Harmful Algal Blooms (HABs): A GIS Study of the Long Island Coast

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1 Tim D Agostino APEC 480 Project 5: Harmful Algal Blooms (HABs): A GIS Study of the Long Island Coast

2 Background: Harmful algal blooms (HABs) are a phenomenon in which particular harmful species of algae reproduce in prodigious quantities and upset the ecological balance in aquatic habitats. This is a global problem, but has been observed in Long Island waterways. Colloquially referred to as Red Tide, these algal blooms are caused by the dinoflaggelate species Alexandrium fundyense, and literally create streaks of red in Long Island harbors and bays. Long Island has a history of these HABs, and in the 1950s, the area suffered from a variety of green tide blooms. More recently, the Great South Bay was hit by brown tides in the 1980s, which caused damage to eelgrass fisheries. At present, the Peconic Estuary, Shinnecock Bay, and Northport and Huntington Harbors are suffering from red tide outbreaks. The algae in these outbreaks synthesize deadly biotoxins which make filter-feeding shellfish unfit for consumption and sometimes even kill marine animals outright. This has had incredible ecological and economic consequences for Long Island fisheries and has greatly changed the ecological dynamics of these habitats. Areas have been closed to shellfishing and according to Woods Hole Oceanographic Institute (WHOI), red tide outbreaks cost New England fisherman more than $3 million each week at their peak. As a Northport native, I am particularly interested in studying the red tide afflicting Northport Harbor, but I would extend my study to the greater Long Island area and include the Peconic Estuary, Long Island Sound and other Long Island waterways. Preliminary laboratory testing has linked these blooms to eutrophication-linked factors, such as excessive nitrogen levels in the water. The spatial context of this problem is incredibly important, as municipalities need to identify afflicted areas in order to close the waterway to shellfishing and protect human consumers. In addition, the correlation between red tides and high nitrogen outputs is of great importance on Long Island, where many homes are not connected to sewers and instead utilize basic cesspools that leach nitrogen. Geographic Information Systems (GIS) will provide crucial functionality in addressing this problem, by allowing me to create chronological maps of HABs areas, map the spread and begin the process of predicting future outbreaks by mapping nitrogen loads linked to residences and treatment plants. In the future, these results may even provide the means of establishing variable buffer along the Long Island coastline to prevent excessive nitrogen outflows into waterways. Long Island waterways are home to a wide variety of species and provides habitat for diverse populations of aquatic species. The Long Island sound itself represents one of the largest estuaries in the northeast of the United States and has historically been a source of fishing and tourism dollars. As such, for economic and ecological reasons, my study is of crucial importance. Literature Review: Prior research on this issue has been conducted by organizations such as Woods Hole Oceanographic Institute (WHOI). Scientists at WHOI have studied the larger New England area and red tides for decades. These studies have been conducted by scientists aboard research

3 vessels and WHOI now sends out research cruises to study the extent of the tides. So far, these scientists have determined that the algae cells can spread via currents and that winds are sometimes sufficient to prevent HABs in the near-shore waters of southern New England. In addition, these scientists have conducted studies that lead them to believe that the massive algal bloom experienced in the northeast in 2005 was caused by abundant rain and northerly and easterly winds that allowed the cells to spread into Cape Cod Bay. However, Dr. Christopher Gobler from Stony Brook University is also an expert in the field and has been studying brown tide for a decade. Dr. Gobler has made use of molecular genetic techniques to explore how the algae utilize nitrogen from sources like nitrate and ammonium and incorporate it into their DNA. His studies have allowed him to begin to explore how the maritime environment changes during blooms and the technical processes in which the various species of algae utilize nitrogen sources. In this way, these studies have been very useful and valuable because they have suggested the basic underpinnings of how these HABs spread and factors that may influence their growth. However, these studies still leave many questions. For example, the major sources of nitrogen loads and their locations compared to the peak extent of the HABs cannot be inferred from these studies. In addition, scientists still need to analyze the geographic spread of the HABs in order to better predict where and when outbreaks will occur. Hypotheses: I am trying to determine the factors that influence the spread and growth of HABs, such as red tide. In particular, I wish to determine the effect of nitrogen outflows from residential cesspools and treatment plants on HABs. Data from prior scientific works suggest that algal blooms are linked to nitrogen releases, so I wish to determine what influence, if any, residential sources of nitrogen (such as cesspools) as well as releases from treatment plants have on the development of HABs. If such a correlation is found to exist, I would like to use my results and data in future work. For instance, I would like to corroborate the my conclusions by using nitrogen outflow data, coupled with supplementary data such as water temperature and positions of algal cyst beds to predict future blooms and their locations. This research has the intriguing possibility of leading to the development of buffer zones along the coast of Long Island. These variable width buffers would represent areas that cannot be developed and would help mitigate nitrogen releases into Long Island waterways. Data: In order to conduct my research, I need to obtain satellite imagery as well as government building records. Specifically, I will need to obtain a multi-band Landsat image. This satellite image of Long Island and its surrounding waterways will provide separate rasters representing various different wavelengths. This data will allow me to pick out the various hues produced by the HABs. Furthermore, it would be useful to have a Digital Elevation Model (DEM) raster of the Long Island Area (30 m resolution). In addition, I will need the locations of single family residences (SFRs). This data is readily available in county records, which I found posted online

