotes presence ?; = co-dominant (i.e. at least 10% of the total number of species) A* = dominant (i.e. highest percentage number of species)

174 APPENDIX E.1. (continued)

SPECIES SITE J J AON DJF

Dinobryon bararicum +

D. cylindricum

D. divergens

D. sertularia

Diploneis sp.

Epichrysis sp.

Epithemia sp.

Euastrum denticulatum

Euastrum sp,

Endorina elegans

Euglena gracilis

E. proxima

E. sp.

Eunotia sp.

Fragilaria sp,

Francea tuberculata

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) A* = dominant (i.e. highest percentage number of species) APPENDIX E. 1. (continued)

SPECIES SITEJJAAONDJFMA

F. ovalis

Glenodinium penardiforme

Gloeoactinium limneticum

Golenkinia radiata

Gomphonema sp.

Gomphosphaeria wichurae

Gymnodinium neglectum

G. palustre

Gyrosigma acuminatum

G. sp.

Hantzschia amphioxys

Hemidinium nasutum

Rirchneriella lunaris

K. 1. var. dianae

K. subsolitaria

Mallomonas acaroides

+ = denotes presence * = co=dominant (i.e. at least 10% of the total number of species) ** = dominant (i.e. highest percentage number of species) APPENDIX E, 1. (continued)

SPECIES SITEJJAAONDJFMA

M. allantoides

M. allorgei

M. alpiwa

M. caudata

M. elongata

M. lychensis

M. majorensis

M. tonsurata

M. sp,

Melosira distans

M. granulata

M. g. var. angustissima

M. italica

M. varians

Meridion circulare

Micractinium pusillurn

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ** = dominant (i.e. highest percentage number of species) APPENDIX E.1. (continued)

SPECIES

Monochrysis aphanaster

Monosiga varians

Navicula arvensis

N. cf. lyra

N. cryptocephala

N. hambergii

N. sovereignae

N. sp.

Neidium sp.

Nitzschia acicularis

N. apiculata

N. dissipata

N. palea

N. paleacea

N. parvula

N. sublinearis

+ = denotes presence number of species) * = co-dominant (i.e. at least 10% of the total ** = dominant (i.e. highest percentage number of species) 178 APPENDIX E. 1. (continued)

SPECIES SITEJJAAONDJFMA

N. thermalis

N. sp.

Oocystis borgei

0. parva

0. sp.

Ophiocytium capitaturn

0. cochleare

Oscillatoria geminata

0. meslini

0. nigra

0. subtilissima

Pandorina morum

Pediastrum duplex

P. tetras

P. t. var. tetraodon

Peridinium bipes var. travectum C T

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ** = dominant (i.e. highest percentage number of species) APPENDIX E .l. (continued)

SPECIES SITEJJAAONDJFMA

P. cf. volzii

P. cinctum

P. inconspicuum

P. sp.

Phacotus angustus

Phacus suececus

Phormidium, angustissimum

P. sp.

Pinnularia sp.

~seudote'traedronneglectum

Pteromonas angulosa

P. sinuosa

Quadrigula chodati

Q. closteriodes

Raphidiopsis curvata

+ = denotes presence * = co-dominant (i. e. at least 10% of the total number of species) ** = dominant (i. e. highest percentage number of species)

180 . APPENDIX E. 1. (continued)

SPECIES SITEJJAAONDJFMA

Rhizosolenia eriensis

R. longiseta

Rhodomonas minuta

Scenedesmus abundans

S. acuminatus

S. alternans

S. arcuatus var. platydisca

S. armatus var. boglariensis

S. bijuga

S. b. var. alternans

S. denticulatus

S. dispar

S. ecornis

S. opoliensis

S. quadricauda

S. spinosus

+ = denotes presence * = co-dominant (i.e. at least 10 of the total number of species) ** = dominant (i.~.highest percentage number of species) APPENDIX E. 1. (continued)

SPECIES SITEJ J AA 0 N D J F M A

Scenedesmus sp.

Schroederia setigera

Selenastrum bibrianum

S. b. var. gracile

S. gracile

Sennia parvula

Skeletonema potomos

Sorastrum americanum

S. , spinulosum

Sphaerocystis schroeteri

Spirulina laxa

Staurastrum asinosum var. annulatum C T

S. monticulosum

S. paradoxurn

S. quadricuspidatum

S. sp.

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ** = dominant (i.e. highest percentage number of species) APPENDIX E. 1. (continued)

SPECIES SITEJJAAONDJFMA

Stauroneis phoenicenteron

Stephanodiscus nigarae

Surirella sp.

Synedra acus

S. rumpens

S. ulna s. sp.

Synura petersonii

S. uvella

S. sp.

Tetraedron arthrodesmifome

T. caudatum var. longispinum

T. minimum

T. muticum

T. regulare

T. r. var. incus

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ** = dominant (i.e. highest percentage number of species) APPENDIX E. 1. (continued)

SPECIES SITEJJAAONDJFMA

T. trigonum

T. t. var. setigerum

Tetrastrum heteracanthum

T, staurogenieforme

Trachelomonos gibbosa

T. hispida v. coronata

T. volvocina

SJnid chrysophytes

Unid coccoids

Unid dinoflagellate

Unid flagellate

Unid green filament (3 mdia.)

Unid pennate

+ = denotes presence * = co-dominant (i.e. at least 10% of the total number of species) ** = dominant (i.e. highest percentage number of species)

184 APPENDIX E.2. Algal Cell Density, Biomass, Cell Carbon, and Species Present

SITE PERIOD S EASON DENSITY BIOMASS CELL CARBON Nr). #ru/ 1 mq/1 u q-atm/l SPECIES

C July 8-10, 1976 Summer 22970.4 21 .7l92 57 T July 8-10, 1976 Summer 91 53 -1 14-3477 49 C July 20-22, 1976 Summer 30090 -4 15.3558 38 T July 20-22, 1976 Summer 10225.0 7 -3870 4 5 C August 3-5, 1976 Summer 25566.2 13.7313 42 T August 3-5, 1976 Summer 18967 -7 32 .YO85 39 C August 27-29, 1976 Summer 59223 -0 22.3045 44 T August 27-29, 1976 Summer 10354 -6 17.5502 54 C October 23-25, 1976 Fall 2 5261 -4 6.6 523 4 7 T October 23-25, 1976 Fall 67 53.4 9.3140 50 C November 12-14, 1976 Fall 16085.4 8.7727 51 T November 12-14, 1976 Fall 1565.4 2.3297 41 C December 25-27, 1976 Winter 2168 -2 1.4469 4 3 T December 25-27, 1976 Winter 1371-8 2 .O 582 4 3 C January 14-16, 1977 Winter 2920.7 4 -1486 58 T January 14-16, 1977 Winter 1250.5 0 -8057 30 C February 11-13, 1977 Winter 2858 -0 3 -4626 72 T February 11-13, 1977 Winter 1282.2 1.5098 53 C March 11-13, 1977 Spring 5867.9 14.3878 58 T March 11-13, 1977 Spring 1366 -2 2 -4386 44 C April 15-17, 1977 Spring 10471-3 7 -3933 53 T April 15-17, 1977 Spring 3848.4 11 -4082 50 APPENDIX E.3. Algal Cell Density, Biomass, Cell Carbon, and Species Present by Group

Density Biomass Cell Carbon Site Period Group #m/l 1 % mg/l _ I % pg-atmil 1 No. Species I I I I July 8-10, 1976 Blue-greens Chrysophytes Diatoms Euglenophytes Flagellates Greens Dinoflagellates

