Hydrocarbon Contamination from Coastal Development - ACS

14 Hydrocarbon Contamination from Coastal Development 1

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Richard H. Pierce , Robert C. Brown , Edward S. Van Vleet , and Rosanne M. Joyce 1

Mote Marine Laboratory, Sarasota,FL33577 Department of Marine Science, University of South Florida, St. Petersburg,FL33701

Downloaded by UNIV QUEENSLAND on June 21, 2013 | http://pubs.acs.org Publication Date: April 21, 1986 | doi: 10.1021/bk-1986-0305.ch014

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Hydrocarbon analyses were obtained for samples of surface sediment, oysters and water from four areas in Charlotte Harbor, Florida. Each area represented a different type of coastal development activity including: residential development canals; municipal and industrial impact; commercial fishing and marine industry facilities; and a nondeveloped control area. Characterization of hydrocarbons was performed using high resolution glass capillary GC-FID chromatograms of the aliphatic (saturated) and aromatic/olefinic (unsaturated) hydrocarbon fractions and by GC-MS analysis of select aromatic components. Residential canal systems contained petroleum contamination resulting from marina and highway service station activities, contamination indicative of crankcase oil which diminished with distance from the source. Total hydrocarbon content of canal sediment ranged from more than 50 ug/g air-dry sediment at a marina to less than 5 ug/g at nonimpacted areas. Sediment collected near municipal-industrial activities exhibited high concentrations of a broad range of heavy, residual fuel oils (85 ug/g sediment). The highest contamination was observed at commercial fishing port areas, contamination indicative of a low to mid-boiling range fuel oil attaining a concentration of 142 ug/g sediment, compared to less than 5 ug/g in unimpacted areas. Oyster samples generally reflected the contamination observed in sediment. Water samples exhibited different hydrocarbon patterns than oysters or sediment, consisting primarily of terrigenous and marine biogenic material. Biogenic hydrocarbons with chromatographic patterns that mimic some petroleum characteristics were observed in certain areas, showing the importance of obtaining pre-oil spill data for accurate interpretation of oil spill impact. Additional information from time series sampling is needed to ascertain rates of hydrocarbon input and degradation. 0097-6156/86/0305-O229$06.00/0 © 1986 American Chemical Society

In Organic Marine Geochemistry; Sohn, M.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.


