TRIENNIAL REVIEW OF COLIFORM DATA - SOUTH SHELLFISH LAND NUMBER 18S TOWNS OF SOUTHAMPTON, EAST HAMPTON, SOUTHOLD AND SHELTER ISLAND 2013-2017

PREPARED: June 2018

New York State Department of Environmental Conservation Shellfish Growing Area Classification Unit 205 N. Belle Meade Road, Suite 1 East Setauket, 11733

INTRODUCTION

Shelter Island Sound, South (SISS), is located between the north shore of the of , New York and along the entire southern shoreline of Shelter Island. It extends as far west as Jessup Neck on the south fork (SF), as north as Cedar Beach Point and Paradise Point on the (NF); and as far east as Barcelona Point on the SF to Mashomack Point on Shelter Island (SI). It also runs all along the south shore of Shelter Island from Mashomack Point on the east to Crab Creek Point on the west. The area that is sampled covers portions of four towns: Southampton; East Hampton; Southold; and Shelter Island. This includes the area located north of Noyack Bay, south of Southold Bay, the area between North Haven and Shelter Island and the area south of Mashomack Point, including outer Sag Harbor.

The underwater lands of Shelter Island Sound South (SISS) fall under the jurisdiction of New York State and are considered state underwater lands. This large embayment is approximately 4,725 acres. There are no areas classified as uncertified year-round or seasonally uncertified in Shelter Island Sound South. There once was a small seasonal marina closure in Smith Cove (near station 29.1). It was closed during the period from May 15 through October 31 (both dates inclusive), but it has since been reclassified as certified year-round. There is no legal description for any part of this southern section of SISS.

MAP 1.

In May 2002, it came to the attention of the Shellfisheries Program that the Smith Cove marina was no longer serving in that capacity. On June 25, 2003, the area was reclassified as certified, year- round. The entire area of Shelter Island Sound South has been designated as shellfish growing area (SGA) 18S and has been divided into a southeast (SE) and southwest (SW). They are not always sampled together, but this report evaluates both sides together.

West Neck Harbor and Coecles Harbor are tributaries of Shelter Island Sound South, but they are their own SGA areas (20 and 25, respectively). Their water quality evaluations and shoreline surveys are completed separately.

The purpose of this report is to evaluate the bacteriological water quality data collected in Shelter Island Sound South to ensure that the present growing area classification is still valid. Data have been collected during the period from February 2013 through December 2017.

It is imperative that all certified shellfish lands meet the criteria of the National Shellfish Sanitation Program (NSSP) and Model Ordinance (MO) and are properly classified for the safe harvest of shellfish. It is also important to determine whether uncertified shellfish lands have the potential to be reclassified as certified or seasonally uncertified when evaluations are complete and support such findings.

V. WATER QUALITY STUDIES

A. Map of Sampling Stations. There are seven stations on the west side of SISS and thirteen stations on the SE. (see Map 1 above). All 20 stations are in certified waters.

B. Sampling Plan and Justification. 1. Adverse pollution conditions (APC). The conditions under which water quality data were previously analyzed (APC after rainfalls) were not used for any part of the Shelter Island Sound South evaluation. APC is a targeted wet weather condition, with rainfalls greater than or equal to 0.25 inches, during ebbing tides. As described below, Shellfisheries is using Systematic Random Sampling (SRS) to plan, collect and evaluate water quality data in all NYS SGAs.

The first shoreline, pollution source survey of Shelter Island was completed in 1988. That report was a complete survey of Shelter Islands north and south shorelines, done by M. Davidson. D. Lewis took responsibility of the north fork in 1999, he completed a follow-up shoreline survey of only the northern side of Shelter Island in 2003. A follow-up shoreline survey of SISS was completed in October 2008. The next complete shoreline survey report will be due in 2020.

In October 1989, the Department instituted emergency closure procedures after extraordinary rainfalls. When an area receives more than 3.0 inches of rain in any 24-36-hour period (see attached "Notice to Shellfish Harvesters", Appendix 1), it would be closed to harvesting immediately. Shellfishing would be suspended and can only be reopened after water quality has been demonstrated to meet criteria and shellfish have adequate time to naturally cleanse themselves of potential pathogens.

2. Systematic Random Sampling (SRS). Random sampling was employed in studying this area. SRS requires collecting six samples per year in certified shellfish lands. The sampling year is divided into seven segments to give us more time to accomplish projected sampling runs during the colder, windier months, and holiday seasons, ensuring that each area is sampled at least six times by the end of the year. The year-round, cold and warm weather analyses were completed using the SRS method. Sufficient SRS data, between 33 and 40 data points were used for the year-round evaluation.

