URI Watershed Watch Program Bristol Harbor Monitoring Results May 2015

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1 University of Rhode Island Cooperative Extension URI Watershed Watch Natural Resources Science Dept. The Coastal Institute in Kingston 1 Greenhouse Road Kingston, RI Linda T Green, Program Director lgreen@uri.edu Elizabeth M. Herron, Program Coordinator eherron@uri.edu URI Watershed Watch Program Bristol Harbor Monitoring Results May 2015 Elizabeth Herron and Linda Green, URI Watershed Watch Water Quality Summary: An additional year of monitoring on more sites, with sites added in Mt Hope Bay, combined with another year of unique weather continues to strengthen our understanding of conditions in Bristol Harbor and adjacent waters. As discussed in previous reports, both the on-site monitoring and laboratory analyses indicate that with the exception of the Silver Creek outlet (#3), Bristol Harbor itself is in generally good condition. Nutrients were low to moderate, although in some cases quite variable between years and even sampling events. Dissolved oxygen levels were usually sufficient for most aquatic life; although recently (since 2011) there have been periods of low dissolved oxygenat a number of sites, which creates stressful conditions for species such as clams. Algae levels were generally in the low to moderate range, but algal blooms were noted at a number of sites. Mill Pond (#5) has had extended periods of elevated algae combined with higher bacteria levels, limiting recreational usage of the pond for a number of seasons. In the harbor, bacteria levels were often within both acceptable shellfishing and swimming criteria, but were generally higher in 2011 and 2012 than other years. Save Bristol Harbor (SBH) continues to use the data generated through this monitoring effort to target upsteam sources by adding additional upstream monitoring sites (#14 DaPonte Pond /Wood St. and #15 Silver Creek at Gooding Ave. in The need to better understand the Silver Creek watershed developed after the 2009 results identified the creek as a source of excess nitrogen and bacteria. Monitoring at the upstream sites strengthens the indications that the sources are upstream of where Silver Creek enters the harbor, but we haven t quite nailed down specific sources yet. The dynamic nature of the harbor ensures that there will be fluctuations in water quality from year to year particularly in response to variable weather patterns. The commitment of Save Bristol Harbor to comprehensive, long-term data collection in order to establish and confirm baseline conditions and track trends is commendable and vital for protecting this important resource. Ideally, a full ten years of data are typically needed to develop good baseline data. During that time other hot spots may emerge, and most normal annual weather cycles will have been encountered. Continued expanded monitoring in the Silver Creek watershed to better bracket current problem areas is critical to identify sources and to affect solutions. Visible water quality improvement from watershed remediation efforts often lag behind the actual work, so there is a lot of work ahead for the members of this dedicated organization and its partners. With six years of monitoring data now available, Bristol Harbor and its watershed is much better understood now. University of Rhode Island, United States Department of Agriculture, and local governments cooperating. Cooperative Extension in Rhode Island provides equal opportunities without regard to race, age, color, national origin, sex or sexual preference, creed, or handicap. 1

2 Introduction: For the sixth year volunteers coordinated by Save Bristol Harbor (SBH) monitored water quality monitoring in the Bristol Harbor watershed. Save Bristol Harbor s Predictive Habitat Model Committee began the water quality data collection phase of the model development process in cooperation with the University of Rhode Island (URI) Watershed Watch program in the spring of The committee, composed of scientists from Roger Williams and Brown Universities, SBH volunteers, as well as students from Mt. Hope High School and Roger Williams University, initially identified eight (8) monitoring sites around the perimeter of Bristol Harbor for monitoring. Dock and shoreline sites allowed easy and safe access for volunteers, and good distribution around the harbor (see Table and Figure 1a for harbor site information). As a result of finding high nitrogen and bacteria at #3 Silver Creek outlet, in 2010 three upstream sites were added, as well as an additional shoreline site closer to Narragansett Bay (#12 Herreshoff Dock). Two more upstream sites (#14 and #15) were added in 2012 to better target potential contamination sources. Successful monitoring efforts fostered town wide interest in water quality. Thus in 2014 sites along the Bristol shoreline on Mt Hope Bay were added, increasing understanding of local coastal conditions (see Table and Figure 1b for Mt Hope Bay site information). Brief descriptions of key parameters monitored, the criteria used to assess conditions, data summaries, including charts and discussions of the results, follow. An overview of the SBH monitoring program and parameters not discussed can be found in the Appendices. Figure 1a. Bristol Harbor Monitoring Sites Table 1a: Bristol Harbor Water Quality Monitoring Site Information ( sites) Site ID Site Description Site ID Site Description Site ID Site Description BH 1 Elks Club Dock BH 6 Sanroma BH 11 Silver West Branch BH 2 BH Inn Dock BH 7 BH Yacht Club Dock BH 12 Herreshoff Dock BH 3 Silver Creek Outlet BH 8 Brito Dock BH 13 Mack s Dock BH 4 Windmill Point Dock BH 9 Silver Bridge BH 14 DaPonte P/Wood St BH 5 Mill Pond BH 10 Silver East Branch BH 15 Gooding 2

