Contaminants, Pollution and Potential Anthropogenic Impacts in Chagos/BIOT
A broad range of chemical contaminants and pollutants have been measured within the Chagos Archipelago. Contamination is amongst the lowest in the world. Whilst much data is in the open literature, the chapter also includes details of extensive pollution monitoring for the atoll Diego Garcia which hosts a military facility. Hydrocarbons present are primarily of a natural origin with negligible evidence of contamination from petroleum or combustion origins. Tar balls, however, have been reported on several beaches in the Archipelago. Analyses of faecal steroids provide negligible evidence of sewage contamination. ‘Persistent organic pollutants’ (POPs), including PCBs and pesticides, were generally below analytical detection limits, as were polyfluorinated compounds, brominated, chlorinated and organo-phosphorous flame retardants, fluorinated tensides, and surfactants (PFOS). Antifouling biocides and herbicides in Diego Garcia show negligible contamination. Metal concentrations are very low. Levels of most contaminants are typically comparable to those recorded in environments perceived to be pristine, for example, the Antarctic. In Diego Garcia, extensive monitoring includes regular analyses in accredited US laboratories of over one hundred metals and organic contaminants. Results generally reveal concentrations below detection limits. This is in agreement with the open literature surveys. These legislated assessments are designed to ensure both environmental and human health preservation. Whilst many detection limits are higher than those of the independent surveys, they generally confirm the pristine nature of the Archipelago. Beach surveys, however, revealed a surprisingly high number of pieces of debris throughout the Archipelago, mainly plastics of South East Asian origin. The number of litter pieces in Diego Garcia was less than in the other atolls, reductions being attributed to beach clean-up events. Microplastic contamination is shown to be both widespread and relatively high compared to other locations on a global scale, and there were significantly more microplastics at uninhabited atolls compared to the Diego Garcia, showing the potential for microplastics to accumulate in remote locations. Holothurian (sea cucumber) poaching has been another significant environmental pressure on the coral reefs of Chagos and is included in this review, in view of the reported ecological benefits of the group to reef health and resilience.
KeywordsCoral Reef Flame Retardant Faecal Steroid Water Lens Antifouling Biocide
Some of this material was published previously in Sheppard et al. (2012) and is reproduced with permission of Wiley & Sons.
- Everaarts JM, Booij K, Fisher CV, Maas YEM, Nieuwenhuize J (1999) Assessment of the environmental health of the Chagos archipelago. Linn Soc Occas Publ 2:305–326Google Scholar
- Fowler SW (1990) PCBs in the environment: the Mediterranean marine ecosystem. In: Waid JS (ed) PCBs and the environment, vol III. CRS Press, Boca Ratón, pp 209–239Google Scholar
- Hirai H, Takada H, Ogata Y, Yamashita R, Mizukawa K, Saha M, Kwan C, Moore C, Gray H, Laursen D, Zettler ER, Farrington JW, Reddy CM, Peacock EE, Ward MW (2011) Organic micropollutants in marine plastics debris from the open ocean and remote and urban beaches. Mar Pollut Bull 62:1683–1692CrossRefGoogle Scholar
- Ministry of Defence (2008) Marine environmental radioactivity surveys at nuclear submarine berths 2006. Ministry of Defence, London, Document Identifier: DSTL/PUB27329, pp 81–85Google Scholar
- Price ARG (1999) Broadscale coastal environmental assessment of the Chagos Archipelago. In: Sheppard CRC, Seaward MRD (eds) Ecology of the Chagos Archipelago. Westbury Publishing/Linnean Society, London, pp 285–296Google Scholar
- Readman JW, Tolosa I, Bartocci J, Cattini C, Price ARG, Jolliffe A (1999) Contaminant levels and the use of molecular organic markers to characterize the coastal environment of the Chagos archipelago. Linn Soc Occas Publ 2:297–304Google Scholar
- Shen L, Reiner EJ, Macpherson KA, Kolic TM, Sverko E, Helm PA, Bhavsar SP, Brindle ID, Marvin CH (2010) Identification and screening analysis of halogenated norhornene flame retardants in the Laurentian Great Lakes: Dechloranes 602, 603, and 604. Environ Sci Technol 44(2):760–766CrossRefGoogle Scholar
- Sheppard CRC (2002) Island elevations, reef condition and sea level rise in atolls of Chagos, British Indian Ocean Territory. In: Linden O, Souter D, Wilhelmsson D, Obura D (eds) Cordio report 2002. Kalmar University, Kalmar, pp 202–211Google Scholar
- Sheppard CRC, Ateweberhan M, Bowen BW, Carr P, Chen CA, Clubbe C, Craig MT, Ebinghaus R, Eble J, Fitzsimmons H, Gaither MR, Gan C-H, Gollock M, Guzman A, Graham NAJ, Harris A, Jones R, Keshavmurthy S, Koldewey H, Lundini CG, Mortimer JA, Obura D, Pfeiffer M, Price ARG, Purkis S, Raines P, Readman JW, Riegl B, Rogers A, Schleyer M, Seaward MRD, Sheppard ALS, Tamelander J, Turner JR, Visram S, Vogler C, Vogt S, Yang JM-C, Yang S-Y, Readman JW, Riegl B, Rogers A, Schleyer M, Seaward MRD, Sheppard ALS, Tamelander J, Turner JR, Visram S, Vogler C, Vogt S, Yang JM-C, Yang S-Y, Yesson C (2012) Reefs and islands of the Chagos Archipelago, Indian Ocean: why it is the world’s largest no-take marine protected area. Aquat Conserv Mar Freshwat Ecosyst. doi:DOI: 10.1002/aqc.1248, Published online in Wiley Online Library (wileyonlinelibrary.com)CrossRefGoogle Scholar
- Engineering Concepts Inc and Shimabukuro, Endo & Yoshizaki Inc (2010) Sustainable yield and maximum safe water production study. US Navy Support Facility, Diego Garcia, BIOT. Prepared for Department of the Navy, Hawaii, 242ppGoogle Scholar
- Spalding MD (2006) Illegal sea cucumber fisheries in the Chagos archipelago. SPC Bêche-de-Mer Inf Bull 23:32–34Google Scholar
- Wolschke H, Sturm R, Ebinghaus R (2011) Analysis of flame retardants and polyfluorinated compounds in sediment samples from the Chagos Archipelago. Report to the University Of Warwick and Save Our Seas Foundation. pp 18Google Scholar