4 and in a digital format. For example, Town of Huntington records on land uses are available to the public on the town s website, by clicking on the Property Info and Tax Assessment Information tabs. Alternately, or as a supplement, a land use map would aid my analysis by providing a rough map of the different zoning areas on Long Island. Through my research, I also located the Town of Huntington s ecode, which lists minimum sanitation specifications and maximum effluent concentration limits. Through the use of these worst-case acceptable values for cesspools, I can obtain an estimate of the discharges from homes and businesses based on their zoning classifications and age. In addition, the Office of Wastewater Management produced a Report on the Sewage Treatment Plants of Suffolk County. In this report, I found information about nitrogen effluent levels that I could use as estimates at the each of the treatment plants in the county. Lastly, I would utilize dissolve nitrogen data for the Long Island area that has already been collected or is continuously being collected. Using a search engine, I found that this data is collected using Niskin water sampling bottles aboard research vessels such as the John Dempsey (Long Island Sound Hypoxia Season Review). This is a good example of the type of data that I would need to obtain for my study. Methods: In order to conduct this analysis, I would bring each band of my multi-band Landsat image into ArcGis as separate rasters. I would unzip the data, and connect to my project folder using ArcGIS. I would create a new file geodatabase, make it my default database and save my layers to it. For my projection, I would use a coordinate system such as NAD_1983_New York_Long_Island, or UTM-NAD-1983-Zone 19N. In order to speed-up my subsequent steps, I would also create a mask of the general Long Island geographic region, in Geoprocessing Environments Raster Analysis. Much like as in project 3, I would use the Fill, Flow Direction, and Basin tools to prepare my DEM and gain a sense of the direction of waterflow on Long Island. I would also use the Flow Accumulation tool to help me in my analysis of the cumulative flow effects. Re-running Flow Accumulation on areas with residential land use codes would allow me to isolate these areas and determine their influence on the local waterways. Using my Landsat image, I would run the raster calculator with an equation that specified areas with a flow accumulation value greater than a determined threshold number (in project 3 we used 10000) and that also had integer values in the band raster that corresponded to the red pigment characteristic of Alexandrium fundyense. This would allow me to locate the red tide regions and this process could be repeated with Landsat images from different times of the year. As part of my future research, I could also use the Cost-Weighted-Distance tool to develop the protective buffers to prevent excessive nitrogen loads along the coasts. I could run this using inverse slopes and SFR density values separately, but I could also combine them into one map. Using the dissolved nitrogen data that I obtained from other researchers, I could use the attribute table to compare the levels in various locations and I could create a heat map of the highest concentrations. On this map, I could also depict the areas with the greatest concentration of housing, as well as the locations of treatment plants. This would be a very valuable map for the

