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Beach tar contamination in Jamaica
Volume 21/Number
7/July 1990
Marine Pollution Bulletin, Volume 2I. No. 7, pp. 331-334. 1990.
0025-326X/90 $3.00+0.00 ~ 1990 Pergamon Press pie
Printed in Great Britain.
Beach Tar Contamination in Jamaica MARGARET A. J. JONES and PETER R. BACON
Zoology Department, University of the West Indies, Kingston 7, Jamaica, WL
The quantity of stranded beach tar on Jamaican beaches was measured by collecting beach tar residues from twenty-nine beach stations around the Jamaican coast on monthly visits for 13 months. Stranded beach tar was found to be very persistent. The east coast and Kingston Harbour Area are subjected to constant relatively large amounts of fresh tar; the north coast, although receiving small amounts of fresh tar, appeared to have been impacted by a particular incident about two years ago giving highly skewed distributions; the west coast is virtually clean and the south coast (with the exception of the Kingston Harbour Area) showed no evidence of stranded beach tar pollution at any time during the study.
Since 1979 the Intergovernmental Oceanographic Commission's Regional commission for the Caribbean and Adjacent Regions (IOCARIBE) has conducted a monitoring programme for petroleum pollution in the Wider Caribbean area. The programme was implemented within the IOCARIBE marine pollution research and monitoring programme which is called CARIPOL. One of the parameters measured in this study was stranded beach tar. The results for the region indicated that the problem of beach contamination by tar is serious in many locations, with numerous beaches having average concentrations in excess of 100 g m -1 of shore front (Atwood et al., 1987). During this programme, beach tar data were collected for the Kingston Harbour Area in Jamaica as well as some south-eastern beaches (Gillett, 1985; Provan, 1985; Wade et al., 1987). However, sampling was restricted to one or two visits for some sites. This paper details levels of stranded beach tar collected from twenty-nine beach stations distributed around the entire coastline of Jamaica, over the period December 1987-November 1988. This paper revises the data which has been submitted to the CARIPOL database in Miami, Florida. M a t e r i a l s and M e t h o d s A preliminary survey of the Jamaican coastline was carried out in November 1987 in order to locate suitable beach stations according to specifications set out by CARIPOL (IOCARIBE, 1980; UNESCO, 1984). Some sites may not have had all these characteristics but were
chosen because of their economic, social or cultural importance to Jamaica. The beach stations are shown in Fig. 1. This preliminary survey was conducted by land over 5 days. From this survey, 29 beach sites were chosen. Sampling was conducted over a 5 day period once a month for 13 months, December 1987 to December 1988, inclusive. All beach sites were visited once a month as beach tar has been shown to be the best indicator of persistent oil pollution.
Collection and Analysis At each beach, transect lines of 1 m width were run from the water line to the backshore where the first signs of stable vegetation began and all visible pieces of tar were collected, taken back to the laboratory and weighed. The beaches were not cleaned after each sampling period and the tar collected was not thrown back. Hence, the tar collected on each visit represented older persistent tar as well as freshly deposited tar. For a particular beach no effort was made to note the exact location at which each transect was run. Each sampling period therefore represented a random analysis of the amount of beach tar present at a particular site for a particular month. Tar balls that were heavily encrusted with extraneous matter were extracted by dissolving the ball in hexane, filtering, weighing the material and subtracting the weight of the debris from the initial weight of the material. Where possible large particles such as sticks and stones were removed manually. Levels of tar for each beach were recorded as g m -~ of shore front. Beach tar was statistically analysed using the Friedman Two-Way Analysis by Ranks for Randomized Blocks followed by multiple comparisons. The Kruskal-Wallis Analysis by Ranks and the K-Sample Slippage Test (Conover, 1968) were used for analysis of-geographical blocks. Results A total of 332 visits were made to these beach stations and tar was found on 40% of these visits (Table 1). The occurrence of tar was found to be consistent with regard to spatial and temporal influences. Of the 29 sites, 26 were visited every month. Of these 26 sites 38.5% recorded no tar at any time. Tar collected from any site at any time ranged from 0-11 940 g m-1. By month, the total tar collected ranged from 930 g m -1 in September 1988 to 15, 592 g m -1 in February 1988 with means of 331
Marine Pollution Bulletin
,a • O
--
O No ~ontaminatio n • Mil
W W ~
~
~
//~
J
•~//
MO
~_~
,
Heavy Contamination(>100~-500)
i
'
,
i0:i 00~50ko
Gross Contamination(~500) W West Coast Block N North Coast Block E East Coast Block S South Coast Block K Kingston Harbour & Area Blcok
Blocks designated by different lower case letters are significantly different from each other (P <0.01). Means in g m -I.