3 Figure 1b. Mt Hope Bay Monitoring Sites Table 1b: Mt Hope Bay Water Quality Monitoring Site Information (2014 sites) Weather summary: Weather can significantly affect water quality, often confounding the assessment of water quality trends. Dry periods reduce stream flow, which can concentrate pollutants due to the loss of dilution. Alternatively dry weather can reduce pollutants that would be washed off the landscape with stormwater. Intense storms can dramatically increase runoff, often resulting in flooding or scouring of stream beds, both of which can increase movement of contaminants. These short-term events can result in significant variation of water quality conditions both between sites and overtime. This summary is based on weather data from the URI Weather Station in Kingston, RI, which may not exactly represent conditions in Bristol, but provides a good overview. Departures from normal were in relation to average temperature and precipitation values over the past thirty (30) years. The winter of 2014 (January March) was unusually cold, with temperatures several degrees below normal, resulting in ice forming in freshwater wetlands throughout the Bristol Harbor and Mt Hope Bay watersheds. Temperatures during most of the spring and summer (April August) remained about or below normal, which likely kept water temperatures somewhat lower than recent seasons. This was quite a departure from recent trends of warmer than normal temperatures recorded most months during the past six years (figure 2). With the exception of a slightly wetter than normal July, most of the growing season of 2014 was at or below normal precipitation levels (figure 2). In general, the current precipitation pattern seems to be one of periods of extreme rain events followed by dry periods. So while on an annual 3

4 Figure 2. Weather Summary Charts basis we are getting about average amounts of precipitation, we aren t getting the type of lazy summer rains that allows most of the precipitation to soak into the ground. Reduced groundwater often leads to dry streambeds, such as the condition of Silver Creek at Goodings Avenue during much of the summer (BH #15). In addition, we are seeing more heavy rain events, so called gully washers that create problems with erosion, flooding and increased stormwater runoff which carries more contaminants into receiving waters like Bristol Harbor or Mt Hope Bay. Field monitoring descriptions and summaries: Volunteers measured a number of key water quality indicators using field kits and instruments. These field measurements included temperature, dissolved oxygen (DO), salinity and also processing of samples for subsequent URIWW laboratory analysis of chlorophyll. Water samples were taken from a depth of half a meter (0.5m) from the surface or midway to the bottom using either a sampling pole or the one arm sampler the volunteer s arm. With the exception of temperature, duplicate samples were collected, and then duplicate measurements were made for each of the field parameters, with the average reported in Figures 3a, 3b and 3c. Dissolved oxygen and water temperature data tell us quite a bit about the health of the harbor. Oxygen is critical to the survival of most of the animals and plants that live in the water; generally the more oxygen, the healthier the ecosystem. Dissolved oxygen levels below 5 milligrams of oxygen per liter of water (mg/l) can be stressful to many forms of life, particularly at the juvenile life stage. Dissolved oxygen (DO) levels below 2 mg/l, also known as hypoxic or low oxygen, are lethal for many species. When DO concentrations fall below 0.5 mg/l, the water is called anoxic, and plants or animals that require oxygen can t survive in that area. Oxygen enters the water through two natural processes: (1) diffusion from the atmosphere and (2) photosynthesis by aquatic plants, including algae. The mixing of surface waters by wind and waves increases the rate at which oxygen from the air can be dissolved or absorbed into the water. 4