5 purposes of my study and would be a first step towards supporting my hypotheses. I could then plot my results on graphs in order to more effectively communicate my results to the public and other researchers. Anticipated Results: After completing this research, I believe that I will see a correlation between areas of high density housing close to the shore and HABs. In addition, I believe that I will see a similar correlation as one nears a treatment plant. I expect that there will be a strong correlation that as the distance between human developments and the shore decreases, the extent of the HABs increases. I also expect that these results will allow me to make fairly accurate predictions of where the HABs will be located each year based on the nitrogen levels in a particular body of water. Should the variable buffers I develop be implemented, I expect that I will see a corresponding drop in the dissolved nitrogen levels in nearby waters and a concomitant reduction in the extent of the HABs. Policy Applications: My research could result in significant policy changes. If my data and analysis present a strong argument that treatment plants and near-shore developments are responsible for the HABs that are causing millions of dollars in damages, legislation might be developed to address my findings. For example, the variable buffer, or a modified version of it, may be adopted and be used in future zoning decisions. In addition, new regulations on treatment plant effluent may be developed. These more stringent constraints would reduce the acceptable nitrogen concentration of the water that these plants release off of Long Island. Likewise, my results might also encourage lawmakers to further regulate the use of cesspools and prohibit the user of older cesspools that lack nitrogen reducing technologies. My data might also help in deciding on the coastal areas in which shellfishing would be prohibited. Since the shellfish can accumulate the biotoxins produced by the HABs, these prohibited areas could be used to prevent instances of paralytic shellfish poisoning (PSP) in humans.

6 Budget: Please see below for the preliminary budget proposal for this research project: Proposed Research Budget Item Rate (per hr) Hours Cost GIS Analyst Office Supplies N/A N/A 100 Internet Access Assumed to be preexisting 0 ArcGIS Software Based on single user license 200 Dissolved Nitrogen Data N/A - Freely available online 0 Research Assistant Satellite Data* N/A N/A 150 Computer 800 Travel Expenses None Anticipated 0 *Estimate based off of prices on: Total Direct Costs Additional Indirect Costs Total Cost Timeframe: It is expected that this project will be completed over a series of stages. These stages, while distinct, will at times be carried out simultaneously in order to be efficient and save time. During the first stage, the research assistant will purchase the relevant satellite data for use in the project. In addition, he or she will research, identify, and locate the treatment plants on Long Island. Listings of these plants are readily available online and this is not expected to be an arduous task. Furthermore, the laboratory assistant will communicate with other researchers, such as those at WHOI, in order to obtain their maps and water collection data. This data is important to this research project and this task will free the ArcGIS Analyst of approximately 100 hours of labor over the course of a month. In the second stage, the ArcGIS Analyst will use the data obtained in order to implement the research project. While this research will likely not be excessively labor intensive, it would be ideal if the experiments/map-creations were repeated during different times of the year. As such, it would be best to dedicate five years to this project so that results could be corroborated and patterns could be uncovered. In order to use time effectively, some of this down time could be used to write the reports and project conclusions for publication. It is anticipated that the ArcGIS analyst could pursue other projects at the same time as this one and it is hoped that this will help reduce expenditures of both time and financial resources. However, this project is deserving of the expense and will provide exciting new insights and potential solutions to a daunting environmental problem.

7 Works Cited: Bush, Leah. "Red Tide Expected to Arrive, Exit Early." Northport Patch. Northport Patch, 23 Mar Web. 17 May Branca, Barbara A., and Paul C. Focazio. Harmful Algal Blooms Plague Long Island Waters. Issue brief. Stony Brook U. Web. 14 May < Habitat/BTRI/Fall09-HABs.pdf>. "Early Onset of Harmful Algal Bloom Leads to Long Island Shellfish Bed Closures - News and Features." NCCOS News and Features. The National Centers for Coastal Ocean Science, 11 Apr Web. 17 May "Landsat.org." About Landsat.org. Landsat.org. Web. 12 May Sound Health 2012 Status and Trends in the Health of the Long Island Sound. Issue brief. New England Interstate Water Pollution Pollution Control Commission, Web. 16 May < USA. Connecticut Department of Energy and Environmental Protection Long Island Sound Hypoxia Season Review Web. 12 May USA. Department of Health Services. Office of Wastewater Management. Report on the Sewage Treatment Plants of Suffolk County 2012 Performance Evaluation. By Walter Dawydiak and Walter Hilbert Web. 11 May < rvices/wastewater%20management/2012%20stp%20report.pdf>.