CRANBERRY BOG NUTRIENT LOSS STUDY 2011-03/604

2011 - 2015

PREPARED BY:

TOWN OF CARVER WITH PROJECT PARTNERS BUZZARDS BAY COALITION, MARINE BIOLOGICAL LABORATORY, UNIVERSITY OF MASSACHUSETTS CRANBERRY STATION

PREPARED FOR:

MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION BUREAU OF WATER RESOURCES

AND

U.S. ENVIRONMENTAL PROTECTION AGENCY REGION 1

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CRANBERRY BOG NUTRIENT LOSS STUDY 2011-03/604

2011 - 2015

PREPARED BY:

TOWN OF CARVER WITH PROJECT PARTNERS BUZZARDS BAY COALITION, MARINE BIOLOGICAL LABORATORY, UNIVERSITY OF MASSACHUSETTS CRANBERRY STATION

PREPARED FOR:

MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION BUREAU OF WATER RESOURCES

AND

U.S. ENVIRONMENTAL PROTECTION AGENCY REGION 1

MASSACHUSETTS EXECUTIVE OFFICE OF ENERGY and ENVIRONMENTAL AFFAIRS Matthew A. Beaton, Secretary

DEPARTMENT OF ENVIRONMENTAL PROTECTION Martin Suuberg, Commissioner

BUREAU OF WATER RESOURCES Douglas Fine, Assistant Commissioner

DIVISION OF MUNICIPAL SERVICES Steven J. McCurdy, Director

This project has been financed partially with federal funds from the US Environmental Protection Agency (USEPA) to the Massachusetts Department of Environmental Protection (MassDEP) under a 604(b) Competitive Grant. The contents do not necessarily reflect the views and policies of EPA or of MassDEP, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use.

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Introduction Background For more than 100 years, cranberry bogs have been an important part of the landscape and heritage of southeastern Massachusetts and they play a significant role in the local economy. Cranberries rank first in value of Massachusetts' food crops (USDA/NASS 2014) and approximately 25% of the nation’s cranberry crop is produced within Massachusetts. Almost all of this all of this production occurs in coastal watersheds. Nutrients supplied in the form of fertilizers are required in cranberry production. Because cranberry agriculture is intimately connected to natural waterways and cranberry bogs use ponds and rivers both as water sources and locations for flood discharge, nutrient management poses a challenge for both farm and watershed management. The supply of nitrogen from fertilizers is the most important controlling factor in cranberry nutrition (UMass BMP). At the same time, nitrogen runoff from coastal watersheds is the major cause of water decline in Massachusetts estuaries (EPA Coastal Condition Report). Phosphorus fertilizer is also used in cranberry production (UMass BMP) and phosphorus management is also an important concern, especially where discharge from cranberry bogs occurs to freshwater ponds. Quantifying the role of cranberry bogs in the nutrient balance of coastal watersheds is important to: (1) understand contributions of cranberry bogs relative to other sources, and (2) to identify cranberry farm management practices that increase nutrient retention and/or reduce nutrient releases. Currently, nutrient exchanges between cranberry bogs and coastal watersheds are very poorly understood. Only two studies in Massachusetts have estimated the amount of either nitrogen or phosphorus that is discharged from cranberry bogs. A 1995 study of one bog in Bourne, MA with a now‐ uncommon system of flow‐through water management (bogs directly adjacent to a river channel) found net nitrogen losses of 21.2 lbs/acre/year. The other, a 2005 study of six different bogs over two years that was designed to quantify phosphorus dynamics showed net phosphorus losses of 1.1 to 6.1 lbs/acre/year and net nitrogen losses ranging from 3.7 to 13.5 lbs/acre/year. An improved understanding of the impact of cranberry agriculture is a critical factor in the development of effective and economic watershed‐wide management plans to ensure the restoration of impaired waters in Southeastern Massachusetts. The up to six‐fold difference in nutrient loading values makes it difficult to develop comprehensive management plans for eliminating sources of pollution.

In Massachusetts, the Weweantic River Watershed supports more cranberry bog acreage than any other coastal watershed. The Weweantic River and Wareham River watersheds are the largest and third largest sub watersheds in the Buzzards Bay basin. Water quality in both rivers and their associated estuaries suffers from nutrient over enrichment that is derived multiple sources including cranberry bogs, septic systems, storm water, and lawn fertilizer. Both estuaries are listed on the State’s Integrated List of Impaired Waters as impaired because of nutrient loads. Both estuaries show eelgrass loss, high summer phytoplankton biomass and oxygen depletion that are characteristic of high nitrogen loads and the upper Weweantic River estuary is among the most eutrophic of all Buzzards Bay embayments (BBC Monitoring Data). Preliminary modeling by the Buzzards Bay National Estuary Project suggested that 4

nitrogen loadings to the Weweantic River may be more than 300% over those needed to return the estuary to its pre‐eutrophic condition An analysis of the Wareham River by the Massachusetts Estuaries Project (Howes et al. 2013) indicated that an overall 38% reduction in nitrogen loading was required in order to restore water quality and cranberry agriculture was estimated to be a major source of nitrogen (25 to 57% of the locally controllable load is subwatersheds). Purpose and Approach The objective of this project was to provide a better estimate of nitrogen and phosphorus exchanges in cranberry bogs in the Weweantic and Wareham River Watersheds. The project was a partnership between five organizations: the Town of Carver, the University of Massachusetts Cranberry Station (Cranberry Station), the Marine Biological Laboratory (MBL), the Cape Cod Cranberry Growers’ Association (CCCGA), and the Buzzards Bay Coalition (Coalition). All partners agreed that improved scientific information is needed to understand how cranberry bogs affect nutrient concentrations in downstream waters. The project selected six bogs for detailed study. To examine how bog configuration influences nutrient exchanges, three bogs were identified in each of two configuration types: (1) pass‐through bog systems that have a long pathway to the receiving body via a channel (referred to here as “long tail” type bogs), and (2) closed‐loop bog systems that receive and discharge water from the same waterbody (referred to here as “closed loop” type bogs). For this study, pass‐through bogs were differentiated from flow‐ through bogs, with a pass‐through bog defined as bog systems in which water is not recirculated back to the origin point and that do not have constant streamflow through the bog. To select the study bogs, a list of potential sites was compiled by representatives of the Cranberry Station, MBL, the Coalition, and CCCGA. Criteria that influenced selection included: (1) bogs that had a single bed with a clear inflow and outflow (some bog systems set‐up with inter‐connected beds were avoided because of the difficulty to isolate inputs and releases), (2) bogs that received historical and current fertilizer and water management typical of the region, (3) bogs that had clear long tail or closed loop configurations, and (4) bogs that had owners and managers willing to provide physical access, notice of water movement dates, and information on historical and current bog fertilizer and water management. Site visits to ten potential study bogs were conducted on August 11th and 23rd, 2011. Final selection was made after those site visits. To determine nutrient movement through surface and groundwater into and out of the bogs, each bog was monitored for 17 months beginning in September 2012. Surface water samples were collected from the pond or river water source and where water entered and exited the bog. For long‐tail bogs surface water samples were also collected at a point downstream in the outlet channel before it discharged to a receiving water. To determine nutrient concentrations in inflowing and outflowing groundwater, sampling wells were installed upgradient and downgradient of the bog bed. Total water fluxes in and out of the bogs were estimated by logging water levels and changes to water volumes on the bogs, logging flows in inlet or outlet channels, and using estimates of water pumped onto and released during bog operations, depending on the particular bog configuration. 5

In each bog, nutrient concentrations were measured about every eight weeks in surface waters (source water, bog inlet, bog outlet and downstream in long tail channel) and in groundwater (up‐ and downgradient). Nutrient concentrations were measured in the bog inlet and outlet surface water more frequently (up to several times in a 24 to 72 hr period) during harvest and winter frost protection floods when large quantities of water were moving. Water samples were analyzed for particulate organic carbon (POC), particulate organic nitrogen (PON) + ‐ (surface water samples only), ammonium (NH4 ), nitrate+nitrite (hereafter referred to as NO3 ), total 3‐ dissolved nitrogen (TDN), soluble reactive phosphorus (PO4 ) and total phosphorus (TP). Nutrient applications and water manipulations in the bogs were documented by the managers and provided to the Cranberry Station staff. Growers selected fertilizer rates based on the nitrogen requirements of the bogs (determined by evaluation of plant growth, color, crop potential, and cultivar) and were consistent with the fertilizer application rates over the previous six years on that bog and regional practice. Growers provided records to the CCCGA of fertilizer applications rates and dates, and bog crop yields. Detailed Site Descriptions Bogs were located within a 3 mi radius in the towns of Carver, Wareham, Middleborough and Plymouth (Fig. 1). The size of the study bogs ranged from 2.9 to 7.8 acres (Table 1). Detailed maps of all the study bogs are included in Appendix A. Benson’s Pond East Street bog is a solitary bog just east of East Street in Middleborough. Benson’s Pond East Street bog is fed by an irrigation channel that runs alongside the bog and which comes from a larger bog system on the west side of East Street. The discharge from Benson’s Pond East Street bog is directly back to the irrigation channel. The irrigation channel continues about 1,000 feet where it connects with a stream that feeds into the Weweantic River.

Lincoln Bog is a system of five bogs located in Carver, MA. The bogs are linked such that water generally flows from Clear Pond to the northwestern‐most bog and then flows from that bog to the other bogs. Our study site was the northwestern‐most bog that had an inlet from Clear Pond and an outlet to the adjoining bog to the southwest. The final outlet of the bog system was pumped from the northeastern‐ most bog back to Clear Pond.

Pierceville Bog is located in West Wareham and consists of a relatively large system (45 acres) of four interconnected bogs. The bogs are fed by a pump from one main irrigation pond and additional pumps at two smaller water sources. For this study, we used only the southeastern most bed that is connected to the system outlet. The outlet of the system is a channel that runs north, perpendicular to Papermill Road and connects to a stream that runs into the Weweantic River approximately 0.25 mile downstream.

Rocky Pond Bog is a solitary bog (4 acres) located within the Myles Standish State Forest that is fed from an irrigation pump at Rocky Pond, a large natural pond. The outlet of the bog is a channel that runs south to Federal Pond, which the Southeast bog at Rocky Pond also connects to approximately 400 feet downstream of the outlet from the Northwest bog. The water from the Rocky Pond bogs travels through 6

a series of channels, ponds, and streams before reaching the Weweantic River Reservoir approximately five miles away.

State bog is a system of five bogs located in East Wareham, MA that is fed by Spectacle Pond. The bogs are irrigated from the pond and flooded individually from a canal connected to Spectacle Pond and running along the south edge. The flow exiting the bogs returns to Spectacle Pond via that same canal. This study used Bed 3 of this system.

