Chlorinated pesticides in the Rio Palizada, Campeche, Mexico

Marine Pollution Bulletin Marine Pollution Bulletin, Volume 26, No. 11, pp. 648-650, 1993. Printed in Great Britain.

0025-326X/93 $6.00+0.00 © 1993 Pergamon Press Ltd

Chlorinated Pesticides in the Rio Palizada, Campeche, Mexico G. GOLD-BOUCHOT, T. SILVA-HERRERA and O. ZAPATA-PI~REZ

Centro de Investigaci6n y de Estudios Avanzados, Unidad MOrida, Departamento de Recursos del Mar, Apdo. Postal 73-Cordemex, Mdrida, Yucatdn, 97310Mdxico A regionally coordinated programme for marine pollution assessment and control for the Wider Caribbean Region (CEPPOL) was established jointly in 1990 by the Intergovernmental Oceanographic Commission of UNESCO (IOC) and the United Nations Environmental Programme (UNEP), catering to the immediate and long-term requirements of the Cartagena Convention and its Protocols, as well as the requirements of the Member States of the IOC Subcommission for the Caribbean and Adjacent Regions (IOCARIBE) (IOC, 1990). CEPPOL is part of the Caribbean Environment Programme, as implemented under the authority of the Contracting Parties to the Cartagena Convention and of IOCARIBE, and under the authority of the member States of IOCARIBE. CEPPOL includes baseline studies of pesticide contamination and the formulation of control measures. To carry out this activity, seven pilot studies are currently underway in the Caribbean and adjacent regions. The State of Campeche, where Laguna de Trrminos is located, is a major rice producer in Mexico, which is one of the critical crops of the CEPPOL organochlorine programme (IOC, 1990). Rice production in Campeche accounted for 9.3 to 20.0% of Mexico's national production in the period 1982-1986 (INEGI, 1990) and the land used for this crop accounted for 17.5 to 30.5% of the total rice-producing land in Mexico. Another important crop in Campeche is sugar cane, with an average annual production of 28 000 t obtained from 60 000 Ha (INEGI, 1990). A great deal of this land belongs to the Palizada river basin. The area is also a main shrimp producer in Mexico, with an annual mean catch of 18 000 t, which represents 38 to 50% of the national catch in the Gulf of Mexico. The main objective of this study is to assess the concentration of organochlorine pesticides in recent sediments, oysters ( Crassostrea virginica), clams ( Rangia cuneata), mussels (Brachidontes recurvus) and juvenile shrimps (Penaeus setiferus) in Rfo Palizada, Campeche, Mexico. The field site for this pilot study is Laguna de Trrminos, a 2500 km 2 coastal lagoon in southwestern Gulf of Mexico (see Fig. 1) between 18020 ' and 19000 , N, and 91000 ' and 92020 ' W. This lagoon has been systematically studied and is probably one of the best known in Mexico; it is shallow with a mean depth of 3 m, and a maximum depth of 10 m at Puerto Real. Several rivers (most of them from the Usumacinta-Grijalva basin) drain into the lagoon, with a mean annual 648

Gulfof Mexico

f Isla del Carmen

R, ~ u m ~

Fig. 1 Map of the Laguna de T~rminos region and the lower Rio Palizada field site from this study.

discharge of 6 x 1 0 9 m 3 year -~, the most important being the Candelaria River at the southeast (GutirrrezEstrada & Castro del R/o, 1988). An excellent review of this lagoon can be found in Yfifiez-Arancibia & Day (1988). The general study area is Laguna de TErminos (Fig. 1), particularly the Rio Palizada which is shown inside the rectangle in Fig. 1, together with the position of the sampling stations. Samples collected with a 0.1 m 2 Van Veen grab at eight stations distributed along Rio Palizada and the main lagoons close to its mouth, consisted of sediments, American oysters (Crassostrea virginica), mussels (Brachidontes recurvus) and juvenile shrimp (Penaeus setiferus) at station 1, and clams (Rangia cuneata) at station 3. Oysters were also collected at another bed, a few kilometres east from station 1 (station 9) and close to the mouth of River Chumpfin. No bivalves could be found at the other sampling stations. Sediment samples were placed in glass jars which were cleaned with chromic acid and hexane. Organisms were wrapped in aluminium foil, previously cleaned with hexane and heated at 450°C for two hours. All samples were transported to the laboratory at Merida under refrigeration for further analysis. The solvents used were distilled twice in an all-glass still. Florisil was purified by

