Dinoflagellates? Sounds like something out of Jurassic Park. But unlike T-Rex, these particular creatures cannot be seen or heard coming a mile away; and while they admittedly do not devour their prey whole, they nonetheless claim more victims each year than larger, more dramatic predators such as the Great White Shark.

For those unfamiliar with the rich complexities of microbiology, “dinoflagellates” are actually microscopic proto-plants commonly associated with warmer, tropical waters. To a marine biologist like Professor Victor Axiak, the fact that these potentially dangerous organisms have recently made an appearance in the Mediterranean is both a matter of professional interest, as well as cause for concern. Either way, they provide further evidence that the marine environment around us is slowly but surely changing.

“At present, we are discovering something like 15 new species every year,” says Prof. Axiak, who seems mildly surprised at my interest in dinoflagellates. “Many of these are attributable to the ‘Lessepsian migration’: the gradual introduction of new species since the opening of the Suez Canal. Global warming could also be a factor, as many of these species are native to warmer waters: mainly, the Red Sea and the Indian Ocean. Naturally, this increase in alien species is also having an impact on existing marine ecosystems…”

But before looking at the effects of this curious alien invasion, let’s start with a much more familiar aspect of the ongoing sea-change. Pollution – a phenomenon which (unlike many of the other changes) has a direct and immediate bearing on our ability to enjoy summer while it lasts.

For several years, Prof. Axiak has regularly analysed the results of tests carried out annually on samples of Maltese bathing water by the Public Health Department. Together, we examine the results of last year’s tests, and I am surprised to note that in this age of greater environmental awareness and Blue Flag beaches, there appears to have been a slight deterioration in overall seawater quality. Some parts of Malta and Gozo (and especially Comino, whose beaches score maximum points for cleanliness) remain as limpid as crystal clear as ever; but others register noticeably higher bacterial levels than usual. Gozo appears to been particularly affected, with bays such as Xlendi and the Inland Sea at Dwejra taking a discernable bacterial nosedives in the past 12 months. More worryingly, Golden Sands in Malta – which attracts thousands of bathers each week – comes in third in the pollution list after Balluta (which has hogged the number spot for years) and Salini.

My surprise doubles when Prof. Axiak quotes a recent EU report on bathing water in all 27 member states, which claims that Malta has actually registered “significant improvement” over last year. So the question remains… whose reports are we to believe?

“Usually, the public health department conducts two specific tests on samples gathered from all beaches and bays,” Prof. Axiak explains. “The tests concern primarily faecal coliforms and total coliform bacteria – basically, microscopic organisms, arising mainly from sewage pollution, which can be harmful in large quantities…”

Herein lies the inconsistency. For while these two tests suffice to give a clear indication of bacterial pollution, the EU’s bathing directive insists on an additional three tests which, according to Prof. Axiak, are virtually useless.

“In past years Malta has been ticked off for not carrying out visual and olfactory tests – basically, checking for pollution which can be seen or smelt. One of the tests involves shaking seawater in a test-tube: if the water produces lasting foam, it is an indication of bacterial pollution. But the initial two tests we have always carried out will reveal the precise levels of bacteria anyway… so what’s the point?”

Apart from insisting on useless tests, Prof. Axiak feels that the EU’s attitude towards the issue of seawater testing can also be counterproductive.

“Unlike previous years, in 2006 the health department conducted all five tests, including the test-tube shaking one. So when the EU’s report came out, it noted Malta’s observance of the EU directive as an ‘improvement’. And yet, as can be seen from the test results themselves, the quality of bathing water has actually deteriorated marginally over last year. We are not talking about an alarming deterioration – in fact, some areas have improved – but there has been a noticeable decline in overall quality.”

And this, Prof. Axiak maintains, may be “lulling us into a false sense of security.” After all, if the EU has given you a seal of approval, why take any measures to improve the situation?