5 Figure 3a. Bristol Harbor Sites (Arranged from Southeast to Northwest) 2014 Field Dissolved Oxygen and Temperature Data Charts (Silver Creek #3 included in Figure 3b Silver Creek sites 5

6 Figure 3a (cont d.) Bristol Harbor Dissolved Oxygen and Temperature Data Charts 6

7 Figure 3b Dissolved Oxygen and Temperature Silver Creek Outlet and Upstream Sites 7

8 Figure 3b (cont d). Dissolved Oxygen and Temperature Silver Creek Outlet and Upstream Sites Temperature and salinity dictate the maximum DO that water can hold. As the temperature increases, the amount of oxygen decreases. Higher salinity and suspended solids levels also reduce the amount of oxygen. These factors combine to affect DO levels. For example, salt water at 5 C can contain up to 10.5 mg/l, but at 25 C it can only hold 7.0 mg/l. Whereas freshwater at 5 C can hold up to 12.8 mg/l, and 8.3 mg/l DO at 25 C. Dissolved oxygen is used by aquatic animals, as well as by plants and algae at night when there isn t any sunlight for photosynthesis. Thus DO levels are typically lowest early in the morning before the rising sun triggers photosynthesis and drives up DO levels. This is why SBH volunteers monitor around 6:00 am. Bacteria, fungi, and other decomposer organisms also reduce DO levels by consuming oxygen while breaking down organic matter, such as dead algae. Consequently algae blooms often cause DO declines when the algae die off and are decomposed. In 2014, DO at sites around Bristol Harbor were unusually low with nearly all reporting DO values within the stressful range at least once. Brito Dock (#8) where circulation and wind/wave mixing is often better, was the only harbor site where DO values remained Good all season. Sanroma (#6), which oftenhas had DO in the stressful range, had levels that dipped into lethal (< 2 mg/l) levels in early summer, with stressful values for much of the season. Dissolved oxygen at low levels at the Elk s Club (#1) was unexpected as that site has typically reported high DO concentrations. Silver Creek continued to have potentially stressful DO levels through much of the summer in its lower reaches sites #3 Silver Creek outlet and #9 Silver Bridge (Figure 3b). The upper reaches reflected the influence of slower flowing water and periods of low flow resulting from the dry summer season, reducing dissolved oxygen content. In fact Silver Creek at Gooding Ave. (#15) dried up completely for most of the late summer and fall. As in 2013, the impact of drier summer weather may also have driven the sharp DO decline at #14 and the other freshwater portions of Silver Creek. (Figure 3b). Dissolved oxygen levels at the Mt Hope Bay sites (BH#16 18) were generally in the good to fair (stressful) range (Figure 3c), and generally higher than the Harbor. 8

9 Figure 3c Dissolved Oxygen and Temperature Mt Hope Bay Sites Chlorophyll is a photosynthetic pigment found in all plants, including algae. Chlorophyll-a (chla) is the most common form and is analyzed by URIWW to estimate the abundance of algae in the water; the higher the chl-a level, the more algae. Like all plants, algae need sunlight to convert energy and nutrients (nitrogen and phosphorus) into food via photosynthesis. But algae are sensitive to harmful ultraviolet rays in sunshine. Thus chl-a levels tend to be higher just below the surface where they still have access to sunlight but the water filters out harmful wavelengths. Forming the base of the aquatic food web, algae are essential for a healthy harbor. They are eaten by zooplankton (microscopic animals) and small fish, which are eaten by larger animals. Animal abundance in an estuary often depends on the amount of algae. But too much algae, visible as green blooms or cloudy water, can result in poor water clarity, unpleasant odors, and lead to low oxygen particularly in bottom waters and sometimes even fish kills. The USEPA s National Coastal Assessment (NCA) program criteria for chl-a in northeastern estuaries are: <5 ppb (low) Good; 5 20 ppb (moderate) Fair; and > 20 ppb (elevated) Poor (USEPA 2008). 9