Fig. 1 Map of Jamaica showing: Twentpnine beach stations at which tar levels were determined over the period December 1987December 1988; Qualitative assessment of the state of beach tar contamination based on mean levels; Designation of geographical blocks, means for each block and significant differences between blocks.
34.5 + 11.6 and 577.5 + 2264.8, respectively. For the whole island, Discovery Bay with a range of 60511940 g m -~, a total of 52 399.3 and a mean of 43 666.6 + 3104.9 was the site with the highest level of tar. Stranded beach tar occurred in many physical forms, as described by Wade et al. (1987). Discovery Bay revealed by far the most consistent occurrence of large tar balls; the heaviest one being found in December 1987 with a weight of 2902.9 g and dimensions of 16.0 c m x 16.0 cm x 8.0 cm. The largest ball was found in Februar~ 1988 at the same site with dimensions 22.0 cruX 26.0 cmX 11.0 cm and weighing 1859.8 g. The levels of petroleum residues detected mostly produced non-normal, highly skewed distributions. Usually this type of data is normalized by logarithmic manipulation. This was not possible in this work because of the high percentage of 0 values which prevented the normalization of the data sufficiently to meet the basic assumptions underlying parametric tests. Statistical analysis of the data by site indicated a high level of significance (P < 0.001). Because of the nature of the tests used all sites that were not visited for the full 12 month period were omitted. The beach stations were also grouped into geographical blocks and comparative analysis shoWed a high level of significant difference (P < 0.01) among the blocks (Fig. 1). Barnswell beach was grouped with the Kingston Harbour sites to form the 'Kingston Harbour Area' Block because of its 332
proximity, the westward moving Caribbean Current which may carry material from one bay to the next and because statistical analysis by site indicated that Sites 23 and 25 were significantly different from the other south coast sites. By month it was found that the levels of beach tar detected over the period December 1987-August 1988 are significantly higher (P < 0.001) than those detected over the period September-December 1988. This is due to the occurrence of Hurricane Gilbert on 12 September, 1988. Although statistical tests show a significant difference in overall levels of tar detected before and after Hurricane Gilbert, it has been shown that the contaminated beaches were restricted to three main areas before the hurricane and remained restricted to these same areas after the hurricane (Jones, 1989b) although there were variations in the actual quantities of tar found at individual sites. In February 1988, the level of tar detected was also significantly higher than all other values indicating that in February significantly higher levels of beach tar were being deposited on Jamaican beaches. This corresponds with the occurrence of pelagic tar in Jamaican waters (Jones, 1989a) as a result of the strong northerly winds.
Discussion The levels of beach tar detected in this study give a vivid indication of the state of oil pollution in Jamaica.
e,.,O
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. "18. 19. 20. 21. 22. 23, 24. 25. 26. 27. 28. 29.
Negril Bloody Bay Sandy Bay Montego Freeport Montego Airport Falmouth Burwood Rio Bueno Discovery Bay Pear Tree Bottom Priory Mammee Bay Ocho Rios Annotto Bay Hope Bay Blue Hole Long Bay Manchioneal Holland Bay Bowden Lyssons Kgn. Harbour B~ Salt Pond Beach Wreck Point Barnswell Gut River Alligator Pond Parker's Bay Bluefields
Site number and name
56.0 0 0 0 0
54.2 0 0 0.6 20.2
0 0 0 0 0 0 369.1 194.1 7208.4 193.1 23.6 10.9 0 0 0 1.8 0
Dec
T A B L E
1
0 0 0 0 0 0 937.6 1950.2 1769.0 401.2 308.2 1.5 0 0 0 0 0 . 19.8 0 0 0 105.4 . 268.6 0 0 0 0
Jan 37.0 0 38.2 0 0 0 376.7 2113.1 11 940.1 90.6 9.7 8.1 13.1 0 0 270.2 31.9 . 229.7 0 0 0.4 0.9 . 432.6 0 0 0 0
Feb
.