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This project was undertaken to identify petroleum hydrocarbon c o n t a m i n a t i o n r e s u l t i n g from c o a s t a l development a c t i v i t i e s i n t h e C h a r l o t t e Harbor e s t u a r i n e system l o c a t e d on the Southwest F l o r i d a coast (Figure 1). The o v e r a l l g o a l was t o a s s e s s p r e s e n t p e t r o l e u m c o n t a m i n a t i o n and t o p r o v i d e b a s e l i n e d a t a t o p r o v e t h e e x t e n t and d u r a t i o n of a d d i t i o n a l impact from f u t u r e c o a s t a l development and oil spills. E n v i r o n m e n t a l impact from l a r g e o i l s p i l l s i n the coastal marine environment i s r e a d i l y o b s e r v a b l e and e a s i l y documented. The e x t e n t and d u r a t i o n of c o n t a m i n a t i o n a f t e r t h e s u r f a c e o i l has been removed and weathered, however, a r e n o t so e a s i l y ascertained e s p e c i a l l y when p r e - s p i l l c o n d i t i o n s a r e not known ( 1 - 6 ) . Problems a l s o a r i s e when a t t e m p t i n g t o document c h r o n i c p e t r o l e u m d i s c h a r g e s from v a r i o u s c o a s t a l development a c t i v i t i e s . The d e t e c t i o n o f petroleum hydrocarbons i s h i n d e r e d by t h e p r e s e n c e o f r e c e n t l y b i o s y n t h e s i z e d ( b i o g e n i c ) hydrocarbons and h y d r o c a r b o n s resulting from combustion (pyrogenic). Source identification also is complicated by differential weathering through degradation, e v a p o r a t i o n and s o l u b i l i z a t i o n of p e t r o l e u m components ( 1 - 6 ) . The C h a r l o t t e Harbor e s t u a r i n e system was chosen f o r t h i s s t u d y because i t i s one o f t h e l a r g e s t and p o s s i b l y one o f t h e l e a s t c o n t a m i n a t e d e s t u a r i e s i n F l o r i d a (7.)· R e c e n t l y , however, t h e a r e a has become one of the most r a p i d l y d e v e l o p i n g i n the U n i t e d S t a t e s (8^). A r e c e n t r e v i e w o f s c i e n t i f i c i n f o r m a t i o n about Charlotte Harbor emphasized the p o t e n t i a l f o r environmental impact from development and v a r i o u s s o u r c e s o f p e t r o l e u m c o n t a m i n a t i o n (£)· A two-year investigation was undertaken to determine the c o m p o s i t i o n and c o n c e n t r a t i o n o f hydrocarbons i n sediment, water and c o m m e r c i a l l y i m p o r t a n t marine organisms t h r o u g h o u t C h a r l o t t e Harbor. The e n t i r e p r o j e c t was d e t a i l e d i n an u n p u b l i s h e d r e p o r t t o t h e Florida Department o f N a t u r a l Resources ( 1_0 ). The first-year p r o j e c t r e v e a l e d l i m i t e d petroleum contamination a s s o c i a t e d with c e r t a i n land-use a c t i v i t i e s (6,10). The second-year study, the p r i m a r y s u b j e c t o f t h i s p r e s e n t a t i o n , i n v e s t i g a t e d the problem a r e a s i n more d e t a i l t o c h a r a c t e r i z e the t y p e of p e t r o l e u m c o n t a m i n a t i o n and t o i d e n t i f y p r o b a b l e s o u r c e s . Methods Study L o c a t i o n . C h a r l o t t e Harbor i s l o c a t e d on t h e Southwest Florida c o a s t between 27°05'N and 26°27'N latitude (Figure 1). During the f i r s t y e a r s t u d y , c e r t a i n a r e a s were i d e n t i f i e d as c o n t a i n i n g petroleum contamination (6,10). T h r e e a r e a s were chosen f o r more i n t e n s i v e s t u d y d u r i n g t h e second y e a r of t h e i n v e s t i g a t i o n including: P o r t C h a r l o t t e - P u n t a Gorda development c a n a l systems ( A r e a A, F i g u r e 1 ) ; C a l o o s a h a t c h e e R i v e r downstream from F o r t Myers ( A r e a B, F i g u r e 1); and t h e Matanzas Pass a r e a b e h i n d F o r t Myers Beach ( A r e a C, Figure 1). A nondeveloped a r e a i n an a q u a t i c p r e s e r v e a t S a n i b e l I s l a n d was chosen as the c o n t r o l a r e a ( A r e a D, Figure 1). The study a r e a s a r e d e s c r i b e d as f o l l o w s :


PIERCE ET AL.

Hydrocarbon Contamination from Coastal Development


14.

F i g u r e 1. C h a r l o t t e areas l o c a t i o n .