10 Figure 4a Bristol Harbor Sites Chlorophyll Data Charts (Arranged from Southeast to Northwest) (Silver Creek #3 included in Figure 4b Silver Creek sites) 10

11 Figure 4a (cont d.) Bristol Harbor Chlorophyll Data Charts 11

12 Figure 4b Silver Creek and Upstream Sites Chlorophyll Data Charts 12

13 Figure 4b (cont d) Silver Creek and Upstream Sites Chlorophyll Data Charts Bristol Harbor sites generally had moderate algae levels throughout the summer of 2014, an indicator of a healthy aquatic ecosystem (figure 4a). However algae bloom were evident at sites #5 Mill Pond, and #4 Windmill Point in early July, and a much larger bloom was recorded at #7 Bristol Harbor Yacht Club in June, with moderate levels the remainder of the season. Figure 4b shows that very significant algal blooms were again experienced in several of the Silver Creek sites (sites #3, #9, #10, #14), requiring a change in scale for these charts. The remaining Silver Creek sites tend to be flowing more often, thus floating algae are not able to accumulate in the same way as they can at the slower flowing sites. However an algal bloom was conspicuous in the fall at #11 Silver West and downstream at #15 Silver at Gooding Ave. The Mt Hope Bay sites had algal levels in the moderate to low range throughout the monitoring season. Figure 4c Mt Hope Bay Sites Chlorophyll Data Charts 13

14 Figure 4c (cont d) Mt Hope Bay Sites Chlorophyll Data Charts Shellfish Waters Bacteria Monitoring: Fecal coliform bacteria are an indicator of fecal contamination and potentially disease causing organisms or pathogens. The National Shellfish Sanitation Program has established the maximum acceptable level at 14 fecal coliform per 100 ml for waters from which shellfish can be harvested. The standard was designed to prevent human illness associated with the consumption of fresh and frozen shellfish, and thus is quite conservative. Because bacteria levels can fluctuate dramatically and be impacted by shortterm intermittent, localized sources such as waterfowl droppings, bacteria averages are typically reported as the geometric mean. This statistical method transforms a set of highly variable data (as bacteria can be) in order to better represent an average level. Thus a single very high sample will not overwhelm routine low or below detection values as might happen with arithmetic averaging. Fecal coliforms at all of the in-harbor sites continued to be variable in 2014, with sites frequently exceeding the shellfish criteria (figure 5). Most Bristol Harbor sites had geometric means that met the shellfishing standards (figure 6). Mill Pond (#5) and the Silver Creek sites and harbor sites adjacent to the creek s outflow continued to have extended periods of high fecal coliform levels throughout much of the monitoring season (Table 2). The data from Mt Hope Bay supported the belief that stormwater is a significant source of bacteria since high levels were noted at those sites when the Bristol Harbor system was also experiencing higher levels (June and October) in table 2). 14

15 Table Shellfish Bacteria Indicator Data Fecal Coliform Bacteria 15-May 12-Jun 10-Jul 7-Aug 4-Sep 2-Oct GEOMEAN Site ID Most Probable Number of Fecal coliform per 100 ml BH17 <10 31 <10 <10 <10 86 <10 BH18 <10 75 <10 10 <10 <10 <10 BH16 <10 <10 10 <10 <10 <10 <10 BH12 <10 <10 10 <10 <10 20 <10 BH1 <10 <10 87 <10 <10 75 <10 BH2 <10 <10 <10 10 <10 20 <10 BH <10 < BH5 124 > < BH6 10 < <10 20 <10 BH7 <10 <10 10 <10 <10 10 <10 BH8 <10 no sample <10 <10 <10 10 <10 BH3 < BH9 < < BH14 < < BH < BH10 < BH15 < <4 Dry Dry 9 Fecal coliform shellfish waters maximum = 14 CFU (or MPN) Figure 5. Multi-year Shellfish Bacteria Indicator Data Chart Figure Shellfish Bacteria Indicator Data Fecal Coliform Bacteria Chart Swimming Waters Bacteria Monitoring: Enterococcus spp. is the indicator bacteria for water quality at public beaches. Based on federal recommendations, the Rhode Island Department of 15