White Springs bog is a solitary bog located within the Myles Standish State Forest that is fed by an inlet channel from Barrett Pond, which is a natural pond approximately 800 feet away. Water exits the bog from a channel on the southwest corner of the bog that extends approximately 500 feet before going under East Head Road and then Cranberry Road, where it connects to a stream that feeds into the Weweantic River.

All the bogs received between 25 and 45 lbs/ac of nitrogen fertilizer and 5 to 14 lbs/ac phosphorus during the years of measurement in 2012 and 2013 (Table 2). Across all bogs, the mean rate of fertilizer application during the study years was similar to the average of the preceding three to four years and to that applied in typical regional practice. The mean yield of cranberries across all bogs varied from 178 to 183 barrels/ac and was also relatively constant both across study years and in comparison with the preceding three to four years (Table 2). Average cranberry yield of all the study bogs ranged from 178 barrels/ac from 2009 to 2011 to 183 barrels/ac in 2012 and 2013.

Harvest floods occurred between September 25 and October 31 in both years and lasted six to 27 days (Table 3). Winter floods were more variable and occurred between December 14 and February 7 and lasted from as little as four days to as long as 49 days (Table 3).

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Methods

The methods utilized are described in detail in the Quality Assurance Project Plan (QAPP) for this project (approved by MassDEP/EPA on August 7, 2012). Here we will briefly describe the methods used as well as deviations from the QAPP. Hydrologic Measurements Onset Hobo Level Loggers were installed in PVC housings on the outgoing flumes on White Springs, Pierceville, Lincoln, Rocky Pond, and Benson’s Pond bogs. The stage height derived from the logger pressure reading was calibrated against fixed points at each site (e.g., top of the flume structure). This allowed determination of the bog water level relative to the elevation of the bog platform. These measurements combined with the measured area of the bog platform and the bog perimeter ditches, allowed calculation of total water volume on each bog. The level loggers were programmed to collect pressure readings every 15 minutes. These data were downloaded at least once every 3 months. Reference air pressure, required for calculation of water depths from logger pressure readings, was recorded with a separate centrally‐located Hobo logger at the Cranberry Station. In a few instances, loggers were lost or stolen. These cases created gaps in the record of bog levels, but new loggers were installed when this was discovered and these gaps were filled as much was possible based on the settings of boards in the bog outlet water control structures and grower records. At the three long‐tail sites (Pierceville, White Springs, and Rocky Pond), stream outlet discharge was measured four times over the course of the study, distributed across periods of high flow and low flows. This was used to create a rating curve to allow calculation of stream discharge from the level readings on the outlet structures. Discharge measurements were made from stream cross sections and velocities measured with a Marsh‐McBurney velocity meter (Gore et al. 2007).

Groundwater Well Installation At each bog, permanent groundwater wells for the collection of shallow groundwater were installed adjacent to the bog on the upgradient and downgradient sides. Wells were constructed from 1.5‐in diameter Schedule 80 PVC tubing and screened with 0.010 inch slots on a 2 ft interval at the bottom of each tube. Holes for the wells were dug with a 3.5” bucket auger to about 2 ft below the water table. Excavated soil was maintained at the surface to preserve the layering structure. The well tubing was then pushed into the hole until refusal. The remainder of the hole was back filled with native sand to cover the screened interval after which native soil was returned to the hole in reverse order of excavation and compacted in 6 intervals. Some fine soil was retained to fill near the surface and compacted to serve as a seal. In addition, four to six groundwater drive point micro‐wells (AMS Inc.) were installed at each bog in a line between the permanent PVC wells. These wells consisted of 1.5 in stainless steel drive points with a screen and hose connected to 0.25 in outside diameter nylon tubing that extended to the surface. The micro‐wells were inserted by driving with a 0.625 in diameter pipe that was driven to about 2 ft below the water table and then withdrawn leaving the points and tubing in place. Native soil was compacted at the surface to complete the installation. These additional groundwater wells were sampled whenever 8

the permanent wells were sampled. These micro‐point wells served in lieu of drive point well sampling in the original project design. Dates of installation of wells varied and depended on the ease or difficulty of installing wells in the particular substrates that existed on bog's upgradient and downgradient sides. Nutrient Sampling Surface water samples were collected from the bog source waters, inlet, outlet, and downstream in long tail channel at a depth of 15 centimeters below the surface either by hand or with a bottle attached to a sampling pole. Groundwater samples were collected by pumping with a battery operated peristaltic pump (Geotech Environmental Equipment, Inc.). Wells were pumped dry, and then allowed to refill with fresh groundwater that was then collected as the sample. Samples were kept on ice and then transported to the Cranberry Station for processing on the same day they were collected. 1. Non‐Flood Conditions During non‐flood conditions, samples were collected from surface water (source, inlet, outlet and long tail channels) and groundwater (up‐ and downgradient) approximately every eight weeks from September 2012 to January 2014. All bogs were sampled either on the same day or over two consecutive days. These non‐flood samplings provided information on nutrient concentrations during periods when water was not actively pumped or intentionally moved by bog managers. 2. Flood Conditions During the harvest floods, samples from bog inlets or outlets were collected more frequently to characterize nutrient concentrations during the flood period (typically 7 to 14 days). In 2012, grab samples were collected: (1) before the harvest flood began, (2) during the flood, and (3) during the flood release, and (4) approximately one day after the flood release. The direction of water flow influenced which sample points were collected. Inlets were sampled while water was moved onto bogs and outlets were sampled when water was released. When a flood occurred quickly and without notice from managers, no pre‐harvest flood sample was collected. In these cases, we used the samples at the inlet collected from the non‐flood period at the closest time to the flood to estimate nutrient concentrations in incoming floodwater. In 2013, the sampling resolution was increased. At all bogs, samples were collected one day prior to flooding, three times during bog flooding, once after the floodwater was on the bog three times during the flood release, one day after the flood was released, and three to five days after the flood was released. Groundwater wells were also sampled one day prior to flooding, while the floodwater was on the bog, and three to five days after the flood release. The three sampling times during the flooding or flood release were timed to capture the beginning of water movement, the mid point of water movement and just before the end of water movement. As a rule of thumb, the mid point samples were collected when the bog ditches were roughly half full. 3. Sample Filtration

+ ‐ 3‐ Samples for NH4 , NO3 , and PO4 were filtered through 47 mm 0.45 um cellulose acetate filters. + ‐ 3‐ Subsamples for NH4 , NO3 , PO4 and total dissolved nitrogen (TDN) were immediately frozen. Unfiltered samples were collected for total phosphorus, acidified to pH 2 with sulfuric acid and 9

refrigerated. For analysis of particulate organic carbon and nitrogen (POC and PON), a known volume of approximately 100 to 200 ml was filtered under low vacuum through pre‐combusted 25mm Whatman GF/F filters and oven dried at 60 oC. 4. Nutrient Analysis

+ All analyses were performed at the Ecosystems Center of the MBL. NH4 was analyzed colorimetrically ‐ using the indophenol method. NO3 was analyzed colorimetrically by copper‐cadmium reduction on a ‐ Lachat autoanalyzer. TDN was analyzed using a digestion with persulfate digestion to NO3 and ‐ subsquent analyzsis of NO3 by copper‐cadmium reduction on a Lachat AutoAnalyzer. Dissolved organic + ‐ 3‐ nitrogen (DON) was calculated as TN minus (NH4 + NO3 ). PO4 samples were analyzed colorimetrically 3‐ on a Lachat autoanalyzer. TP was analyzed by digestion with persulfate to PO4 and subsequent analysis 3‐ of PO4 on a Lachat autoanalyzer. Filters for POC and PON analysis were analyzed by combustion in a Perkin Elmer elemental analyzer. Further details on protocols and methods are contained in the project QAPP. 5. Analysis of Nutrient Concentration Data For groundwater, mean solute concentrations were averaged across all up‐ or downgradient wells on each sampling date. Median concentrations of all samples were calculated for up‐ and downgradient sides of each bog. For surface waters there was generally only one sampling location for bog source water, inlets and outlets so single samples from each location were collected at each sampling time. Where multiple samples were collected to assess sampling and analytical variability, these samples were averaged. Median concentrations of all samples were calculated for source, inlet and outlet locations. 6. Calculation of Water Volumes The surface area of each bog was determined from Google Earth satellite imagery. Area was measured to both the inner and outer edges of bog ditches. This allowed calculation of the area of ditches and of the growing bed. Field measurements were made of the depth of the bog ditches and the elevation difference between the bottom of the ditches and the top of the growing bed. The volume of water on each bog and in bog ditches was calculated from level logger depth measurements and the area of the bog ditches and the bog platform. Water levels were calculated from level logger pressure corrected for the atmospheric pressure from the reference logger. The depth of the water over the pressure sensors was measured in the field at several times during the year to validate the depth calculations. The water depth over the level logger was converted to a volume of water in the bog by multiplying it by the surface area of the ditches (when the water level was below the surface of the bed) or by the area of the ditches plus the growing platform (when water level was above the surface of the bed). The timing of the flood on each bog was determined from plots of bog water volume against time. Rapid changes in volume signified the start or end of a flood. The 48 hours either before or after these periods of rapid change were designated to represent pre‐ and post‐flood bog volumes. When there were questions about when the flood began or ended, we choose to use the most inclusive set of dates (i.e., longest flood periods). 10

The volume of surface water that was moved onto a bog during a flood was calculated as the peak (i.e., maximum recorded) flood volume minus the average of the volume for the 48 hours pre‐flood minus the volume of any rain that fell during the period of rapid rise in water level. For the harvest floods, the period of rapid rise in water level generally occurred over several days and ended at the peak water level. For the winter floods, there was larger variation in flood water levels. To account for this, the period of rapid rise in water was set at one week. In some cases, peak water level was not reached in the first week of a winter flood. Daily precipitation values were obtained for the NOAA National Climatic Data Center station in East Wareham, MA (station ID GHCND:USC00192451). The volume of surface water that was released from a bog during a flood was calculated as the peak flood volume minus the average of the volume for the 48 hours post‐flood minus an estimate of seepage of water from the bog into groundwater during the flood. We used estimates of total seepage of 11 cm for harvest floods and 46 cm for winter floods derived from Kennedy (2015). For one site (White Springs), use of the 46 cm groundwater seepage estimate for winter floods resulted in a negative surface water volume moving off the bog. For White Springs winter flood calculations, the estimate of groundwater seepage during harvest floods was substituted for that of winter floods. White Springs bog has been identified based on observations by growers and previous researchers as a natural point of groundwater upwelling because there is a consistent flow of water in the ditches even during non‐flood conditions. Because this bog generally gains groundwater during non‐flooding situations, it is reasonable to expect that it may lose less groundwater to seepage during flooding conditions than other bogs. 7. Calculation of Nutrient Inputs and Outputs During Floods The input of nitrogen or phosphorus to bogs was calculated as the sum of the nitrogen or phosphorus load from surface water moved onto the bog during the flood and the nitrogen or phosphorus load from rain:

