Landbased Pollution Sources and Marine Environmental Quality in the Caribbean

The near shore coastal and marine environment of several Caribbean islands is their most biologically productive and economically important zone. However, almost all landbased activities possess the real potential of degrading the quality of near shore waters and ultimately diminishing the utility of the marine resource. This condition is largely attributed to the individual smallness of the islands and their geographic proximity to each other.

Available sanitary water quality data from across the region indicated that while recreational areas are in general safe for water contact activities, bacterial densities in excess of several international criteria are consistently recorded in harbours. Organochlorine pesticide residues were generally in the 5 ng l^-1 range in unfiltered sea water but were significantly higher (1-100) ng g^-1 in limited samples of sediment and biota. Additional data requirements to gain further insight into the current state of the Caribbean environment are also identified.

A summary of the major land based sources of marine pollution (including sewage, industrial effluents and agricultural run-off) in the insular Caribbean is presented.     

The Distribution and Impacts of Dioxins and Polychlorinated Biphenyls in the Taiwan Er-Jen River

Abstract

The distribution and impacts of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and polychlorinated biphenyls (PCBs) in the Taiwan Er-Jen River were investigated by monitoring fish distribution and measuring PCDD/DFs and PCBs levels in sediment and fish samples. Most of the fish collected are pollution-resistant species such as Oreochromis spp, Liza macrolepsis, Channa spp and Megalops cyprinoides. the most polluted river sections are in the upstream where large amount of waste effluents from households, livestock rearing and nearby dumping sites were discharged into the river, and the lower reaches of the river where metal recovery activities including open burning of waste electrical wire/scrap occurred. Sediment samples collected near the burning site show 2,3,7,8-TCDD toxicity equivalents (TEQ) ranging from 0.014 to 14.2 ng g^?1 by PCDD/DFs and from 0.015 to 1.03 ng g^?1 by coplanar PCBs (Co-PCBs). the fish samples show TEQ ranging from 0.029 to 0.615 ng g^?1 by PCDD/DFs and from 0.012 to 0.12 ng g^?1 by Co-PCBs. Possible PCDD/DFs sources are discharged PCBs, open burning of waste wire/scrap, and pentachlorophenol. the consumption of these fish will cause an average intake of 54 pg kg^?1 d^?1 TEQ. the prevention of direct discharge of livestock and the dumping of waste effuents into River Er-Jen as well as the control of metal recovery activities appears to be the first step toward the restoration of River Er-Jen.     

Seasonal variation of the concentrations of 137Cs in sediment,sea water,and some organisms collected from Izmir Bay and Didim

¹³⁷Cs in the marine environment mainly originates from fallout of atmospheric nuclear weapon tests, accidental releases from nuclear facilities, and from the Chernobyl accident. After the latter accident, many studies have been carried out in Turkey. The objective of this study is to assess the spatial distribution of ¹³⁷Cs in the coastal marine environment of the Aegean Sea.

The concentrations of ¹³⁷Cs in sediment, sea water, mussel (Mytilus galloprovincialis), and fish samples collected from the coast of the Aegean Sea at Izmir Bay and near Didim (Akbük) have been monitored for seasonal variability by the means of gamma spectroscopy: they vary between 0.10 ± 0.01 and 1.5 ± 0.3 Bq kg^?1, 1.3 ± 0.1 and 4.3 ± 0.4 Bq m^?3, <0.2 and 1.3 ± 0.3 Bq kg^?1, and 0.20 ± 0.03 and 1.8 ± 0.3 Bq kg^?1, respectively.     

Sewage fluxes and seasonal dynamics of physicochemical characteristics of the Bhagirathi-Hooghly River from the lower stretch of River Ganges,India

ABSTRACT

To understand the temporal variations of the physicochemical characteristics of the Bhagirathi-Hooghly River (BHR), three locations representing three districts of West Bengal were selected. The material fluxes from 34 drains during pre-monsoon season was quantified. The analysis of variance (ANOVA) revealed that no significant spatial variations were observed for the physicochemical parameters, whereas seasonal variations were significant. The mean discharge was found to be highest (247.2?×?10³?m³?d^?1) in the midstream drains. Highest mean concentrations of dissolved oxygen (DO) (7.35?mg?L^?1) and nitrate (0.81?mg?L ^?1) were observed during the post-monsoon season followed by the monsoon and pre-monsoon. According to the BIS, WHO and the European standard of water quality (pH, 6.5–8.5; Nitrate, 0–2.5?mg?L^?1;DO, ≥5?mg?L^?1), the results of the respective parameters revealed the BHR system is maintained at high to good water quality, meaning that the BHR system is slightly altered from its pristine environment. The mean concentrations of biological and chemical oxygen demands were found to be high during the monsoon season, revealing that a large quantity of refractory organic matter is transported to the eastern Bay of Bengal from the Ganges.     