16 Environmental Management (RIDEM) set the primary contact (swimming) water quality standard for salt waters at a geometric mean of 35 enterococcus/100 ml for five or more samples. Geometric means for non-swimming fresh waters is 54 enterococcus/100 ml. To be more responsive to short term events, the Rhode Island Department of Health (RIHealth) adopted a single sample standard for swimming advisories at licensed beaches. For salt waters, the RIHealth beach standard is 104 most probable number (MPN - a statistically based reporting method) enterococci/100 ml, and 61 MPN/100 ml for fresh water. Table Swimming Bacteria Indicator Data: Enterococcus Bacteria 15-May 12-Jun 10-Jul 7-Aug 4-Sep 2-Oct GEOMEAN Site ID Most Probable Number of Enterococci per 100 ml BH17 <10 31 <10 <10 <10 86 <10 BH18 <10 75 <10 10 <10 <10 <10 BH16 <10 <10 10 <10 <10 30 <10 BH12 < <10 <10 74 <10 BH1 <10 <10 31 <10 <10 74 <10 BH2 <10 <10 <10 <10 < <10 BH <10 <10 < <10 BH5 20 > < >73 BH6 < <10 31 <10 BH7 <10 10 <10 <10 <10 31 <10 BH8 <10 no sample <10 <10 <10 52 <10 BH3 < >24196 >69 BH BH BH BH BH Dry Dry 189 Enterococcus salt water swimming single sample maximum = 104 MPN (35 geomean) Enterococcus fresh water single sample swimming maximum = 61 MPN (33 geomean) Figure 7. Multi-year Swimming Bacteria Indicator Chart In 2014, Enterococci values in the harbor were generally at levels considered safe for swimming (Table 3). However, Mill Pond (#5) exceeded safe swimming values 3 out of 6 times, and the Silver Creek Bridge site (#9) exceeded standards every time (not a good place fro swimming!) The drier conditions helped to keep values relatively low, as compared to 2012 values (figure 7). The remainder of the harbor and bay sites had seasonal geometric means well within the range considered safe for swimming (figure 8). As with fecal coliform, the Silver Creek systems had elevated enterococci levels throughout most of the season. Fortunately there is little to no swimming at these sites, but these results confirm that the creek and its watershed are likely a significant source of bacteria to the harbor. 16

17 Figure Bristol Harbor Sites Enterococci Bacteria Data Chart Bristol Harbor Nutrients, : Figure 9. Nutrients in the Coastal Zone (from Nitrogen is a natural and essential part of all marine ecosystems, as it is required for the growth of algae or phytoplankton, the primary producers that form the base of the harbor s food web (USEPA 2008; figure 9.) Excess nitrogen (N) adversely affects water quality and degrades habitat, ultimately impacting a wide range marine organisms including fish and shellfish. Nutrient overloading in marine ecosystems over-stimulates the growth of algae. Too much algae blocks sunlight to eelgrass, reducing the quality and area of this valuable nursery habitat and feeding ground. In addition, living and dying algae consume oxygen, leading to hypoxic (low oxygen) and anoxic (no oxygen) conditions. This process of water quality decline creates a chain reaction of negative impacts known as eutrophication. Poor water clarity, bad odors, stressed marine organisms and even fish kills are all symptoms of eutrophic conditions marine organisms including fish and shellfish (Howes et al. 1999). Total nitrogen, which includes both organic nitrogen (the N found in live, dead or decomposing plants and animals) as well as inorganic (the N that is dissolved into solution or bound to sediments, etc.) is widely used by scientists as an indicator of eutrophication or nutrient enrichment in marine waters. Levels below 350 parts per billion (ppb) are characteristic of low 17