Blue-greens Chrysophytes Diatoms Flagellates Greens Dinoflagellates

July 20-22, 1976 Blue-greens Diatoms Flagellates Greens

Blue-greens Chrysophytes Diatoms Flagellates Greens Dinoflagellates

August 3-5, 1976 Blue-greens Chrysophytes Diatoms Flagellates Greens Dinoflagellates

Blue-greens Diatoms Euglenophytes Flagellates Greens Dinoflagellates

August 27-29, 1976 Blue-greens Chrysophytes Diatoms Flagellates Greens Dinoflagellates r-e~iaouhmmm r.+marn~ urimm~d~mhmrnri ~imuri NU NU^ N N 3 ri ri N ri N 4 N

- --

m-o-ha r.umr.um ~~GNUma3-u urinmmm me-mumh mmrimrn -ma-- m~3r-a~oarnuma NGUNG ~u-ma hmmm~hoirnrnri- o~riauoe-40- "97-9" 3?"7"3 00~0"???:a, oaumoo OOOGGG ddddd oosoo

m 8 a ~rimmmum???q mrimham 4 ...... ??4"79 7"9" tY""P?4:-??-? \ mummmmw ammm <;&LAG ummmum mmouriri ommum mccim O~m.mri~rnoa-h ur.4mm~m mm~riaumm wuod xm~~m g iUm hU Nrirnm mmmhh m ~m4rim* amn m 3 N u di NQ m m3 NGN 3 ri 4 APPENDIX E,3 (continued)

-- Bioma Cell Carbon Site Period Group - mg/l - ug-atm/l No. Species

December 25-27, 1976 Dinoflagellates

January 14-16, 1977 Blue-greens Chrysophytes Diatoms Euglenophytes Flagellates Greens Dinoflagellates

Blue-greens Chrysophytes Diatoms Euglenophytes Flagellates Greens Dinoflagellates

February 11-13, 1977 Blue-greens Chrysophytes Diatoms Euglenophytes Flagellates Greens Dinoflagellates

Blue-greens Chrysophytes Diatoms Euglenophytes Flagellates Greens Dinoflagellates

March 11-13, 1977 Blue-greens Chrysophytes Diatoms Flagellates Greens Dinoflagellates

Blue-greens Chrysophy tes Diatoms Euglenophytes Flagellates Greens Dinoflagellates APPENDIX E.3 (continued)

Den Bioma Cell Carbon Site Period Group #ml 1 mgll ug-atmll No. Species

C April 15-17, 1977 Blue-greens C Chrysophytes C Diatoms C Euglenophytes C Flagellates C Greens C Dinoflagellates

T Blue-greens T Chrysophytes T Diatoms T Flagellates T Greens T Dinoflagellates APPENDIX E.4. Algal Species,,Cell Density, Biomass, and Cell Carbon by Period, Site, and Season

PERIOD = July 8-10, 1976 SITE = C SEASON = SUMMER

SPECIES DENSITY BIOMASS CELL CARBON #m/l % mg/l % yg-atm/l

ACHNANTHES LANCELOLATA VAR. ROSTRATA ACHNANTHES SP . AGMENELLUM QUADRIDUPLICATUM ANABAEXA AEQUALIS ANABAEXA CIRCINALIS ANACYSTIS CYANEA ANACYSTIS INCERTA ANKISTRODESMUS FALCATUS ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS ANKISTRODESMUS NANOSELENE APHANIZOMENON FLOS -AQUAE CHARACIUM FALCATUM CHLAMYDOMONAS BOTRYS CHLORELLA SP. COCCOCHLORIS AERUGINOSA

CRYPTOMONAS EROSA CRYPTOMONAS OVATA CYCLOTELLA GLOMERATA CYCLOTELLA SP. CYCLOTELLA STELLIGERA DACTYLOTHECE CONFLUENS EUGLENA SP . FRAGILARIA SP. FRANCEA TUSERCULATA GOLENKINIA RADIA'IA MALLOMONAS ACAROlDES MELOSIRA DISTANS MELOSIRA GRANOLATA MELOSIRA GRANULATA ANGUSTISSIMA MELOSIRA ITALICA NAVICULA SP. NITZSCHIA ACICULARIS NITZSCHIA SP. OOCYSTIS BORGEI OSCILLATORIA SUBTILISSIMA PEDIASTRUM DUPLEX PEDIASTRUM TETRAS VAR. TETRAOWN PERIDINIUM SP . PHORMIDIMUM ANGUSTISSIMUM RAPHIDIOPSIS CURVATA RHIZOSOLENIA ERIENSIS RHODOMONAS MINUTA SCENEDESMUS ACUMINATUS SCENEDESMUS ARCUATUS V. PLATYDISCA SCENEDESMUS QUADRICAUDA SCHROEDERIA SETIGERA

TETRAEDRON CAUDATUM VAR. LONGISPINUM TETRAEDRON REGULARE TETRAEDRON TRIGONUM WID COCCOID UNID PENNATE

PERIOD = July 8-10, 1976 SITE = T SEASON = SUMMER ACHNANTHES SP. D 23.56 ACTINASTRUM HANIZSCHII: VAR. FLWIATTLE G 11.78 AGMENELLUM QUADRIDUPLICATUM B 282.72 ANABAENA SPIRILLIFORMIS 0 35.34 ANACYSTIS CYANEA B 82.46 ANACYSTIS INCERTA B 270.94 ANKISTRODESMUS FALCATUS G 58.90 ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS G 47.12 ANKISTRODESMUS NANOSELENE G 341.62 CHARACIUM LIMNETICUM G 23.56 CHLAMYDOMONAS BOTRYS G 47.12 CHLORELLA SP. G 35.34 CHROOMONAS COERULEA F 141.36 CLOSTERIOPSIS LQNGISSIMA G 23.56 COCCOCHLORIS AERUGINOSA B 35.34 COCCOMONAS ORSICULARIS G 11.78 COELASTRUM MICROPORUM G 23.56 CROCIGENIA QUADRATA G 11.78 CRUCIGENIA TETRAPEDIA G 11.78 CRYPTOMONAS EROSA F 318.06

* B=Blue greens; C=Chrysophytes; D=Diatoms: ~=~ugleno~+tes:F=Flagellates: G=Greens; P=Dinoflagellates APPENDIX E. 4. (cont~nued)

PERIOD = July 8-10, 1976 SITE = T SEASON = SUMKER

SPECIES GROUP * DENSITY CELL CARBON Pm/l % pg-atm/l

CYCLOTELLA GLOMXRATA 1.21 CYCLOTELLA MENEGHINIANA 0.48 FRANCEIA OVALIS 0.03 KIRCHNERIELLA LIJNARIS 0.02 MALLOMONAS ALPINA 2.21 MELOSIRA DISTANb 0.73 MELOSIRA GRANUWiTA ANGUSTISSIMA 31.56 NITZSCHIA ACICUIARIS 0.12 NITZSCHIA SP. 0.07 OOCYSTIS BORGEI 0.10 OPHIOCYTIUM CAPlTATUM 0.02 PANDORINA MORUM 0.31 PEDIASTRUM TETRAS 0.17 PERIDINIUM CINCllUM 76.41 PHORMIDIUM ANGUSTISSIMUM 0.13 PTEROMONAS ANGULOSA 0.25 RHIZOSOLENIA ERIENSIS 0.19 RHODOMONAS MINUTA 0.83 SCENEDESMUS BIJUGA 0.01 SCENEDESMUS QUADRICAUDA 0.45 SCHROEDERIA SETIGERA 0.08 SKELETONEMA POTOMOS 0.09 SYNURA WELLA C 11.78 1.32 TETRAEDRON TRIGONUM G 23.56 1.00 TETRAEDRON TRIGONUM V. SETIGERUM G 11.78 0.03 TETRASTRUM HETERACANTHUM G 11.78 0.08 UNID CHRYSOPHYTES C 11.78 0.11 UXID COCCOID 0.48 UNID FLAGELLATE 0.01