Coming back to the test results themselves, Prof. Axiak cautions against jumping to drastic conclusions. “The advantage of regular testing over time is that you can see a pattern emerging. Sometimes, a beach which has always been clean will register a sudden increase in bacteria lasting only a week or two. When this happens, it usually concerns an infrastructural problem affecting that particular area: for instance, a faulty sewage pumping station, which would pump untreated sewage straight into the sea instead of redirecting it to the main outfalls at either Wied Ghammieq, ic-Cumnija or Ras il-Hobs in Gozo. Another possibility is the illegal dumping of waste.”

According to Prof. Axiak, these random occurrences are usually quite easy to rectify, and the damage caused, while unpleasant and occasionally hazardous for bathers, is not considered very serious. “But then, you also have cases where there are signs of consistent pollution, lasting several weeks and sometimes progressively deteriorating. These are usually indications of more serious problems.”

But as far as Prof. Axiak is concerned, there is another reason to step up our efforts to combat all forms of sea pollution. It seems that faecal coliform bacteria – the kind of pollution caused by untreated sewage – is not the only noxious organism to be found our waters. One other “alien” species is ostreopsis ovata, one of the aforementioned dinoflagellates to have recently been identified in Greece, Italy and now even Malta, where it was discovered by local researcher Sarah Debono during tests carried out recently at Salini.

Prof. Axiak is quick to point out that the simple incidence of the organism is not in itself any cause for concern. “In small quantities, ostreopsis ovata is not particularly harmful. It is only when the alga blooms that you may have a potentially dangerous situation.”

Last summer, a number of beaches on the Livorno and Ligurian coast of northern Italy were affected by what biologists refer to as HAB (“harmful algal bloom”). This phenomenon, hitherto unknown in Italy, is only too familiar on the Pacific coasts of Mexico and southern California, where it has earned itself a notorious nick-name: “Red Tide”.

Assuming that the same thing could happen here… how “harmful” is a harmful algal bloom, anyway?

Prof. Axiak replies slowly and cautiously: “Without meaning to sound alarmist, the effects can be serious. Take what happened in parts of Italy last year. Apart from the fact that several people had to be hospitalised, they also had to close down the beaches. The repercussions of this on the area’s tourism industry were enormous, causing damages running into millions of euros. Other industries also suffered. For instance, fish which consumed the alga became contaminated. So the fisheries lost millions, too. We are not only talking about health risks; the economic consequences can be just as severe.”

On a physical level, exposure to dinoflagellate toxins (or consumption of contaminated seafood) is no laughing matter, either. Prof Axiak outlines three basic harmful physical effects: paralytic, amnesiac and diarrhoetic shellfish poisoning. All three are potentially life-threatening, although the third can be caused by a wide variety of other factors, and is therefore very rarely attributed to algae.

“Amnesiac shellfish poisoning is a particularly nasty condition. It occurs when toxins secreted by the alga affect the human nervous system. Among other things, it results in loss of memory…”

At this point, I venture to suggest that in some cases, amnesia might not be such a bad thing. Prof. Axiak laughs. “I know, a lot of people find the notion quite amusing. Even when I mention this in conferences, there are jokes about how some people could benefit from a little memory loss. But joking apart, it is a potentially very dangerous condition. The same is also true of paralytic shellfish poisoning, which as the name suggests induces paralysis…”

In some cases – including the Livorno outbreak last summer – infection is not limited to bathers. People have also been known to inhale these micro-organisms in droplets of sea-spray, sometimes at quite a distance from the shore. But Axiak stresses that these are only worst-case scenarios.

“The fact that this alga has been detected in Malta doesn’t mean it will automatically bloom and become dangerous,” he explains. “But it happened in Italy, and given the same conditions it could happen here as well. The reason I mention these cases is to illustrate why testing for these algae is more important than testing for other forms of pollution. The trouble is that this kind of testing is not required by any EU directive, probably because it is a good deal more expensive than simply shaking a test-tube to see if there is any foam…”

But while discussing the possible effects of a bloom in Malta, the recent discovery of these algae in itself raises an immediate question. If these are tropical organisms, what are they doing here in the first place?