18 nutrient waters, while values above ppb indicate nitrogen enrichment (Howes et al. 1999). Total nitrogen (TN) levels in most of the Bristol Harbor sites have been at low to moderate levels throughout most of the seasons since 2009, with the exception of Silver Creek outlet (#3) and upstream sites. In general, with exception of the Mill Pond (#5) and Sanroma (#6) sites, harbor annual TN averages have decreased or remained fairly stable since monitoring began (figure 10a). Total nitrogen values at #5 and #6 were unusually high in 2014, marking an increase in a trend that has been occurring for the past several years. The TN levels in the upstream tributaries (Silver Creek sites #9 - #15) continue to be very high, on average more than double the harbor sites (figure 10b). These data are particularly interesting because TN at the two downstream sites (#3 and #9) are lower than upstream sites and continue to decline. Total nitrogen at the upstream sites (#10 - #15) are quite high, with levels increasing are you move upstream. This suggests that there may be areas downstream from those stream segments that act as nitrogen sinks, where N is trapped and converted to its atmospheric form of nitrogen gas (N2 or N2O) by microbes, keeping it from flowing downstream. Protecting and enhancing these wetland areas helps reduce the impact from stormwater runoff. Maintaining the expanded monitoring upstream on Silver Creek will be important for tracking changes in incoming nitrogen, and perhaps to identify potential nitrogen sinks. The Mt Hope Bay sites were in the low to moderate range for TN. Figure 10a. Mt Hope Bay / Bristol Harbor Annual Total Nitrogen Data Chart Figure 10b. Mt Hope Bay / Bristol Harbor 2014 Total Nitrogen Data Chart Ammonia-nitrogen (NH4-N) is the most reactive form of N in aquatic systems. It is soluble, readily adheres to soils and sediments, and is converted to nitrate by microbes when oxygen is present through a process called nitrification. Nitrification requires a substantial amount of oxygen and 18

19 carbonate, thus can reduce both DO levels and ph slightly. In excess, ammonia-nitrogen can be toxic, particularly to early life stages of a variety of aquatic species. The level at which ammonia becomes lethal is dependent on water temperature, ph, and salinity, so site specific criteria are applied (see for more information). In general, given the conditions in Bristol Harbor, the chronic exposure critical ammonia level would be >650 ppb, much higher than the levels found at any Save Bristol Harbor site (Figure 11a). Interestingly, NH4-N levels in Silver Creek (#3) have declined to levels consistent, and even lower that the other harbor sites. Typically, NH4-N starts out low each season, peaking in mid-summer or early autumn, however in 2014 it increased with each successvie monthly sample, as illustrated by the 2014 monthly results (figure 11b). Mt Hope Bay sites were similar to the Bristol Harbor sites. Figure 11a. My Hope Bay / Bristol Harbor Annual Ammonia-Nitrogen Data Chart Figure 11b. Mt Hope Bay / Bristol Harbor 2014 Ammonia-Nitrogen Data Chart Nitrate + nitrite-nitrogen (NO3-N) is also a soluble form of N, and is readily taken up for use by algae and submerged vegetation during the summer growing season. When oxygen is absent (anoxic conditions), bacteria convert nitrate-n to gaseous N (N2 or N2O) through a process called denitrification, which removes N from the soil-water environment. In 2014 NO3-N levels were typically near or below the 10 ppb minimum detection level for most sites, except the Silver Creek sites, as well as Mill Pond and Sanroma. The Mt Hope Bay sites were also uniformly low. Results for the harbor sites have been relatively consistent since Figure 12a and 12b show the comparatively high levels in the upstream Silver Creek sites (#9 - #15). Nitrate + nitrite-n levels in these sites were high throughout most of the 2014 monitoring season (figure 12b). 19

20 Figure 12a. Mt Hope Bay / Bristol Harbor Annual Nitrate + nitrite-nitrogen Data Chart Figure 12b. Mt Hope Bay / Bristol Harbor 2014 Nitrate + nitrite-nitrogen Data Chart Dissolved Inorganic Nitrogen (DIN): The National Coastal Assessment program uses dissolved inorganic nitrogen (DIN), which includes ammonia-n (NH4-N) and nitrate + nitrite-n (NO3-N), as a key component in its coastal conditions assessment. For northeastern estuaries, DIN levels <100 ppb are considered Good, ppb considered Fair, and > 500 ppb considered Poor water quality (USEPA 2008). All of the harbor sites except #3 had higher DIN levels in 2014 than the previous year. In fact where Silver Creek discharged into the harbor (#3) exhibited a significant Figure 13a. Mt Hope Bay / Bristol Harbor Sites Annual Dissolved Inorganic Nitrogen Data Chart 20