PERIOD = July 20-22, 1976 SITE = C SEASON = SUWR ACHNANTHES SP. D 164.9 0.34 ACTINASTRUM HANTZSCHII VAR. FLWIATILE G 23.6 0.15 AGMENELLUM GUADRIDUPLICATUM B 141.4 0.07 AMPHORA OVALIS 0.52 ANABAENA AEGUALIS 35.01 ANABAENA SPIRILLIFORMIS 9.54 ANACYSTIS , CYANEA 1.43 ANACYSTIS CYANEAE 2.86 ANACYSTIS INCERTA 2.58 ANKISTRODESMUS FALCATUS 0.11 ANKISTRODESMUS FALCATUS V. SPIRRILLIFORMIS G 70.7 0.04 ANKISTRODESMUS NANOSELENE G 188.5 0.07 APHANIZOMENON FLOS -AQUAE 44.80 CHLAMYDOMONAS BOTRYS 0.05 CLOSTERIOPSIS LONGISSIMA 0.28 COELASTRUM MICROPORUM 0.82 CRYPTOMONAS EROSA 32.47 CYCLOTELLA SP. 15.68 CYMBELLA SP. 0.36 GOLENKINIA RADIATA 0.69 KIRCHNERIELLA LUNARIS 0.06 MELOSIRA DISTANS 1.dl MELOSIRA GRANULATA 0.24 MELOSIRA GRANULATA ANGUSTISSIMA 16.11 NAVICULA SP. 0.52 NITZSCHIA ACICULARIS 0.05 NITZSCHIA SP. 0.45 PANDORINA MORUM 0.63 PHORMIDIUM ANGUSTISSIMLIM 9.26 QUADRIGULA CLOSTERIODES 0.04 RAPHIDIOPSIS CURVATA 3.48 RHODOMONAS MINUTA 0.18 SCENEDESMUS DENTICULATUS 0.19 SCENEDESMUS QUADRICAUDA 0.48 SCHROEDERIA SETIGERA 0.08 SKELETONEMA POTOMOS 0.30 STAURASTRUM MONTICULOSUM 0.15 TETRAEDRON TRIGONUM 1.00

PERIOD = July 20-22, 1976 SITE = T SEASON = SUMMER

AGMENELLUM QUADRIDUPLICATUM 0.63 ANACYSTIS INCERTA 1.36 ANKISTRODESMUS FALCATUS 0. 52 0.12 0.08 CHWDOMONAS BOTRYS 0.05 CHROOMONAS COERULEA 0.16 CHRYSAMOEBA RADIANS 1.73 COELASTRUM MICROPORUb! 1.23 CRYPTOMONAS EROSA 28.41 CRYPTOMONAS OVATA 5.09 CYCLOTELLA SP . 8.34 FRAGILARIA SP. 0.67

* B=Blue greens; C=Chrysophytes; D=Diatoms; E=Euglenophytes; F=Flagellates;.G=Greens: P=Dinoflagellates 191 APPENDIX E. 4. (continued)

PERIOD = July 20-22, 1976 SITE = T SEASON = SUMMER

SPECIES -GROUP* DENSITY BIOMASS CELL CARBON #m/1 % mg/l pg-atm/i

GOLENKINIA RRDIATA 0.11 KIRCHNERIELLA LUNARIS 0.02 MALLOMONAS SP. 0.05 MELOSIRA DISTANS 2.75 MELOSIRA GRANULATA 0.24 MELOSIRA GRANULATA ANGUSTISSIMA 11.41 MICRACTINIUM PUSILLUM 0.09 NAVICULA SP. 0.05 NITZSCHIA ACICULARIS 0.05 NITZSCHIA SP. 0.13 OOCYSTIS BORGEI 0.20 OSCILLATORIA GEMINATA 1.29 OSCILLATORIA SUBTILISSIMA 0.30 PANDORINA MORUM 0.63 PEDIASTRUM DUPLEX 5.09 PEDIASTRUM TETRAS 0.17 PERIDINIUM SP. 7.47 PHORMIDIUM ANGUSTISSIMUM 0.09 RAPHIDIOPSIS CURVATA 0.06 RHODOMONAS MINUTA 0.99 SCENEDESMUS ACUMINATUS 0.08 SCENEDESMUS ECORNIS 0.03 SCENEDESMUS QUADRICAUDA 1.02 SCHROEDERIA SETIGERA 0.13 SKELETONEMA POTOMOS 0.15 SPHAEROCYSTIS SCHROETERI 0.11 TETRAEDRON MINIMUM 0.05 TETRAEDRON REGULARE V. INCUS 0.03 TETRASTRUM HETERACANTHUM 0.08 UNID CHRYSOPHYTES 0.11 UNID COCCOID 0.41 UNID DINOFLAGELLATE 1 .dl

. PERIOD = August 3-5, 1976 SITE = C SEASON = SUMMER ACHNANTHES DEFLEXA ACHNANTHES SP. AGMENELLUM QUADRIDUPLICATUM ANABAENA AEQUALIS ANACYSTIS INCERTA ANKISTRODESMUS FALCATUS ANKISTRODESMUS FALCATUS V. SPIRILLIFORMI ANKISTRODESMUS NANDSELENE APHANIZOMXNON FLOS -AQUAE CERACIUM HIRUDINIELLA CRYPTOMONAS EROSA CRYPTOMONAS OVATA CYCLOTELLA SP. CYMBELLA SP. FRANCEIA OVALIS GOMPHOSPHAERIA WICHURAE GYMNODINIUM NEGLECTUM KIRCHNERIELLA LUNARIS MALLOMONAS ALPINA MELOSIRA DISTANS MELOSIRA GRANULATA ANGUSTISSIMA MELOSIRA ITALICA NAVICULA SOVEREIGNAE NAVICULA SP. NITZSCHIA ACICULARIS NITZSCHIA SP . OOCYSTIS BORGEI PEDIASTRUM DUPLEX PERIDINIUM SP . PHORMIDIUM ANGUSTISSIMLIM PINNULARIA SP . RAPHIDIOPSIS CURVATA RHIZOSOLENIA ERIENSIS RHIZOSOLENIA LONGISETA RHODOMONAS MINUTA SCENEDESMUS ACUMINATUS SCENEDESMUS QUADRICAUDA SCHROEDERIA SETIGERA SKELETONEMA POTOMOS SPHAEROCYSTIS SCHROETERI STADRASTRUM PARADOXUM TETRAEDRON CAUDATUM VAR. LONGISPINUM

PERIOD = August 3-5, 1976 SITE = T SEASON = SUMMER

ACHNANTHES SP. D 11.8 ACTINASTRUN FAYTZSCHII VAR. FLWIArILE G 94.2 AG%NELLLX QUADRIDUPLICAT~JE: a 165.9 ANABAENA VARIABILIS ANACYSTIS INCERTA

* B=Blue greens; C=Chrysophytes; D=Diatoms; E=Euglenophytes; APPENDIX E.4. (continued)