Volume 2 6 / N u m b e r 11/November 1993

extracting it for 8 h with hexane in a Soxhlet apparatus. All samples were freeze-dried upon arrival at the laboratory. Both sediments and organisms were analysed according to established methodologies (UNEP, 1982a,b). Samples were extracted in hexane in a Soxhlet extractor, and the extract separated into three fractions in a column with Florisil. The fractions were evaporated in a Kuderna-Danish apparatus and the purified extracts were analysed by capillary gas chromatography and electron capture detection (UNEP, 1988) in a Hewlett Packard 5890 Series II gas chromatograph, connected to a personal computer equipped with a Hewlett Packard 3365 Series II software. The gas chromatograph was fitted with a split/splitless capillary injector and a 30 m×200 ~tm SE-54 capillary column. The temperature programme was 70°C initial temperature for 2 min, then increased at a rate of 3°C min -I to 265°C, and held for 25 min. Some samples were spiked with 2,4,5 Toxachlorobenzene (2,4,5-TCB) as an internal standard to check the efficiency of recovery for the analytical procedure. Analytical standards were provided by the IAEA/ILMR Marine Environmental Studies Laboratory in Monaco. Sedimentary organic carbon was determined by wet oxidation with potassium dichromate, and grain size by the method of Bouyoucos (Holme & Mclntyre, 1982). As part of the quality control procedures, the intercalibration sample IAEA-351 was analysed in duplicate along with the samples (Table 1). These data are for average of two analyses and are compared to consensus values (Villeneuve & Mee, 1989) in Table 1. Grain size and organic carbon content of the sediments, given in Table 2, show that the organic carbon concentration increases along the river towards the lagoon and that the clay fraction decreases in the same direction. No similar trend is apparent for the other size fractions. The sediments seem very homogenous with the exception of station 1, which shows a very high value of organic carbon, probably due to the greater primary productivity of the lagoon. Organochlorine concentrations for sediments are presented in Table 3. The largest number of different organochlorine compounds, as well as the highest concentrations, were found at station 1. Stations 3 and 7 exhibited relatively high concentrations of particular organochlorines. Table 4 shows the results for the extractable lipids and organochiorine compounds for all the organisms analysed. The highest lipid values were found in the clam (Rang& cuneata) and the oysters (Crassostrea virginica) from station 9. The highest concentrations of DDD and Aroclor 1254 were found in the clams; the highest levels of endrin and aldrin were noted in oysters at station 9, while the juvenile shrimp exhibited the lowest concentrations of all compounds. Although it has been suggested that there is a direct relation between the amount of lipids in an organism and the concentration of lipophilic compounds such as organochlorine pesticides, no such relationship was apparent (r=0.382; P<0.53) in our results. This is also the case in much larger data sets, such as those from the National Status and Trends Program of NOAA (NOAA,

TABLE 1 Concentrations of chlorinated compounds, in ng g-~ dry weight, in intercalibration sample IAEA-351.

Compound

This study (ng g-i)

Consensus (ng g l)

24 32 120 351

33 + 11 27 _+9 150 + 36 64(I-280

DDT DDD DDE Aroclor 1260

TABLE 2 Organic carbon content and grain size fractions for recent sediments of the Palizada River.

St. no.