Spatial distribution of perfluorooctane sulfonate (PFOS) in major rivers in southwest Nigeria

Concentrations of perfluorooctane sulfonate (PFOS) were measured for the first time in major rivers within southwest, Nigeria. PFOS was concentrated from water and sediment using solid-phase extraction, identified and quantified with high-performance liquid chromatography coupled with tandem mass spectrometry. Concentrations of PFOS ranged from 1.71 to 16.19 ng L^?1 in water, and from 1.64 to 10.29 ng g^?1 in sediments across all locations. Comparatively, the concentrations of PFOS observed in this study were within the range ever measured in the environment. Field-based sediment water distribution coefficients (log K_d, L kg^?1) ranged from 2.08 to 3.56. While no correlation was observed between K_d and organic carbon contents, there was significant positive correlation between K_d and salinity (r² = 0.7867), which suggested that activities capable of increasing salinity can enhance PFOS removal from the environment.     

Transport of Sewage Sludge From the 106-Mile Site - Results From an October Survey

Abstract

Approximately 8 million tons of sewage sludge were disposed of annually at the 106-Mile Deepwater Municipal Sludge Dump Site (106-Mile Site) between 1987 and 1990. Beginning in 1988 and continuing to the present, the focus of monitoring at the 106-Mile Site moved towards improved understanding of the fate of the sludge. A survey conducted in October 1989 was designed to (1) detect the presence of any sludge particles that settle rapidly following disposal, (2) determine if sludge could be detected in the surface waters at locations away from the immediate disposal site, and (3) determine if water quality was degraded, by assessing whether the Environmental Protection Agency's marine water quality criteria were being exceeded.

The survey showed that the sludge does have a rapidly settling component composed of organic floc. mineral grains, and other heavy, gritlike particles, all of which are relatively large. These particles may settle at rates of between 8 and 180 m h^?1 and may reach the sea floor within 1 to 13 days following disposal. Even though a rapidly settling component is present in the sludge, a significant fraction of the sludge was detectable in the form of intact sludge plumes in the upper 35 m of the water column at least 15 km from the Site. in addition, unique tracers of sludge such as xylem tracheids and Clostridium perfringens plus elevated total suspended solids and trace metals concentrations, were found at locations up to 40 km from the Site. the presence of these tracers correspond with in situ transmissometry data suggesting that a fraction of the sludge was remaining in the near-surface waters above the seasonal pycnocline. Concentrations of metals were below EPA chronic marine water quality criteria, which indicates that the water quality downstream of the Site was not impaired. the detection of sludge downstream of the 106-Mile Site is consistent with the southwestward movement of the surface water mass during the survey, as recorded by satellite-tracked surface drifters and current vectors derived from a current meter moored at 100-m depth immediately west of the Site. Near-surface transport was generally towards the southwest at a speed of approximately 22 cm s^?1?.     

Trace Metals in Fish and Crustaceans - Identifying Heavier Polluted Areas in the Ghanaian Continental Shelf

Abstract

The concentrations of four trace metals, namely copper, lead, cadmium and manganese, were determined in six fish species and three crustaceans collected from five sites spanning over 70% of the Ghanaian coastline.

Copper and lead were determined in Barracuda (Spraena spraena), the Ribbon fish (Trichiurus lepturus), the Sardine (Sardinella spp), the Sole (Cynoflossus senegalensis), the Sea Bream (Pagrus coupei) and the Soldier fish (Cynapastas marmuratus). Cadmium and manganese were analyzed in the Blue Crab (Callinectes sepidus), the Spiny lobster (Panilirus regius) and the edible shrimp (Crago septempinosus). Sampling sites included Takoradi, Elmina, Cape Coast, Accra and Tema.

Lead and copper in the fishes ranged 0.25-0.94 μgg^?1 fresh weight and 0.40-2.54 μgg^?1 dry weight (FW) respectively whilst cadmium and manganese in the crustaceans ranged 0.05-0.083 μgg^?1 FW and 0.554-1.404 μgg^?1 FW respectively.

