Operational monitoring and forecasting of bathing water quality through exploiting satellite Earth observation and models: The AlgaRisk demonstration service

Abstract

a b s t r a c tCoastal zones and shelf-seas are important for tourism, commercial fishing and aquaculture. As a result the importance of good water quality within these regions to support life is recognised worldwide and a number of international directives for monitoring them now exist. This paper describes the AlgaRisk water quality monitoring demonstration service that was developed and operated for the UK Environment Agency in response to the microbiological monitoring needs within the revised European Union Bathing Waters Directive. The AlgaRisk approach used satellite Earth observation to provide a near-real time monitoring of microbiological water quality and a series of nested operational models (atmospheric and hydrodynamic-ecosystem) provided a forecast capability. For the period of the demonstration service (2008-2013) all monitoring and forecast datasets were processed in near-real time on a daily basis and disseminated through a dedicated web portal, with extracted data automatically emailed to agency staff. Near-real time data processing was achieved using a series of supercomputers and an Open Grid approach. The novel web portal and java-based viewer enabled users to visualise and interrogate current and historical data. The system description, the algorithms employed and example results focussing on a case study of an incidence of the harmful algal bloom Karenia mikimotoi are presented. Recommendations and the potential exploitation of web services for future water quality monitoring services are discussed.

Assessing risks and mitigating impacts of harmful algal blooms on mariculture and marine fisheries

“…Some HABs are difficult to detect, notably for species which bloom below the sea surface and evade in situ monitoring and satellite imaging (Shutler et al 2015). It is also often difficult to attribute cause(s) to observed impacts on complex marine systems, particularly when they involve cryptic species and nonspecific mechanisms, such as the depletion of dissolved oxygen and suffocation of (shell)fish by HABs such as Karenia mikimotoi (Davidson et al 2009;Shutler et al 2015). Since the 1960s, the number of hypoxic or anoxic 'dead zones' in coastal waters has doubled every decade (Diaz & Rosenberg 2008).…”

“…Originating offshore around the UK (Davidson et al 2009;Shutler et al 2015), high biomass blooms (>1000 cells/mL) of Karenia mikimotoi have been increasingly frequent and have been associated with significant finfish kills, including for caged fish in inshore waters (Jenkinson & Connors 1980;Silke et al 2005;Davidson et al 2009). Farmed shellfish including mussels, oysters and clams (Tapes semidecussatta) in the UK and Ireland, and hatchery raised juvenile bivalve spat have also periodically suffered significant mortalities, along with crustaceans and other benthic invertebrates, in conjunction with K. mikimotoi blooms (Raine et al 2001;Silke et al 2005).…”

“…For example, an abundant supply of dissolved nutrients, calm sea state, warming, increasing stratification and increased sunlight over a period of weeks may allow the algae to grow in high concentrations, and then, dramatic and significantly increased turbulent sea state (causing increased vertical mixing) over several hours can result in bloom termination (e.g. Shutler et al 2015). The challenge of understanding HAB occurrence and toxicity is further complicated by ecological interactions between HAB species and other members of plankton communities, which vary both spatially and temporally in species composition, genetic diversity and physiological status (Anderson et al 2012a;Davidson 2014).…”

“…Recent calculations have suggested that current seafood consumption could be met by extending mariculture offshore, into less than 1% of Exclusive Economic Zones belonging to coastal states (Gentry et al 2017). Some HABs, however, originate in open oceanic waters (Davidson et al 2009(Davidson et al , 2016Trainer et al 2012;Shutler et al 2015;Gobler et al 2017), indicating that some algal species may present similar or even greater risks as mariculture moves offshore.…”

A Review of the Tools Used for Marine Monitoring in the UK: Combining Historic and Contemporary Methods with Modeling and Socioeconomics to Fulfill Legislative Needs and Scientific Ambitions

“…Models have been used to provide advance-warning of algal blooms in support of the EU Bathing Waters Directive (Shutler et al, 2015), assessment of eutrophication OSPAR (Lenhart et al, 2010) and the identification of areas at high risk from the introduction of non-indigenous species . Model information has also been used to estimate the physical loss of potential habitat supporting common eelgrass, Zostera marina beds and northern horsemussel, Modiolus modiolus, reefs that are important in European waters (ICES, 2016a).…”