In January 1997, the Shellfish Growing Area Classification Unit switched over to SRS to monitor water quality in all our SGAs. With SRS, monitoring can be scheduled months ahead and sampled regardless of rainfall. As a result, water sampling runs required for the evaluation of certified and seasonally uncertified areas are planned in advance so that effects of random nonpoint pollution events can be captured if they occur.

This growing area is affected by randomly occurring, intermittent events (stormwater runoff after rainfall) and is not impacted by discharges from sewage treatment facilities or combined sewer overflows. (see Appendix 2). Therefore, SRS can be used for the area. Information is available at the Interstate Shellfish Sanitation Conference website: http://www.issc.org/client_resources/2007%20nssp%20guide/section%20ii%20chap%20iv.pdf.

In 1997, the SRS sampling year was divided into eight segments. In 1998, the year was divided into seven week segments to try and ensure that each area is sampled at least six times by the end of the year. The strategy now is (3) eight week segments and (4) seven week segments. Sampling runs are scheduled by the unit’s biologists prior to the start of each calendar segment. The only environmental condition considered during sample planning is the tide cycle. Ebbing tides are still a requirement and are considered APC.

Biologists target sampling to occur during the ebb tide, but must also ensure that the tidal stage is not so low in some areas that boat navigation is not possible. One day per week is also maintained for scheduling makeup runs when weather conditions or other unexpected events, such as equipment failure or staffing shortages, precluded successful completion of a planned sample run.

Other limitations on sample planning include the state's current restriction on the use of overtime by Department employees, which was stringently implemented beginning in 2010 and resulted in significant impacts to the sampling program. To adhere to the current policy, sample collection efforts must occur within the normal workday, including travel time to and from the growing area. Once water samples are collected, they cannot be held for more than thirty (30) hours prior to laboratory processing, which uses a modified A-1 method to estimate the most probable number (MPN) of fecal coliform bacteria present in each sample.

This method requires 24 hours from the time the procedure is initiated to obtain results. To ensure the entire process of sample collection and analysis can be concluded within the standard Monday through Friday workweek, sample collection is limited to a Monday through Thursday schedule.

Trips conducted on Thursday must also be concluded, with samples returned to the laboratory by 2pm. As a result, sample scheduling is limited to approximately 3.5 days per week instead of the five previously utilized days. When compounded with the need to target the ebb tide, these restrictions severely limit sampling opportunities and hamper the unit's ability to make up sampling runs that are cancelled due to weather conditions or unforeseen events.

SRS evaluations require 30 SRS data points and determine the Geometric Mean and 90th percentile (%tile), instead of the median and % > 330 (for total coliform) or 49 (for fecal) data evaluations. The tidal range for SISS is referenced with the Noyack Bay (west side) and Sag Harbor (east side) tide charts. The tidal ranges on the east and west sides is from -0.4’ to 3.5’. All water samples were collected at various stages of ebb tide and analyzed during year-round, cold and warm weather seasons. (see Tables 1, 2 and 3).

Colder months bring extreme weather including heavy winds and the holiday season, sometimes making it difficult to get out on the water to sample. In addition to the SRS sampling requirements, seasonal areas require a sample for each month that the area is open during the seasonal period. This significantly increases the number of samples required from an area on a yearly basis.

C. Sample Data Analysis and Presentation. Routine water samples were collected by the Department of Environmental Conservation (DEC). All samples were analyzed by the laboratory at DEC.

In February 2003, NYSDEC management selected the modified A-1 method for enumerating fecal coliform bacteria (FC) in water samples and dropped all total coliform testing. Lab staff were responsible for too many things and something had to be cut from their program. The decision was made to cut program costs, reduce the time needed to generate data (especially for emergency situations), eliminate the amount of time needed to prep glassware and provide the lab with more time to conduct other lab responsibilities.

This was another, time and money savings choice the lab made with little input from the sanitation unit.

Since the A-1 method yields only fecal coliform data, shellfish lands are currently classified using the fecal coliform standards specified in 6 NYCRR Part 47 "Certification of Shellfish Lands." The 3 tube, 3 dilution multiple tube fermentation procedure is used in conjunction with the Systematic Random Sampling strategy to assess the MPN/100ml for each sample. The NSSP and MO require that each growing area be evaluated on either the total or fecal coliform data. Fecal coliforms have been chosen to evaluate SISS.