The Barracuda accumulated the greatest amount of metals whilst the sardine accumulated the least. with the crustaceans, there was a significant difference between the amounts of the metals accumulated. the blue crab accumulated the greatest and the edible shrimp the least.

The analysis showed that: (i) there was a positive correlation between the metals bioconcentrated and the extent of pollution of the marine waters and (ii) along the Ghanaian Continental Shelf, the extent of pollution was of the increasing order as: Elmina = Cape Coast < Takoradi < Accra < Tema. Pollution of the marine waters could be minimized by control of flow of pollutants from land based activities.     

Arsenic in Two Taiwanese Bivalves,Crassostrea Gigas (Thumberg) and Meretrix Lusoria Röding

Abstract

Arsenic, one of the most toxic elements, is present naturally in marine organisms at much higher concentrations than in terrestrial organisms. the arsenic contents in two marine bivalves, Crassostrea gigas (Thumberg) and Meretrix lusoria Röding, from Taiwan were investigated. the total arsenic content of C. gigas (33.7–60.5 μg g^?1) is higher than that of M. lusoria (30.2–34.6 μg g^?1). These two bivalves from Lu-kang contain more arsenic in soft tissues than specimens from other areas (significant at 1%, t-test). On the other hand, samples from Pen-hu contain less arsenic than those from other areas (significant at 5%). the arsenic contents of other Indo-Pacific bivalves are also given for comparison.     

Microscale variation in<Emphasis Type="Italic"> Aat</Emphasis> (aspartate aminotransferase) is supported by activity differences between upper and lower shore allozymes of<Emphasis Type="Italic"> Littorina saxatilis</Emphasis>

The role of natural selection in maintaining inherited variation in morphological characters is indisputable. In contrast, genetic variation in allozyme loci is mostly assumed neutral or under weak selection, although enzyme functions are critical to central metabolic processes. A locus coding for aspartate aminotransferase (AAT) is polymorphic with two alleles in the rocky shore gastropod Littorina saxatilis. One allele (Aat ¹²⁰ ) is most frequent (0.8–0.9) in upper shore subpopulations, while the other (Aat ¹⁰⁰ ) dominates (0.7–0.8) lower shore subpopulations only meters below. Earlier studies show this variation to be maintained by divergent selection, but the mechanism is unknown. We measured enzyme activities in AAT extracts from individuals of known Aat genotype in populations from two islands and at three different temperatures. In all treatments lower shore homozygotes (Aat ^100/100 ) had higher enzyme activity than upper shore homozygotes (Aat ^120/120 ), with heterozygotes having intermediate levels of activity. AAT has a central role in anaerobic energy production in marine mollusks during low-tide periods of emergence, and it might appear surprising that upper shore snails, which are most likely to be emerged, have lower enzyme activity. However, upper shore snails are forced to survive long periods of desiccation, and a low metabolic rate will help to conserve limited resources of energy and nutrients and reduce accumulation of waste products.Communicated by L. Hagerman, Helsingør     

A review of marine pollution issues in the Caribbean

Marine pollution and coastal degradation have become serious development issues in the Caribbean. Early evidence of marine pollution was mainly anecdotal, but within the last 10--15 years, work conducted by universities and research institutions in the Region has provided the beginnings of a database that identifies several common marine pollution problems. The United Nations Environment Programme (UNEP), the Intergovernmental Oceanographic Commission (IOC) and the Pan American World Health Organization (PAHO/WHO) have also been instrumental in co-ordinating several marine pollution studies. In the English-speaking Caribbean, the University of the West Indies, the Institute of Marine Affairs in Trinidad and Tobago, and the Caribbean Environmental Health Institute located in St Lucia, have taken a lead role in identifying marine pollution problems in their Sub-Region. For the Wider Caribbean a database for petroleum pollution and marine debris has been developed. Land-based sources of marine pollution have been identified as a major problem, with several hot spots identified in mainland countries and in some of the larger industrialised islands. Organic and nutrient pollution, particularly from sewage, is most widespread and is possibly the most serious marine pollution problem in the Caribbean. A lack of capital investment funds to install the appropriate infrastructure to deal with sewage and other liquid effluents is a major stumbling block to solving the problem of marine pollution in the Caribbean. Other factors include political will and administrative and legal structures to regulate human development activities.     