21 decrease from the previous year, likely due to lower DIN values in the Silver Creek system overall too(figure 13a). The DIN levels in the harbor and Mt Hope Bay sites were in the moderate or fair range in 2014, with significant increases noted at Mill Pond (#5) and Sanroma (#6) (figure 13b). Those elevated DIN levels could drive algal production, resulting in blloms if sufficient phosphorus and other micronutrients were availalble. Figure 13b. Mt Hope Bay / Bristol Harbor Sites 2014 Dissolved Inorganic Nitrogen Data Chart Phosphorus: In most estuaries such as Bristol Harbor, nitrogen is the primary nutrient that controls algal and plant growth. However phosphorus (P) is also essential for life, and in salt water environments P levels are considered in relationship to N levels. If large amounts of nitrogen are available, with adequate phosphorus present, algal blooms can occur. Phosphorus was analyzed as the total form, which includes P bound in particulate (organic and inorganic) matter, and soluble or dissolved forms which are readily used by algae. Dissolved inorganic P (known as dissolved P (DIP) or orthophosphate P) has been analyzed in Bristol Harbor since Figure 14a. Bristol Harbor Annual Total Phosphorus Data Chart Total Phosphorus: Except for the Silver Creek sites, annual total phosphorus (TP) values have generally been below 100 ppb, the level of concern based on the amount of nitrogen typically found in estuaries (Figure 14a). Total phosphorus levels in the harbor have generally been below the level of concern, similar to TN levels. However TP annual concentrations have been somewhat variable, and several sites have had some years with high levels. Total phosphorus levels at Silver Creek (#3) have been decreasing, while upstream sites have been somewhat more variable. In particular, Silver Bridge (#9), the next site upstream, has had rapidly increasing TP levels, suggesting either dilution, absorption by sediments or attenuation of the phosphorus 21

22 between the 2 sites is occurring (similar to TN attenuation). In general stream TP concentrations followed a similar pattern as did the bacteria suggesting the strong influence of stormwater on TP values (figure 14b). Figure 14b. Mt Hope Bay / Bristol Harbor 2014 Total Phosphorus Data Chart Dissolved Phosphorus: Dissolved inorganic phosphorus (DIP) is the portion of P readily available for use by aquatic organisms, and is analogous to DIN. The National Coastal Assessment program uses DIP as a key component in its coastal conditions assessment. DIP surface concentrations <10 ppb are considered Good, ppb considered Fair, and >50 ppb considered Poor. Rhode Island doesn t have criteria for DIP, but maintaining low stream levels reduces harbor inputs. Figure 15a. Mt Hope Bay / Bristol Harbor Annual Dissolved Phosphorus Data Chart In 2014 annual DIP levels were generally in the moderate or fair range for nearly all of the sites, including most of Silver Creek and Mt Hope Bay. The Silver Creek Bridge (#9) site was the only one that exceeded fair criteria in 2014 for DIP (Figure 15a). For a second year, elevated DIP levels were recorded at the Bridge (#9) for much of the season in 2014, rather than the intermittent DIP noted in earlier seasons (figure 15b). Continued monitoring will be important to try to identify the source of the DIP, and to determine if it s part of an overall trend. 22

