Testing for Optical Testing for Optical Brighteners in the Tidal Brighteners in the Tidal Creeks of New Hanover Creeks of New Hanover

CountyCounty

EVS 595EVS 595

Mary TavaresMary Tavares

December 13December 13thth 2007 2007

BackgroundBackground

Three New Hanover County Tidal Three New Hanover County Tidal creekscreeks

1.1. Futch CreekFutch Creek

2.2. Bradley CreekBradley Creek

3.3. Hewletts CreekHewletts Creek

Optical brightenersOptical brighteners Fecal coliform bacteria Fecal coliform bacteria Combined testing – detection of Combined testing – detection of

human fecal contaminationhuman fecal contamination

IntroductionIntroduction

Tidal Creek ecosystems are abundant along Tidal Creek ecosystems are abundant along the SE NC coast -74 in 4 countiesthe SE NC coast -74 in 4 counties

Located behind barrier islands and drain into Located behind barrier islands and drain into the ICW or feed into larger estuaries or riversthe ICW or feed into larger estuaries or rivers

Collective importance (materials transfer and Collective importance (materials transfer and other ecological processes) equal or exceed other ecological processes) equal or exceed larger estuaries in certain geographic regions larger estuaries in certain geographic regions (Dame et al. 2000)(Dame et al. 2000)

Materials transfer, habitatMaterials transfer, habitat Shellfishing, finfishing, real-estateShellfishing, finfishing, real-estate

Development and Water Development and Water QualityQuality

SE NC is undergoing an increase in SE NC is undergoing an increase in tourism and populationtourism and population

Shellfishing areas closed to harvest Shellfishing areas closed to harvest Fecal coliform bacteria- estimator of Fecal coliform bacteria- estimator of

pathogenic bacteriapathogenic bacteria NCDWQ NCDWQ 200 CFU/100mL200 CFU/100mL (human (human

contact waters), contact waters), 14 CFU/100mL14 CFU/100mL (shellfishing)- no more than 10% (shellfishing)- no more than 10% samples exceeding 43 CFU/100mLsamples exceeding 43 CFU/100mL

2 sources: run-off or sewer and septic2 sources: run-off or sewer and septic

Source 1: runoffSource 1: runoff

Strong relationship between percentage Strong relationship between percentage impervious surface and mean estuarine impervious surface and mean estuarine fecal coliform abundance ( Mallin et al. fecal coliform abundance ( Mallin et al. 2000b)2000b)

>29% impervious surface= degraded>29% impervious surface= degraded >10%= impaired>10%= impaired <10% acceptable<10% acceptable Changes in land use planning and Changes in land use planning and

developmentdevelopment

Source 2: Septic and Source 2: Septic and Sewer leaksSewer leaks

Bradley and HewlettsBradley and Hewletts 1215 septic systems1215 septic systems Point sourcePoint source Easier to trace and eliminateEasier to trace and eliminate Increased measures to detect public Increased measures to detect public

healthhealth Optical brightenersOptical brighteners

Optical BrightenersOptical Brighteners Compounds added to Compounds added to

laundry detergentslaundry detergents Adsorb to clothing to Adsorb to clothing to

form a light reflective form a light reflective layerlayer

Exited by light in the Exited by light in the near UV range (360-near UV range (360-365nm)365nm)

Emit light in blue range Emit light in blue range (400-440nm)(400-440nm)

Fluorescence given off Fluorescence given off second excited stage-second excited stage-fluorometerfluorometer

Optical Brightners cont.Optical Brightners cont.

97% detergents97% detergents Flourescent Flourescent

whitening agents whitening agents (FWA’s)(FWA’s)

Textiles, plastics, Textiles, plastics, synthetic fibers, synthetic fibers, paperpaper

Medical, chemical, Medical, chemical, petroleum petroleum applicationsapplications

Optical brighteners in Optical brighteners in waterwayswaterways

Household plumbing-combination of Household plumbing-combination of grey and waste watergrey and waste water

WWTPs not a source due- UV light WWTPs not a source due- UV light destroys both fecal coliform bacteria destroys both fecal coliform bacteria and OBsand OBs

Photo-decay and biodegradation rates Photo-decay and biodegradation rates of OBof OB