Harbor

hydrocarbon

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AREA A. T h i s a r e a r e p r e s e n t s impact from c o a s t a l residential development, e x t e n d i n g i n t o the mouth o f t h e Peace R i v e r and upper C h a r l o t t e Harbor. Primary sources of contamination are expected t o be stormwater runoff (automobile r e l a t e d petroleum), municipal sewage and s m a l l b o a t marina a c t i v i t i e s . S u r f a c e sediment was c o l l e c t e d from f o u r t e e n s i t e s , water from e i g h t s i t e s and o y s t e r s from t h r e e s i t e s , r e p r e s e n t i n g c o n d i t i o n s i n t h e development c a n a l s a t P o r t C h a r l o t t e a c r o s s the mouth o f t h e Peace R i v e r and i n t o t h e c a n a l s o f P u n t a Gorda. AREA B. T h i s a r e a i n c l u d e s t h e C a l o o s a h a t c h e e R i v e r a t F o r t Myers and t h e mouth o f t h e r i v e r a t San C a r l o s Bay, downstream from F o r t Myers. I t i s p a r t i c u l a r l y s u s c e p t i b l e t o o i l s p i l l s because o f t h e I n t r a c o a s t a l Waterway (ICW) and t h e C a l o o s a h a t c h e e R i v e r , which would c a r r y any s p i l l downriver from t h e F o r t Myers a r e a . I t was chosen t o r e p r e s e n t an a r e a which r e c e i v e s c h r o n i c i n p u t from m u n i c i p a l and i n d u s t r i a l a c t i v i t i e s and r e p r e s e n t s a h i g h r i s k a r e a for future o i l s p i l l s . S u r f a c e sediment and o y s t e r s were c o l l e c t e d from v a r i o u s s i t e s . AREA C. Matanzas P a s s , b e h i n d F o r t Myers Beach on E s t e r o I s l a n d , r e p r e s e n t s impact from commercial f i s h i n g and heavy marine i n d u s t r y operations. The e n t i r e a r e a from C a r l o s Bay t h r o u g h Matanzas Pass t o B i g C a r l o s Pass i n E s t e r o Bay was s t u d i e d i n an attempt t o u n d e r s t a n d t h e d i s t r i b u t i o n o f c o n t a m i n a t i o n from t h e d e v e l o p e d marine industrial area out i n t o t h e nondeveloped Estero Bay. Sediment samples were c o l l e c t e d from e i g h t s i t e s , o y s t e r s from f i v e s i t e s and water from f o u r s i t e s . AREA D. T h i s a r e a i n c l u d e s sediment from t h r e e s i t e s a p p r o x i m a t e l y one m i l e o f f s h o r e from S a n i b e l I s l a n d and C a p t i v a I s l a n d and o y s t e r s and sediment from mangrove f r i n g e s w i t h i n t h e w i l d l i f e p r e s e r v e on the e s t u a r i n e s i d e o f t h e i s l a n d , r e p r e s e n t i n g nonimpacted c o n t r o l areas· Sampling Technique. S u r f a c e sediment ( t o p 5 cm) was c o l l e c t e d as a composite o f a t l e a s t t h r e e grabs w i t h a P e t i t e Ponar sediment sampler, t o p r o v i d e 500 g wet w e i g h t o f r e l a t i v e l y u n d i s t u r b e d sediment f r o m each s i t e . Each sediment grab was placed i n a s t a i n l e s s s t e e l t r a y and the t o p 5 cm o f sediment r e t r i e v e d w i t h a s t a i n l e s s s t e e l scoop and p l a c e d i n a p r e c l e a n e d g l a s s j a r w i t h aluminum l i n e d c a p s . J a r s were p l a c e d on i c e f o r t r a n s p o r t and s t o r e d a t 4°C u n t i l a n a l y z e d . S u f f i c i e n t sediment was c o l l e c t e d f o r d u p l i c a t e h y d r o c a r b o n a n a l y s i s w i t h e x t r a sediment f o r a d d i t i o n a l analyses i f necessary. E f f i c a c y o f s t o r a g e a t 4°C was v e r i f i e d by a n a l y s i s of samples b e f o r e and a f t e r s t o r a g e f o r s e v e r a l months and by a n a l y s i s o f s t a n d a r d i n t e r c a l i b r a t i o n sediment a f t e r s t o r a g e f o r s e v e r a l months. The o y s t e r , C r a s s o s t r e a v i r g i n i c a , was the s p e c i e s used t o m o n i t o r uptake by s e s s i l e f i l t e r - f e e d i n g o r g a n i s m s . A t l e a s t two dozen l a r g e o y s t e r s were c o l l e c t e d from each organism s a m p l i n g s i t e . These were r i n s e d i n ambient water, wrapped i n aluminum f o i l and s t o r e d i n p l a s t i c bags on i c e f o r t r a n s p o r t t o t h e l a b o r a t o r y where they were t h e n f r o z e n i n t h e i r s h e l l s u n t i l ready f o r a n a l y s i s . Near s u r f a c e water samples were c o l l e c t e d w i t h a p r e c l e a n e d metal sampler. Samples o f 10 t o 15 l i t e r s were c o l l e c t e d a t each s i t e and p l a c e d i n 20 l i t e r g l a s s c a r b o y s f o r i n - f i e l d e x t r a c t i o n as



14. PIERCE ET AL.


d e s c r i b e d below. from p a r t i c u l a t e were o b s e r v e d .