Heavy Metal Concentrations in Sea Urchin Tissues From Egypt,Ireland and United Kingdom

Abstract

Sea urchins (Paracentrotus lividus) were collected from the Mediterranean coast off Alexandria, Egypt and the Atlantic coast of Ireland to the west of Galway. Samples of another urchin species, Psammechinus miliaris, were collected from the entrance to Southampton Water, U.K. Both the Alexandria coast and Southampton Water receive domestic and industrial waste water inputs whilst the western Irish coast is relatively unpolluted.

Sampled animals were dissected to separate coelomic fluids, Aristotle's lantern, gonads and tissue (digestive tract plus connective tissue). the concentrations of heavy metals (cadmium, copper, lead, nickel and zinc) in the different parts were measured using flame atomic absorption spectroscopy.

Many levels of heavy metals in the different parts were similar in specimens taken across the wide range of sites and the two species. A notable exception was the high level of copper (33 μg g^?1 dry wt.) and zinc 328 μg g^?1? dry wt.) in urchin tissue from Southampton Water.

The metal concentrations in the gonads of Paracentrotus lividus are of particular interest because of human consumption of this species. the highest levels of copper (3.3–5.2 g^?1? dry wt.) and zinc (74–181 μ g^?1? dry wt.) dry wt.) in gonads were found in the samples from Egypt. Data from this study are compared with other results reported from the Mediterranean.

A simple, short term, elevated water column copper uptake experiment was undertaken with Paracentrotus lividus which showed an increase in gonad concentrations of this element.     

Concentrations of Hchs and Ddts in the Tissues of River Dolphins,Platanista Gangetica,From the River Ganges,India

Abstract

Concentrations of HCH and DDT organochlorine insecticide residues were measured in blubber, muscle and oil samples from three specimens of river dolphins, Platanista gangetica, from the River Ganges, India. Concentrations of HCH and DDT ranged from 94 to 289 ng g^?1 and from 1324 to 9388 ng g^?1 on wet wt. basis respectively. Comparisons are made with other aquatic mammals and other studies on river dolphins. P. gangetica appears to exhibit similar patterns of accumulation with age and with ß-HCH and p-p′-DDE being accumulated to higher levels than other HCH isomers and parent DDT and its other metabolites, respectively. These organochlorines may pose a health risk to river dolphin populations that are already showing evidence of environmental stress. Further studies are recommended.     

Effects of zinc oxide nanoparticles on growth and antioxidant enzymes of Capsicum chinense

Abstract

The effects of suspensions of zinc oxide nanoparticles at concentrations between 100 and 500?mg L^?1 on germination of Capsicum chinense seeds and vigor of plants were evaluated using a randomized complete design with four replications, resulting in increased germination and improved development of lengths of plumule and radicle. The activities of peroxidase, catalase and ascorbate peroxidase were determined, showing that at all concentrations the activities of the former two enzymes were increased, whereas the activity of the latter was reduced at 500?mg L^?1. Pretreatments of seeds with ZnO nanoparticles can improve germination and development of seedlings and the activities of antioxidant enzymes.     

Histology of Sculpin spp. in East Greenland. II. Histopathology and trace element concentrations

Abstract

For many years, the sculpin has been utilized as a sentinel monitoring species for anthropogenic impacts on the marine environment. To further develop its potential as a screening model body burden of several trace elements, including cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb) and selenium (Se), were investigated. In addition, histopathology in shorthorn sculpins (Myoxocephalus scorpius; n?=?20) and fourhorn sculpins (Myoxocephalus quadricornis; n?=?10) were examined at three sites around the Scoresby Sound settlement in Central East Greenland. Fourhorn sculpins caught at the most distant site from the settlement, contained significantly higher hepatic Cu and Cd concentrations as well as significantly elevated gill Pb levels compared to the shorthorn sculpins collected at two other sites closer to the settlement. Histological examinations showed that fish with significantly higher concentrations of hepatic Cd and Se exhibited greater nuclear alterations, interstitial hyperplasia/hypertrophy, interstitial mononuclear infiltrations and granulomas. Further, fish with higher Cd and Cu gill tissue levels displayed a significantly higher number of cytoplasmic alterations and lamellar epithelium lifting, hypertrophic and hyperplastic epithelium along with mucus cell hyperplasia. While the presence of liver lesions were not species or sex-specific, the presence of gill lesions decreased in the order female fourhorn sculpins?>?female shorthorn sculpins?>?male fourhorn sculpins?>?male shorthorn sculpins. Hepatic Hg concentrations exceeded known lowest observable effect doses (LOED) for fish (0.1–0.5?μg g^?1 ww) in 27% of fish, while liver Cd residues in 80% exceeded LOED (0.42–1.8?μg g^?1 ww). Based upon these results, data suggest that using the sculpin as a valuable sentinel fish species histopathology may serve as a reliable tool for assessing marine ecosystem exposure to trace metals. However, confounding physiological and ecological factors also need to be considered.     