Organic carbon (%)

Sand (%)

Silt (%)

Clay (%)

6.52 1.86 1.25 1.34 1.28 0.76 0.91 0.87

66.5 78.8 52.7 29.0 62.5 56.5 50.5 62.5

31.5 20.2 44.3 68.4 34.0 40.0 44.0 34.0

2.0 1.0 3.0 2.6 3.5 3.5 5.5 3.5

l 2 3 4 5 6 7 8

TABLE 3 Organochlorine compound concentrations, in ng g-1 dry weight, of sediments of the Palizada River. St. no. 1 2 3 4 5 6 7 8

Lindane

DDD

DDE

Aldrin

HCB

Aroclor 1260

Aroclor 1254

0.57 n.d. n.d. n.d. n.d. n.d. n.d. n.d.

n.d. n.d. n.d. n.d. 0.55 n.d. 0.45 n.d.

17.67 0.24 0.55 n.d. 0.40 n.d. 0.43 0.46

n.d. 0.27 9.02 n.d. n.d. n.d. n.d. 3.73

0.32 n.d. n.d. n.d. n.d. n.d. n.d. n.d.

12.99 n.d. n.d. n.d. n.d. 1.53 n.d. n.d.

258.6 n.d. 11.40 0.55 0.13 2.00 12.55 1.83

n.d.=not detected. TABLE 4 Organochlorine compound concentrations, in ng g J dry weight, in organisms from the Palizada River Estuary, Campeche, Mexico.

Organism Lindane

DDD

Endrin

Aldrin

Aroclor 1254

Lipids (%)

Shrimp Oyster 1 Oyster 9 Mussel Clam

n.d. 1.85 1.28 4.09 16.8

n.d. n.d. 56.7 n.d. n.d.

n.d. 5.26 6.56 n.d. n.d.

0.69 2.0 1.65 3.09 3.96

2.36 2.71 4.82 2.52 8.68

n.d.* 0.66 0.45 1.25 1.21

*n.d.=not detected.

1989; 1991). The relation between total organochlorines and organic carbon in sediments is excellent, however, and is statistically significant (r----0.9771; P-<0.000), as can be seen in Fig. 2. A comparison of our results with those of VfizquezBotello (1990) and Vfizquez-Botello et al. (1992) reveals good agreement, with the exception of both Aroclors and endrin (Table 5). In general, most concentrations are low, and considered as not dangerous. A similar comparison for organochlorine pesticide concentrations in organisms is presented in Table 6, showing greater differences, with higher values of endrin and aldrin in the case of Vfizquez-Botello et al. (1992). Direct comparison between these data is difficult, however, because 649

Marine Pollution Bulletin

of the differences in analytical methodologies, biological species studied, sampling times, and the way that data are reported.

200 -

150 -

_A

This work was funded under contract FP/5101-90-02-6212 by the IOC/ UNEP CEPPOL Programme. We thank the people from the Centro Regional de Investigaciones Pesqueras de Ciudad del Carmen for the help and logistical support they gave us for the field work. Our gratitude to Dr. Luis Capurro, Gustavo de la Cruz and a reviewer for their critical comments on an earlier version of this manuscript.

g ioo -

o o-

-5o

0

I I

I

2

I

I

3

I

4

5

I

6

I

7

Organic carbon (%) Fig.

2 Relation between organic carbon and total organochlorines in sediments from Rio Palizada.

TABLE

5

Comparison of the concentrations of organochlorine compounds in sediments found in this study with published values in the same area. All data as ng g-~ dry weight.

Compound

This Study

V~izquezBotello, 1990

V~zquezBotello, et al. 1992

ZDDT Lindane Aldrin HCB Endrin Aroclor 1254 Aroclor 1260

11.38 0.57 4.34 1/.32 n.d. 41 7.26

10.85 n.d.* n.d. n.d. n.d. -? -t

27.3 n.d. 17.4 n.d. 86.6 n.d. n.d.

n.d.=not detected, t = n o t reported.

TABLE

6

Comparison of the concentrations of organochlorine compounds in organisms from the Palizada River found in this study with those from the literature. All data as ng g-' dry weight.

Compound

This Study

V~izquezBotello, 1990

Lindane ZDDT Endrin Aldrin PCBs

0.89 6.01 56.7 5.91 2.28

-t 17.88 1110.3 269.65 -t

n.d.=not detected, t = n o t reported.