Nitrogen IN = [(Vpeak ‐ Vpre‐flood ‐ Vrain during input) * Cinput ] + [(Vrain during entire flood ‐ VRain during input) * Crain ] (1)

The concentration of the water coming into the bog (Cinput) was calculated as the average concentration of surface water samples collected at the bog inlet. The concentration of nitrogen in rain (Crain) was determined using data from a National Atmospheric Deposition Program station in Truro, MA (NTN Site MA01), where nitrogen concentrations were typically measured weekly. When there were multiple samples of precipitation concentration analyzed over the time period of a flood, a weighted average was calculated based on the flood dates. In the instances when rain occurred on the bogs during foods but no precipitation nitrogen concentration was available from those dates, the nitrogen concentrations from the last date available before the flood began and the first data after the flood ended were averaged. The concentration of phosphorus in rainwater was assumed to be zero based on very low concentrations reported for global assessments that include the eastern US (Mahowald et al. 2008, Vet et al. 2014). The output of nitrogen or phosphorus to surface water was calculated as the nitrogen or phosphorus moved out of the bog during the flood:

Nitrogen OUT = [(Vpeak ‐ Vpost‐flood ‐ Vseepage) * Coutput ] (2) 11

The concentration of the water leaving the bog (Coutput) was calculated as the average concentration of surface water samples collected at the bog outlet (for closed loop bogs) and as the average concentration of surface water samples collected downstream in the outlet channel (for long tail bogs). The flux of nitrogen or phosphorus to surface water was calculated as:

(3) Nitrogen Flux = Nitrogen OUT – Nitrogen IN

Positive values represent a net release of nutrient to surface waters and negative values represent a net retention of nutrient from surface waters.

Phosphorus Flux = (Vpeak ‐ Vpost‐flood ‐ Vseepage) * Coutput ] ‐ (Vpeak ‐ Vpre‐flood) * Cinput (4)

(4)

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Results Source water

+ ‐ ‐1 The concentrations of NH4 and NO3 in the majority of source water samples was less than 0.1 mg N L (Fig. 2). The concentrations of DON in bog source waters were generally higher than concentrations of + ‐ ‐1 NH4 and NO3 , with majority of samples having concentrations of 0.1 mg L or greater (Fig. 2). In bog + ‐ source waters, PON concentrations were typically higher than the concentrations of NH4 and NO3 with a lower percentage of PON samples having concentrations less than 0.1 mg L‐1 (Fig. 2). However, PON concentrations were generally low relative to DON with the majority of samples having PON concentrations of 0.15 mg L‐1 or less (Fig. 2).

3‐ ‐1 The concentrations of PO4 in the vast majority of bog source water samples was less than 0.03 mg P L 3‐ (Fig. 3). The concentrations of TP were higher than for PO4 and many more TP samples compared with 3‐ ‐1 PO4 samples had concentrations between 0.03 and 0.20 mg P L (Fig. 3).

+ ‐1 The median concentrations of NH4 in bog source water samples ranged from 0.01 to 0.02 mg N L ‐ (Table 4). The median concentrations of NO3 in bog source water samples ranged from below the detection limit of 0.0035 mg L‐1 to 0.025 mg N L‐1 (Table 4). The median concentrations of DON ranged from 0.17 to 0.34 mg N L‐1 (Table 4). Median PON concentrations ranged from 0.04 to 0.41 mg N L‐1 + ‐ (Table 4). Levels of NH4 and NO3 were similar and low across all sites. DON concentrations were similar around 0.2 mg L‐1 at most sites, however, at 0.34 mg L‐1, the median DON concentration at Benson’s Pond was notably higher. PON concentrations were more variable among bogs than the other nitrogen forms measured (Table 4).

3‐ The median concentrations of PO4 were very low and the source waters to four of the six bogs had median concentrations below the detective limit of 0.0078 mg L‐1 (Table 4). The median concentrations 3‐ ‐1 of TP were higher than concentrations of PO4 but were also low and ranged from 0.01 to 0.09 mg L 3‐ (Table 4). The highest median PO4 and TP concentrations in source water were both from Pierceville Bog.

+ ‐ In general, concentrations of NH4 and NO3 in bog source waters were consistent during the year, + ‐ though higher NH4 or NO3 concentrations were observed either just before or during the 2013 winter + ‐ flood at three bogs (Lincoln Bog, State Bog, Pierceville) (Fig. 4). Relatively high levels of NH4 and NO3 occurred in the source waters of White Springs Bog leading up to the fall 2013 flood (Fig. 4). DON and PON concentrations were more variable over time than the inorganic nitrogen forms. Concentration peaks in PON were observed during the harvest 2013 flood in all bogs (Fig. 4). Peaks in the concentration of DON were observed with the onset of the harvest 2013 flood at Lincoln Bog and State Bog. A large spike in DON concentration occurred at the end of the harvest 2013 flood at Benson’s Pond (Fig. 4).

3‐ The concentrations of PO4 and TP in the source waters to all bogs varied little during non‐flood periods (Fig. 5). Large spikes in the concentration of TP were observed during harvest 2013 flood at Benson’s Pond and Pierceville Bogs (Fig. 5). Smaller spikes in concentration were observed in TP during the harvest 2013 floods at Lincoln Bog and State Bog and during the winter 2013‐2014 floods at Lincoln, Pierceville, and Rocky Pond Bogs. 13

Groundwater

+ ‐ The concentrations of NH4 and NO3 in the majority of up‐ and downgradient groundwater samples was ‐1 + ‐ less than 0.1 mg N L (Fig. 6). The distributions of concentrations of NH4 and NO3 in up‐ and downgradient groundwater were similar (Fig. 6). A slightly higher number of samples that exceeded 1.2 mg N L‐1 occurred in downgradient compared with upgradient groundwater (Fig. 6). The concentrations + ‐ of DON in up‐ and downgradient groundwater were higher than for NH4 and NO3 and many more DON + ‐ ‐1 samples compared with NH4 and NO3 samples fell between 0.15 and 0.5 mg N L . The distributions of concentrations of DON in up‐ and downgradient groundwater were generally similar, but a higher number of samples with DON greater than 1.2 mg N L‐1 occurred in downgradient groundwater (Fig. 6).

3‐ The concentrations of PO4 in the vast majority of up‐ and downgradient groundwater samples was less ‐1 3‐ than 0.03 mg P L (Fig. 7). The distributions of PO4 in up‐ and downgradient groundwater were very 3‐ similar (Fig. 7). The concentrations of TP were higher than for PO4 and many more TP samples 3‐ ‐1 compared with PO4 samples had concentrations between 0.03 and 0.10 mg P L (Fig. 7). The distributions of TP in up‐ and downgradient groundwater were generally similar, but a slightly higher number of samples with TP greater than 0.24 mg P L‐1 occurred in downgradient groundwater (Fig. 7).

+ ‐1 The median concentrations of NH4 ranged from 0.01 to 0.09 mg N L in upgradient groundwater and from 0.01 to 0.43 mg N L‐1 in downgradient groundwater (Table 5). The greatest difference between + + median up‐ and downgradient NH4 concentrations occurred in Pierceville Bog where NH4 concentration was 0.01 mg N L‐1 upgradient and 0.43 mg N L‐1 downgradient. The median concentrations ‐ ‐1 of NO3 ranged from 0.01 to 0.44 mg N L in upgradient groundwater and from below the detection limit ‐1 ‐ to 0.20 mg N L in downgradient groundwater (Table 5). The median concentrations of NO3 in downgradient groundwater was nearly identical to that in upgradient groundwater in two bogs (Benson's Pond, Rocky Pond) and lower than upgradient groundwater in the other four bogs (Table 5). The median concentrations of DON ranged from 0.10 to 0.32 mg N L‐1 in upgradient groundwater and from 0.08 to 0.25 mg N L‐1 in downgradient groundwater (Table 5). The median concentrations of DON were slightly higher in downgradient groundwater in two bogs (Lincoln, Pierceville) and very slightly lower in the other four bogs (Table 5).

3‐ The median concentrations of PO4 for both up‐ and downgradient groundwater was below the detection limit at all bogs (Table 6). The median concentrations of TP were higher than concentrations of 3‐ PO4 but were also low. The median concentration of TP in downgradient groundwater was higher than in upgradient groundwater at Pierceville Bog but nearly identical in the other five bogs (Table 6).

+ The mean concentrations of NH4 from replicate wells varied very little over time in the upgradient + groundwater of all bogs (Fig. 8). The mean concentrations of NH4 also varied little over time in the + downgradient groundwater of three bogs but there were modest increases in NH4 in the fall of 2013 in ‐ the downgradient wells in State and Pierceville Bogs (Fig. 8). The mean concentrations of NO3 in both up‐ and downgradient groundwater at most times in most bogs were below 1 mg N L‐1 (Fig. 8). However, ‐ + mean NO3 concentrations varied more than NH4 concentrations. In Benson's Pond, Lincoln and White ‐ Springs bogs, NO3 concentrations were higher on some dates in upgradient groundwater but varied ‐ little in downgradient groundwater (Fig. 8). In contrast, in State and White Springs Bogs, mean NO3 were higher on some dates in downgradient groundwater but varied little in upgradient groundwater 14

‐ (Fig. 8). The mean concentrations of NO3 were most variable in the downgradeint groundwater of State Bog where they ranged between 0 and 8 mg N L‐1 (Fig. 8). The mean concentrations of DON were consistently less than 2 mg N L‐1, varied little over time, and were very similar in up‐ and downgradient groundwater in five of the six bogs (Fig. 8). State Bog was the exception, where DON concentrations ranged between near zero to more than 5 mg N L‐1 (Fig. 8). There were no clear patterns associated with the timing of bog flooding for any of the dissolved nitrogen forms in either up‐ or downgradient groundwater.