23 Figure 15b. Mt Hope Bay / Bristol Harbor 2014 Dissolved Phosphorus Data Chart Hats off to these outstanding water quality volunteers Bob and Denise Arsenault, Beth Battery, Christine Bean, Kevin Beauleiu, Janet Christopher, Kin Conlon, Elizabeth Cox, Aly Dion, Susan Donovan, Katie Eagan, Haley Goss, Rob & Gwen Hancock, Barbara Healy, Julia Hill, Mike Kotuby, Clara Mendonca, Clara Mendonca, Marguerite Moran, Burke and Bryce O Brien, Valerie Malone and Mike Oliver, Samantha Palumbo, Gregory Rego, Mary Shannahan, Ethan Tucker, and Dan Vilinski. These outstanding individuals got up very early each Thursday morning throughout the 2014 season, rain or shine, working in teams to monitor their site and get their samples to their local coordinators for transportation to the URI. and especially to their resolute local coordinators (and fellow dedicated water quality monitors): Bob Aldrich and Keith Maloney. Each season these fine gentlemen work tirelessly and cheerfully to recruit volunteers, coordinate training sessions, keep in touch with everyone, ensure that the local volunteers had all the necessary equipment, supplies and any other resources they need and act as couriers, delivering samples on a monthly basis with cheery greetings to the URI Watershed Watch staff and student interns. Please see the Save Bristol Harbor website ( to learn more about their efforts or how you can help. Keith Maloney and Bob Aldrich do whatever it takes to protect Bristol Harbor (Photo from news/bristol-recycles-tohelp-clean-up-the-fourth/) 23

24 References: Howes, Brian, Tony Williams and Mark Rasmussen, BayWatchers II Nutrient related water quality of Buzzards Bay embayments: a synthesis of Baywatchers monitoring Olli, Kalle Drainage basin nutrient inputs and eutrophication: an integrated approach. ebook, Universesity of Tartu, Institute of Botany and Ecology, Tartu, Estonia - National Oceanic and Atmospheric Administration s (NOAA) Ocean Service Education Monitoring Estuaries website Russian River Pathogen Project (RRPP) Working Draft Report, Updated 01/28/ Save Bristol Harbor website United States Environmental Protect Agency (EPA), National Estuary Program Coastal Condition Report Introduction University of Rhode Island (URI) Office of Marine Programs Discovery of Estuarine Environments website University of Rhode Island Watershed Watch website (includes monitoring manual, data, fact sheets, and links to local, regional and national information) Appendix A. Volunteer Monitoring Overview Volunteer Monitoring: Save Bristol Harbor volunteers were trained by URI Watershed Watch (URIWW) staff to conduct water quality monitoring. The volunteer monitors were provided with equipment and supplies as well as detailed, written monitoring procedures manuals. Monitoring followed a schedule designed to cover the period of peak biological activity in the harbor - from mid-may through mid-october. The schedule consisted of biweekly early morning on-site monitoring of water temperature, salinity, dissolved oxygen and chlorophyll sample collection and processing. (See URIWW monitoring manuals and field quality assurance project plans available at for more specific information.) All on-site monitoring data was submitted to URIWW on monitoring postcards or online. In addition to the bi-weekly on-site monitoring, once a month the volunteers also collected a suite of water samples, which were brought to a central collection point in Bristol. There samples were packed on ice in a cooler and brought to the state-certified URIWW Analytical Laboratory in Kingston. Bacteria, ph, nitrogen, phosphorus, and chlorophyll were analyzed according to standard URIWW laboratory procedures (see Quality Assurance Project Plan: University of Rhode Island Watershed Watch Analytical Laboratory for additional information). The sampling schedule was designed to ensure that monitoring occurred early in the morning in order to measure the lowest daily dissolved oxygen, and that the samples would reach the URIWW laboratory within acceptable hold times. 24

25 2014 ph Data: ph Data Chart Appendix B. Additional Water Quality Results Bristol Harbors Sites 15-May 12-Jun 10-Jul 7-Aug 4-Sep 2-Oct MEAN Standard ph Units BH17-Kickemuit BH18-Annawanscutt Drive BH16-RWU Dock BH12-Herreshoff BH01-Elks Club BH02-Bristol Harbor Inn BH04-Windmill Pt BH05-Mill Pond BH06-Sanroma BH07-Bristol Yacht Club BH08-Brito Dock BH03-Silver Creek BH09-Silver Bridge BH14-DaPonte/Wood St BH10-Silver East BH15-Silver Gooding Ave Dry Dry 7.2 BH11-Silver West