.
0 0 0 0 0 0 358.8 332.8 4079.6 23.5 28.4 13.8 0 0 0 14.0 2.9 . 130.3 0 0 3.2 25.2 . 256.1 0 0 0 0
Mar 0 0 0 0 0 5.4 24.9 393.8 3894.5 58.3 7.3 33.2 0 0 0 19.2 5.9 . 65.8 0 0 . 120.5 . 754.0 0 0 0 0
Apr
.
.
802.9 0 0 0 0
497.8 0 0 . 19.6
0 0 0 0 0 0 100.1 250.0 5321.5 30.7 8.4 10.1 0 0 0 5.0 32.0
May
.
753.3 0 0 0 0
150.0
278.6 0 0
0 0 12.4 4.3 0 0 105.4 102.6 6838.5 10.4 8.7 9.4 0 0 0 0 0
Jun
.
191.5 0 0 0 0
13.2
507.5 0 0
0 0 0 0 0 0 770.7 223.0 4553.7 250.5 23.5 10.5 0 0 0 0 0
Jul
7.0 10.2 192.7 0 0 0 0
0 0 0 13.4 0 0 546.6 37.4 4075.4 10.9 4.5 7.3 0 0 0 0 0 20.6 186.0 0 0
Aug
Levels of beach tar (gm -1) at twenty-nine beach stations during the period December 1987-December 1988.
65.2 0 0 0 0
-
77.9
-
0 0 0 0 0 0 0 0 605.0 0 0 0 0 0 0 0 0 86.1 95.9 0 0
Sep
101.1 0 0 0 0
118.5
0 0 0 0 0 0 0 0 1020.0 0 0 0 0 0 0 0 51.3 104.2 0 0
Oct
118.2 0 0 0 0
-
52.9
-
0 59.4 122.8 0 0
0 0 0 0 0 0 0 0 1093.6 0 22.3 3.6 0 0 0
Dec
37.0 0 50.6 17.7 0 5.4 3589.9 5597.0 52 399.3 1069.2 444.6 108.4 13.1 0 0 310.2 72.7 217.4 2292.6 0 0 4.2 711.3 10.2 3992.2 0 0 0 0
Total
U~
e-
t,J
<
Marine Pollution Bulletin Figure 1 shows a qualitative analysis of the levels of tar found at each site. In addition to fresh sources of oil in the Discovery Bay region of the north coast, it appears that this area was impacted by a particularly large spill approximately two and a half years ago and this is the reason for the persistently high levels of beach tar recorded, even after Hurricane Gilbert. The east coast also shows a high level of beach tar pollution. At each sampling period fresh tar was detected indicating that the east coast is being impacted by a regular supply of fresh tar. This is expected on this windward coast exposed to the prevailing north east trade winds and the Caribbean Current. Such coasts have been shown to be more contaminated than leeward coasts (Atwood e t al., 1987). The likely source of this pollution is ships utilising the Windward Passage and spills contaminating the Caribbean Current (Wade e t al., 1987). These sources of contamination do not appear to affect the south eastern or north eastern coasts and this may indicate that in the event of a large spill (by tankers utilizing the Windward Passage) the east coast may absorb the bulk of contamination. The south coast block (excluding the Kingston Harbour area) is the only block in which all sites recorded an absence of beach tar on 100% of the visits. However, the report of a spill in the Alligator Pond area in N o v e m b e r 1988 (Jones, 1989) and the history of spills in this area (Anon, 1981a, b, c: G o v e r n m e n t of Jamaica, 1987) indicate that the south coast is susceptible to occasional spills which may impact the coastline. With respect to stranded beach tar, the Kingston H a r b o u r area has been assessed as heavily contaminated and the occurrence of very fresh samples at various periods indicates that there is a persistent problem here. The source of the pollution to this area has been shown to be mostly local (Provan, 1985), as this area is the capital city and supports a high level of commercial and industrial activities, including the island's only oil refinery. Atwood e t al. (1987) indicate that when values of beach tar reach 10 g m -t beach users get soiled by tar and at values approaching 100 g m -1 beaches b e c o m e virtually unusable for tourist purposes. This has serious implications for Jamaica, based on the assessment of beach tar levels detected in this survey and the dependence of the e c o n o m y on tourism. The heavily contaminated north coast (mean level of beach tar 372.0 g m -t) and the west coast are the hub of tourism and the occurrence of beach tar in the quantities found in this study may have detrimental long term effects on the tourism industry.