3‐ The mean concentrations of PO4 in up‐ and downgradient groundwater in all bogs and varied little over 3‐ ‐1 time (Fig. 9). In only one instance did the mean PO4 concentration exceed 0.1 mg P L (Fig. 9). The mean concentrations of TP varied little in upgradient groundwater and rarely exceeded 0.2 mg P L‐1 (Fig. 9). TP concentrations varied more in downgradient groundwater but there was no consistent timing to the period of higher concentrations (Fig. 9). There were no clear patterns associated with the time of 3‐ bog flooding for either PO4 or TP concentrations in either up‐ or downgradient groundwater (Fig. 9). Surface water

+ ‐ ‐1 The median concentrations of NH4 and NO3 in inlet and outlet surface water were 0.05 mg N L or less + ‐ (Table 7). The distributions of concentrations NH4 and NO3 in inlet and outlet surface water were very + similar, but a slightly smaller percentage of samples of NH4 in outlet water had concentrations less than ‐1 + 0.02 mg N L and a slightly higher percentage of samples of NH4 in outlet water had concentrations greater than 0.25 mg N L‐1 (Fig. 10). The concentrations of DON in inlet and outlet water were higher + ‐ than for NH4 and NO3 (Fig. 10) and the distributions of concentrations of DON in inlet and outlet water surface water were generally similar, but a slightly higher percentage of samples of inlet water compared with outlet water had concentrations between 0.2 and 0.4 mg N L‐1 and concentrations greater than 1.2 mg N L‐1 (Fig. 10). The concentrations of PON in inlet and outlet surface water were also generally similar but a higher number of samples of outlet water had low PON concentrations of below 0.02 mg N L‐1 (Fig. 10).

3‐ The concentrations of PO4 in the vast majority of inlet and outlet surface water samples was less than ‐1 3‐ 0.05 mg P L (Fig. 11). The distributions of PO4 in inlet and outlet surface waters were generally very 3‐ similar (Fig. 11). The concentrations of TP were higher than for PO4 and the distributions of TP in inlet and outlet water were generally similar (Fig. 11), but a larger fraction of TP samples of inlet water had concentrations less than 0.05 mg P L‐1 and a greater percentage of samples of outlet had concentrations greater than 0.24 mg P L‐1 (Fig. 11).

+ ‐1 The median concentration of NH4 ranged from 0.008 to 0.022 mg N L in inlet surface water and from 0.014 to 0.027 mg N L‐1 in outlet surface water (Table 7). No bog had differences in median inlet and + ‐1 outlet surface water NH4 concentrations that exceeded 0.02 mg N L (Table 7). The median ‐ ‐1 ‐1 concentration of NO3 ranged from 0.003 to 0.038 mg N L in inlet surface water to 0.005 to 0.023 mg L ‐ in outlet surface water (Table 7). Differences between inlet and outlet surface water NO3 concentrations were also small and were always less than 0.04 mg N L‐1 (Table 7). The median concentrations of DON in inlet surface water of 0.089 to 0.336 mg N L‐1 were very similar to median concentrations of DON in outlet surface water of 0.157 to 0.304 mg N L‐1 (Table 7). Median 15

concentrations of TN in inlet surface water of 0.262 to 0.793 mg N L‐1 were very similar to those of 0.314 to 0.763 mg N L‐1 in outlet surface water (Table 7).

3‐ The median concentrations of PO4 in inlet surface water were very low and ranged from below the ‐1 3‐ detection limit to 0.036 mg P L (Table 8). Median concentrations of PO4 were also similarly low in outlet surface water (Table 8). The White Springs and Benson’s Pond Bogs were the only bogs in which 3‐ there were clear differences in PO4 concentration between median inlet and outlet water (Table 8). The median concentrations of TP ranged from 0.014 to 0.126 mg P L‐1 in inlet surface water and from 0.021 to 0.137 mg P L‐1 in outlet surface water (Table 8).

+ ‐ The concentrations of NH4 , NO3 and DON in all bogs varied relatively little in both inlet and outlet surface water and remained generally less than 1.5 mg N L‐1 during the year (Fig. 12). The concentrations of PON were more variable but were in the same general range (Fig. 12). In some cases, concentrations of nitrogen forms changed abruptly during flooding events, but these changes were generally fairly low in magnitude, short in duration and varied greatly among bogs. For example, PON increases were observed in both inlet and outlet surface water during the 2013 harvest flood (Fig. 13). In inlet water, this increase was greatest in Lincoln, Rocky Pond and White Springs Bogs but much less in Benson's Pond, Pierceville and State Bogs (Fig. 13). In outlet water, this increase occurred in Lincoln and Pierceville Bogs, was relatively small in Benson’s Pond and was absent in Rocky Pond, State and White Springs Bogs (Fig. 13).

3‐ In four of six bogs, the concentrations of PO4 in inlet surface water varied relatively little over time and did not change in response to the timing of bog flooding (Fig. 14). Pierceville Bog was a notable 3‐ exception, in which both PO4 and TP increased in inlet surface water during the Fall 2012 and Fall 2013 3‐ floods (Fig. 10). In three of six bogs, PO4 and TP concentrations also varied little over time (Fig. 14) but 3‐ 3‐ both PO4 and TP increased during the fall 2012 and fall 2013 floods in Pierceville Bog (Fig. 14), PO4 and 3‐ TP increased during the Fall 2013 flood in White Springs Bog (Fig. 15) and TP but not PO4 increased during the fall 2012 and 2013 floods in Lincoln Bog (Figs. 14, 15). Long Tail vs Closed Loop There was no evidence that concentrations of TN decreased significantly after passage through the long tail outlet channels of the three long‐tail bogs compared with concentrations at the bog outlets (Fig. 16). In the Pierceville and White Springs Bogs during most of the year TN concentrations were actually higher at the end of the long tail than before the start of the long tail channel at the bog outlet. There was also 3‐ not evidence that PO4 or TP concentrations decreased after passage through long tail outlet channels (Fig. 17). On average, there was almost no change in TP or TDN between the bog outlet and the end of the long tail channel during harvest floods and a small increase in TP and TDN at the end of the long tail channels compared with bog outlets during non‐flood conditions (Fig. 18). There was a larger increase in TDN at the end of the long tail channels compared with bog outlet during the winter floods. On average, TN was higher at the end of the long tail channels compared with bog outlets in the fall harvest and non flood conditions but lower at the end of long tail channels during winter floods (Fig. 18). 16

Net Nutrient Fluxes Fluvial flux is calculated based on the change of incoming and outgoing surface water concentrations only, with positive fluxes indicating a net export of nutrient from the bog and negative fluxes indicating the bog serves as a nutrient sink. The fluvial flux of TDN, ranged from ‐2.36 to 3.84 lb/ac during harvest floods and from ‐1.20 to 10.59 lb/ac during winter floods (Table 10). The fluvial flux of TN during harvest floods ranged from ‐4.40 to t0 13.02 lb/ac (Table 10). Fluvial flux of TN could only be calculated for two winter flood events, which had fluxes of ‐0.50 and ‐0.57 lb/ac (Table 10). The fluvial flux of TP ranged from 0.10 to 5.67 lb/ac during harvest floods and from ‐0.35 to 1.68 lb/ac during winter floods (Table 10). Flux was also calculated to take into account nitrogen deposition by rain and loss of water by groundwater seepage. The net TDN flux including precipitation ranged from ‐2.43 to 2.97 lb/ac during harvest floods and from ‐2.29 to 6.84 lb/ac during winter floods (Table 10). The flux including precipitation of TN ranged from ‐2.51 to 11.39 lb/ac during harvest floods (Table 10). The fluxes including precipitation of TN measured during winter floods on two bogs were ‐0.58 and ‐2.15 lb/ac (Table 10). The flux including precipitation of TP ranged from ‐0.01 to 4.81 lb/ac during harvest floods and from ‐0.75 to 0.86 lb/ac during winter floods (Table 10). The average net fluvial flux of TDN during harvest floods for closed loop bogs was higher than that for long tail bogs (Figure 19). The average net fluvial flux of TDN during winter floods was almost the same for closed loop bogs as for long tail bogs (Figure 19). During harvest floods, the average net fluvial flux of TN for closed loop bogs was lower than for long tail bogs (Figure 19). Closed loop bogs had higher average net TP fluvial fluxes than long tail bogs during both harvest and winter floods (Figure 19). The average flux including precipitation of TDN was lower in long tail bogs than in closed loop bogs during both harvest and winter floods (Figure 20). The average flux including precipitation of TN was higher in long tail bogs than in closed loop bogs during harvest floods (Figure 20). For TP, the average flux including precipitation was higher in closed loop bogs than in long tail bogs during both harvest and winter floods (Figure 20).

17

Discussion Bog Selection and Management The bogs selected for this study were of size, configuration, age and condition typical of cranberry farms in the region. They also received typical management of flooding for fall harvests and winter frost protection. The duration of the harvest floods varies based on the time required to move water onto and off of the bog, the availability of equipment, manpower and weather. Despite variation in duration of harvest floods, none was exceptional and all fell within the range of standard practices. Rates of fertilizer application for bogs in this study were also typical and with the range of common practice for southeastern MA. Fertilizer application rates in any one year vary based on the age and condition of cranberry vines but all bogs received relatively similar and typical fertilizer application rates in the years preceding and during this study. The average yield across all six study bogs of 178 barrels/ac in 2008‐ 2011 and 183 barrels/ac in both 2012 and 2013 were slightly higher than averages for the entire state of MA, 162 barrels/acre from 2008 to 2011, 163 barrels/ac in 2012 and 139 barrels/ac in 2013 (USDA 2014). There was no evidence that the patterns of nutrient concentration observed in this study were in any way the result of unusual or atypical bog management that would have either increased or decreased nutrient concentrations.

This study did not consider less typical "flow through" bogs in which bog beds are not physically separated from surface water bodies by dikes. Flow through bogs represent a relatively small and declining proportion of all cranberry bogs in operation in MA.

While the six bogs examined in this study do not encompass the full range of cranberry bog types and management in MA coastal watersheds, the inclusion of six cranberry bogs substantially expanded the number of bogs from which information on nutrient concentrations and exchanges is available.

Groundwater The similarity of concentrations of all forms of dissolved nitrogen and phosphorus measured in groundwater up‐ and down‐gradient of cranberry bogs in his study provide no clear evidence that any of these solutes moved in significant amounts between bogs and the adjacent groundwater. The + ‐ dominance of NH4 and DON in groundwater and the low amounts of NO3 were typical of groundwater from relatively forested or rural regions of southeastern MA (Kroeger et al. 2006). This was consistent 3‐ with the study bogs locations in zones with relatively low housing density. The very low levels of PO4 in groundwater are consistent with very high adsorption of P in well aerated soils with high iron content such as those that occur in southeastern MA.