Criteria for SRS: Bacteriological water quality data at a station are acceptable when the Geometric Mean of the fecal coliform analysis does not exceed an MPN/100ml of 14 or when the 90th percentile (%tile) of the same analysis, does not exceed an MPN/100ml of 49. If the results at a station fail to meet either of these standards, that station may need to be reclassified as seasonally uncertified or uncertified, year-round.

Criteria for APC: (historical, no longer used). Bacteriological water quality data at a station are acceptable when the median total coliform MPN/100ml is 70 or less and no more than 10% of the samples exceed an MPN/100ml of 330; or, when the median fecal coliform MPN/100ml is 14 or less and no more than 10% of the samples exceed an MPN/100ml of 49.

If an uncertified or seasonally uncertified station meets these criteria during an evaluation, and there is enough wet weather data associated with the evaluation, it may be possible to consider an upgrade of the shellfish classification. It may also be necessary to consider a downgrade if a station is no longer meeting the criteria for a certified shellfish growing area.

For the past year, the lab has put another constraint on our sample planning. To keep the number of samples that they need to process down, the lab has been restricting the sanitation program to only 300 samples per week. This is mostly due to the program’s Marine Biotoxin Monitoring Program conflicting with lab time and when the lab is scheduled for FDA proficiencies. In the past, there was no limit and at other times, 400 were allowed.

To offset good tide weeks when the sample counts can be high, there are usually bad tide weeks. During those weeks, the biologists are hard pressed to even schedule 100 samples. This 300 limit can only be achieved if biologists cut out the sampling of uncertified stations throughout the year and seasonal stations in the summer. If this continues, the data needed to consider the reclassification of uncertified and seasonally uncertified stations will not be collected and the biologists will no longer be able to support any SGA reopening’s.

The National Shellfish Sanitation Program (NSSP) Analysis of Shelter Island Sound South is presented as follows:

1. Station by station array. Tables 1, 2 and 3 – Year-round SRS Analysis, Cold (December - April) and Warm (May-November) Weather, Seasonal Analyses.

2. Daily sampling results. Tables 1, 2 and 3 - All fecal coliform and environmental data for Shelter Island Sound South, including tides.

3. NSSP compliance. Overall compliance with NSSP criteria can be found in Table 4. It lists the present SGA classification of each station and indicates whether it meets or fails to meet the NSSP criteria during the time of year it is certified for harvest. Stations which do not comply, as a result of the most recent analysis are noted with an asterisk (*).

4. Classification of stations. There is one shellfish growing area classification for the SISS: certified. (see Map 1). This most recent evaluation shows that all stations are meeting their NSSP, year-round classification during the months that they are certified for shellfishing, except station 36.1 (at the mouth of Little Northwest Creek).

VI. INTERPRETATION OF DATA

A. Meteorological and Hydrographic Conditions. To satisfy the requirements of the NSSP and the Model Ordinance (MO), data were analyzed under SRS conditions. During this evaluation period, rainfall recorded in this area ranged between 0.02 -1.92 inches; rainfall readings are recorded every 24 hours. Ebbing tides are still a requirement and are considered APC. All samples were collected at various stages of ebb tide.

Most of the rain data used in these evaluations are collected from the USGS Real Time, Rain data station in Sag Harbor, NY and the Weather Underground, WLNG Radio rain station, also in Sag Harbor. Both can be found at these websites: https://waterdata.usgs.gov/ny/nwis/uv?cb_00045=on&format=html&period=1&site_no=4059 25072165601; and https://www.wunderground.com/personal-weather- station/dashboard?ID=KNYSAGHA6#history Precipitation data for this area used to be collected from the Sag Harbor Wastewater Treatment Plant on Bay Street in the Village of Sag Harbor, NY and occasionally, rainfall totals are verified with them.

There was one emergency closure in Shelter Island Sound South during this evaluation period. From September 4, through 13, the outer Sag Harbor area was closed to shellfishing from the northernmost tip of the breakwater to the northernmost tip of Barcelona Point.

1. SRS Evaluation. Sufficient SRS data were available to properly evaluate the year- round, cold and warm evaluations: between 33 and 40 (year-round), 15 and 36 (cold) and 33 and 40 (warm) SRS data points were collected to evaluate SISS, respectively. Due to the sampling nature of these two areas, SE and SW are mostly sampled at different times and with other growing areas. This, as well as bad weather and broken equipment, contributes to a difference in the total number data points for each of the areas.