Inventories and Distribution of Radiocaesium in Arctic Marine Sediments: Influence of Biological and Physical Processes

Abstract

Extensive surveys of sediment burdens of radiocaesium, specifically ¹³⁷Cs, and other radioactive contaminants in the Arctic during the 1990′s, indicate that almost all anthropogenic radionuclides buried on continental shelves adjacent to Alaska are derived from global bomb fallout. the ¹³⁷Cs (half-life: 30.2y) activities observed in surface (0–4 cm) marine sediments however, vary widely, albeit much less than the expected current inventory resulting from bomb fallout at this latitude (～100mBq cm^?2). This observed geographical variation provided the opportunity to evaluate physical and biological mechanisms that may affect caesium biogeochemistry on Arctic continental shelves. We investigated whether high biological productivity in portions of the Bering and Chukchi Seas is effective in removing dissolved radiocaesium from the water column, and whether biological production in overlying water affects total radiocaesium inventories in sediments. Based upon C/N ratios in the organic fraction of shallow sediments, we found no evidence that higher inventories or surface activities of radiocaesium are present in areas with higher deposition of particulate organic matter. Based upon stable carbon isotope ratios of organic matter in sediments, we found no evidence that terrestrial runoff contributes proportionally to higher surface activities, although terrestrial runoff may affect total inventories of the radionuclide. Radiocaesium content of surface sediments was significantly correlated with total organic carbon content of sediments and the proportion of sediments in the finest sediment fractions. Because high current flow can also be expected to influence distributions of those sedimentary parameters, we conclude that re-distribution of     

Heavy Metal Pollution in Sediment from the Eastern Adriatic Coast,Croatia

Abstract

Sediment samples were collected from the Adriatic Sea in areas near large coastal towns along the eastern Adriatic coast (Zadar, [Ncirc]ibenik, Split, Plo?e and Dubrovnik).

Considerable quantities of untreated effluents are discharged via freshwater runoff and a variety of industrial waste waters, significantly affecting the quality of marine sediments.

Distribution of some trace metals (Pb, Cu, Ni, Cr, Zn, Mn, Cd, and Al) involved in problems related to metal pollution in Adriatic sediment were examined. Values are expressed as a total concentration of heavy metals of sediment dry weight.

Spatial distribution of some trace metal values in sediments and correlation of results for grain size effect were examined. the trace elements in marine sediments generally remain in the fine grained fraction, often in the silt-clay fraction. Higher values of heavy metals in some areas (Split, Sibenik) could be attributed to anthropogenic effects, i.e. to land-based activities. the main cause of higher values of some metals at open sea sites and in some coastal areas are probably caused naturally by sedimentation processes in those areas. Our results show that the sediments undoubtedly play a key role in determining the transport and ultimate fate of contaminants.     

Interactions Among the Copper Species and Forms in Sea Water/Sediments and Copper Bioaccumulation in Oysters

Abstract

Earlier papers indicated that the first incident of green discoloration in oysters (Crassostrea gigas) and the mass mortality observed in 1986 along the Taiwan Erhjin Chi coastal area were caused by the higher contents of total copper and copper species (mainly bioavailable and free ion) in sea water. the copper in sea water would be sorbed by suspended matter and transferred to sediments, and the copper in the sediments would also be desorbed to sea water. Processes of copper adsorption and desorption are the major factors influencing the contents of total copper and copper species in sea water and sediments. in this study, the Erhjin Chi sediments were mixed with sea water by a shaker technique. When the mixture was shaken for one hour, analogous to tidal mixing in estuaries, only copper desorption from sediments was observed. If the shaking time is increased for more than 3 hours, the copper released from the sediments was resorbed to the remaining solid phases. the higher the contents of mud (91.71%) and total copper (701 mg kg^?1) in sediments, the higher the copper desorption rate (1.86 ppm hr^?1) and copper adsorption rate (0.50 ppm hr^?1) were observed. in sediments containing lower mud (0.80%) and lower copper (43.5 mg kg^?1), the copper desorption and adsorption rates were 0.83 ppm hr^?1 and 0.22 ppm hr^?1, respectively. the interactions among the total copper and copper species in sea water and sediments, chemical and ecological parameters, and copper bioaccumulation in oysters in the Erhjin Chi estuarine and coastal area are also discussed.     