650

V~izquezBotello, et aL 1992 -t 84.8 796.2 119.7 -t

Rosales et al 1979 t 6.0 -'~ -~ 19.0

Gutierrez-Estrada, M. & Castro del R/o, A. (1988). Origin and geological development of the terminos lagoon In Ecology of Coastal Ecosystems in the Southern Gulf of Mexico: The Terminos Lagoon Region, (Y~ifiez-Arancibia, A. & J. W. Day, Jr. eds.), pp. 89-110, Inst. Ciencias del Mar y Limnologia (UNAM)-Coast. Ecol. Inst. (LSU). Editorial Universitaria, M6xico, D.E Holme, N. A. & Mclntyre, A. D. (1982). Methods for the A?udyof Marine Benthos. Blackwell, Oxford. INEGI (1990). El Sector Alimentario en M#xico. Instituto Nacional de Estadfstica, Geograffa e Inform~.tica. M6xico, D.F. 118 pp. IOC 11990). IOC-UNEP Regional Workshop to Review Priorities for Marine Pollution Monitoring, Research, Control and Abatement in the Wider Caribbean. San Jose, Costa Rica, 24 30 August 1989. Workshop Report No. 59. Paris. NOAA (1989). A Summary of Data on Tissue Contamination from the First Three Years 11986-1988) of the Mussel Watch Project. National Status and Trends Program Progress Report. National Oceanic and Atmospheric Administration Technical Memorandum NOS-OMA 49. Rockville, Maryland, U.S.A NOAA (1991) Second Summary of Data on Chemical Contaminants in Sediments from the National Status and Trends Program. National Status and Trends Program Progress Report. National Oceanic and Atmospheric Administration Technical Memorandum NOS-OMA 59. Rockville, Maryland, U.S.A. Rosales, L., Botello, A. V., Bravo, H. & Mandelli, E. F. 11979). PCB's and organochlorine insecticides in oysters from coastal lagoons of the Gulf of Mexico. Bull. Environ. Contam. Toxicol. 21,652-656. UNEP (1982a). Determination of DDT's, PCB's and Other Hydrocarbons in Marine Sediments by Gas-Liquid Chromatography. Reference Methods for Marine Pollution Studies No. 17. United Nations Environment Programme, Geneva. UNEP (1982b). Determination of DDT's and PCB~ in Selected Marine Organisms. Reference Methods for Marine Pollution Studies No. 14. United Nations Environment Programme, Geneva. UNEP (1988). Determination of DDT's attd PCBZ~"by Capillary Gas Chromatography and Electron Capture Detection. Reference Methods for Marine Pollution Studies No. 40. United Nations Environmental Programme, Geneva. V~izquez-Botello, A. (1990). lmpacto Ambiental de los Hidrocarburos Organoclorados y de lo Microorganismos Pat6genos Especificos en las Lagunas Costeras del Golfo de M#xico. lnforme Final 1989-1990, Proyecto OEA-CONACyT. Instituto de Ciencias del Mar y Limnologfa, UNAM, Mdxico, D.F. Vfizquez-Botello, A., Ponce-V61ez, G., Toledo, A., Dfaz-Gonz~ilez, G. & Villanueva,S. (1992). Ecolog/a, recursos costeros y contaminaci6n en el Golfo de M6xico. Ciencia y Desarrollo XVII (102): 28-48. Villeneuve, J. P. & Mee, L. D. (1989). Chlorinated Hydrocarbons in 7ima Homogenate 1AEA--351: Results of a World-Wide Exercise. International Laboratory of Marine Radioactivity/IAEA Intercalibration Exercise Report No. 44, Monaco. Yfifiez-Arancibia, A. & Day, J. W. Jr. (Eds.) (1988). Ecology of Coastal Ecosystems in the Southern Gulf of Mexico: The Terminos Lagoon Region. Inst. Ciencias del Mar y Limnologfa (UNAM)-Coast. Ecol. Inst. (LSU). Editorial Universitaria, M~xico, D.E