In addition, station HB is fairly new and only 15 data points were available to analyze during the cold evaluation. Because SISS is certified year-round, most of the sampling occurs during the spring, summer and fall. If the weather is bad in the winter, this area can be dropped when sample counts are restricted (for reasons mentioned above). That contributes to the low, cold weather availability of data. During the year-round evaluation, all stations appear to meet the fecal coliform SRS criteria and agree with their present shellfish classification, except for station 36.1 (MPN 63). (see Tables 1 and 3).

Station 36.1 is located at Little Northwest Creek and on several occasions, dry and wet, during all years, there have been high coliform counts. A little more than half of those dates had less than half an inch of rain. Only on one warm date, was there a high rainfall of 1.15 inches where the MPN was 240, in June 2012. Strangely, high counts were seen with very little rain. There is very little residential development around this creek; some at the inlet on the northwest corner. There is a large golf course located on the southeast side and numerous mosquito ditches surrounding the area. These tend to be conduits of runoff, potentially contributing coliform bacteria (from wildlife) if conditions are right. This might be one reason for the occasional high counts.

The SRS, year-round data analysis (Table 1) shows that all stations are meeting criteria for certified shellfish lands, except as mentioned, station 36.1. This small creek is classified as certified year-round, but will need to be reclassified as seasonally uncertified, probably during the months May through November. A radial closure will be needed around the mouth and a new station will need to be placed to determine how far this closure should be extended out.

2. Seasonal Evaluations. A cold weather, seasonal analysis was completed for this area using SRS data. This was to ensure that even though station 36.1 was not meeting the year-round and warm analyses, it would meet a cold, seasonal evaluation. Station 36.1 does meet the cold weather evaluation, as do all of the remaining stations in SISS; data were evaluated from December through April (2006-2017). (see Table 2).

A warm weather analysis was also completed to make sure all of the certified stations are passing during the warm weather season. As with the year-round, station 36.1 is not meeting the warm weather criteria for a certified shellfish land. The area was evaluated with data from May through November (2011-2017) and all of the remaining stations in SISS are meeting the warm weather criteria. (see table 3).

B. Variability in Data. Variability in data can be a result of varying rainfall and tides (not being able to get to a station), in combination with winds to create a wide range of potential coliform results for each area. The number of SRS data points can vary slightly from station to station due to sampling constraints, such as unexpected boat problems, bad weather or limited laboratory staff, media and lab error, which require cutting back on the number of samples collected throughout the year. These variables interfere with the ability to always collect all samples on a given sampling day.

Samples being collected at a new station called HB (Havens Beach), is still trying to catch up to the 30 samples needed when off season evaluations are conducted. It has met the year- round and warm sampling, but not the cold season. This time of year was never targeted because there have not been any seasonal areas.

VII. CONCLUSIONS

A. Area Map with Suggested Seasonal Closures. A seasonal closure is recommended for all of Little Northwest Creek and the area around station 36.1. Since the station is outside the mouth, a radial closure will be needed. An additional station further out will also need to be established to help determine where the water quality is acceptable.

B. Legal Description. There is no legal description for any part of the south side of Shelter Island at this time.

C. Management Plan. This area is not presently part of any conditionally approved or conditionally restricted program.

D. Recommendations for Sanitary Survey Improvements. All stations meet their present shellfish growing area classifications and the NSSP criteria for certified shellfish lands except for station 36.1. It is not clear why this station is failing to meet the year-round criteria, but an additional station is going to be added beyond 36.1, and the area will be proposed for seasonal reclassification. The station failed to meet the year-round and warm SRS evaluations.

It is possible, as seen in some other shellfish growing area evaluations, that high coliform counts causing a station to exceed certified criteria are isolated; they can’t be associated with any particular situation or pollution source.

Routine water quality monitoring and survey updates of the Shelter Island Sound South area will continue as required.

SUMMARY

1. Station 36.1 will be proposed for seasonal reclassification, open during the months of December through April.

2. A new station will be added a little further out beyond station 36.1 to monitor water quality beyond this station. It will be called station 36.1A. The remaining sampling stations are adequate to monitor the few pollution sources and classify water quality in this area.

Table 4. Shelter Island Sound South. Sampling Stations, Existing Classifications and Present NSSP Results.