No attempt was made t o d i f f e r e n t i a t e d i s s o l v e d f r a c t i o n s so t h a t t o t a l water column h y d r o c a r b o n s

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Hydrocarbon A n a l y s i s . Sediment samples were thawed and mixed t o p r o v i d e a homogeneous sample. A p p r o x i m a t e l y 150 g wet w e i g h t was p l a c e d i n a S o x h l e t e x t r a c t i o n a p p a r a t u s and s a p o n i f i e d - e x t r a c t e d w i t h benzene /0.5 Ν KOH-methanol (50/50) ( c a . 250 ml t o t a l ) f o r 24 h o u r s , o r u n t i l t h e e x t r a c t i o n s o l u t i o n was c l e a r ( 6 , 1 1 , 1 2 ) . An i n t e r n a l s t a n d a r d c o n s i s t i n g o f c a . 50 ug each o f 5 , a - a n d r o s t a n e and o - t e r p h e n y l was added p r i o r t o e x t r a c t i o n t o p r o v i d e a s s u r a n c e o f extraction efficiency, separation of saturated and unsaturated fractions and t o p r o v i d e a standard reference f o r t h e gas c h r o m a t o g r a p h i c d a t a system. Methylstéarate ( t h e m e t h y l e s t e r o f s t e a r i c a c i d ) was added t o s e l e c t samples t o v e r i f y s a p o n i f i c a t i o n efficiency. The s a p o n i f i e d s o l u t i o n was e x t r a c t e d w i t h 3 χ 50 ml hexane and t h e r e s u l t i n g hexane-benzene s o l u t i o n was washed w i t h distilled w a t e r t o remove r e s i d u a l ROH-MeOH. The benzene-hexane was t h e n r e d u c e d t o a volume o f c a . 0.1 ml by r o t a r y e v a p o r a t i o n , f o l l o w e d by p u r g i n g w i t h N^ gas i n a warm bead b a t h (45°C) a n d r e p e a t e d a d d i t i o n of hexane t o r e p l a c e benzene w i t h hexane. A f i n a l sample volume o f 1 ml hexane was added t o a column o f 2 g n e u t r a l a l u m i n a (80/20 mesh), 2 g silica g e l (100/200 mesh) and 1 g sodium sulfate ( g r a n u l a r ) f o r c l e a n - u p and s e p a r a t i o n i n t o a l i p h a t i c ( s a t u r a t e d ) and a r o m a t i c / o l e f i n i c ( u n s a t u r a t e d ) f r a c t i o n s . Alumina, s i l i c a g e l and sodium s u l f a t e were a c t i v a t e d a t 500°C f o r 4 h o u r s and s t o r e d a t 110°C u n t i l u s e d . The s a t u r a t e d f r a c t i o n was e l u t e d w i t h 3 bed volumes ( bv) o f hexane and t h e u n s a t u r a t e d f r a c t i o n was e l u t e d w i t h 3 bv o f hexane and benzene (50/50). Each f r a c t i o n was t h e n r e d u c e d t o 0.5 ml volume under a stream o f N gas as d e s c r i b e d above i n p r e p a r a t i o n f o r GC a n a l y s i s . O y s t e r s were thawed, opened w i t h a c l e a n k n i f e , t h e l i q u i d d r a i n e d o f f , and a composite o f s e v e r a l whole o y s t e r s c o l l e c t e d . The e n t i r e sample o f each s i t e was homogenized and d i v i d e d i n t o f o u r subsamples. Two were s u b j e c t e d t o t h e a n a l y t i c a l scheme, t h e t h i r d a r c h i v e d and f r o z e n f o r f u r t h e r a n a l y s i s , i f n e c e s s a r y , and t h e f o u r t h d r i e d a t 103°C t o o b t a i n t h e d r y w e i g h t . F o r a n a l y s i s , c a . 10-15 g wet-weight t i s s u e was t r a n s f e r r e d t o a t a r e d , hexane washed 250 ml b o i l i n g f l a s k . The i n t e r n a l s t a n d a r d m i x t u r e was added a t t h i s p o i n t i n a c e t o n e s o l u t i o n . A 50 ml p o r t i o n o f 2.0 Ν aqueous KOH was added t o t h e f l a s k c o n t a i n i n g t h e t i s s u e f o r s a p o n i f i c a t i o n under r e f l u x f o r 4 h o u r s (h) o r u n t i l t h e t i s s u e was w e l l d i g e s t e d . An e q u a l volume o f s a t u r a t e d NaCl s o l u t i o n was added t o t h e m i x t u r e , and t h e s o l u t i o n e x t r a c t e d w i t h t h r e e 50 ml p o r t i o n s o f hexane. The e x t r a c t s were combined, r e d u c e d i n volume w i t h a vacuum r o t a r y e v a p o r a t o r and t r a n s f e r r e d t o a cleaned v i a l . The r e m a i n i n g s o l v e n t was r e d u c e d t o 1 ml volume i n p r e p a r a t i o n f o r s e p a r a t i o n i n t o s a t u r a t e d and u n s a t u r a t e d f r a c t i o n s and GC a n a l y s i s as d e s c r i b e d above f o r s e d i m e n t s . Water samples were p r o c e s s e d i n t h e f i e l d u s i n g a p o r t a b l e w a t e r e x t r a c t o r c o n s i s t i n g o f a s t i r r i n g b l a d e o p e r a t e d by a b a t t e r y powered r e v e r s i b l e d r i l l which f i t s i n t o t h e 20 l i t e r g l a s s carboy (Mi). The e x t r a c t i o n p r o c e d u r e c o n s i s t e d o f p l a c i n g 10 t o 15 l i t e r s 2