PERIOD = August 3-5, 1976 SITE = T SCASCJ': = SUMliI.1' SPECIES -GROUP * DENSITY BIOMASS CELL CARBON h/l % mg/1 % 119-atn/l

ANKISTRODESMUS FALCATUS CHROOMONAS REFLEXA CRYPTOMONAS EROSA CRYPTOMONAS OVATA CYCLOTELLA GLOMERATA CYCLOTELLA SP. GOLENKINIA RADIATA MELOSIRA DISTANS MELOSIRA GRANULATA ANGUSTISSIMA MELOSIRA ITALICA NAVICULA SP. NITZSCHIA SP. NITZSCHIA THERMALIS OSCILLATORIA MESLINI OSCILLATORIA NIGRA OSCILLATORIA SUBTILISSIMA PANDORINA MORUM PEDIASTRUM TETRAS VAR. TETRAODON PERIDINIUM CINCTUM PERIJ:!IIC\I I?ICOYSPICUL'?l PSECDOTETRAEDROK NEGLECTUK RHODOMONAS MINUTA SCENEDESMUS ABUNDNYS SCENEDESMUS BIJUGA VAR. ALTERNANS SCENEDESMUS QUADRICAUDA SCHROEDERIA SETIGERA SKELETONEMA POTOMOS SPHAEROCYSTIS SCHROETERI SYNEDRA ACUS

TETRASTRUM STAUROGEXIEFORME TRACHELOMONAS HISPIDA V. CORONATA UNID FLAGELLATE

PERIOD = August 27-29, 1976 SITE

ACHNANTHES DEFLEXA D ACHCI'ANTHES SP. D AGMENELLUM QUADRIDUPLICATUM B AMPHORA OVALIS D ANABAENA CIRCINALIS B ANABAENA VARIABILIS B ANACYSTIS INCERTA B ANKISTRODESMUS FALCATUS G ANKISTRODESMlS FALCATUS V. SPIRILLIFORMIS G APHANIZOMENON FLOS -AQUAE B CAPARTOGRAMMA CRUCICULA D CHARACIUM LIMNETICUM G CKLAMM)OMONAS BOTRYS G CRYPTOMONAS EROSA F CYCLOTELLA GLOMERATA D CYCLOTELLA SP. D CYMBELLA SP. D EUASTRUM SP. G KIRCHNERIELLA LUNARIS G MALLOMONAS ALLANTOIDES C MELOSIRA DISTRNS D MELOSIRA GRANULATA ANGUSTISSTMA D MELOSIRA VARIANS D NAVICULA SP. D NEIDIUM SP. D NITZSCHIA ACICULARIS D NITZSCHIA PARWLA D NITZSCHIA SP. D OSCILLATORIA GEMINATA B PANDORINA MORUM G PEDIASTRUM DUPLEX G PEDIASTRUM TETRAS G PERIDINIUM CINCTUM P PERIDINIUM INCONSPICUUM P PHORMIDIUM ANGUSTISSIMUM B RAPHIDIOPSIS CURVATA B RHODOMONAS MINUTA F SCENEDESMUS ACUMINATUS G SCENEDESMUS DENTICULATUS G SCENEDESMUS QUADRICAUDA G SCHROEDERIA SETIGERA G SYNEDRA SP. D TETRAEDRON TRIGONUM G -UNID COCCOID G * B=Blue greens; C=Chrysophytes; D=Diatoms; E=Euglenophytes; F=Flagellates; G=Greens; P=Dinoflagellates

193 APPENDIX E.4. (continued)

PERIOD = August 27-29, 1976 SITE = T SEASON = SUMMER

SPECIES GROUP * DENSITY BIOMASS CELL CARBON #m/1 a - ug-atm/l ACHNANTHES SP. 0.04 AGMENELLUM QUADRIDUPLICATUM 0.49 ANABAENA VARIABILIS 4.76 ANACYSTIS CYANEA 1.43 ANACYSTIS INCERTA 1.12 ANKISTRODESMUS FALCATUS 0.25 ANKISTRODESMUS FALCATUS V. SPIRILLIFI 0.06 CHLAMYDOMONAS BOTRYS 0.05 CHROOMONAS COERULEA 0.07 CHROOMONAS REFLEXA 0. 50 COSMARIUM SP. 0.05 COSMARIUM SUBRENIFORME 0.13 CRUCIGENIA APICULATA 0.03 CRUCIGENIA TETRAPEDIA 0.13 CRYPTOMONAS EROSA 60.88 CRYPTOMONAS OVATA 12.36 CYCLOTELLA GLOMERATA 0.87 CYCLOTELLA SP . 3.85 DINOBRYON DIVERGENS 1.41 GYMNODINIUM NEGLEC'IUM 1.05 KIRCHNERIELLA SUBSOLITARIA 0.02 MALLOMONAS ELONGATA 1.01 MALLOMONAS SP. 0.05 MELOSIRA DISTANS 1.68 MELOS IRA GRANULATA 7.55 MELOSIRA GRANULATA ANGUSTISSIMA 10.93 NAVICULA SP. 0.05 NITZSCHIA ACICULRRlS 0.05 NITZSCHIA SP . 0.11 OSCILLATORIA GEMINATA 0.96 PANDORINA MORUM 0.31 PEDIASTRUM TETRAS 0.17 PERIDINIUM BIPES V TRAVECTUM 9.95 PERIDINIUM CINCTUM 10.91 PERIDINIUM SP. 4.98 PHORMIDIUM ANGUSTISSIMUM 0.04 PINNULARIA SP . 0.31 RAPHIDIOPS IS CURVATA 0.04 RHIZOSOLENIA ERIENSIS 0.04 RHOWMONAS MINUTA 1.01 SCENEDESMUS ALTERNANS 0.30 SCENEDESMUS BIJOGA 0.03 SCENEDESMUS QUADRICAUDA 0.81 SCENEDESMUS SPINOSUS 0.08 SCHROEDERIA SETIGERA 0.26 SELENASTRUM BIBRIANUM 1.87 SKELETONEMA POTOMOS 0.15 STAURASTRUM PARADOXUM 0.38 SYNURA WELLA 43.73 TETRAEDRON TRIGONUM 0.50 TETRASTRUM HETERACANTHUM 0.34 TRACHELOMONAS GIBBOSA 12.77 UNID COCCOID 1.23 UNID FLAGELLATE 0.01

PERIOD = October 23-25, 1976 SITE = C SEASON = FALL

ACTINASTRUM HANTZSCHII VAR. FLUVIATILE G 11.78 AGMENELLUM QUADRIDUPLICATUM B 129.60 ANACYSTIS CYANEA B 188.50 ANACYSTIS INCERTA B 1231.19 ANKISTRODESMUS CONVOLUTUS G 29.47 ANKISTRODESMUS FALCATUS G 212.06 ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS G 3363.91 CHLORELLA SP. G 200.26 CHLOROGONIUM SPIRALE G 11.79 CHROOMONAS COERULEA F 11.79 COELASTRUM MICROPORUM G 47.13 COSMARIUM ABBREVIATUM G 70.68 COSMARIUM REGNELLI G 47.13 CRUCIGENIA RECTANGULARIS G 23.56 CRYPTOMONAS OVATA F 412.40 CYCLOTELLA GLOMERATA D 648.01 CYCLOTELLA SP . D 400.59 EUASTRUM DENTICUUTUM G 5.89 FRANCEIA OVALIS G 35.34 GLOEOACTINIUM LIMNETICUM B 11.78 KIRCHNERIELLA LUNARIS G 35.34 MELOSIRA DISTANS D 2586.38 MELOSIRA GRANULATA ANGUSTISSIMA D 1396.12 NAVICULA SP. D 29.46 NITZSCHIA ACICULARIS D 818.88 NITZSCHIA SP. D 153.18 OSCILLATORIA GEMINATA B 6227.20