334
Conclusions The levels of stranded beach tar in Jamaica's coastal environment appear to be higher than expected or previously recorded. The north coast appears to be receiving fresh tar in small amounts, although older tar from an earlier spill still persists in large quantities. The east coast is constantly being impacted by fresh tar brought to the coast by the prevailing winds and the Caribbean Current. The south and west coasts appear to be free of stranded beach tar now, although areas along the south coast have been susceptible to spills. The Kingston H a r b o u r Area reported seven sightings of spills (sLicks/sheens) over the period of this study (Jones, 1989a) and, based on the levels of beach tar detected, still appears to have a high level of petroleum contamination. Thanks are due to the Petroleum Corporation of Jamaica and the Zoology Department, Universityof the West Indies for funding to carry out this work and to many un-named visitors to the island who gave information. Anon. (1981a). Tanker with 6.5 m Gallons Aground near St. Elizabeth. The Daily Gleaner (24.2.81), 1. Anon. (1981b). Oil Tanker Runs Aground. The Jamaica Daily News (24.2.81), 1. Anon. (1981c). Government Moves to Counter Effects of Oil Spill. The Daily Gleaner (26.2.81), I. Atwood, D. K., Burton, E J., Corredor, J. E., Harvey, G. R., MataJimenez, A. J., Vasquez-Botello,A. & Wade, B. A. (1987). Results of the CARIPOL Petroleum Pollution Monitoring Project in the Wider Caribbean. Mar. Pollut. Bull. 18,540-548. Conover, W. J. (1968). Two K-Sample Slippage Tests. J. Amer. Statist. Assoc. 63,614-626. Gillett, V. V. (1985). An Evaluation of Oil Pollution in the Coastal Waters of the Approaches to Kingston Harbour, Jamaica, during 1980-1982. M.Phil. Thesis, University of the West Indies, Mona, Jamaica. Government of Jamaica (1987). Jamaica, Country Environmental Profile. Ministry of Agriculture and Ralph Field Ass. Inc. IOCARIBE (1980). CARIPOL Manual for Petroleum Pollution Monitoring. Jones, M. A. J. (1989a). An Evaluation of the Status of Oil Pollution in the Jamaican Coastal Environment. M.Phil. Thesis, Universityof the West Indies, Mona, Jamaica. Jones, M. A. J. (1989b). Effect of Hurricane Gilbert on Beaches and the Status of Coastal Oil Pollution. In Assessment of the Economic hnpacts of Hurricane Gilbert on Coastal and Marine Resources in Jamaica (P. R. Bacon, ed.), pp. 55-59. Regional Coordinating Unit,
UNEP, Kingston,Jamaica. Provan, M. (1985). The Status of Oil Pollution in Kingston Harbour. M.Phil. Thesis, Universityof the West Indies, Mona, Jamaica. UNESCO (1984). Intergovernmental Oceanographic Commission Manuals and Guides No. 13. Manual for Monitoring Oil and Dissolved/Dispersed Petroleum Hydrocarbons in Marine Waters and on Beaches. Wade, B. A., Provan, M., Gillett, V. & Carroll, E (1987). Oil Pollution of Jamaican Coastal Waters and Beaches: Results of the IOCARIBE/ CARIPOL Monitoring Programme (Jamaica) 1980-1983. Carib. J. Sci. 23, 93-104.
