Last week was an interesting week on Tenerife. It began, as so many crises in tourism do, with sensationalist reports in the British tabloid press, this time claiming beach closures due to harmful “microalgae”. Some publications even published stories of “flesh eating sea fleas” attacking a swimmer in Australia, alongside the story to seemingly imply some sort of tenuous link between the stories. The Tenerife government, and The Canary Islands government, were quick to respond, stating categorically that no beaches have had to be closed, explaining that microalgal blooms at this time of year are normal from time to time, particularly when the sea is a little warmer than usual.
Environmentalists pointed out that the Canary Islands dump large amounts of untreated sewage directly into the sea, with very little control, and that they had been complaining about this for many years. To which the government health departments responded strongly saying that microalage, or cyanobacteria to give its correct name, it is not actually algae at all, is completely natural and that it is totally incorrect to suggest that sewage waters might be the cause of these blooms having increased in number, as they are a natural phenomena and so not connected to any anthropogenic sources, and besides, they repeatedly insisted, all the beaches are clean.
As the week continued so pictures and videos from residents on Tenerife started to flood social media showing beaches awash with froth and foam, as bathers frolicked in the background; tourist resort complexes on the south of the island caught on video apparently discharging dirty waters at night directly into the ocean, and of course more and more images of cyanobacterial colonies blooming along the coasts.
While not necessarily always dangerous cyanobacteria can cause all sorts of upsets if come into direct contact with, including skin rashes, stomach bugs and even liver failure.
The politicians, sanitary officials, and various scientists all tried to calm the situation, reinforcing the message that there was no sewerage issues on Tenerife, and that the green-blue algae cyanobacteria, which is in fact not an algae at all, was totally natural and, though possibly an inconvenience, the fiberous greeny-brown floating mats were, they said, certainly not a serious danger to tourists nor a reason to close any beaches.
One politician scored honesty points by publishing a video of untreated sewage waters discharging from Tenerifes capital, under the main concert hall. Yet, the rest of the political classes assured us that these two subjects were completely separate and unconnected, that this is a very well studied subject and that this year`s mixture of warmer than usual oceans, coinciding with summer heat waves and repeated episodes of Calima, depositing iron rich dust on the surface of the water, had simply created an usually ideal set of conditions for the cyanobacteria to thrive. Everything should return to normal soon, they comforted.
Not all scientists, however, agreed that it was all so simple. Environmentalist and professor of Environmental Chemistry, Julio Muñiz Padilla, commented “out of an obligation” on his facebook page “there is a relationship between the outcropping of tropical cyanobacteria colonies and the discharges of nutrients such as phosphorus and nitrogen from the emissions of unpurified water” suddenly finding himself at the centre of the storm, as his post went viral he received insults and threats, as well as congratulations, and was accused of being neglectful, trying to harm the island’s tourism.
He has stuck to his guns though, pointing to several factors in his conclusions saying “Fortunately, most fecal bacteria cannot withstand the salt content of the sea, so waters from the sanitation network contribute contamination of pathogens to the sea, only in extreme conditions, so waste water treatment plants (WWTP) are not necessary to kill all the bugs that live in sewage water, as they will be killed off by the salinity of sea water, disinfecting it naturally, however it should” he pointed out “be used to reduce the nutrients that dirty water contains, namely: organic carbon, nitrogen in the form of ammonia and organic phosphorus.”
“If we wanted to reuse water from a WWTP, recycling it would necessitate two complementary processes; The first is disinfection, to eliminate bacteria and viruses, for which chlorine or some chlorine derivative such as bleach is used; The second is tuning of the water, through electrodialysis, reverse osmosis or ion exchange, which consists of lowering the salts so that it is better suited to industrial, agricultural or simple street cleaning.”
“In conclusion, the waters that we pour into the sea, purified or not, carry bacteria that, in contact with the sea, are usually eliminated.”
So there we had it, a scientist seeming to agree that bacteria in sewage had in no way caused the problem.
However, he wasn´t finished “But” he continued “in the marine environment there are other bacteria that resist salt. For example, some cyanobacteria, which used to be called microalgae. These bacteria, which are photosynthetic, take CO2 to form sugars and N2-binding agents to produce amino acids, in water that is rich in Phosphorus (P) and metals such as iron, when temperatures are higher than usual, they can aggregate forming extensive filamentous colonies, just like the ones that now invade our coasts.”
Padilla agrees wholeheartedly with the protestations of some biologists and politicians who insisted that these bacteria, like the tropical Trichodesmiun, do not have their origin in sewage discharges. However, he says he is not talking about isolated bacteria but colonies, of which there has been explosive growth that is possible if, you add nitrogen, and CO2, in the air or dissolved in the water itself, if you add nutrients such as phosphorus and ammonia, in coastal areas with uncontrolled water discharges. Then that’s the problem.
“Cyanobacteria are very competitive, as they can withstand poor nutrient media, in phosphorus-rich media, such as those supplied by unpurified water, at warm temperatures, cause them to multiply.”
He points out that in laboratories where they cultivate phytobacteria for further study, such as those of the Instituto de Productos Naturales under the CSIC in La Laguna (Tenerife), Phosphoric acid-rich culture media are used for exponential growth in rooms heated to high temperatures and illuminated with an adequate frequency light.
“That is to say, there is a relationship between filamentous colonies of cyanobacteria and the emissions of unpurified water in our islands.”
Padilla clearly states that bacteria such as this are natural indeed, in doing so he exposes the weasel words of politicians and ministers rushing to shirk responsibility. Cyanobacteria are always present in the sub-tropical ocean, they play a major role in phytoplankton, which is often attached to the hulls of boats that sail through tropical seas, and certainly not caused by discharges of untreated water. Colony formations have previously occurred in the Canary Islands, in 2011 in the waters of Lanzarote and in 2004 Tenerife, and these colony formations are favoured by the presence of untreated waters rich in phosphorus, nitrogen and iron that we pour into the sea. So there is a link, and a clear link between the two.
He finishes his statement on social media by saying “Climate change will continue to promote these manifestations so we must reduce those factors that are in our hands, that is nothing more than to eliminate the discharge of untreated nutrient-rich waters into the sea.”
Los informes que he publicado en los últimos días se han vuelto virales. Nunca he pretendido este protagonismo que, de…