Station Existing Classification Fails to Meet NSSP

17 certified no 18 certified no 19 certified no 23 certified no 27 certified no 17.1 27.1 certified no 34 certified no 37 certified no 39.1 certified no 30 certified no 30.1 certified no 28 certified no 29.1 certified no 29.2 certified no 27.1 certified no 31 certified no 31.1 certified no 35 certified no 36.1 certified yes * HB certified no

APPENDIX 1.

NOTICE TO ALL SHELLFISH HARVESTERS EMERGENCY CLOSURES FOLLOWING EXTRAORDINARY RAINFALL EVENTS

On October 20, 1989, the New York State Department of Environmental Conservation designated most bays and harbors in Nassau and western Suffolk counties as temporarily uncertified for the harvest of shellfish following a rainfall that measured nearly 4.5 inches in some areas. That first “Emergency Rainfall Closure” of shellfish harvest areas lasted between four (4) and seven (7) days. During that time the DEC, in cooperation with bay constables and other staff from the environmental bureaus of several towns, was able to collect and examine water samples from nearly all the areas affected by the closures. The results indicated that all areas closed on an emergency basis were adversely affected by the runoff from that extraordinary rainfall and the closures were appropriate and necessary to protect public health.

Since that first emergency closure there have been many more heavy rainfalls that were followed by emergency closures of harvest areas. In each of those cases, water sampling was done in key areas to determine when it was possible to re-open. The results clearly indicated that excessive storm water runoff following rainfalls greater than three (3) inches had significant adverse effects on water quality. The results also showed that water quality improvements were detectable by the third and fourth days of the closures, when compared to results from samples collected on the first and second days of the closure. Areas will only be re-opened after water quality has been demonstrated to meet certified area criteria and shellfish have adequate time to naturally cleanse themselves of potential pathogens.

Please Note: DEC has since determined that it may be necessary to implement emergency closures in some areas, during the summer months after rainfalls that are less than 3 inches. Recent events have shown that certain areas are adversely affected by less than 3” when water temperatures are warmer. It also may be necessary to extend closures beyond seven (7) days when water quality does not improve by the sixth day (per Title 6NYCRR, Parts 42.17 “Sanitary Control over Shellfish” and 47.4 “Certification of Shellfish Lands”).

Based on what we have learned from our experience with several emergency rainfall closures, any area that is closed on a temporary emergency basis following a rainfall of more than 3 inches will remain closed for at least 3 full days.

NORTH SHORE: All north shore embayments affected by extraordinary rainfall will be closed for at least three days. However, due to the relatively large tidal ranges on the north shore, north shore areas may re-open on the fourth day if testing of water samples demonstrates acceptable water quality. Likely exceptions are Stony Brook and Mount Sinai Harbors which are relatively shallow and have very narrow inlets to the Sound. In those areas it may take a day or two longer for water quality to return to acceptable levels.

SOUTH SHORE: On the south shore, areas SS1 (Hempstead Bay), SS2 (South Oyster Bay) and SS3 (Great South Bay, Babylon) will be entirely uncertified for at least four days when emergency closures are necessary. East of the Robert Moses Causeway, the northern portions of areas SS4, SS5, and SS6 and the western portion of SS7 (Bellport Bay) will be included in the emergency closures, but areas in the southern portion of Great South Bay, SS4, SS5 and SS6, as well as the eastern portion of SS7 may remain certified. During most recent closures, a line running from where the Robert Moses Causeway comes ashore on the north side of Captree Island, running through several navigational buoys along the east/west channel in the northern part of the bay to a buoy south of Howells Point then proceeding southeasterly to the flag pole at Bellport Beach on the barrier beach, has been used as the temporary closure line.

The large drainage area, smaller tidal ranges and small ocean inlets all cause contaminated runoff to adversely affect water quality in portions of Hempstead, South Oyster Bay and Great South Bay for several days. Therefore, some south shore embayments may remain closed for 7 days, excluding the day the closure designation is made, or longer if water quality has not improved by the sixth day.

EAST END EMBAYMENTS: Generally, all of Moriches Bay and Shinnecock Bay will be closed following extraordinary rainfall events. In the Flanders Bay, Peconic and areas, all the enclosed bays, harbors and creeks within the Towns of Riverhead, Southold, Shelter Island, Southampton and East Hampton will be designated as uncertified following rainfalls of more than 3 inches.

Based on results of sampling during recent emergency closures, many east end embayments may re-open after 4 or 5 days if water sampling demonstrates acceptable water quality. However, on a case-by-case basis some areas may remain closed for longer periods. For example, Flanders Bay has remained closed for as long as 7 days.