+ There were two instances, in State and Pierceville Bogs, where modest increases of groundwater NH4 concentrations measured downgradient of bogs in the fall of 2013 indicated that some exchange into the groundwater may have occurred. Neither of these was clearly associated with the timing of the 2013 + fall harvest flood and the magnitude of these patterns was low. Even if NH4 had exchanged into the + groundwater from bogs, the likelihood that NH4 would move through groundwater to surface waters is low because of the presence of cation exchange capacity in soils from the glaciated Northeast US region ‐ (Cornell University Cooperative Extension 2007). Concentrations of NO3 , which would be more likely to 18

‐ move from soils to groundwater, were uniformly low and there was no evidence that NO3 moved from bogs to groundwater.

Concentrations measured in groundwater from a series of shallow wells adjacent to bogs cannot provide quantitative information on the rates of exchange of water (and hence nutrients) between the bog and the adjacent groundwater. This is because groundwater, particularly in regions that potentially contain pockets of fine textured materials or deposits of organic material, can be heterogeneous and may move at substantially different rates over relatively short distances and water sampled by groundwater wells may be moving at different rates. What our sampling did show, however, was that there were no instances in which patterns of concentrations indicated that substantial movement of nutrients from bogs to shallow adjacent groundwater occurred.

Surface Waters The median TN concentrations in inlet and outlet surface waters were relatively low and similar (within ~30% of each other). There was higher variation in TN concentration between bogs than between inlets versus outlets. The two bogs in the least developed surroundings (Rocky Pond and White Springs, which are both located in the Myles Standish State Forest) had the lowest inlet TN concentrations. During the majority of the year, our measurements suggest that outlet concentrations of TN are influenced more by the overall watershed loading than by cranberry agriculture practices. However, during flood events, the large spikes in nitrogen concentrations often observed overwhelm the background levels of nitrogen and appear to be a result of flooding practices.

The TN in both the inlets and outlets was dominated by the organic forms of nitrogen rather than the inorganic forms of nitrogen. Spikes in TN concentration associated with flooding events were generally due to increase in organic forms of N, though in two cases (Rocky Pond harvest 2013 and White Springs winter 2013‐14) spikes in TN were dominated by increases in NO3. The increases of organic forms of nitrogen is consistent with the flooding practices where leaves and berries are agitated in the water.

The patterns observed in surface water nitrogen concentrations did not clearly group by the closed loop or long tail bog configurations. Other factors appear to be more important in determining how bog concentrations vary than the whether a bog is a closed loop or long tail configuration. The result that surface water concentrations generally either stayed the same or increased as the water traveled down the long tail was counter‐intuitive to our original hypothesis. The difference between natural stream flow and how water passes through the long tails provides a potential explanation for this difference. In natural streams and wetlands where flow is faster, less attenuation of nutrients is observed. In the case of cranberry bogs, flow is artificially controlled such that during most of the year, there is low flow into the long tails but after a flood event, a large volume of water is released in a short period of time, resulting in relatively high flow rates that are not conducive to large amounts of nutrient attenuation. The one exception observed in this study was that TN appeared to be removed as water travelled down the long tail during winter floods. 19

Nutrient Fluxes At the beginning of this project we hypothesized that a long tail at the exit of the bog would provide a substrate and time for attenuation of nutrients in the water leaving the bog. Comparing the harvest flood fluvial fluxes between closed loop and long tail bogs, indicates that there are not large differences in nutrient export between bog types. The fluvial fluxes of TDN and TP were higher in the closed loop bogs than the long tail bogs, suggesting a potential advantage of long tail bogs for retention of TDN and TP; however, there is significant variability between individual bogs of each type, which indicates that a number of other factors may be equally important to bog configuration in determining nutrient fluxes. For TN, the long tail bogs had an average higher fluvial flux during harvest floods than closed loop bogs. This may be a result of the flood release waters scouring the sides of channels (that generally remain dry) and collecting leaf litter and sediment particles.

The average fluvial flux of TDN during winter floods was very similar between closed loop and long tail bogs. Lower fluxes of TP in long tail bogs during winter floods suggest that in this case, the long tail does provide an opportunity for nutrient attenuation, which may occur as sediments suspended in the flood release waters settle out in the channel or by some of the TP in the flood release waters adsorbing to exposed sediments in the channel. As with the harvest fluxes, the high variability between individual bogs of each type during winter floods, suggest that additional parameters are likely important for determining fluxes.

To put the fluxes observed during this study in perspective, the harvest flood fluxes were compared to those observed by a previous study of non flow‐through bogs (DeMoranville and Howes, 2005). The average fluvial flux of TN during harvest floods was slightly higher in this study than the earlier study (Fig. 21), however, the difference was not statistically significant (t‐test, p=0.9). The average fluvial flux of TP during harvest floods in this study was also slightly higher than that observed in the earlier study (Fig. 21), but again the difference was not statistically significant (t‐test, p=0.6). While there was relatively high variability in the magnitude of nutrient fluxes between individual bogs, the similarity between the average results found here and in the earlier study indicate that do represent an accurate range of fluxes. Therefore, this study supports the loading values for non flow‐through cranberry bogs currently being used by the Massachusetts Estuaries Project (MEP) as reasonable estimates.

While this study looking at six bogs is an important expansion of existing studies on nutrient release from cranberry bogs in Southeastern MA, we have still sampled a relatively small portion of the existing cranberry bogs. The high variability between bogs, and even between events on the same bog, observed in this study make it clear that there are a number of factors influencing nutrient loss. More research comparing differences other than bog configuration should help provide insight into the importance of various factors for determining the nutrient flux from different types of bogs.

Particularly given this variability, it is very encouraging that the average fluxes between this study and DeMoranville and Howes (2005) were so similar. The MEP estimates appear to be useful numbers for large scale modeling, however, determining the nutrient loading of any one specific bog remains difficult. Using loading estimates very similar to ours, the analyses done by the Massachusetts Estuaries 20

Project indicate that cranberry bogs can be significant fractions of total watershed nitrogen loading when there are a high density of bogs in the watershed.

21

References Cornell University Cooperative Extension 2007. Cation exchange capacity. Agronomy Fact Sheet 22. Department of Crop and Soil Sciences, Cornell University, Ithaca, NY. http://nmsp.cals.cornell.edu/publications/factsheets/factsheet22.pdf. Accessed June 29, 2015.

DeMoranville, C. and B. Howes (2005) Phosphorus Dynamics in Cranberry Production Systems: Developing the Information Required for the TMDL Process for 303D Water Bodies Receiving Cranberry Bog Discharge. Final Project Report to Massachusetts Department of Environmental Protection.

Gore, J. A. (2007) Discharge measurements and streamflow analysis. In: Methods in Stream Ecology (Hauer, F. R. and Lamberti G. A., Eds.). Academic Press, Burlington, MA.

Howes, B. L. and J. M. Teal (1995) Nutrient balance of a Massachusetts cranberry bog and relationships to coastal eutrophication. Environmental Science & Technology 29(4): 960‐974.

Howes B.L., R.I. Samimy, E.M. Eichner, S.W. Kelley, J.S. Ramsey, D.R. Schlezinger (2013). Linked Watershed‐Embayment Model to Determine Critical Nitrogen Loading Thresholds for the Wareham River, Broad Marsh and Mark’s Cove Embayment System, Wareham, Massachusetts, SMAST/DEP Massachusetts Estuaries Project, Massachusetts Department of Environmental Protection. Boston, MA.

Kennedy, C. D. (2015) Hydrologic and nutrient response of groundwater to flooding of cranberry farms in southeastern Massachusetts, USA. Journal of Hydrology 525:441–449.

Kroeger, K.D., M. L. Cole and I. Valiela. 2006. Groundwater‐transported dissolved organic nitrogen from coastal watersheds. Limnology and Oceanography 51:2248‐2261.

Mahowald, N., et al. (2008), Global distribution of atmospheric phosphorus sources, concentrations and deposition rates, and anthropogenic impacts, Global Biogeochem. Cycles, 22, GB4026, doi:10.1029/2008GB003240.

Vet, R., et al. (2014) A global assessment of precipitation chemistry and deposition of sulfur, nitrogen, sea salt, base cations, organic acids, acidity and pH, and phosphorus. Atmospheric Environment, Volume 93, Pages 101‐116.

USDA (United States Department of Agriculture). 2014. Cranberry highlights. National Agricultural Statistics Service, New Jersey Field Office. http://www.nass.usda.gov/Statistics_by_State/New_Jersey/Publications/Cranberry_Statistics/CRA NSUM_Final.pdf. Accessed June 20, 2015. 22

Tables

Table 1. Bog Study Sites.

Bog name Site Area Location Bog type GPS Coordinates Abbrev. (acres)

Pierceville PV 3.7 Papermill Rd, West Wareham Long tail 41° 46’ 49.11”N 70° 46’ 13.45”W Rocky Pond – RP 4.2 Bare Hill Rd, Myles Standish Long tail 41° 53’ 10.03” N NW bog State Forest, Plymouth 70° 41’ 53.80” W White Springs WS 7.8 E Head Rd off Cranberry Rd, Long tail 41° 50’ 23.23” N Carver 70° 41’ 45.65”W Benson’s Pond BP 2.9 East St/Char Mar Lane, Closed loop 41° 49’ 24.44”N (East St) Middleborough 70° 46’ 18.10” W Lincoln Bog LB 5.2 Wareham St, Carver Closed loop 41° 49’ 48.48” N 70° 44’ 32.67” W State Bog SB 2.9 Cranberry Experiment Station, Closed loop 41° 46’ 01.22” N Wareham 70° 40’ 07.19” W

23

Table 2. Fertilizer rates and cranberry yields for four years before and two years during our study.