7/July 1990
Marine Pollution Bulletin, Volume 2I. No. 7, pp. 331-334. 1990.
0025-326X/90 $3.00+0.00 ~ 1990 Pergamon Press pie
Printed in Great Britain.
Beach Tar Contamination in Jamaica MARGARET A. J. JONES and PETER R. BACON
Zoology Department, University of the West Indies, Kingston 7, Jamaica, WL
The quantity of stranded beach tar on Jamaican beaches was measured by collecting beach tar residues from twenty-nine beach stations around the Jamaican coast on monthly visits for 13 months. Stranded beach tar was found to be very persistent. The east coast and Kingston Harbour Area are subjected to constant relatively large amounts of fresh tar; the north coast, although receiving small amounts of fresh tar, appeared to have been impacted by a particular incident about two years ago giving highly skewed distributions; the west coast is virtually clean and the south coast (with the exception of the Kingston Harbour Area) showed no evidence of stranded beach tar pollution at any time during the study.
Since 1979 the Intergovernmental Oceanographic Commission's Regional commission for the Caribbean and Adjacent Regions (IOCARIBE) has conducted a monitoring programme for petroleum pollution in the Wider Caribbean area. The programme was implemented within the IOCARIBE marine pollution research and monitoring programme which is called CARIPOL. One of the parameters measured in this study was stranded beach tar. The results for the region indicated that the problem of beach contamination by tar is serious in many locations, with numerous beaches having average concentrations in excess of 100 g m -1 of shore front (Atwood et al., 1987). During this programme, beach tar data were collected for the Kingston Harbour Area in Jamaica as well as some south-eastern beaches (Gillett, 1985; Provan, 1985; Wade et al., 1987). However, sampling was restricted to one or two visits for some sites. This paper details levels of stranded beach tar collected from twenty-nine beach stations distributed around the entire coastline of Jamaica, over the period December 1987-November 1988. This paper revises the data which has been submitted to the CARIPOL database in Miami, Florida. M a t e r i a l s and M e t h o d s A preliminary survey of the Jamaican coastline was carried out in November 1987 in order to locate suitable beach stations according to specifications set out by CARIPOL (IOCARIBE, 1980; UNESCO, 1984). Some sites may not have had all these characteristics but were
chosen because of their economic, social or cultural importance to Jamaica. The beach stations are shown in Fig. 1. This preliminary survey was conducted by land over 5 days. From this survey, 29 beach sites were chosen. Sampling was conducted over a 5 day period once a month for 13 months, December 1987 to December 1988, inclusive. All beach sites were visited once a month as beach tar has been shown to be the best indicator of persistent oil pollution.
Collection and Analysis At each beach, transect lines of 1 m width were run from the water line to the backshore where the first signs of stable vegetation began and all visible pieces of tar were collected, taken back to the laboratory and weighed. The beaches were not cleaned after each sampling period and the tar collected was not thrown back. Hence, the tar collected on each visit represented older persistent tar as well as freshly deposited tar. For a particular beach no effort was made to note the exact location at which each transect was run. Each sampling period therefore represented a random analysis of the amount of beach tar present at a particular site for a particular month. Tar balls that were heavily encrusted with extraneous matter were extracted by dissolving the ball in hexane, filtering, weighing the material and subtracting the weight of the debris from the initial weight of the material. Where possible large particles such as sticks and stones were removed manually. Levels of tar for each beach were recorded as g m -~ of shore front. Beach tar was statistically analysed using the Friedman Two-Way Analysis by Ranks for Randomized Blocks followed by multiple comparisons. The Kruskal-Wallis Analysis by Ranks and the K-Sample Slippage Test (Conover, 1968) were used for analysis of-geographical blocks. Results A total of 332 visits were made to these beach stations and tar was found on 40% of these visits (Table 1). The occurrence of tar was found to be consistent with regard to spatial and temporal influences. Of the 29 sites, 26 were visited every month. Of these 26 sites 38.5% recorded no tar at any time. Tar collected from any site at any time ranged from 0-11 940 g m-1. By month, the total tar collected ranged from 930 g m -1 in September 1988 to 15, 592 g m -1 in February 1988 with means of 331
Marine Pollution Bulletin
,a • O
--
O No ~ontaminatio n • Mil
W W ~
~
~
//~
J
•~//
MO
~_~
,
Heavy Contamination(>100~-500)
i
'
,
i0:i 00~50ko
Gross Contamination(~500) W West Coast Block N North Coast Block E East Coast Block S South Coast Block K Kingston Harbour & Area Blcok
Blocks designated by different lower case letters are significantly different from each other (P <0.01). Means in g m -I.