Soaps and TPSoaps and TP

Likely sources for fecal Likely sources for fecal coliform and optical coliform and optical

brightener contaminationbrightener contaminationFecal BacteriaFecal Bacteria Optical BrightenerOptical Brightener Probable CauseProbable Cause

HighHigh HighHighSewer pipe leak or Sewer pipe leak or failing septic systemfailing septic system

HighHigh LowLowOther warm blooded Other warm blooded mammal source or mammal source or human waste from human waste from other source such as other source such as out-houseout-house

Low Low HighHigh Gray water in storm Gray water in storm water systemwater system

Low Low LowLow Background Background fluorescence or fluorescence or insignificant insignificant contaminationcontamination

Methods for detecting Methods for detecting OBsOBs

Cotton pads in Cotton pads in waterways- collect, dry, waterways- collect, dry, and expose to UV light: and expose to UV light: inexpensive yet low inexpensive yet low sensitivitysensitivity

High performance liquid High performance liquid chromatography- high chromatography- high sensitivity- expensive- sensitivity- expensive- highly technicalhighly technical

Fluorometer- simple, Fluorometer- simple, moderate expense, high moderate expense, high sensitivitysensitivity

MethodsMethods

Monthly sampling at high tide, boat or shoreMonthly sampling at high tide, boat or shore Temperature, salinity, dissolved oxygen, Temperature, salinity, dissolved oxygen,

conductivity, pH, turbidity conductivity, pH, turbidity Fecal coliform- membrane filtration methodFecal coliform- membrane filtration method Fluorometry- kit addedFluorometry- kit added

1.1. Lamp emitting near UV light 310-390nmLamp emitting near UV light 310-390nm

2.2. 1 filter 300-400nm light range1 filter 300-400nm light range

3.3. 436 nm filter to greater decrease 436 nm filter to greater decrease background fluorescencebackground fluorescence

Statistical analysesStatistical analyses

RegressionRegression CorrelationCorrelation Scatter PlotScatter Plot Significant relationship between Significant relationship between

optical brighteners and fecal optical brighteners and fecal coliform bacteriacoliform bacteria

Analyzed as whole and by creekAnalyzed as whole and by creek

Site DescriptionsSite Descriptions Bradley Creek, Futch Bradley Creek, Futch

Creek, and Hewletts Creek, and Hewletts CreekCreek

Monitored 1993-2007 Monitored 1993-2007 UNCW’s Aquatic UNCW’s Aquatic Ecology LabEcology Lab

Bradley and Hewletts Bradley and Hewletts ranked 1ranked 1stst and 2 and 2ndnd for for population density, population density, developed land and developed land and impervious surfaceimpervious surface

Futch ranked fifthFutch ranked fifth

Rating systemRating system

Dissolved oxygen, chlorophyll a, Dissolved oxygen, chlorophyll a, turbidity, fecal coliform bacteriaturbidity, fecal coliform bacteria

NC state standard <10%=GoodNC state standard <10%=Good 10-25%=Fair10-25%=Fair > 25%= Poor> 25%= Poor

Bradley Creek Bradley Creek Largest watershed- ICWLargest watershed- ICW Developments pose water Developments pose water

quality concern, Clean quality concern, Clean Water Trust fund mitigationWater Trust fund mitigation

Closed to shellfishing 1947Closed to shellfishing 1947 Highest population (13,657)Highest population (13,657) Developed land (77%)Developed land (77%) Impervious cover (21%)Impervious cover (21%) One of most polluted creeks One of most polluted creeks

in countyin county 2005-2006 5 out of 7 2005-2006 5 out of 7

stations received poor stations received poor ratingrating

Human-sourced fecal Human-sourced fecal bacteria found at station bacteria found at station BC-NBU in July and August BC-NBU in July and August and BC-SB in June of 2006and BC-SB in June of 2006

Hewletts CreekHewletts Creek Drains into ICW, freshwater Drains into ICW, freshwater

and saltwater sitesand saltwater sites 2005-2006, fecal coliform 2005-2006, fecal coliform

taken only at freshwater- all taken only at freshwater- all sites given a poor ratingsites given a poor rating

Substantial sewage spill Substantial sewage spill occurred Feb. 27occurred Feb. 27thth 2006 2006