Nitrogen Fertilizer Phosphorus Bog Year applied Fertilizer applied Yield lbs/ac Nlbs/ac P barrels/ac Benson's Pond 2008 - 2011 Avg 25 6 112* 2012 37 7 207 2013 32 14 181 Lincoln Bog 2009 - 2011 Avg 34 8 226** 2012 36 5 188 2013 36 5 218 State Bog 2008 - 2011 Avg 43 10 71 2012 33 10 82 2013 35 10 115 Pierceville 2008 - 2011 Avg 34 8 252 2012 27 5 262 2013 27 5 196 Rocky Pond 2008 - 2011 Avg 40 11 235 2012 33 10 205 2013 33 10 194 White Springs 2008 - 2011 Avg 27 7 170 2012 28 5 152 2013 32 14 196 MEAN all bogs 2008 - 2011 Avg 34 8 178 2012 33 7 183 2013 33 10 183 *2011 only (renovated 2009) **average 2009-2011

24

Table 3. Dates of Flood Events

Harvest 2012 Winter 2012‐2013 Harvest 2013 Winter 2013‐2014 No. No. No. No. Date Date of Date Date of Date Date of Date Date of Bog start end days start end days start end days start end days Bensons Pond 9/29 10/16 17 12/14 12/18 4 9/25 10/22 27 NA 1/13 NA Lincoln Bog 9/25 10/1 7 1/7 2/4 28 9/30 10/7 7 12/14 1/4 22 Pierceville 10/7 10/15 8 12/17 2/4 49 10/14 10/22 8 12/15 1/4 20 Rocky Pond 10/17 10/24 8 1/2 1/14 13 10/14 10/25 12 12/19 1/9 21 State Bog 9/30 10/5 6 1/3 2/1 30 10/1 10/7 7 12/23 1/10 19 White Springs 10/3 10/11 9 NA 2/7 NA 10/17 10/31 14 12/29 1/10 11

25

Table 4. Median nutrient concentrations in bog source waters.

nNH4 NO3 DON PON TN PO4 TP Bog (mg L ‐1 )(mg L ‐1 )(mg L ‐1 )(mg L ‐1 )(mg L ‐1 )(mg L ‐1 )(mg L ‐1 ) Benson's Pond 12 0.011 0.011 0.343 0.182 0.534 BMDL 0.045 Lincoln Bog 12 0.011 0.025 0.206 0.408 0.769 0.008 0.039 State Bog 18 0.021 0.011 0.205 0.035 0.316 BMDL 0.018 Pierceville 14 0.010 0.021 0.244 0.140 0.552 0.017 0.091 Rocky Pond 15 0.007 BMDL 0.170 0.049 0.219 BMDL 0.014 White Springs 9 0.010 0.004 0.211 0.071 0.357 BMDL 0.015

26

Table 5. Nitrogen concentrations in groundwater.

Groundwater Concentrations ‐1 ‐1 ‐1 ‐1 NH4 (mg L )NO3 (mg L ) DON (mg L )TDN (mg L ) Bog n Median Min Max Median Min Max Median Min Max Median Min Max Benson's Pond Upgradient 16 0.015 BMDL 0.030 0.045 BMDL 6.272 0.315 0.000 1.207 0.426 0.056 6.905 Downgradient 21 0.019 BMDL 1.699 0.048 BMDL 1.890 0.164 0.000 0.813 0.620 0.077 10.745 Lincoln Bog Upgradient 16 0.020 BMDL 0.792 0.078 BMDL 3.413 0.126 0.012 0.345 0.367 0.090 3.489 Downgradient 16 0.040 BMDL 0.112 0.008 BMDL 0.590 0.156 0.000 0.371 0.206 0.069 0.710 State Bog Upgradient 29 0.016 BMDL 0.198 0.438 BMDL 1.568 0.170 0.000 1.297 0.731 0.173 8.400 Downgradient 31 0.019 BMDL 3.335 0.197 BMDL 7.136 0.156 0.000 4.879 1.596 0.185 9.297 Pierceville Upgradient 14 0.006 BMDL 0.091 0.044 BMDL 0.547 0.122 0.000 1.378 0.330 0.079 0.872 Downgradient 19 0.426 BMDL 3.481 0.009 BMDL 1.001 0.252 0.000 1.753 0.867 0.314 4.650 Rocky Pond Upgradient 41 0.010 BMDL 0.723 0.013 BMDL 0.900 0.097 0.000 0.689 0.171 0.035 1.104 Downgradient 32 0.043 BMDL 0.378 0.011 BMDL 1.503 0.078 0.000 0.442 0.239 0.045 1.944 White Springs Upgradient 23 0.086 BMDL 0.344 0.011 BMDL 2.450 0.201 0.000 1.671 0.480 0.079 3.772 Downgradient 20 0.012 BMDL 0.369 BMDL BMDL 0.112 0.110 0.000 0.694 0.271 0.036 0.797

27

Table 6. Phosphorus concentrations in groundwater.

Groundwater Concentrations PO4 (mg L‐1)TP (mg L‐1) Bog n Median Min Max Median Min Max Benson's Pond Upgradient 16 BMDL BMDL 0.012 0.033 BMDL 0.058 Downgradient 21 BMDL BMDL 0.029 0.036 BMDL 0.102 Lincoln Bog Upgradient 16 BMDL BMDL 0.033 0.033 BMDL 0.082 Downgradient 16 BMDL BMDL 0.013 0.031 BMDL 0.225 State Bog Upgradient 29 BMDL BMDL 0.177 0.037 BMDL 0.303 Downgradient 31 BMDL BMDL 0.378 0.038 BMDL 0.698 Pierceville Upgradient 14 BMDL BMDL 0.012 0.020 BMDL 0.059 Downgradient 19 BMDL BMDL 0.084 0.054 BMDL 0.231 Rocky Pond Upgradient 41 BMDL BMDL 0.025 0.017 BMDL 0.090 Downgradient 32 BMDL BMDL 0.264 0.022 BMDL 0.663 White Springs Upgradient 23 BMDL BMDL BMDL 0.022 BMDL 0.073 Downgradient 20 BMDL BMDL BMDL 0.021 BMDL 0.122

\

28

Table 7. Nitrogen concentrations in surface waters.

Surface water Concentrations ‐1 ‐1 ‐1 ‐1 ‐1 NH4 (mg L )NO3 (mg L ) DON (mg L )TNPON (mg L ) (mg L ) Bog n Median Min Max Median Min Max Median Min Max Median Min Max Median Min Max Benson's Pond Input 10 0.014 BMDL 0.201 0.020 BMDL 0.169 0.336 0.074 0.763 0.257 0.021 0.461 0.660 0.390 1.165 Output 17 0.023 BMDL 0.585 0.016 BMDL 0.178 0.174 0.000 0.478 0.304 0.018 0.592 0.607 0.081 1.193 Lincoln Bog Input 7 0.018 BMDL 0.062 0.038 0.004 0.134 0.246 0.000 0.330 0.226 0.100 1.045 0.450 0.222 1.174 Output 18 0.014 BMDL 0.300 0.005 BMDL 0.622 0.246 0.000 0.674 0.379 BMDL 1.733 0.563 0.204 2.646 State Bog Input 14 0.022 BMDL 1.061 0.013 BMDL 1.093 0.236 0.000 0.883 0.171 BMDL 2.095 0.793 0.256 2.467 Output 12 0.025 BMDL 1.061 0.006 BMDL 0.037 0.304 0.028 1.143 0.449 BMDL 2.095 0.763 0.263 2.467 Pierceville Input 30 0.018 BMDL 0.842 0.016 BMDL 0.135 0.288 0.000 1.719 0.121 BMDL 0.887 0.445 0.139 2.415 Output 35 0.024 BMDL 0.529 0.012 BMDL 1.392 0.271 0.000 1.076 0.186 0.041 3.211 0.588 0.268 4.342 Rocky Pond Input 15 0.008 BMDL 0.117 0.004 BMDL 1.498 0.175 0.000 0.602 0.049 BMDL 0.507 0.288 0.117 1.535 Output 34 0.027 BMDL 0.632 0.023 BMDL 0.256 0.160 0.000 0.823 0.046 BMDL 1.112 0.314 0.032 1.648 White Springs Input 11 0.018 BMDL 0.191 0.003 BMDL 0.016 0.089 0.005 0.727 0.030 BMDL 0.529 0.262 0.049 1.195 Output 28 0.023 BMDL 0.511 0.006 BMDL 3.332 0.157 0.000 0.416 0.078 BMDL 0.471 0.343 0.035 0.849

29

Table 8. Surface water phosphorus concentrations at all six study sites.

Surface water Concentrations ‐1 ‐1 PO4 (mg L ) TP (mg L ) Bog n Median Min Max Median Min Max Benson's Pond Input 10 0.008 BMDL 0.033 0.041 0.033 0.082 Output 17 0.018 BMDL 0.048 0.056 0.017 0.108 Lincoln Bog Input 7 0.014 BMDL 0.067 0.046 0.023 0.104 Output 18 0.012 BMDL 0.168 0.137 BMDL 0.794 State Bog Input 14BMDLBMDL0.0150.031BMDL0.091 Output 12 BMDL BMDL 0.023 0.043 0.011 0.106 Pierceville Input 30 0.036 BMDL 0.372 0.126 0.029 1.008 Output 35 0.030 BMDL 0.332 0.096 0.033 0.654 Rocky Pond Input 15BMDLBMDL0.0190.014BMDL0.089 Output 34 BMDL BMDL 0.041 0.021 BMDL 0.126 White Springs Input 11 0.016 BMDL 0.153 0.051 BMDL 0.397 Output 28 0.041 BMDL 0.339 0.084 BMDL 0.441

30

Table 9. Water Balance floods in thousand gallons (Tgal).

Precipitation Volume on Precipitation during flood Volume off Seepage Bog Flood Bog area at surface during inflow (post inflow) at surface estimate (ac) (Tgal) (Tgal) (Tgal) (Tgal) (Tgal) Bensons Pond Fall 2012 2.9 1,266 123 37 1,265 338 Bensons Pond Winter 201213 2.9 no data 0 0 0 1,411 Bensons Pond Fall 2013 2.9 4,110 0 57 3,872 338 Bensons Pond Winter 201314 2.9 no data 0 0 0 1,411 Lincoln Bog Fall 2012 5.2 7,123 0 379 7,123 608 Lincoln Bog Winter 201213 5.2 4,952 31 248 6,737 2,542 Lincoln Bog Fall 2013 5.2 7,123 0 56 7,123 608 Lincoln Bog Winter 201314 5.2 4,952 150 352 6,737 2,542 Pierceville Fall 2012 3.7 5,184 28 7 4,184 436 Pierceville Winter 201213 3.7 4,212 341 202 3,510 1,824 Pierceville Fall 2013 3.7 5,533 0 8 5,059 436 Pierceville Winter 201314 3.7 3,589 108 252 3,977 1,824 Rocky Pond Fall 2012 4.2 1,469 0 141 1,309 494 Rocky Pond Winter 201213 4.2 1,914 2 25 484 2,065 Rocky Pond Fall 2013 4.2 2,237 9 11 2,185 494 Rocky Pond Winter 201314 4.2 2,953 60 247 2,945 2,065 State Bog Fall 2012 2.9 2,514 114 13 2,265 342 State Bog Winter 201213 2.9 2,656 1 157 1,051 1,431 State Bog Fall 2013 2.9 1,590 0 38 1,050 342 State Bog Winter 201314 2.9 1,260 52 163 660 1,431 White Springs Fall 2012 7.8 5,050 29 74 5,034 917 White Springs Winter 201213 7.8 3,002 0 0 2,625 917 White Springs Fall 2013 7.8 5,050 18 31 5,034 917 White Springs Winter 201314 7.8 3,002 390 47 2,625 917

31

Table 10. Fluxes of nitrogen and phosphorus during floods.