Luminescence in the oxidation of isoproterenol by the superoxide anion radical in dimethyl sulfoxide

Chemiluminescence appearing during oxidation of isoproterenol using chemical system involving superoxide anion radical has been studied. Chemiluminescence and fluorescence spectra were measured. The chemiluminescence spectrum was measured with cut‐off filters and revealed bands with maximum at 440, 480, 550, 640 and 700 nm. The bands at 480, 640 and 700 nm were similar to those observed for singlet oxygen. The fluorescence spectrum exhibited maximum at 560 nm.

The inhibitory effect of several biologically important compounds known as O₂ ^?‐ HO^? and ¹O₂ scavengers on the light emission was studied.

The obtained results indicate that oxidation of isoproterenol by O₂ ^?‐ involves products in the electronically excited states. The data also seem to indicate the protective effect of isoproterenol on the deoxyribose degradation.     

Organochlorines in the surface sediments of the Bahiret el Bibane lagoon (Tunisia,Southwestern Mediterranean Sea)

Organochlorines (including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs)) were analysed in 10 surface sediment samples collected from the Bahiret el Bibane lagoon, which is one of the most productive lagoons and one of the most important active commercial fish traps in the southern Tunisia. The aim was to obtain information concerning the recent deposition of these compounds in this area, together with the levels, the distribution and any potential biological risk. Total concentrations of OCPs and PCBs in the sediments ranged from below the limit of detection (?1 and from 29.5 to 88.2?ng?g^?1?dw, respectively. The spatial distribution of PCBs suggested that the sources of these contaminants are probably located outside the lagoon and are transported by water currents and atmospheric deposition. Compared with some other regions of the world, the Bahiret el Bibane lagoon exhibited low to moderate levels of PCBs and OCPs. According to established sediment quality guidelines, PCBs and Lindane at most of the study sites would be more concerned for the ecotoxicological risk in the Bahiret el Bibane lagoon. The results of this study could provide a useful aid for the sustainable marine management of the region.     

Reassessment of the Ocean-To-Atmosphere Flux of Carbon Monoxide

Abstract

Carbon monoxide (CO) in the surface sea waters is produced predominantly by photochemical processes, oxidized by micro-organisms and outgassed to the atmosphere. to assess carbon monoxide flux from the oceans to the atmosphere, the photochemical production and microbial oxidation of carbon monoxide in the oceanic mixed-layer was investigated during several oeanographic cruises and in the laboratory. the photoproduction rate of carbon monoxide was found to be well correlated to the concentration of dissolved organic carbon (DOC) in coastal and open ocean surface waters. Taking a global average carbon monoxide production rate of 10 ± 2 nmole litre^?1 (mg DOC hr)^?1 in the surface open ocean water, and 25 ± 7 nmole litre^?1 (mg DOC hr)^?1 in coastal sea water, at cloud-free summer solar noon, the photochemical production of carbon monoxide in the global oceans is estimated to be at a rate of 1200 ± 200 Tg CO y^?1. the microbial carbon monoxide turnover time in the mixed-layer was observed to range from hours in a coastal estuary to 16 days in the Pacific along 1057deg; W in dark incubations. Natural sunlight can largely inhibit the microbial consumption of carbon monoxide in surface water. On a global scale, microbial consumption is responsible for the loss of less than 10% of photochemical produced carbon monoxide in the surface ocean. Field measurements have shown that the net transport of carbon monoxide from the euphotic zone to the underlying deeper ocean water is limited and that the overall life time in surface sea waters is less than 3-4 hours. When combined, these field measurements with the photoproduction and microbial consumption rates obtained, we estimate the oceanic flux to the atmosphere is about 1000 ± 200 Tg CO y^?1, which represents the largest single source of atmospheric carbon monoxide.