Special sampling ordered Special sampling ordered (2,200-20,000 CFU per 100mL)(2,200-20,000 CFU per 100mL)

July 1, 2005 3 million gallon July 1, 2005 3 million gallon spill- resulting in fish kill, high spill- resulting in fish kill, high persistent fecal coliform persistent fecal coliform bacteria in sedimentsbacteria in sediments

Recent study-human sourced Recent study-human sourced fecal coliform bacteria at fecal coliform bacteria at station NB-GLR June and July station NB-GLR June and July 20062006

Futch CreekFutch Creek New Hanover-Pender Line-ICWNew Hanover-Pender Line-ICW Lowest population(2108), Lowest population(2108),

development (42.9%), and development (42.9%), and impervious surface coverage impervious surface coverage (6.9%)(6.9%)

1995 and 1996 two channels at 1995 and 1996 two channels at mouth dredgedmouth dredged

Re-opened to shellfishingRe-opened to shellfishing 2005-2006- three stations in 2005-2006- three stations in

lower section received good lower section received good rating, one in middle creek rating, one in middle creek displayed higher counts yet displayed higher counts yet remained within the state remained within the state standard, upper two fair and standard, upper two fair and poor ( lower than before poor ( lower than before dredging event yet higher than dredging event yet higher than 2004-2005)2004-2005)

Recent study found human Recent study found human sourced fecal bacteria in water sourced fecal bacteria in water at site FC-17at site FC-17

Futch CreekFutch CreekFutch Creek

Date Site colonies mean Stdev

9/13/2007 FC-13 94 5.5 0

10/31/2007 FC-13 1 2.6 0.1

11/16/2007 FC-13 4400 2 0

9/13/2007 FC-17 135 6.4 0.1

10/31/2007 FC-17 9 3.4 0

11/16/2007 FC-17   3.4 0

9/13/2007 FC-4 7 3 0.1

10/31/2007 FC-4 2 2 0

11/16/2007 FC-4 3800 3.2 0.1

9/13/2007 FC-6 56 3.2 0.1

10/31/2007 FC-6 3 2.3 0

11/16/2007 FC-6 6400 2.2 0.1

9/13/2007 FC-8 17 3.3 0.1

10/31/2007 FC-8 0 2.5 0.1

11/16/2007 FC-8 4800 2.3 0

9/13/2007 FOY 24 4.4 0

10/31/2007 FOY 4 2.8 0.0

11/16/2007 FOY 7000 2.5 0.1

Futch Cont.Futch Cont. Pearson’s Product Pearson’s Product

Moment correlation Moment correlation coefficient yielded coefficient yielded 0.072190.07219 with a p- with a p-value of 0.8425value of 0.8425

No significant No significant relationship was relationship was found between found between optical brighteners optical brighteners and fecal coliform and fecal coliform bacteria at Futch bacteria at Futch Creek.Creek.

Bradley Creek ResultsBradley Creek ResultsBradley Creek Fecal coliform OB  

Date Site Colonies Mean Stdev

9/21/2007 BC-76 1 7.1 0.1

10/16/2007 BC-76 4 4.1 0.1

11/27/2007 BC-76 13 2.8 0.1

9/21/2007 BC-CR 360 12.6 0.2

10/16/2007 BC-CR 1100 8.2 0.2

11/27/2007 BC-CR 48 11 0.2

9/21/2007 BC-NB 147 23.5 0.1

10/16/2007 BC-NB 5 4.9 0.1

11/27/2007 BC-NB 60 4.4 0.1

9/21/2007 BC-NBU 180 23.9 0.2

10/16/2007 BC-NBU 70 17.3 0.3

11/27/2007 BC-NBU 169 21.3 0.2

9/21/2007 BC-SB 43 27 0.1

10/16/2007 BC-SB 166 11.7 0.1

11/27/2007 BC-SB 58 13.1 0.1

9/21/2007 BC-SBU 745 26.5 0.5

10/16/2007 BC-SBU      

11/27/2007 BC-SBU 85 24.7 0.6

Bradley Creek Results Bradley Creek Results cont.cont.