Fig. 1 Map of Jamaica showing: Twentpnine beach stations at which tar levels were determined over the period December 1987December 1988; Qualitative assessment of the state of beach tar contamination based on mean levels; Designation of geographical blocks, means for each block and significant differences between blocks.
34.5 + 11.6 and 577.5 + 2264.8, respectively. For the whole island, Discovery Bay with a range of 60511940 g m -~, a total of 52 399.3 and a mean of 43 666.6 + 3104.9 was the site with the highest level of tar. Stranded beach tar occurred in many physical forms, as described by Wade et al. (1987). Discovery Bay revealed by far the most consistent occurrence of large tar balls; the heaviest one being found in December 1987 with a weight of 2902.9 g and dimensions of 16.0 c m x 16.0 cm x 8.0 cm. The largest ball was found in Februar~ 1988 at the same site with dimensions 22.0 cruX 26.0 cmX 11.0 cm and weighing 1859.8 g. The levels of petroleum residues detected mostly produced non-normal, highly skewed distributions. Usually this type of data is normalized by logarithmic manipulation. This was not possible in this work because of the high percentage of 0 values which prevented the normalization of the data sufficiently to meet the basic assumptions underlying parametric tests. Statistical analysis of the data by site indicated a high level of significance (P < 0.001). Because of the nature of the tests used all sites that were not visited for the full 12 month period were omitted. The beach stations were also grouped into geographical blocks and comparative analysis shoWed a high level of significant difference (P < 0.01) among the blocks (Fig. 1). Barnswell beach was grouped with the Kingston Harbour sites to form the 'Kingston Harbour Area' Block because of its 332
proximity, the westward moving Caribbean Current which may carry material from one bay to the next and because statistical analysis by site indicated that Sites 23 and 25 were significantly different from the other south coast sites. By month it was found that the levels of beach tar detected over the period December 1987-August 1988 are significantly higher (P < 0.001) than those detected over the period September-December 1988. This is due to the occurrence of Hurricane Gilbert on 12 September, 1988. Although statistical tests show a significant difference in overall levels of tar detected before and after Hurricane Gilbert, it has been shown that the contaminated beaches were restricted to three main areas before the hurricane and remained restricted to these same areas after the hurricane (Jones, 1989b) although there were variations in the actual quantities of tar found at individual sites. In February 1988, the level of tar detected was also significantly higher than all other values indicating that in February significantly higher levels of beach tar were being deposited on Jamaican beaches. This corresponds with the occurrence of pelagic tar in Jamaican waters (Jones, 1989a) as a result of the strong northerly winds.
Discussion The levels of beach tar detected in this study give a vivid indication of the state of oil pollution in Jamaica.
e,.,O
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. "18. 19. 20. 21. 22. 23, 24. 25. 26. 27. 28. 29.
Negril Bloody Bay Sandy Bay Montego Freeport Montego Airport Falmouth Burwood Rio Bueno Discovery Bay Pear Tree Bottom Priory Mammee Bay Ocho Rios Annotto Bay Hope Bay Blue Hole Long Bay Manchioneal Holland Bay Bowden Lyssons Kgn. Harbour B~ Salt Pond Beach Wreck Point Barnswell Gut River Alligator Pond Parker's Bay Bluefields
Site number and name
56.0 0 0 0 0
54.2 0 0 0.6 20.2
0 0 0 0 0 0 369.1 194.1 7208.4 193.1 23.6 10.9 0 0 0 1.8 0
Dec
T A B L E
1
0 0 0 0 0 0 937.6 1950.2 1769.0 401.2 308.2 1.5 0 0 0 0 0 . 19.8 0 0 0 105.4 . 268.6 0 0 0 0
Jan 37.0 0 38.2 0 0 0 376.7 2113.1 11 940.1 90.6 9.7 8.1 13.1 0 0 270.2 31.9 . 229.7 0 0 0.4 0.9 . 432.6 0 0 0 0
Feb
.