Load including precipitation Load fluvial only Event Bog Net TDN Net TN Net TP Net TDN Net TN Net TP (lb/ac) (lb/ac) (lb/ac) (lb/ac) (lb/ac) (lb/ac) Harvest 2012 Benson's Pond ‐0.27 ‐0.41 ‐0.01 0.03 ‐0.02 0.24 Lincoln Bog 2.97 5.81 4.81 3.84 7.05 5.67 State Bog 0.23 2.52 0.15 0.24 2.54 0.57 Pierceville ‐1.63 0.24 1.51 ‐1.15 1.29 4.21 Rocky Pond ‐0.41 ‐0.42 0.06 ‐0.31 ‐0.32 0.09 White Springs 0.12 0.49 0.42 0.69 0.61 Harvest 2013 Benson's Pond ‐1.62 ‐1.87 0.33 ‐1.23 ‐1.14 0.76 Lincoln Bog ‐1.02 1.60 2.26 ‐0.88 2.31 2.71 State Bog ‐2.43 ‐4.46 0.07 ‐2.36 ‐4.40 0.10 Pierceville ‐0.11 11.39 0.60 0.30 13.02 0.91 Rocky Pond ‐1.69 ‐2.51 0.07 ‐1.46 ‐2.26 0.14 White Springs ‐0.24 ‐0.78 0.88 ‐0.07 ‐0.61 1.21 Winter 2012‐2013 Benson's Pond Lincoln Bog ‐0.22 0.86 1.46 1.68 State Bog Pierceville ‐2.29 ‐2.15 ‐0.17 ‐1.20 ‐0.50 0.40 Rocky Pond ‐0.80 ‐0.58 0.04 ‐0.79 ‐0.57 0.09 White Springs Winter 2013‐2014 Benson's Pond Lincoln Bog 0.49 ‐0.69 1.54 ‐0.35 State Bog 1.56 0.12 1.65 0.12 Pierceville ‐1.22 ‐0.75 0.05 ‐0.08 Rocky Pond ‐0.61 ‐0.42 ‐0.25 0.19 White Springs 6.84 ‐0.13 10.59 ‐0.13

32

Figures

Figure 1. Overview map of the locations of six bog study sites.

33

40 20 NH4 Source water DON Source water 35 30 15 25 20 10

Frequency 15 Frequency 10 5 5 0 0

‐1 ‐1 45 Bin (mg L ) 30 Bin (mg L ) NO3 Source water PON Source water 40 25 35 30 20 25 15 20

15 Frequency 10 Frequency 10 5 5 0 0

Bin (mg L‐1) Bin (mg L‐1) Figure 2. Distribution of nitrogen concentrations in bog source waters.

34

60 PO4 Source water 50

40

30

Frequency 20

10

0

Bin (mg L‐1) 25 TP Source water

20

15

10 Frequency

5

0

Bin (mg L‐1)

Figure 3. Distribution of phosphorus concentrations in bog source water samples. 35

BP Source NH4 NO3 )

-1 1.5 DON PON 1.0

0.5

Nitrogen (mg L Nitrogen (mg 0.0 LB Source )

-1 1.5

1.0

0.5

Nitrogen (mg L (mg Nitrogen 0.0 SB Source )

-1 1.5

1.0 )

1 0.5 ‐ L

Nitrogen (mg L Nitrogen (mg 0.0 (mg PV Source )

-1 1.5

1.0 Nitrogen

0.5

Nitrogen (mg L (mg Nitrogen 0.0 RP Source )

-1 1.5

1.0

0.5

Nitrogen (mg L Nitrogen (mg 0.0 WS Source )

-1 1.5

1.0

0.5

Nitrogen (mg L Nitrogen (mg 0.0

Figure 4. Nitrogen concentrations in the bog source waters over the course of the study period. 36

BP Source TP 0.40 PO4 ) -1 0.30

0.20

0.10

0.00

Phosphorus (mg L Phosphorus (mg LB Source TP 0.40 PO4 ) -1 0.30

0.20

0.10

0.00

Phosphorus (mg L Phosphorus (mg SB Source TP 0.40 PO4 ) -1 0.30

0.20 ) 1 ‐

L 0.10

0.00 (mg

Phosphorus (mg L Phosphorus (mg TP ) PV Source -1 0.40 PO4

0.30

0.20 Phosphorus 0.10

Phosphorus (mg L Phosphorus (mg 0.00 TP ) RP Source -1 0.40 PO4

0.30

0.20

0.10

Phosphorus (mg L Phosphorus (mg 0.00 TP ) WS Source -1 0.40 PO4

0.30

0.20

0.10

Phosphorus (mg L Phosphorus (mg 0.00

Figure 5. Phosphorus concentrations in the bog source waters over the course of the study period.

37

NH4 Upgradient NH4 Downgradient 100 100

80 80

60 60

Frequency 40 40

20 Frequency 20

0 0

Bin (mg L‐1) Bin (mg L‐1) 90 90 NO3 Downgradient NO3 Upgradient 80 80 70 70 60 60 50 50 40 40 Frequency 30 30 20 20 10 10 0 0

Bin (mg L‐1) Bin (mg L‐1) 40 DON Upgradient 40 DON Downgradient 35 35 30 30 25 25 20 20 15 15 Frequency

10 Frequency 10 5 5 0 0

‐1 ‐1 Bin (mg L ) Bin (mg L )

Figure 6. Distribution of dissolved nitrogen concentrations in up‐ and downgradient groundwater samples.

38

120 120 PO Downgradient PO4 Upgradient 4 100 100

80 80

60 60

Frequency 40 40 Frequency 20 20

0 0

Bin (mg L‐1) Bin (mg L‐1) 45 TP Upgradient 45 TP Downgradient 40 40 35 35 30 30 25 25 20 20

Frequency 15 15 10 10 5 5 0 0

Bin (mg L‐1) Bin (mg L‐1)

Figure 7. Distribution of phosphorus concentrations in up‐ and downgradient groundwater samples.

39

BP Up NH4 BP Down NH4 8.0 NO3 8.0 NO3 ) DON) DON -1 -1 6.0 6.0

4.0 4.0

2.0 2.0

Nitrogen (mg L Nitrogen (mg 0.0 L Nitrogen (mg 0.0 LB Up LB Down 8.0 8.0 ) ) -1 -1 6.0 6.0

4.0 4.0

2.0 2.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 SB Up SB Down 8.0 8.0 ) ) -1 -1 6.0 6.0

4.0 4.0 ) 1 ‐ 2.0 2.0 L

Nitrogen (mg L Nitrogen (mg 0.0 L Nitrogen (mg 0.0 (mg PV Down PV Up 8.0

8.0 ) ) -1 -1 6.0 6.0

Nitrogen 4.0 4.0

2.0 2.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 RP Up RP Down 8.0 8.0 ) ) -1 -1 6.0 6.0

4.0 4.0

2.0 2.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 WS Up WS Down 8.0 8.0 ) ) -1 -1 6.0 6.0

4.0 4.0

2.0 2.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0

Figure 8. Mean nitrogen concentrations up‐ and downgradient over the course of the study.

40

Upgradient Downgradient BP TP BP TP 0.3 PO4 0.3 PO4 ) ) -1 -1

0.2 0.2

0.1 0.1

0.0 L Nitrogen (mg 0.0 PhosphorusL (mg LB LB 0.3 0.3 ) ) -1 -1

0.2 0.2

0.1 0.1

0.0 0.0 PhosphorusL (mg PhosphorusL (mg SB SB 0.3

0.3 ) ) -1 -1

0.2 0.2 )

1 0.1 ‐ 0.1 L

0.0 0.0 (mg

PhosphorusL (mg PhosphorusL (mg PV PV 0.3 0.3 ) ) -1 -1

0.2 0.2

Phosphorus 0.1 0.1

0.0 0.0 PhosphorusL (mg PhosphorusL (mg RP RP 0.3 0.3 ) ) -1 -1

0.2 0.2

0.1 0.1 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 WS WS 0.3 0.3 ) ) -1 -1

0.2 0.2

0.1 0.1

0.0 0.0 PhosphorusL (mg PhoshporusL (mg

Figure 9. Phosphorus concentrations in groundwater over the course of the study.

41

50 50 NH4 Inlet NH4 Outlet 40 40

30 30

20 20 Frequency

10 Frequency 10

0 0

‐1 ‐1 80 Bin (mg L ) 80 Bin (mg L ) NO3 Inlet NO3 Outlet 70 70 60 60 50 50 40 40

Frequency 30 30 20 20 10 10 0 0

Bin (mg L‐1) Bin (mg L‐1) 40 DON Inlet 40 DON Outlet 35 35 30 30 25 25 20 20 15 15 Frequency

10 Frequency 10 5 5 0 0

Bin (mg L‐1) Bin (mg L‐1) 40 PON Inlet 40 PON Outlet 35 35 30 30 25 25 20 20

Frequency 15 15 10 10 5 5 0 0

Bin (mg L‐1) Bin (mg L‐1)

Figure 10. Distributions of inorganic and organic nitrogen concentrations in surface water inlet samples and outlet samples.

42

60 60 PO4 Inlet PO4 Outlet 50 50

40 40

30 30

Frequency 20 20 Frequency 10 10

0 0

Bin (mg L‐1) Bin (mg L‐1) 25 TP Inlet 25 TP Outlet

20 20

15 15

10 10 Frequency

5 5

0 0

‐1 ‐1 Bin (mg L ) Bin (mg L )

Figure 11. Distributions of phosphorus concentrations in surface water inlet samples and outlet samples.

43

NH4 BP Input NH4 BP Output NO3 NO3 ) )

-1 DON -1 3.0 DON 3.0 PON PON 2.0 2.0

1.0 1.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 LB Input LB Output ) ) -1 -1 3.0 3.0

2.0 2.0

1.0 1.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 SB Input SB Output ) ) -1 -1 3.0 3.0

2.0 2.0 )

1 1.0 ‐ 1.0 L

Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 (mg PV Input PV Output ) ) -1 -1 3.0 3.0

2.0 2.0 Nitrogen

1.0 1.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 RP Input RP Output ) ) -1 -1 3.0 3.0

2.0 2.0

1.0 1.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 WS Input WS Output ) )

-1 3.0 -1 3.0

2.0 2.0

1.0 1.0 Nitrogen (mg L Nitrogen (mg L Nitrogen (mg 0.0 0.0

Figure 12. Nitrogen concentrations in surface water over the course of the study.

