According to a study by a research group concluded in 2004 (undertaken by Sarah Debono M.Sc), Ostreoposis species had been identified in March 2002 at least in one place: Salina Bay.

However, there is no confirmation that this was the same species as O. ovata, nor that it was going through a bloom period. Other dinoflagellate blooms were however recorded in other places.

Beaches along a 15-mile stretch of the Italian Riviera were described as semi-deserted for a second day last week following a poisoning scare, which affected some 200 bathers.

They were treated in hospital after coming into contact with a poisonous micro alga from tropical Asia.

They complained of fever, nausea and irritation to the eyes and nose after swimming off beaches along the apparently clean Ligurian Sea.

Marine biologists suspect a microscopic alga known as Ostreoposis Ovata. All those reporting sick have now been discharged from a hospital in Genoa.

As a precautionary measure, local authorities have closed the beaches along one of the most frequented stretches of the Italian Riviera until further tests have been carried out to confirm the nature of the toxic effect.

Dinoflagellate and other micro algae blooms may be caused by a number of environmental factors including increase in environmental temperatures, increased nutrients (which in turn are more often related to sewage pollution), relatively calm waters, and others.

Different species have different bloom dynamics and different “bloom releasing” conditions. In this case, it is more likely that the blooms recorded in Italy and known to have caused a severe deterioration in bathing water quality in some coastal regions such as Liguria and more recently in Livorno, are more likely to be due to all such factors.

Increasing sea temperatures in the Mediterranean due to climate change, coupled with increased nutrients in some inshore coastal hotspots of pollution may be the factors leading to such blooms.

This dinoflagellate is known to release toxic chemicals that can cause respiratory problems and skin irritations. Both bathers and non-bathers may be affected since aerosol sea spray carrying this dinoflagellate and its toxins may reach people on the shore through inhalation. The dinoflagellates release other toxins which can be much more dangerous to human health.

Speaking to The Malta Independent on Sunday, Professor Patrick J Schembri said: “The Mediterranean is greatly affected by the climate, perhaps more so than any other sea. The effect of a warming trend on the Mediterranean is best looked for in the deep water (more than 1000m) since shallower water will respond to what may be transient fluctuations in atmospheric conditions rather than long-term climate changes.

“There has been a warming trend in the Mediterranean deep water over the past 40 years or so, but we do not have records beyond that and 40 years is really a very short period of time against the background of the hundreds and sometimes thousands of years in which some climatic fluctuations take place. Thus while some scientists argue that this warming trend is the effect of global climate change, others argue that this is but a temporary climatic fluctuation such as we know from geological evidence of what happened in the past.

“Is the Mediterranean going tropical? The Mediterranean has gone tropical in the past but is has also gone colder and this cycle has happened several time over geological time. What is happening today depends on whether the warming trend is a temporary fluctuation or will continue in the long term.

“Is the Mediterranean changing because of the warming trend? Certainly since the past 40 years or so species adapted to warm water are expanding their range in the Mediterranean and species that are not so tolerant to warm water are contracting their range. Moreover, we are seeing more warm water species entering from the Atlantic and the Red Sea, although in this case the effect is confounded since some of these immigrants are entering because of shipping. Whether this change in the biology of the Mediterranean will continue or not depends on whether the warming is temporary or long-term

Prof. Victor Axiaq said: “We must widen the range of tests we perform on bathing water quality to include specific tests for algae blooms. Admittedly this may be quite expensive to carry out, but such tests may provide us with early warning signals about likely problems, which may develop at a later stage. I think that the most sensible thing is to be on the lookout... rather than to react by crisis management.

“I am not suggesting that there will be blooms of this dinoflagellate in our local waters tomorrow morning... we already have our fair share of jellyfish blooms. But as I had indicated some weeks ago in another Sunday newspaper, we must not allow ourselves to be lulled into a false sense of security simply because we are carrying out the obligatory and guideline tests for bathing water quality as required by the EU. Our bathing waters are too important to adopt this wait-and-see attitude.”