Like many scientists, Axiak is reluctant to commit himself to a single answer. “I suspect that global warming plays a part in it, but it is not the only factor. There is also the aforementioned migration through the Suez. But there could also be other unrelated factors that we don’t know about yet.”

An analogous biological mystery involves the apparently declining population of sea-turtles in the Mediterranean, which many lost no time in attributing to global warming. But as Prof. Axiak points out, it could just as easily be over-fishing, or the loss of sandy beaches, on which turtles lay their eggs. A similar case can be made for recent influxes of that anoxious invertebrate whose regular appearances wreak havoc among bathers… sychophozoa, or as you or I would probably describe it, the common jellyfish.

“It is only relatively recently that people have begun to notice jellyfish in large numbers, which seems to suggest that they have suddenly become numerous than before,” says Prof. Axiak. “But this can be misleading. We have no reliable data about how many jellyfish there were 20, 30 years ago, or before. For one thing, fewer people used to swim in years gone by. Also, mass tourism did not exist, so jellyfish were not considered as much of a problem. But from our recent observations, there does seem to be an increase in jellyfish influxes. In past years we noted how, every 12 or so years, there would be three or four consecutive summers full of jellyfish. What we’re seeing now is the same process, but accentuated so that the jellyfish invasion is occurring more frequently.”

Again, Prof. Axiak is reluctant to provide any direct explanation for the phenomenon. But even if there may be other variables in the equation, Prof. Axiak acknowledges that rising sea temperatures may have facilitated these and other “alien” invasions. What remains practically impossible to establish is the possible long-term consequences of climate change on the Mediterranean’s complex ecosystem.

“One recently discovered example is cauleppa, a form of seaweed which was first identified in the 1990s, and which has spread dramatically ever since. It is difficult to determine the extent of the damage this has caused, but it has certainly affected endemic seaweeds such as poseidonia. The problem in these cases is that ecosystems are complex things, and any effect on one aspect will inevitably have unpredictable knock-on effects on others. Let’s just say if that if an alien species proliferates at the expense of local fish stocks, the consequences could be grave.”

Considering that both the above-mentioned factors – pollution and global warming – are arguably caused by humans, all that was needed to add to the Mediterranean’s woes was another man-made threat: fishing. Animal welfare organisations such as the world Wildlife Fund have warned that indiscriminate (and largely illegal) fishing may have devastating consequences on certain species: bluefin tuna in particular is facing possible “total stocks collapse” as a result of a fishing frenzy driven primarily by the outrageous prices this sea-giant regularly fetches on the Japanese market. What, exactly, does a biologist understand by “total stocks collapse”, and what are the implications for the Mediterranean?

“In conservation terms, there is a critical population point beyond which a species cannot recover naturally,” Prof. Axiak explains with an air of resignation. “I wouldn’t know what the exact point is for tuna, but basically if adult specimens are killed at a faster rate than they can reproduce, then the remaining young will not be able to reproduce fast enough to be viable in the long term. In the case of tuna, the situation is not helped by their complicated reproductive cycle…”

Prof. Axiak goes on to point out that in most cases we are dealing with illegal fishing, involving the use of spotter planes (banned by EU law), and a practice he jokingly describes as “tuna laundering” – whereby larger fishing vessels bribe smaller boats to carry part of their catch in order not to exceed established quotas.

“As regards the consequences of tuna extinction, it is hard to say. We would have wiped out an entire trophic level (i.e., one ‘link’ in the food chain); this in turn would definitely have knock-on effects, but it would be almost impossible to say what these will be. Unlike physics or mathematics, complex biological systems respond to multiple factors in a non-linear way. In laboratory conditions you can test certain conditions and draw certain conclusions; but in the field there will be other factors we don’t know about, and those factors cannot be tested. It is partly for this reason that it took the scientific community so long to convince the world that climate change is real.”