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ORGANIC MARINE GEOCHEMISTRY

o f a water sample i n t h e carboy. The i n t e r n a l s t a n d a r d m i x t u r e was added (5,0t-androstane and o - t e r p h e n y l i n a c e t o n e s o l u t i o n ) , f o l l o w e d by 500 t o 750 ml o f C H C l . The m i x t u r e was s t i r r e d v i g o r o u s l y f o r 5 min and a l l o w e d t o set£Le f o r one hour ( u n t i l phases s e p a r a t e d ) . Water was s i p h o n e d o f f t h e t o p and t h e CH C l ^ r e c o v e r e d f o r h y d r o c a r b o n a n a l y s e s a s d e s c r i b e d above f o r s e a i m e n t s . Prior to f i e l d u s e , t h e e x t r a c t o r was e v a l u a t e d ijpr r e c o v e r y and p r e c i s i o n by s p i k i n g d i s t i l l e d water w i t h 1 mg 1 o f Kuwait c r u d e o i l and comparing recovery with that o b t a i n e d from separatory funnel, l i q u i d - l i q u i d e x t r a c t i o n (10). Gas c h r o m a t o g r a p h i c a n a l y s i s was p e r f o r m e d w i t h each f r a c t i o n u s i n g a V a r i a n V i s t a 6000 gas chromatography (GC) system c o u p l e d w i t h a V i s t a 401 d a t a system ( V a r i a n I n s t r u m e n t s , S u n n y v a l e , C A ) . A flame ionization detector (FID) was u s e d and t h e sample was s e p a r a t e d on a g l a s s c a p i l l a r y column (30 m χ 0.25 mm w i t h WCOT SE-30), t e m p e r a t u r e programmed from 100°C t o 280°C a t 8°/min, and h e l d a t 280°C f o r 10 min, which a l l o w e d o b s e r v a t i o n o f t h e n-alkane homologous s e r i e s from " ^ through ~ 3 2 * **e i n j e c t o r was o p e r a t e d i n t h e s p l i t l e s s mode w i t h septum purge a f t e r 30 s e c . The c a r r i e r and make up g a ^ was Ν · I n j e c t i o n volume was 2 u l ; w i t h an a t t e n u a t i o n o f 4 χ 10 A p p r o x i m a t e l y 10% o f t h e sediment and o r g a n i s m samples were analyzed by combined high resolution gas chromatography-mass spectrometry. Samples were a n a l y z e d on a H e w l e t t - P a c k a r d Model 5992B c o m p u t e r i z e d GC-MS system ( H e w l e t t - P a c k a r d , Avondale, PA) e q u i p p e d w i t h a 30 m DB-5 f u s e d s i l i c a c a p i l l a r y column. Running c o n d i t i o n s were follows: c a r r i e r gas = h e l i u m ; column f l o w r a t e = 1.7 m l min ; i n j e c t i o n p o r t t e m p e r a t u r e = 240°C; s p l i t l e s s i n j e c t i o ^ j mode; column oven temperature programmed f r o m 90-250°C a t 4°C m i n ; e l e c t r o n m u l t i p l i e r v o l t a g e = 1200-2000 eV; GC-MS r u n i n s e l e c t e d i o n m o n i t o r i n g mode; d w e l l t i m e = 100 msec f o r each i o n . Samples were f i r s t a n a l y z e d by e l e c t r o n impact t o o b t a i n t h e t o t a l i o n s p e c t r a t o check f o r interfering ions. Samples were t h e n a n a l y z e d by s e l e c t e d i o n m o n i t o r i n g t o i d e n t i f y and q u a n t i t a t e s p e c i f i c p o l y n u c l e a r a r o m a t i c h y d r o c a r b o n s (PNA) homologues.