* B=Blue greens; C=Chrysophytes; D=DiatomS; E=Euglenophytes; F=Flagellates; G=Greens; P=Dinoflagellates

194 APPENDIX E. 4. (cont~nued)

PERIOD = October 23-25, 1976 SITE = C SEASON = FALL

SPECIES -GROUP* DE BIOMASS CELL CARBON #m/l % ug-atm/l

PEDIASTRUM TETRAS G 35.34 0.58 0. 53 PEDIASTRUM TETRAS VA?. TETRAODON G 5.89 0.02 0.02 PHORMIDIUM ANGUSTISS IMUM B 1720.12 0.82 0.93 QUADRIGULA CLOSTERIODES G 64.80 0.11 0.11 RAPHIDIOPSIS CURVATA B 2698.14 7.70 7.83 RHODOMONAS MINUTA F 488.94 0.91 0.95 SCENEDESMUS ACIJMINATUS G 82.47 0.29 0.29 SCENEDESMUS ALTERNANS G 35.34 0.18 0.18 SCENEDESMUS QUADRICAUDA G 571.60 1.49 1.54 SCENEDESMUS SPINOSUS G 47.12 0.17 0.17 SCHROEDERIA SETIGERA G 359.36 1.35 1.35 SELENASTRUM BIBRIANUY G 141.37 2.46 2.24 SKELETONEMA POTOMOS D 135.51 0.24 0.22 STAURASTRUM PARADOXUM G 11.79 0.13 0.12 STAURASTRUM SP. G 5.89 0.44 0.37 TETRAEDRON ARTHRODESMIFORME G 35.35 0.23 0.23 TETRAEDRON CAUDATUM VAR. LONGISPINUM G 35.34 0.01 0.02 TETRAEDRON TRIGONUM G 23.56 1.17 1.oo TETRASTRUM HETERACANTHUM G 53.02 0.40 0.38 UNID COCCOID G 270.99 1.62 1.58

PERIOD = October 23-25, 1976 SITE = T SEASON = FALL ACHNANTHES SP. D 23.56 AGMENELLUM QUADRIDUPLICATUM B AMPHROA OVALIS D ANABAENA FLOS -AQUAE B ANACYSTIS INCERTA B ANACYSTSS THERMRLIS B ANKISTRODESMUS FALCATUS G ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS G CHROOMONAS COERULEA F CHROOMONAS REFLEXA F CLOSTERIOPSIS LONGISSIMA G CRUCIGENIA FENESTRATA G CRUCIGEXIA QUADRATA G CRYPTOMONAS EROSA F CRYPTOMONAS CKOSA V REFLEXA F CRYPTOMONAS OVATA F CYCLOTELLA GLOMERATA D CYCLOTELLA SP. D CYMBELLA SP . D FRANCEA TUBERCULATA G FRANCEIA OVALIS G GOMPHOSPHAERIA WICHURAE B CYMNODINIUM PALUSTRE P MALLOMONAS CAUDATA C MALLOMONAS SP. C M?&LOMONAS TONSURATA C MELOSIRA DISTANS D MELOSIRA GRANULATA ANGUSTISSIMA D NAVICULA SOVEREIGNAE D NAVICULA SP. D NITZSCHIA ACICULARIS D NITZSCHIA SP. D OOCYSTIS BORGEI G OSCILLATORIA GEMINATA B PEDIASTRUM DUPLEX G PERIDINIUM SP. P PHORMIDIUM ANGUSTISSIMUM B RHODOMONAS MINUTA F SCENEDESMUS ARMATUS V. BOGLARIENSIS F. BI G SCENEDESMUS BIJUGA G SCENEDESMUS DENTICULATUS G SCENEDESMUS QUADRICAUDA G SCENEDESMUS SPINOSUS G SELENASTRUM EIBRIANUM G SORASTRUM SPINULOSUM SYNEDRA ACUS SYNURA WELLA C TETRAEDRON ARTHRODESMIFORME G TETRASTRUM HETERACANTHUM G UNID COCCOID G

PERIOD = November 12-14, 1976 SITE = C SEASON = FALL

ACHNANTHES LANCEOLATA D 2.34 ACHNANTHES SP. D 28.84 ACTINASTRUM HANTZSCHII VAR. FLWIATILE G 57.69 AGMENELLUM QUADRIDUPLICATUM B 26.50 AMPHORA OVALlS D 7.02 ANACYSTIS INCERTA B 461.76

* B=BlUe greens; C=Chrysophytes; D=Diatoms; E=Euglenophytes; APPENDIX E.I. (contrnued)

PERIOD = November 12-14, 1976 SITE = C SEASON = FALL

BIOMASS CELL CARBON SPECIES q-atm/l mg/l % u

ANKISTRODESMUS FALCATUS ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS ANKISTRODESMUS FUSIFORMIS CHLORELLA SP. CLOSTERIOPSIS LONGISSIMA CXYPTO?DNAS ERCSh CRYPTO>IO?IAS OVhTA CRYPTOMONAS PHASEOLUS CYCLOTELLA GLOMERATA CYCLOTELLA SP. CYMBELLA SP. EUASTRUM DENTICULATUM KIRCHNERIELLA LUNARIS MELOSIRA DISTANS MELOS IRA GRANULA'PA MELOSIRA GRANULA'PA ANGUSTISSIMA NAVICULA SP, NEIDIUM SP. NITZSCHIA ACICULARIS NITZSCHIA PRLEA NITZSCHIA SP. NITZSCHIA THERMALIS OOCYSTIS SP. OSCILLATORIA GEMCNATA PEDIASTRUM TETRA!: PERIDINIUM CINCTIJM PHORMIDIUM ANGUS'PISSIMUM PTEROMONAS S INUOBA QUADRIGULA SP . RHIZOSOLENIA LONGISETA

SCENEDESMUS ACUMINATUS SCE:EDES!).'JS QChD3ICAUDA SC:

PERIOD = November 12-14, 1976 SITE - T SEASON = FALL ACHNANTHES SP. D ANACYSTIS INCERTA B ANKISTRODESMUS FALCATUS G ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS G ASTERIONELLA FORMOSA D CHLAMYDOMONAS BOTRYS G CHROOMONAS REFLEXA F COCCOMONAS ORBICULAR18 G CRYPTOMONAS EROSA F CRYPTOMONAS PHASEOLUS CYCLOTELLA GLOMERATA CYCLOTELLA SP . DENDROMONAS CRYPTOSTYLIS DENDROMONAS SP. DINOBRYON CYLINDRICUM DINOBRYON SERTULARIA EUNOTIA SP. GOLENKINIA RADIATA CYMNODINIUM NEGLECTUM GYROSIGNA ACUMINATUM MALLOMONAS ACARDIDES MALLOMONAS TONSURATA MELOSIRA DISTANS MELOSIRA GRANULATA ANGUSTISSIMA NAVICULA SP. NEIDIUM SP. NITZSCHIA ACICULARIS NITZSCHIA PALEA NITZSCHIA PAR- NITZSCHIA SP. NITZSCHIA THERMALIS PHORMIDIUM ANGUSTISSIMUM RHODOMONAS MINUTA SCENEDESMUS QUADRICAUDA SCHROEDERIA SETIGERA SURIRELLA SP. SYNEDRA SP. SYNURA WELLA UNID CHRYSOPHYTES UNID COCCOID 0.00 UNID FLAGELLATE F 13.25 0.84 0.00 0.04 0.01 * B=Blue qrews; C=Chrysophytes; D=Diatoms; F=Euglenophytes; F=Flagellates; G-Greens; P=Dinoflagellates APPENDIX E. 4. (continued)