Pearson’s Product Pearson’s Product Moment analysis Moment analysis determined a determined a correlation correlation coefficient of coefficient of 0.6962030.696203 at a p- at a p-value of 0.003value of 0.003

A significant A significant relationship was relationship was foundfound

Hewletts Creek ResultsHewletts Creek Results

Hewletts Creek        

Date Site colonies mean Stdev

9/13/2007 HC-2 2 2.3 0.1

10/15/2007 HC-2 24 2.9 0.1

11/25/2007 HC-2 4 1.8 0.1

9/13/2007 HC-3 13 3.2 0.1

10/15/2007 HC-3 4 3.5 0.1

11/25/2007 HC-3 11 2.2 0.1

9/13/2007 MB-PGR 1115 25.7 0.5

10/15/2007 MB-PGR 940 25.3 0.2

11/25/2007 MB-PGR 145 20.1 0.2

9/13/2007 NB-GLR 375 12.7 0.1

10/15/2007 NB-GLR 45 7.6 0.1

11/25/2007 NB-GLR 427 7.5 0.1

9/13/2007 SB-PGR 105 9 0.1

10/15/2007 SB-PGR 11 5.8 0

11/25/2007 SB-PGR 169 6.2 0.1

Hewletts Creek Results Hewletts Creek Results cont.cont.

The Pearson’s The Pearson’s Product Moment Product Moment correlation coefficient correlation coefficient of 0.8837 at a p-value of 0.8837 at a p-value of 0.0001of 0.0001

A positive A positive relationship was relationship was found between optical found between optical brighteners and fecal brighteners and fecal coliform bacteriacoliform bacteria

Data Set AnalysisData Set Analysis

Product Moment – Product Moment – correlation correlation coefficient of coefficient of 0.3243480.324348 at a p- at a p-value of 0.0248value of 0.0248

A relationship was A relationship was foundfound

Regression and Regression and Scatter plot Scatter plot

DiscussionDiscussion

Positive results at Hewletts Creek and Positive results at Hewletts Creek and Bradley Creek indicate viable Bradley Creek indicate viable methodology for future studiesmethodology for future studies

Past or present sources at Hewletts Past or present sources at Hewletts Creek?Creek?

Futch Creek- likely source of fecal Futch Creek- likely source of fecal coliform bacteria is wildlife not humanscoliform bacteria is wildlife not humans

Bradley Creek- fecal coliform bacteria Bradley Creek- fecal coliform bacteria possibly coming from run-offpossibly coming from run-off

Discussion Cont.Discussion Cont.

Fluorescence from other sourcesFluorescence from other sources Refinement of fluorometric methodologyRefinement of fluorometric methodology Increased research during site selectionIncreased research during site selection Sampling at low tideSampling at low tide Determine source of fecal bacteria Determine source of fecal bacteria

through chemical, genotypic, or through chemical, genotypic, or phenotypic methodsphenotypic methods

The results of this preliminary The results of this preliminary experiment found an overall experiment found an overall

relationship between optical brightener relationship between optical brightener values and fecal coliform bacteria values and fecal coliform bacteria

counts. Therefore this project can be counts. Therefore this project can be considered a viable resource when considered a viable resource when

developing further experiments developing further experiments involving optical brighteners and fecal involving optical brighteners and fecal

coliform bacteria contamination in coliform bacteria contamination in waterways. waterways.

AcknowledgementsAcknowledgements

I would like to thank Dr. Michael Mallin, I would like to thank Dr. Michael Mallin, research professor at UNC Wilmington’s research professor at UNC Wilmington’s Center for Marine Science, for oversight, Center for Marine Science, for oversight, guidance, and editorial comments. For guidance, and editorial comments. For

methodology assistance, editorial comments, methodology assistance, editorial comments, and support I thank Matthew McIver, Aquatic and support I thank Matthew McIver, Aquatic

Ecology Lab manager. For advising and Ecology Lab manager. For advising and support I thank Dr. Jeffery M. Hill, Graduate support I thank Dr. Jeffery M. Hill, Graduate

Program Coordinator of Environmental Program Coordinator of Environmental Studies at UNCW. For field, laboratory and Studies at UNCW. For field, laboratory and

editorial assistance I thank Byron Toothman, editorial assistance I thank Byron Toothman, Rena Spivey, Brad Rosov, Ned Durant and Rena Spivey, Brad Rosov, Ned Durant and

Kimberly Duernberger Kimberly Duernberger

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