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T

2

Q u a l i t y Assurance. The q u a l i t y a s s u r a n c e program c o n s i s t e d o f a sample c h a i n o f c u s t o d y v e r i f i c a t i o n , p r e c a u t i o n s t o g u a r d a g a i n s t and t o d e t e c t sample c o n t a m i n a t i o n , v e r i f i c a t i o n o f p r e c i s i o n and a c c u r a c y and i n t e r c a l i b r a t i o n w i t h two o t h e r l a b o r a t o r i e s t o v e r i f y r e s u l t s from o u r e x t r a c t i o n and a n a l y s i s p r o c e d u r e s . T h i s program i s d e t a i l e d i n t h e u n p u b l i s h e d F i n a l Report o f t h e o v e r a l l study t o t h e F L Department o f N a t u r a l Resources (^0 ). Interlaboratory calibration consisted o f t h r e e phases : 1 ) instrument inter c a l i b r a t i o n by comparing r e s u l t s o f s t a n d a r d h y d r o c a r b o n s o l u t i o n s ; 2) methods i n t e r c a l i b r a t i o n by comparing r e s u l t s o f a n a l y s e s o f a s t a n d a r d sediment sample (Duwamish-I), s u p p l i e d by D r . W i l l i a m MacLeod o f t h e NOAA, Northwest and A l a s k a F i s h e r i e s C e n t e r , S e a t t l e , WA {±3); a n d 3) sample i n t e r c a l i b r a t i o n , c o n s i s t i n g o f t h e exchange among t h e t h r e e p a r t i c i p a t i n g l a b o r a t o r i e s o f t h r e e sediment samples from t h e s t u d y a r e a s . R e s u l t s and D i s c u s s i o n P e t r o l e u m h y d r o c a r b o n i d e n t i f i c a t i o n was b a s e d p r i m a r i l y on t h e GC-FID chromatogram p a t t e r n s o f t h e s a t u r a t e d and unsaturated