.
0 0 0 0 0 0 358.8 332.8 4079.6 23.5 28.4 13.8 0 0 0 14.0 2.9 . 130.3 0 0 3.2 25.2 . 256.1 0 0 0 0
Mar 0 0 0 0 0 5.4 24.9 393.8 3894.5 58.3 7.3 33.2 0 0 0 19.2 5.9 . 65.8 0 0 . 120.5 . 754.0 0 0 0 0
Apr
.
.
802.9 0 0 0 0
497.8 0 0 . 19.6
0 0 0 0 0 0 100.1 250.0 5321.5 30.7 8.4 10.1 0 0 0 5.0 32.0
May
.
753.3 0 0 0 0
150.0
278.6 0 0
0 0 12.4 4.3 0 0 105.4 102.6 6838.5 10.4 8.7 9.4 0 0 0 0 0
Jun
.
191.5 0 0 0 0
13.2
507.5 0 0
0 0 0 0 0 0 770.7 223.0 4553.7 250.5 23.5 10.5 0 0 0 0 0
Jul
7.0 10.2 192.7 0 0 0 0
0 0 0 13.4 0 0 546.6 37.4 4075.4 10.9 4.5 7.3 0 0 0 0 0 20.6 186.0 0 0
Aug
Levels of beach tar (gm -1) at twenty-nine beach stations during the period December 1987-December 1988.
65.2 0 0 0 0
-
77.9
-
0 0 0 0 0 0 0 0 605.0 0 0 0 0 0 0 0 0 86.1 95.9 0 0
Sep
101.1 0 0 0 0
118.5
0 0 0 0 0 0 0 0 1020.0 0 0 0 0 0 0 0 51.3 104.2 0 0
Oct
118.2 0 0 0 0
-
52.9
-
0 59.4 122.8 0 0
0 0 0 0 0 0 0 0 1093.6 0 22.3 3.6 0 0 0
Dec
37.0 0 50.6 17.7 0 5.4 3589.9 5597.0 52 399.3 1069.2 444.6 108.4 13.1 0 0 310.2 72.7 217.4 2292.6 0 0 4.2 711.3 10.2 3992.2 0 0 0 0
Total
U~
e-
t,J
<
Marine Pollution Bulletin Figure 1 shows a qualitative analysis of the levels of tar found at each site. In addition to fresh sources of oil in the Discovery Bay region of the north coast, it appears that this area was impacted by a particularly large spill approximately two and a half years ago and this is the reason for the persistently high levels of beach tar recorded, even after Hurricane Gilbert. The east coast also shows a high level of beach tar pollution. At each sampling period fresh tar was detected indicating that the east coast is being impacted by a regular supply of fresh tar. This is expected on this windward coast exposed to the prevailing north east trade winds and the Caribbean Current. Such coasts have been shown to be more contaminated than leeward coasts (Atwood e t al., 1987). The likely source of this pollution is ships utilising the Windward Passage and spills contaminating the Caribbean Current (Wade e t al., 1987). These sources of contamination do not appear to affect the south eastern or north eastern coasts and this may indicate that in the event of a large spill (by tankers utilizing the Windward Passage) the east coast may absorb the bulk of contamination. The south coast block (excluding the Kingston Harbour area) is the only block in which all sites recorded an absence of beach tar on 100% of the visits. However, the report of a spill in the Alligator Pond area in N o v e m b e r 1988 (Jones, 1989) and the history of spills in this area (Anon, 1981a, b, c: G o v e r n m e n t of Jamaica, 1987) indicate that the south coast is susceptible to occasional spills which may impact the coastline. With respect to stranded beach tar, the Kingston H a r b o u r area has been assessed as heavily contaminated and the occurrence of very fresh samples at various periods indicates that there is a persistent problem here. The source of the pollution to this area has been shown to be mostly local (Provan, 1985), as this area is the capital city and supports a high level of commercial and industrial activities, including the island's only oil refinery. Atwood e t al. (1987) indicate that when values of beach tar reach 10 g m -t beach users get soiled by tar and at values approaching 100 g m -1 beaches b e c o m e virtually unusable for tourist purposes. This has serious implications for Jamaica, based on the assessment of beach tar levels detected in this survey and the dependence of the e c o n o m y on tourism. The heavily contaminated north coast (mean level of beach tar 372.0 g m -t) and the west coast are the hub of tourism and the occurrence of beach tar in the quantities found in this study may have detrimental long term effects on the tourism industry.