44

NH4 BP Input NH4 BP Output NO3 NO3 ) )

-1 DON -1 3.0 DON 3.0 PON PON 2.0 2.0

1.0 1.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L (mg Nitrogen 0.0 0.0 LB Input LB Output ) ) -1 -1 3.0 3.0

2.0 2.0

1.0 1.0 Nitrogen (mg L (mg Nitrogen Nitrogen (mg L Nitrogen (mg 0.0 0.0 SB Input SB Output ) ) -1 -1 3.0 3.0

2.0 2.0 )

1 1.0 ‐ 1.0 L

Nitrogen (mg L Nitrogen (mg Nitrogen (mg L (mg Nitrogen 0.0 0.0 (mg PV Input PV Output ) ) -1 -1 3.0 3.0

2.0 2.0 Nitrogen

1.0 1.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L Nitrogen (mg 0.0 0.0 RP Input RP Output ) ) -1 -1 3.0 3.0

2.0 2.0

1.0 1.0 Nitrogen (mg L Nitrogen (mg Nitrogen (mg L (mg Nitrogen 0.0 0.0 WS Input WS Output ) )

-1 3.0 -1 3.0

2.0 2.0

1.0 1.0 Nitrogen (mg L (mg Nitrogen L (mg Nitrogen 0.0 0.0

Figure 13. Nitrogen concentrations in surface water during the Harvest 2013 flood.

45

Inlet Outlet TP TP BP BP PO4 PO4) ) 1.0 1.0 -1 -1 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0.0 0.0 PhosphorusL (mg PhosphorusL (mg LB LB ) ) 1.0 1.0 -1 -1 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0.0 0.0 PhosphorusL (mg PhosphorusL (mg SB SB ) ) 1.0 1.0 -1 -1 0.8 0.8 0.6 0.6

) 0.4 1 0.4 ‐ L 0.2 0.2 0.0 0.0 (mg

PhosphorusL (mg PhosphorusL (mg PV PV ) ) 1.0

1.0 -1 -1 0.8 0.8 0.6 0.6

Phosphorus 0.4 0.4 0.2 0.2 0.0 0.0 PhosphorusL (mg PhosphorusL (mg RP RP ) ) 1.0

1.0 -1 -1 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0.0 0.0 PhosphorusL (mg PhosphorusL (mg WS WS ) 1.0 )

-1 1.0 -1 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0.0 0.0 PhosphorusL (mg PhosphorusL (mg

Figure 14. Phosphorus concentrations in surface water over the course of the study.

46

TP TP BP Output BP Input PO4 PO4) ) -1 0.6 -1 0.6

0.4 0.4

0.2 0.2

0.0 0.0 PhosphorusL (mg PhosphorusL (mg LB Input LB Output ) ) -1 -1 0.6 0.6

0.4 0.4

0.2 0.2

0.0 0.0 PhosphorusL (mg PhosphorusL (mg SB Input SB Output ) ) -1 -1 0.6 0.6

0.4 0.4 ) 1 ‐

L 0.2 0.2

(mg 0.0

0.0 PhosphorusL (mg PhosphorusL (mg PV Input PV Output ) ) -1 -1 0.6 0.6

0.4 0.4 Phosphorus 0.2 0.2

0.0 0.0 Phosphorus (mg L Phosphorus (mg PhosphorusL (mg RP Input RP Output ) ) -1 -1 0.6 0.6

0.4 0.4

0.2 0.2

0.0 0.0 PhosphorusL (mg PhosphorusL (mg WS Input WS Output ) ) -1 0.6 -1 0.6

0.4 0.4

0.2 0.2

0.0 0.0 PhosphorusL (mg PhosphorusL (mg

Figure 15. Phosphorus concentrations in surface water during the Harvest 2013 flood. 47

PV outlet long tail )

-1 4.0

3.0

2.0

1.0

0.0 RP Total NitrogenL Total (mg ) 1 ) ‐

-1 4.0 L

3.0 (mg 2.0

1.0

0.0 Nitrogen WS Total Nitrogen (mg L Nitrogen (mg Total )

-1 4.0

3.0

2.0

1.0

0.0 Total Nitrogen (mg L Nitrogen (mg Total

Figure 16. Total nitrogen concentrations in the bog outlet and long tail stations during the Harvest 2013 flood.

48

PV outlet long tail 0.5 0.4 0.3 )

-1 0.2 L 0.1 0.0 ) Total Phosphorus (mg Total 1 RP ‐ 0.5 L

0.4 (mg 0.3 )

-1 0.2 L 0.1 0.0 Total Phosphorus (mg Total Phosphorus WS 0.5 0.4 0.3 )

-1 0.2 L 0.1 0.0 Total Phosphorus (mg Total

Figure 17. Total phosphorus concentrations in the bog outlet and long tail stations during the Harvest 2013 flood.

49

Figure 18. Effect of the long tail channel on nitrogen concentrations under different conditions.

50

Figure 19. Nutrient fluxes during harvest and winter floods based on surface water concentrations entering and exiting the bogs.

51

Figure 20. Nutrient fluxes during harvest and winter floods when precipitation and an estimate of groundwater seepage are included.

52

Figure 21. Comparison of Harvest Flood Fluxes measured in this study with previous study.

53

Appendix A.

Figure A. Map of sampling locations at Benson’s Pond Bog.

Bog Site Latitude Longitude Sample Type Benson's Pond BP1 41°49'23.54"N 70°46'21.00"W surface water Benson's Pond BP2 41°49'22.66"N 70°46'14.58"W surface water Benson's Pond BP4 41°49'25.71"N 70°46'17.03" groundwater Benson's Pond BP5 41°49'22.61"N 70°46'14.63"W groundwater Benson's Pond BP6 41°49'23.54"N 70°46'21.80"W surface water Benson's Pond BP7 41°49'26.31"N 70°46'17.86"W groundwater Benson's Pond BP8 41°49'25.12"N 70°46'14.19"W groundwater Benson's Pond BP9 41°49'23.36"N 70°46'18.71"W groundwater Benson's Pond BP10 41°49'23.57"N 70°46'21.54"W groundwater

54

Figure B. Map of sampling locations at Lincoln Bog.

Bog Site Latitude Longitude Sample Type Lincoln Bog LB1 41°49'49.81"N 70°44'29.44"W surface water Lincoln Bog LB2 41°49'48.96"N 70°44'28.98"W surface water Lincoln Bog LB3 41°49'49.08"N 70°44'36.29"W surface water Lincoln Bog LB5 41°49'51.67"N 70°44'34.38"W groundwater Lincoln Bog LB6 41°49'48.75"N 70°44'28.57"W groundwater Lincoln Bog LB7 41°49'50.45"N 70°44'26.78"W surface water Lincoln Bog LB9 41°49'52.25"N 70°44'31.76"W groundwater Lincoln Bog LB10 41°49'50.34"N 70°44'35.99"W groundwater Lincoln Bog LB11 41°49'46.35"N 70°44'31.24"W groundwater Lincoln Bog LB12 41°49'47.31"N 70°44'30.20"W groundwater

55

Figure C. Map of sampling locations at State Bog.

Bog Site Latitude Longitude Sample Type State Bog SB1 41°45'59.30"N 70°40'3.04"W surface water State Bog SB3 41°46'3.94"N 70°39'58.55"W surface water State Bog SB5 41°46'5.91"N 70°40'7.70"W groundwater State Bog SB6 41°45'58.73"N 70°40'3.92"W groundwater State Bog SB7 41°45'58.42"N 70°40'4.82"W groundwater State Bog SB8 41°45'58.62"N 70°40'4.34"W groundwater State Bog SB9 41°45'58.90"N 70°40'3.53"W groundwater State Bog SB10 41°45'59.01"N 70°40'3.20"W groundwater State Bog SB11 41°46'3.30"N 70°40'0.61"W groundwater State Bog SB12 41°46'5.83"N 70°40'6.56"W groundwater State Bog SB13 41°46'5.88"N 70°40'7.05"W groundwater State Bog SB14 41°46'5.88"N 70°40'8.28"W groundwater State Bog SB15 41°46'5.86"N 70°40'8.91"W groundwater State Bog SB Blue 41°45'57.47"N 70°40'12.46"W groundwater State Bog SB Park 41°46'5.86"N 70°40'8.91"W groundwater

56

Figure D. Map of sampling locations at Pierceville Bog.

Bog Site Latitude Longitude Sample Type Pierceville PV1 41°46'40.87"N 70°46'6.92"W surface water Pierceville PV2 41°46'39.55"N 70°46'1.06"W surface water Pierceville PV3 41°46'41.34"N 70°45'59.40"W surface water Pierceville PV6 41°46'36.60"N 70°46'3.29"W groundwater Pierceville PV7 41°46'39.69"N 70°46'0.07"W groundwater Pierceville PV8 41°46'39.67"N 70°46'7.52"W surface water Pierceville PV9 41°46'59.00"N 70°45'59.78"W groundwater Pierceville PV10 41°46'41.03"N 70°46'6.29"W groundwater Pierceville PV11 41°46'40.32"N 70°46'3.49"W groundwater Pierceville PV12 41°46'38.16"N 70°46'6.99"W groundwater Pierceville PV13 41°46'35.33"N 70°46'0.90"W groundwater

57

Figure E. Map of sampling locations at Rocky Pond Bog.

Bog Site Latitude Longitude Sample Type Rocky Pond RP1 41°53'8.64"N 70°41'50.74"W surface water Rocky Pond RP2 41°53'7.23"N 70°41'52.47"W surface water Rocky Pond RP3 41°53'3.17"N 70°41'51.54"W surface water Rocky Pond RP4 41°53'6.77"N 70°41'52.29"W surface water Rocky Pond RP5 41°53'11.41"N 70°41'52.61"W surface water Rocky Pond RP6 41°53'12.69"N 70°41'54.91"W groundwater Rocky Pond RP7 41°53'6.73"N 70°41'52.09"W groundwater Rocky Pond RP8 41°53'6.96"N 70°41'47.47"W surface water Rocky Pond RP9 41°53'7.37"N 70°41'51.45"W groundwater Rocky Pond RP10 41°53'7.64"N 70°41'51.25"W groundwater Rocky Pond RP11 41°53'7.92"N 70°41'51.00"W groundwater Rocky Pond RP12 41°53'8.28"N 70°41'50.70"W groundwater Rocky Pond RP13 41°53'13.02"N 70°41'53.57"W groundwater Rocky Pond RP14 41°53'12.73"N 70°41'54.19"W groundwater Rocky Pond RP15 41°53'12.48"N 70°41'56.40"W groundwater Rocky Pond RP16 41°53'11.93"N 70°41'57.22"W groundwater Rocky Pond RP17 41°53'13.36"N 70°41'57.44"W groundwater

58

Figure F. Map of sampling locations at White Springs Bog.