PERIOD = December 25-27, 1976 SITE = C SEASON = WINTER

SPECIES -GROUP* DENSITY BIOMASS CELL CARBON #m/l mg/l % sg-atm/l

ACHNANTHES SP. 0.12 AMPHORA OVALIS 0.06 ANACYSTIS INCERTA 0.01 ANKISTRODESMUS CONVOLLWUS 0.00 WKISTRI)DES:.CS FALCATUS 0.04 AYKISTXODES!.!L'S 5ALCATUS V. SPIRILLI 0.01 CHLAMYDOMONAS BOTRYS 0.00 CLOSTERIOPSIS LONGISSIMA 0.03 CLOSTERIUM ACEROSUM 0.04 COCCONEIS SP . 0.05 CRYPTOMONAS EROSA 0.25 CRYPTOMONAS EROSA V REFLEXA 0. 57 CRYPTOMONAS OVATA 2.91 CYCLOTELLA GLOMERATA 0.14 CYCLOTELLA SP. 0.31 CYCLOTELLA STELLIGERA 0.01 CYMBELLA SP. 0.09 CYMBELLA VENTRICOSA 0.01 FRAGILARIA SP. 0.76 0.00 0.69 MELOSIRA GRANULATA 0.15 MELOSIRA GRANULATA ANGUSTISSIMA 3.16 NAVICULA ARVENSIS 0.03 :i AVICULA CRYPTOCEPHALA 0.42 YAVICULA SOVEREIC.VAE 0.02 NAVICULA SP. 0.63 NITZSCHIA ACICULARIS 0.03 NITZSCHIA SP. 0.03 PEDIASTRUM DUPLEX 0.42 PERIDINIUM CINCTUM 2.72 PHORMIDIUM ANGUSTTSSIMOM 0.03 PTEROMONAS SINUOSA 0.01 QUADRIGULA CHOBATI 0.01 RHODOMONAS MINUTA 0.38 SCENEDESMUS ACUMINATUS 0.02 SCENEDESMUS ALTERNWG 0.01 SCENEDESMUS QUADRICAUDA 0 .O8 SKELETONEMA POTOMOS 0.40 SYNEDRA SP. 0.14 WID COCCOID 0.10 UNID FLAGELLATE 0.00 UNID PENNATE 0.02

PERIOD = Decemher 25-27, 1976 SITE = T SEASON = WINTER

ANCHNANTHES SP. ANKISTRODESMUS FALCATUS ASTERIONELLA FORMOSA CHLAMYDOMONAS FENESTRATA CHLAMYDOMONAS FENESTRATA CHLOROGONIUM SPIRALE CLOSTERIOPSIS LONGISSIMA CRYPTOMONAS EROSA CRYPTOMONAS OVATA CYCLOTELLA GLOMERATA CYLOTELLA MENEGHINIANA CYCLOTELLA SP. CYMBELLA SP. DINOBRYON SERTULARIA EUNOTIA SP. GOMPHONEMA SP. CYROSIGMA SSP. CYROSIGNA ACUMINATUM HEMIDINIUM NASUTUM MELOSIRA DISTANS MELOSIRA GRANULATA ANGUSTISSIMA MONODHRYSIS APHANASTER NAVICULA ARVENSIS NAVICULA SP. NEIDIUM SP. NITZSCHIA ACICULARIS NITZSCHIA PALEA NITZSCHIA SP. OSCILLATORIA SUBTILISSIMA PERIDINIUM CINCTUM PHORMIDIUM ANGUSTISSIMUM RHIZOSOLENIA ERIENSIS RHODOMONAS MINUTA SCENEDESMUS QUADRICAUDA SCHROEDERIA SETIGERA STAURONEIS PHOENICENTERON SYNEDRA ACUS SYNEDRA SP. SYNURA PETERSON11 SYNURA WELLA UNID COCCOID UNID FLAGELLATE UNID GREEN FILAMENT (3U DIA.)

* B=Blue greens; C=Chrysophytes; D=Diatoms; E=Euglenophytes; F=Flagellates; G=Greens; P=Dinoflagellates

197 APPENDIX E. 4. (continued)

PERIOD = January 14-16, 1977 SITE = C SEASON = WINTER

SF,ECIES -GROUP* DENSITY BIOMASS CELL CARBON tm/1 % % vg-atm/l

ACHNANTHES DEFLMA D 26.51 0.90 0.09 ACKNANTHES SP. D 110.46 3.78 0.43 AGMENELLUM QUADRIDUPLICATUM B 8.83 0.30 0 .oo ANACYSTIS MARINA B 11.78 0.40 0.14 ANKISTRODESMUS FALCATUS G 19.14 0.65 0.04 ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS G 27.98 0.95 0.02 ANKISTRODESMUS SETIGERUS G 8.83 0.30 0.03 CARTERIA GLOBOSA G 7.36 0.25 0.23 CARTERIA SP. G 4.41 0.15 0.02 CHLAMYDOMONAS SP . G 13.25 0.45 0 .15 CHROOMONAS REFLEXA F 8.83 0.30 0.16 CK .PTOMONAS EROSA F 35.34 1.21 5.96 CRYPTOMONAS OVATA F 5.89 0.20 0.33 CYCLOTELLA BODANICA D 4.41 0.15 0.21 CYCLOTELLA COMTA D 14.73 0.50 0.57 CYCLOTELLA GLOMERATA D 170.85 5.84 0.32 CYCLOTELLA MENEGHINIANA D 8.83 0.30 0.04 CYCLOTELLA SP . D 128.13 4.38 1.74 DINOBRYON BAVARICUF4 C 17.67 0.60 0.63 DINOBRYON DIVERGENS C 13.25 0.45 3 .I9 EUGLENA PROXIMA E 4.41 0.15 0.42 GLENODIWIUM PENARD FORME P 5.89 0.20 2.52 GYMhODXNIUM PALUSTRE P 4.41 0.15 0.61 KIRCIINERIELLA LUNAllIS G 8.84 0.30 0 .Ol KIRCHNERIELLA LUPqARIS VAR. DIANAE G 17.67 0.60 0.00 MALLOMONAS SP. C 4.41 0.1 5 0.03 MELOSIRA DISTANS D 396.20 13.56 2.12 MELOSIRA GRANULATA D 306.34 10.48 10.33 MELOSIRA GRANULATA ANGUSTISSIMA D 357.88 12.25 8.62 NAVICULA CRYPTOCEPIU D 4.41 0.15 0.05 NAVICULA SP. D 78.06 2.67 0.84 NITZSCHIA ACICULAR CS D 44.18 1. 51 0.04 NITZSCHIA DISSIPATA D 8.83 0.30 0.21 NITZSCHIA SP . D 78.06 2.67 0.07 NITZSCiiIA SUBLINEARIS D 8.83 0.30 0.86 PEDIASTRUM DUPLEX G 2.94 0.10 0.85 PEDIASTRUM TETRAS G 2.94 0 .LO 0.07 PHORMIDIUM ANGUSTISSIMUM B 35.34 1.21 0.02 PHORMIDIUM SP . B 89.84 3.07 0.05 RHIZOSOLENIA LONGISETA D 4.41 0.15 0.00 RHOWMONAS MINUTA F 82.47 2.82 0.24 SCENEDESMUS ACUMINATUS G 8.83 0.30 0.05 SCFNEDESMUS DISPAR G 13.25 0.45 0 .O9 SCENEDESWJS 3UADRICAUDA G 67.75 2.31 0.24 SCENEDESMUS SP . G 4.41 0.15 0.01 SCHROEDERIA SETIGERA G 4.41 0.15 0.02 SKELETONEMA POTOMOS D 154.65 5.29 0.44 STAURASTRUM ASPINOSUM V . ANNULATUM G 4.41 0.1 5 0.38 STAURASTRUM QUADRICUSPIDATUM G 4.41 0.15 1.19 SURIRELLA SP. D 4.41 0.1 5 0.42 SYNEDRA RUMPENS D 4.41 0.15 0.02 SYNEDRA SP. D 41.24 1.41 0.99 SYNURA PETERSON11 C 97.20 3.32 11.12 SYNURA WELLA C 169.39 5.79 37.97 UNID CHRYSOPHYTES C 39.76 1.36 0.66 UNID FLAGELLATE F 78.05 2.67 0.15 UNID PENNATE D 13.25 0.45 0.12

