Karenia mikimotoi

Executive summary
The purpose of this report is to review the evidence in the literature regarding potential
human health risks in bathing waters in the UK posed by phytoplankton, cyanobacteria
and macroalgae in relation to the Directive 2006/7/EC of the European Parliament and
of the Council of 15 February 2006 concerning the management of bathing water
quality and repealing Directive 76/160/EEC:
Article 8
Cyanobacterial risks
1. When the bathing water profile indicates a potential for cyanobacterial proliferation,
appropriate monitoring shall be carried out to enable timely identification of health risks.
Article 9
Other parameters
1. When the bathing water profile indicates a tendency for proliferation of macro-algae
and/or marine phytoplankton, investigations shall be undertaken to determine their
acceptability and health risks and adequate management measures shall be taken,
including information to the public.
Terms of reference:
To review existing scientific knowledge of marine macro and micro algae, and the
potential health risks posed by direct contact, in relation to bathing waters and
recreation.
To identify serious gaps in existing knowledge which would compromise the EA’s ability
to comply with Articles 8 and 9 of the 2006 Directive.
If gaps are identified to outline the work necessary to rectify this.
The work is not to include an evaluation of -
the aesthetic impacts of blooms at bathing waters;
the risks caused through the vectoring of shellfish toxins via fish or shellfish.
Conclusions
Based on a review of the extensive literature on potentially harmful algae, risk
assessments have been made primarily with reference to the Environment Agency’s
list of ‘notifiable’ and nuisance bloom-forming phytoplankton and cyanobacteria. An
assessment has also been made of possible hazards presented by marine macroalgae
(seaweeds). These assessments are summarized in the table below.
The risks to human health due to short-term contact, aspiration (ingestion) or inhalation
(of aerosols or dry particles) with marine phytoplankton, including toxic genera, that
presently occur in UK waters are considered to be generally low, as is contact with
seaweeds. In contrast, the risks to human health, either via contact, aspiration or
inhalation, presented by blooms of freshwater cyanobacteria is assessed to be high.
Research requirements as regards human exposure to cyanobacteria in recreational
and other waters as identified by the international community have been highlighted.
iv A Literature review of the potential health effects of marine microalgae and macroalgae