Degradation of Herbicides in the Tropical Marine Environment: Influence of Light and Sediment

Widespread contamination of nearshore marine systems, including the Great Barrier Reef (GBR) lagoon, with agricultural herbicides has long been recognised. The fate of these contaminants in the marine environment is poorly understood but the detection of photosystem II (PSII) herbicides in the GBR year-round suggests very slow degradation rates. Here, we evaluated the persistence of a range of commonly detected herbicides in marine water under field-relevant concentrations and conditions. Twelve-month degradation experiments were conducted in large open tanks, under different light scenarios and in the presence and absence of natural sediments. All PSII herbicides were persistent under control conditions (dark, no sediments) with half-lives of 300 d for atrazine, 499 d diuron, 1994 d hexazinone, 1766 d tebuthiuron, while the non-PSII herbicides were less persistent at 147 d for metolachlor and 59 d for 2,4-D. The degradation of herbicides was 2–10 fold more rapid in the presence of a diurnal light cycle and coastal sediments; apart from 2,4-D which degraded more slowly in the presence of light. Despite the more rapid degradation observed for most herbicides in the presence of light and sediments, the half-lives remained > 100 d for the PS II herbicides. The effects of light and sediments on herbicide persistence were likely due to their influence on microbial community composition and its ability to utilise the herbicides as a carbon source. These results help explain the year-round presence of PSII herbicides in marine systems, including the GBR, but more research on the transport, degradation and toxicity on a wider range of pesticides and their transformation products is needed to improve their regulation in sensitive environments.

[1]  Florent E. Angly,et al.  Diuron tolerance and potential degradation by pelagic microbiomes in the Great Barrier Reef lagoon , 2016, PeerJ.

[2]  F. Kroon,et al.  Using species sensitivity distribution approach to assess the risks of commonly detected agricultural pesticides to Australia's tropical freshwater ecosystems , 2016, Environmental toxicology and chemistry.

[3]  Jochen F Mueller,et al.  Herbicide Persistence in Seawater Simulation Experiments , 2015, PloS one.

[4]  C. Collier,et al.  Lethal and sub-lethal chronic effects of the herbicide diuron on seagrass. , 2015, Aquatic toxicology.

[5]  Jochen F Mueller,et al.  Glyphosate persistence in seawater. , 2014, Marine pollution bulletin.

[6]  J. Brodie,et al.  The potential benefits of herbicide regulation: a cautionary note for the Great Barrier Reef catchment area. , 2014, The Science of the total environment.

[7]  J. Brodie,et al.  Regulation of pesticides in Australia: The Great Barrier Reef as a case study for evaluating effectiveness , 2013 .

[8]  Catherine J. Collier,et al.  Phytotoxicity of Four Photosystem II Herbicides to Tropical Seagrasses , 2013, PloS one.

[9]  L. Wackett,et al.  Evaluating Pesticide Degradation in the Environment: Blind Spots and Emerging Opportunities , 2013, Science.

[10]  C. Cren-olivé,et al.  Accumulation and half-lives of 13 pesticides in muscle tissue of freshwater fishes through food exposure. , 2013, Chemosphere.

[11]  T. Potter,et al.  Atrazine fate and transport within the coastal zone in southeastern Puerto Rico. , 2013, Marine pollution bulletin.

[12]  Jochen F. Mueller,et al.  Pesticide monitoring in inshore waters of the Great Barrier Reef using both time-integrated and event monitoring techniques (2011 - 2012) , 2012 .

[13]  J. Brodie,et al.  The influence of a season of extreme wet weather events on exposure of the World Heritage Area Great Barrier Reef to pesticides. , 2012, Marine Pollution Bulletin.

[14]  Howard I. Maibach,et al.  OECD GUIDELINES FOR THE TESTING OF CHEMICALS In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test Method , 2013 .

[15]  G. Thouand,et al.  New Concepts in the Evaluation of Biodegradation/Persistence of Chemical Substances Using a Microbial Inoculum , 2011, Front. Microbio..

[16]  P. Stefanelli,et al.  Determination of acidic herbicides in cereals by QuEChERS extraction and LC/MS/MS , 2011, Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes.

[17]  T. Egli.  How to live at very low substrate concentration. , 2010, Water research.

[18]  J. Brodie,et al.  Herbicides: a new threat to the Great Barrier Reef. , 2009, Environmental pollution.

[19]  Ken Rohde,et al.  Agricultural lands are hot-spots for annual runoff polluting the southern Great Barrier Reef lagoon. , 2009, Marine pollution bulletin.

[20]  A. Stasinakis,et al.  Diuron biodegradation in activated sludge batch reactors under aerobic and anoxic conditions. , 2009, Water research.

[21]  K. Heimann,et al.  Comparative effects of herbicides on photosynthesis and growth of tropical estuarine microalgae. , 2008, Marine pollution bulletin.

[22]  W. Amelung,et al.  Pesticide fate in tropical wetlands of Brazil: an aquatic microcosm study under semi-field conditions. , 2007, Chemosphere.