PERIOD = January 14-16, 1977 SITE = T SEASON = WINTER

ACHNANTHES SP . 4.42 11.04 15.46 ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS 2.20 CHLAMYDOMONAS BOTRYS 8.84 CHLAMYDOMONAS FENESTRATA 44.18 CRYPTOMONAS EROSA V REFLEXA 2.20 CRYPTOMONAS OVATA 30.93 CYCLOTELLA GLOMERATA 97.19 CYCLOTELLA SP . 83.95 MELOSIRA DISTANS 50.81 MELOSIRA GRRNULATA ANGUSTISSIMA MERIDION CIRCULARE MONOSIGA VARIANS NAVICULA SP. NITZSCHIA ACICULARIS NITZSCHIA PALEA NITZFCHIA SP . NITZSCHIA THERMALIS PERIDINIUM CINCTUM PHACUS SUECECUS PHORMIDIUM ANGUSTISS IMUM RHOWMONAS MINUTA SURIRELLA SP. SYNEDRA ACUS SYNEDRA SP. SYNEDRA ULNA SYNURA PETERSONII UNID COCCOID UNID FLAGELLATE

* B=Blue greens; C=Chrysophytes; APPENDIX E.4. (continued)

PERIOD = February 11-13, 1977 SITE = C SEASON = WINTER

BIOMASS CELL CARBON SPECIES GROUP* DENSITY 11 g-atrn/l #m/l % mg/l %

ACHNANTHES DEFLEXA ACHNANTHES LANCEOLATA ACHNANTHES SP. AGMENELLUM QUADRIDUPLICATUM AMPHORA OVALIS ANACYSTIS INCERTA

ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS ANKISTRODESMUS SETIGEROS BICOSOECA MULTIANNULATA CHLAMYDOMONAS BOTRYS CHLAMYDOMONAS FENESTRATA CKLAMYDOMONAS GLOEOPARA CHLAMYDOMONAS SP . CHLORELLA SP CHROOMONAS REFLEXA CLOSTERIOPSIS LONGISSIMA COSMOCLADIUM SAXONICUM CRUCIGENIA QUADRATA CRYPTOMONAS EROSA CRYPTOMONAS OVATA CYCLOTELLA GLOMERATA CYCLOTELLA SP. CYMBELLA SP. CYXBELLA SP. DINOBRYON DIVERGENS DIPLONEIS SP. EIJNOTIA SP. FRAGILARIA SP. GOLENKINIA RADIATA HANTZSCHIA AMPHIOXYS HEMIDINIUM NASUTUM MALLOMONAS ALLORGEI MELOSIRA DISTANS MELOSIRA GRANULATA MELOSIRA GRANULATA ANGUSTISSIMA MONOSIGA VARIANS NAVICULA ARVENSIS NAVICULA CRYPTOCEPHALA NAVICULA HAMBERGII NAVICULA SP. GEIDIUM SP.

NITZSCHIA PALEA NITZSCHIA PALEACEA NITZSCHIA SP. OSCILLATORIA SUBTILISSIMA PEDIASTRUM TETRAS VAR. TETRAODON PERIDINIUM BIPES V TRAVECTUM PERIDINIUM CINCTUM PHACOTUS ANGUSTUS PHACUS SOECECUS PHORMIDIUM ANGUSTISSIMUM RHODOMONAS MINUTA SCENEDESMUS ABUNDANS SCENEDESlYUS ARCUATUS V. PLATYDISCA SCENEDESMUS OPOLIENSIS SCENEDESMUS QUADRICAUDA SCENEDESMUS SPINOSUS SELENASTRUM BIBRIANUM SKELETONEMA POTOMOS SPIRULINA LAXA SYNEDRA RUMPENS SYNEDWi SP. SYNURA WELLA TETRAEDRON IWTICUM WID CHRYSOPHYPES UNID COCCOID UNID FLAGELLATE UNID PENNATE UNID CHRYSOPHYTE

PERIOD = February 11-13, 1977 SITE = T SEASON = WINTER

ACHNANTHES LANCEOLATA 1.76 ACHNANTHES SP. 5.30 AGMENELLUM QUADRIDUPLICATUM 101.89 ANKISTRODESMUS FALCATUS 17.67 CARTERIA GLOBOSA 1.76 CHLAMYDOMONAS FENESTRATA 29.84 CHLAMYDOMONAS GLOBOSA 33.16 CHLAMYDOMONAS SP. 7.07 CHLOROGONIUM SPIRALE 5.30 CHROOMONAS REFLEXA 5.82 CRYPTOMONAS OBOVATA 7.06

* B=Blue greens; C=Chrysophytes; D=Diatoms; E=Euglenophytes; F=Flagellates; G=Greens; P=Dinoflagellates 199

.APPENDIX E.4. (continued)

7ERIOD = Yarch 11-13, 1977 SITE = C SEASON = SPRSNG

CELL CARBON SPECIES GROUP DENSITY BIOMASS 4m/l % mg/l % kg-atm/l

PERIDINIUM CINCTUM PINNULARIA SP . PSEUDOTETRAEDRON NEGLECTUM RHODOMONAS MINUTA SCENEDESMUS ACUMINATUS SCENEDESMUS QUADRICAUllA SCHROEDERIA SETIGERA SELENASTRUM BIBRIANUM SKELETONEMA POTOMOS SPHAEROCYSTIS SCHROETZRI SURIRELLA SP. SYNEDRA ACUS SYNEDRA SP. SYNEDRA ULNA SYNURA PETERSON11 UNID PENNATE

