Near-real time EO data used to monitor harmful algae

Scientists from the PML are exploiting their unique capability to process Earth Observation (EO) data in near-real time in order to provide early warning of harmful algal blooms (HABs).

Ocean colour data indicated exceptionally high concentrations of chlorophyll-a and a greenish brown tinge to the water around the coasts of Cornwall, The Hebrides and Orkney in late July 2006. These characteristics are often associated with blooms of a potentially harmful type of plankton called dinoflagellates. Dr Peter Miller notified the Environment Agency (EA) in Cornwall and the Marine Laboratory in Aberdeen. Following this water samples were taken at a variety of sites. The dinoflagellate Karenia mikimotoi was found to be present at various sites, a species that can kill fish and shellfish. Warnings were prompty sent to the fishing industry in the affected areas. The Scottish blooms caused some mortalities among fish, crustaceans and shellfish near the coast due to depleted oxygen levels, demonstrating that early warnings could be of critical importance in future to plan mitigating actions. No fish mortalities were recorded following the bloom in Cornwall.

These HAB events were followed up by two projects in 2007 which exploited recently published techniques (Miller et al 2006); i) The Southwest Algal Pilot Project (SWAPP) is an NCOF initiative to trial the use of both EO and an operational shelf ecosystem model to assist the EA with forecasting nuisance blooms affecting bathing water; ii) The Scottish Crown Estate funded PML and the Scottish Association for Marine Science (SAMS) to determine whether the 2006 bloom could have been discriminated using EO data or predicted using models based on environmental parameters. Discussions are underway to advance these pilot projects towards a routine EO water quality monitoring service around the UK coast.

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(a) Southwest approaches (b) Scottish Waters
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Chlorophyll-a scalebar

MODIS Aqua chl-a maps showing two harmful algal blooms of Karenia mikimotoi: (a) Cornwall and Southwest approaches, 18 July 2006 1315 UTC; (b) Scottish waters, composite 25-31 July 2006.

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