[23]  N. Vela,et al.  Persistence of four s-triazine herbicides in river, sea and groundwater samples exposed to sunlight and darkness under laboratory conditions. , 2004, The Science of the total environment.

[24]  T. Anderson,et al.  Effect of sediment on the fate of metolachlor and atrazine in surface water , 2004, Environmental toxicology and chemistry.

[25]  J. Ahtiainen,et al.  Biodegradation of chemicals in a standardized test and in environmental conditions. , 2003, Chemosphere.

[26]  H. Okamura.  Photodegradation of the antifouling compounds Irgarol 1051 and Diuron released from a commercial antifouling paint. , 2002, Chemosphere.

[27]  D. G. Smith,et al.  TURBIDITY SUSPENI)ED SEDIMENT, AND WATER CLARITY: A REVIEW 1 , 2001 .

[28]  Colin D. Brown,et al.  Evaluation of methods to derive pesticide degradation parameters for regulatory modelling , 2001, Biology and Fertility of Soils.

[29]  A Wolfenden,et al.  Handbook of Environmental Fate and Exposure Data for Organic Chemicals , 1990 .

[30]  R M Atlas,et al.  Microbial degradation of petroleum hydrocarbons: an environmental perspective , 1981, Microbiological reviews.

[31]  R. Horvath.  Microbial co-metabolism and the degradation of organic compounds in nature. , 1972, Bacteriological reviews.

[32]  D. Crosby,et al.  Photodecomposition of 2,4-Dichlorophenoxyacetic Acid , 1966 .

[33]  H. Roche,et al.  On the occurrence of a widespread contamination by herbicides of coral reef biota in French Polynesia , 2015, Environmental Science and Pollution Research.

[34]  Britta Schaffelke,et al.  Assessing the additive risks of PSII herbicide exposure to the Great Barrier Reef. , 2012, Marine pollution bulletin.

[35]  J. Brodie,et al.  Dynamics of herbicide transport and partitioning under event flow conditions in the lower Burdekin region, Australia. , 2012, Marine pollution bulletin.

[36]  L. McKinna,et al.  Mapping the pollutants in surface riverine flood plume waters in the Great Barrier Reef, Australia. , 2012, Marine pollution bulletin.

[37]  K. Heimann,et al.  Chronic herbicide exposures affect the sensitivity and community structure of tropical benthic microalgae. , 2012, Marine pollution bulletin.

[38]  Steve Carter,et al.  Long term monitoring of photosystem II herbicides--correlation with remotely sensed freshwater extent to monitor changes in the quality of water entering the Great Barrier Reef, Australia. , 2012, Marine pollution bulletin.

[39]  Britta Schaffelke,et al.  Water quality in the inshore Great Barrier Reef lagoon: Implications for long-term monitoring and management. , 2012, Marine pollution bulletin.

[40]  S. Vardy,et al.  Large-scale pesticide monitoring across Great Barrier Reef catchments--Paddock to Reef Integrated Monitoring, Modelling and Reporting Program. , 2012, Marine pollution bulletin.

[41]  Ryan D R Turner,et al.  River loads of suspended solids, nitrogen, phosphorus and herbicides delivered to the Great Barrier Reef lagoon. , 2012, Marine pollution bulletin.

[42]  K. Fabricius,et al.  Monitoring pesticides in the Great Barrier Reef. , 2010, Marine pollution bulletin.

[43]  H. E. Garrett,et al.  Bioremediation of atrazine-contaminated soil by forage grasses: transformation, uptake, and detoxification. , 2008, Journal of environmental quality.

[44]  Jochen F Mueller,et al.  Photosystem II herbicide pollution in Hong Kong and its potential photosynthetic effects on corals. , 2008, Marine pollution bulletin.

[45]  A. Cessna.  Chapter 23 – Nonbiological Degradation of Triazine Herbicides: Photolysis and Hydrolysis , 2008 .

[46]  L. Wackett,et al.  Chapter 22 – Microbial Degradation of s-Triazine Herbicides , 2008 .

[47]  A. Franco,et al.  Pesticide contamination of the coastline of Martinique. , 2005, Marine pollution bulletin.

[48]  A. Moncada.  ENVIRONMENTAL FATE OF DIURON , 2004 .

[49]  P. Boelen,et al.  UV effects in aquatic organisms and ecosystems , 2003 .

[50]  J. R. Scotti,et al.  Available From , 1973 .

[51]  U. Brinkman,et al.  A study on the behaviour of pesticides and their transformation products in the Scheldt estuary using liquid chromatography-electrospray tandem mass spectrometry. , 2000, Journal of environmental monitoring : JEM.

[52]  D. Barceló,et al.  Chapter 1 - Pesticides their Degradation Products:Characteristics Usage Environmental Behaviour , 1997 .

[53]  W. Boynton,et al.  The decline of submerged vascular plants in upper Chesapeake Bay: summary of results concerning possible causes [Aquatic vegetation, factors as runoff of agricultural herbicides, erosional inputs of sediments, nutrient enrichment and associated algal growth] , 1983 .