334
Conclusions The levels of stranded beach tar in Jamaica's coastal environment appear to be higher than expected or previously recorded. The north coast appears to be receiving fresh tar in small amounts, although older tar from an earlier spill still persists in large quantities. The east coast is constantly being impacted by fresh tar brought to the coast by the prevailing winds and the Caribbean Current. The south and west coasts appear to be free of stranded beach tar now, although areas along the south coast have been susceptible to spills. The Kingston H a r b o u r Area reported seven sightings of spills (sLicks/sheens) over the period of this study (Jones, 1989a) and, based on the levels of beach tar detected, still appears to have a high level of petroleum contamination. Thanks are due to the Petroleum Corporation of Jamaica and the Zoology Department, Universityof the West Indies for funding to carry out this work and to many un-named visitors to the island who gave information. Anon. (1981a). Tanker with 6.5 m Gallons Aground near St. Elizabeth. The Daily Gleaner (24.2.81), 1. Anon. (1981b). Oil Tanker Runs Aground. The Jamaica Daily News (24.2.81), 1. Anon. (1981c). Government Moves to Counter Effects of Oil Spill. The Daily Gleaner (26.2.81), I. Atwood, D. K., Burton, E J., Corredor, J. E., Harvey, G. R., MataJimenez, A. J., Vasquez-Botello,A. & Wade, B. A. (1987). Results of the CARIPOL Petroleum Pollution Monitoring Project in the Wider Caribbean. Mar. Pollut. Bull. 18,540-548. Conover, W. J. (1968). Two K-Sample Slippage Tests. J. Amer. Statist. Assoc. 63,614-626. Gillett, V. V. (1985). An Evaluation of Oil Pollution in the Coastal Waters of the Approaches to Kingston Harbour, Jamaica, during 1980-1982. M.Phil. Thesis, University of the West Indies, Mona, Jamaica. Government of Jamaica (1987). Jamaica, Country Environmental Profile. Ministry of Agriculture and Ralph Field Ass. Inc. IOCARIBE (1980). CARIPOL Manual for Petroleum Pollution Monitoring. Jones, M. A. J. (1989a). An Evaluation of the Status of Oil Pollution in the Jamaican Coastal Environment. M.Phil. Thesis, Universityof the West Indies, Mona, Jamaica. Jones, M. A. J. (1989b). Effect of Hurricane Gilbert on Beaches and the Status of Coastal Oil Pollution. In Assessment of the Economic hnpacts of Hurricane Gilbert on Coastal and Marine Resources in Jamaica (P. R. Bacon, ed.), pp. 55-59. Regional Coordinating Unit,
UNEP, Kingston,Jamaica. Provan, M. (1985). The Status of Oil Pollution in Kingston Harbour. M.Phil. Thesis, Universityof the West Indies, Mona, Jamaica. UNESCO (1984). Intergovernmental Oceanographic Commission Manuals and Guides No. 13. Manual for Monitoring Oil and Dissolved/Dispersed Petroleum Hydrocarbons in Marine Waters and on Beaches. Wade, B. A., Provan, M., Gillett, V. & Carroll, E (1987). Oil Pollution of Jamaican Coastal Waters and Beaches: Results of the IOCARIBE/ CARIPOL Monitoring Programme (Jamaica) 1980-1983. Carib. J. Sci. 23, 93-104.