14. PIERCE ET AL.


hydrocarbon f r a c t i o n s . Additional information regarding petrogenic vs. pyrogenic or biogenic h y d r o c a r b o n s was p r o v i d e d b y GC-MS a n a l y s i s o f s p e c i f i c PNA s e r i e s from t h e u n s a t u r a t e d f r a c t i o n w i t h s e l e c t samples ( 3 , 5 , 1 4 1 5 ) . For comparison, GC-FID chromatograms of representative p e t r o l e u m c o n t a m i n a n t s a r e shown i n F i g u r e 2 and chromatograms o f h y d r o c a r b o n s from v a r i o u s marine p l a n t s ( b i o g e n i c ) a r e g i v e n i n F i g u r e 3. Key p a r a m e t e r s used f o r h y d r o c a r b o n c h a r a c t e r i z a t i o n a r e l i s t e d i n Table I. A r e a A. Samples from A r e a A i n c l u d e d sediment, water and o y s t e r s f r o m P o r t C h a r l o t t e c a n a l s ( S i t e s A-1 t h r o u g h A - 4 ) , t h e Peace R i v e r ( S i t e s A-5 t h r o u g h A - 9 ) , and Punta Gorda r e s i d e n t i a l c a n a l s ( S i t e s A-10 t h r o u g h A - 1 4 ) . Sediment h y d r o c a r b o n s from b o t h c a n a l systems showed a heavy r e s i d u a l c r a n k c a s e o i l - l i k e p e t r o l e u m c o n t a m i n a t i o n from marina and highway s e r v i c e s t a t i o n a c t i v i t i e s ( S i t e A-1, and A-12, Figure 4). This contamination diminished i n r e s i d e n t i a l c a n a l s away f r o m p o l l u t i o n s o u r c e s and d i d n o t appear t o be e x p o r t e d t o nearby bay and r i v e r sediment which e x h i b i t e d a t o t a l l y d i f f e r e n t h y d r o c a r b o n p a t t e r n somewhat r e p r e s e n t a t i v e o f h y d r o c a r b o n s i n r e d mangrove l e a v e s ( S i t e A-6, F i g u r e 4, T a b l e I ) . O y s t e r s c o l l e c t e d w i t h i n t h e c a n a l systems n e a r t h e marinas e x h i b i t e d t h e c r a n k c a s e o i l - l i k e p a t t e r n s , whereas t h o s e away from t h e marina e x h i b i t e d b i o g e n i c m a t e r i a l p a t t e r n s . Water samples i n the Port Charlotte canal system yielded mangrove-hydrocarbon p a t t e r n s s i m i l a r t o t h a t f o u n d i n sediment and o y s t e r s o u t s i d e t h e c a n a l s a l o n g t h e Peace R i v e r and A l l i g a t o r Bay, whereas water c o l l e c t e d from t h e Peace R i v e r e x h i b i t e d v e r y l i t t l e d i s c e r n a b l e hydrocarbon p a t t e r n . Water i n Punta Gorda c a n a l s more c l o s e l y r e f l e c t e d t h e h y d r o c a r b o n p a t t e r n s f o u n d i n sediment and o y s t e r s , i . e . h i g h l y c o n t a m i n a t e d a t t h e marina d i m i n i s h i n g t o v e r y low l e v e l s w i t h i n about a m i l e i n t o o r o u t o f t h e c a n a l s . L o c a l i z e d c o n t a m i n a t i o n o f water and sediment was o b s e r v e d near a d o c k i n g a r e a f o r commercial f i s h i n g b o a t s , a t F i s h e r m a n ' s Wharf a l o n g t h e Peace R i v e r . T h i s p a t t e r n was unique t o t h e a r e a showing a b i m o d a l u n r e s o l v e d complex m i x t u r e (UCM) and a t o t a l sediment h y d r o c a r b o n c o n t e n t o f 90 ug/1 ( S i t e 10, T a b l e I ) . A n a l y s i s o f s e l e c t PNA t o v e r i f y p e t r o l e u m o r i g i n showed t h a t a l l sediment c o n t a i n e d mixed p e t r o g e n i c and p y r o g e n i c m a t e r i a l . The r e l a t i v e abundance o f PNA i n marina sediment, however, was much g r e a t e r (180 ng/g benzanthracenes ) t h a n t h a t f o u n d i n sediment from non-marina a r e a s (

Hydrocarbon Contamination from Coastal Development - ACS

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