PERIOD = March 11-13, 1977 SITE = T SEASON = SPRING

ACHNANTHES SP. AGMCNELLUM QUADRIDUPLICATUM ANKISTRODESMUS FALCATUS G 35.34 ANKISTRODESMUS FALCATUS V. SPIRRILLIFORMIS G 15.90 ASTERIONELLA FORMOSA D 17.67 CHLAMYDOMONAS BOTRYS G 1.76 CHLAMYDOMONAS FFJVESTRATA G 1.76 CLOSTERIOPSIS LONGISSIMA G 1.76 COCCOMONAS ORBICULARIS COCCONEIS SP. CRYPTOMONAS EROSA CRYPTOMONAS OVATA CYCLOTELLA GLOMERATA CYCLOTELLA SP. CYMBELLA SP. DIMOBRYON DIVERGENS DINOBRYON SERTULARIA EPITHEMIA SP. EUGLENA GRACIL,IS EUGLENA PROXIMA EIJYDTIA SP. FRAGILARIA SP. GYMNODINIUM PhUSTRE MALLOMONAS SP. MELOSIRA DISTANS MELOSIRA GRANULATA ANGUSTISSIMA MELOSIRA VARIANS MERIDION CIRCULARE MICRACTINIUM PUSILLUM NAVICULA SP. NEIDIUM SP. NITZSCHIA ACICULARIS NITZSCHIA SP. PINNULARIA SP . RHOWMONAS MINUTA SCENEDESMUS QUADRICAUDA STAURASTRUM SP. SURIRELLA SP. SYNEDRA ACUS

UN ID FLAGELLATE

PERIOD = April 15-17, 1977 SITE = C SEASON = Sprlng

ACHNANTHES SP. D 226.78 0.50 AMPHORA WALIS D 5.89 0.30 AMPHORA SP. D 4 /42 0.04 AN~~~m~VARIABILIS B 70.68 3.34 ANACYSTIS CYANEA B 5.89 0.11 ANKISTRODESMUS FALCATUS G 354.88 0.50 ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS G 122.22 0.05 APHANIZOMENON FLOS -AQUAE B 39.76 9 .O3 ARTHRODESMUS SUBULATUS G 5.89 0.03 ASTERIONELLA FORMOSA D 167.87 0.99 CHLAMYDOMONAS BOTRYS G 23.56 0.05 CKLAMYDOMONAS FENESTRATA G 5.89 0.05 CHROOMONAS COERULEA F 36.81 0.06 COCCONETS SP D 4.42 . 0.07 CRYPTOMONAS OVATA F 188.48 5.99 CYCLOTELLA GLOMERATA D 44.18 0.04 CYCLOTELLA SP. D 951.26 7.28 CWELLA SP. D 51. 54 1.64 DINOBRYON DIVERGENS C 11.78 1.59 EPICHRYSIS SP. C 35.34 0.02 FRAGILARIA SP. D 22.09 0.29 .NALLOMONAS MAJORENSIS C 5.89 * 0.08 B=Blue greens; C=Chrysophytes; D=Dlatoms; E=Euglenophytes; P=Dinof lagellates

201 APPENDIX E.4. (continued)

PERIOD = April 15-17, 1977 SITE = C SEASON = SPRING

SPECIES GROUP DENSITY BIOMASS CELL CARBON #m/l % mg/l % ug-atm/l

MALLOMONAS TONSURATA C 5.89 0.00 0.03 0.03 MELOSIRA DISTANS D 674.42 MELOSIRA GRANULATA D 5z.01 MELOSIRA GRANULATA ANGUSTISSIMA D 3769.73 MELOSIRA VARIANS D 13.35 NAVICULA CRYPTOCEPHALA D 17.67 NAVICULA SOVEREIGNAE D 36.81 NAVICULA SP. D 404.95 NEIDIUM SP . D 5.89 0.05 NITZSCHIA ACICULARIS D 134.00 1.27 NITZSCHIA SP . OPHIOCYTTUM COCHLEARE PEDIASTRUM TETRAS PERIDINIUM CINCTUM PHORMIDIUM ANGUSTI8,SIMUM PINNULARIA SP. RHODOMONAS MINUTA SCENEDESMUSBI JUGA SCELEDES:.lUS QUADRICAUDA SCYR3E3ERIA SETIGEWI SELENASTRUM BIBRIANUM SKELETONEMA POTOMOS SYNEDRA ACUS SYNEDRA SP. SYNEDRA ULNA SYNURA WELm

TRACHELOMONAS VOLVOCINA E 5.89 0.05 UNID COCCOID G 39.76 0.37 UN ID FLAGELLATE F 5.89

PERIOD = April 15-17, 1977 SITE = T SEASON = SPRING

ACHNANTHES SP. D 13.25 ANACYSTIS CYANEA B 4.41 ANKISTRODESMUS CONVOLUTUS G 4.41 ANKISTRODESMUS FALCATUS G 194.40 ANKISTRODESMUS FALCATUS V. SPIRILLIFORMIS G 269.51 ASTERIONELLA FORMOSA D 57.43 BICOSOECA MULTIANNULATA C 26.51 CHLAMYDOMONAS BOTRYS G 101.62 CHLAMYDOMONAS FENESTRATA G 48.60 CHROOMONAS COERULEA F 234.17 CHRYSOCHROMULINA SP. F 4.41 CRYPTOMONAS EROSA V REFLEXA F 561.12 CRYPTOMONAS OVATA F 75.11 CYCLOTELLA GLOMERATA D 30.92 CYCLOTELLA SP. D 57.43 CYMBELLA SP. D 4.41 DENDROMONAS SP. C 35.34 DINOBRYON DIVERGENS C 4.41 EUDORINA ELEGANS G 4.41 EUNOTIA SP. GOLENKINIA RADIATA GOMPHONEMA SP. MALLOMONAS ALLANTOIDES MALLOMONAS LYCHENS IS MALLOMONAS S P . MELOSIRA DISTANS MELOSIRA GRANULATA ANGUSTISSIMA MELOS IRA VARIANS MICRACTINIUM PUSILLUM NAVICULA SP. NITZSCHIA ACICULARIS NITZSCHIA SP. OSCILLATORIA NIGRA PANDORINA MORUM PERIDINIUM CF. VOLZII PHORMIDIUM ANGUSTISSIMUM RHOWMONAS MINUTA SCENEDESMUS ABUNDANS SCENEDESMUS BIJUGA SCENEDESMUS QUADRICAUDA S2LEShS?RL'!.: G.UCILE SKELETOSEYA POTOkOS SPHAEROCYSTIS SCHROETERI SURIRELLA SP. SYNEDRA SP. SYNEDRA ULNA SYNURA SP. SYNURA WELLA TETRASTRUM STAUROGENLEFORME WID CHRYSOPHYlrES * B=Blue greens; C=Chrysophytes; APPENDIX E.5. Chernlcal and Bacterial Data

-SITE DATE- TIME-- TEMP -COD TC TOC TIC TOTN TON NH3 NO3 TP TOP PO4 N:P C1 BACTERIA

COD=Chemical Oxygen Demand: TC=TOtal Carbon; TOC=Total Organic Carbon: TIC=TOtal Inorganic Carbon; TOTN= Total Nitrogen; TON=Total Organic Nitrogen; NH3=Ammonia-~itrogen;N03=Nitrate-Nitrogen; TP=Total Phosphorus; TOP=Total Organic Phosphorus PO4=Ortho-Phosphate Phosphorus; N:P=Total Nitrogen to Total Phosphorus Ratio; Cl=Chloride Ion; Bacteria=Cell Density APPENDIX E.5. (continued) SITE DATE TIME TEMP @ TC TOC TIC TOTM TON NH3 NO3 TP TOP PO4 BACTERIA

COD=Chemical Oxygen Demand; TC=Total Carbon; TOC=Total Organic Carbon; TIC=Total Inorganic Carbon; TOTN=Total Nitrogen; TON=Total Organic Nitrogen; NH3=Amonia-Nitrogen; N03=Nitrate-Nitrogen; TP=Total Phosphorus; TOP=Total Organic Phosphorws PO4=Ortho-Phosphate Phosphorus; N:P=Total Nitrogen to Total Phosphorus Ratio; Cl=Chloride Ion; nacteria=Cell Density