NOTIFICATION: The Department immediately notifies the affected towns, including the bay constables or harbormasters, about all emergency closures. The Department also advises local news media, including cable channel 12 (News 12), Newsday and local radio stations. Although the Department has contacted news media regarding emergency closures, they have not always carried the information provided to them.

You can reach the Shellfisheries “Emergency Closure Information Line” by calling (631) 444-0480. A recorded message is available 24 hours a day, including weekends. During emergency closures, the recording will give the most up-to-date information about which areas are affected by the closures; descriptions of the closure lines will also be provided.

REOPENINGS: When possible, the Bureau of Marine Resources/Shellfisheries Section will begin sampling on the second day of an emergency closure and will attempt to collect samples from as many areas as possible. In the event of widespread closures, north shore areas will usually be sampled on the 2nd and 4th days, and south shore and east end areas will usually be sampled on the 3rd and 5th days. Areas will be re-opened based on demonstrated improvements in water quality, as described above. Sampling assistance from towns may allow earlier openings.

Beginning on the afternoon of the 3rd or 4th day after an emergency closure, an updated message about re-openings will be available at (631) 444-0480 after 4:00 p.m. The updates will be based on the results of water quality testing during the closures.

We ask that all shellfish harvesters make an effort to be aware of weather forecasts that predict unusually heavy rainfall, especially from thunderstorms, tropical systems and nor’easters. Emergency closures will be put into effect in all areas affected by runoff from rainfalls of more than 3 inches that occur over a 24-36 hour period. If you have any questions, please contact us at (631) 444-0492.

Dated: December 1, 2015 James J. Gilmore, Chief East Setauket, NY Bureau of Marine Resources

APPENDIX 2.

Addendum: General Statement for Sanitary Surveys, Pollution Source Survey Reports and Water Quality Evaluation Reports for Shellfish Growing Areas around Long Island

Hydrographic and Meteorological Characteristics of Shellfish Growing Areas on Long Island

(1) Tides in all areas around Long Island are semi-diurnal, meaning there are usually two (2) high and two (2) low tides each day. Tidal amplitude varies from area to area. Generally, tidal range on the north shore and some east end areas is approximately 7 to 8 feet, with the greater range occurring during spring tides which occur with each full and new moon phase. Tidal ranges in the south shore embayments tend to be less and range from 1.5 to 4 feet. The actual tidal range will be noted in the specific pollution source summary and/or the triennial water quality report for each shellfish growing area.

Except in the vicinity of inlets to the ocean or sound, harbor mouths and "narrows" between embayments, currents are generally weak. Currents in inlets, harbor mouths and "narrows" are driven by tides and can approach 2 knots.

(2) Rainfall around Long Island averages approximately 40 inches annually. There is no distinct "rainy season" on Long Island. Rainfall can be very uneven around Long Island and the Shellfish Growing Area Classification Unit has established rain gauges locations around Long Island which are read by DEC employees, Town or County employees, and some cooperating private citizens. The GACU regularly gathers rainfall information from approximately 25 cooperating individuals.

(3) Winds around Long Island can be quite variable. Winds are driven by high and low pressure zones and/or passing warm and cold fronts. There is a slight tendency for winds during the summer months to be from the west or southwest. On-shore breezes (sea breeze) will occur during the summer months as heating of the land results in updrafts over the land mass of Long Island which draws a breeze in off the ocean or Sound. During the winter months the winds tend to be northerly, but on any given day the winds may be from other directions and can vary from one end of the Island to another.

(4) Rivers around Long Island are primarily tidal estuarine in nature. The vast volume of water exchanged in the canals, creeks and rivers on Long Island is tidal water that enters those waterbodies during incoming tides and exits on the outgoing tides. The freshwater component of the outflow from the four (4) largest rivers on Long Island - Nissequoque, Peconic, Connetquot and Carmans Rivers - is relatively insignificant compared to the tidal exchange. Because there is no significant season difference in rainfall around Long Island, there is no significant seasonal variation in the freshwater outflow from the rivers.

(5) Effects of pollution and hydrographic factors. The main pollution sources to most certified shellfish growing areas around Long Island is non-point stormwater runoff following rainfall events. Outgoing tides distribute stormwater runoff seaward from the land based sources.

Due to the relatively shallow nature of all the bays and harbors around Long Island; the semi-diurnal tides; and effects of wind, the water column is well mixed and there tends to be little vertical stratification of the water column with respect to salinity or temperature.