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Adriatic Sea and a plague of invasive algae

caulerpa racemosaIn the recent article of BIRN, under the title “Greening of the Sea Gives Adriatic States the Blues” , there are some worrying  details regarding the state of a plague of this invasive algae in waters of Croatia as well as surrounding countries.

Under the statement “A plague of invasive algae is testing countries’ willingness to work together to save their marine heritage and tourist industries”, Bojana Staniši? writes :

“The pristine waters of the Adriatic have long been the boast of the countries with coastlines alongside it. Azure in colour and much cleaner than the adjoining Mediterranean, they are a major draw for the growing numbers of foreigners holidaying in Slovenia, Croatia, Montenegro and more recently, Albania. With the decline of heavy industry in all, these waters constitute a precious economic asset.

Now they face a new danger. Year by year, an insidious green underwater predator is making its stealthy advance, disturbing the marine environment as it does so and turning pristine sandy and rocky seabeds into thick carpets of waving green fronds.

The state of the once clear waters around the Ligurian island of Elba is a stark warning of what the Adriatic may expect. Formerly home to beds of dazzling coral and molluscs, they were a paradise for divers. “Today, no one goes there for diving,” Professor Francesco Cinelli, a marine biologist at the University of Pisa, laments, peering into the water at the village of Marina di Pisa. “The seabed is covered by a green carpet”, he explains.

Professor Cinelli is talking about Caulerpa Racemosa, an invasive algae that has spread like wildfire in the Mediterranean, and now threatens to do the same in the Adriatic.” … read the rest of the article

2 Responses to “Adriatic Sea and a plague of invasive algae”

  • John Nash on December 11th, 2007 12:09 pm

    As a company we have been trying to market sewage pump-out equipment for boats in Croatia for about 5 years. The closest we have come to realising the installation of a system is a multi take off point system at Marina Lav.


    We are not looking for personal or manufacturer’s profile to be raised or highlighted, just that this topic be raised/discussed and resolved.


    The present situation:

    • There are 50+ marinas, 39+ Fuel filling stations, 320 Charter Companies with 2,600+ vessels for charter, plus many thousands of visitors each season with their own boats sailing in Croatian waters.
    • There may be 5 marinas that offer some type of portable pump-out facility which is not generally advertised.
    • No fuel station offers this service, as far as we are aware.
    • I would suggest most of the charter vessels have holding tanks but, because there are no facilities for pump-out ashore, they empty into the sea.
    • A calculation could easily be made of the tons of raw sewage that is dumped each season into the sea.
    • A large % of Croatia’s GDP comes from Nautical Tourism – part of the attraction is the crystal clear water which will not remain so unless something is done
    • Government regulations I believe, have insisted for a number of years that all new marinas should provide this facility – to my knowledge none have been installed.

    The 3 main arguments raised for not providing the facility are:

    • “there is no sewage system on the coast therefore all sewage is returned to the sea”, but huge investments and improvements are being made to improve this situation. 
    • “people do not ask for the service”, but this is because there is none available
    • “ the fish eat it”, yes they do but a minuscule amount to that which is dumped, the remainder lays on the sea floor suffocating life, the natural production of oxygen and damaging the whole of the food chain


    The solution:


    I believe with 3 small changes to the law the situation would be greatly improved:

    • if Charter vessels had to have holding tanks, with the waste line to sea isolated and a pump-out outlet fitted
    • if marinas had purpose made pump-out systems either to larger holding tanks to be taken away by tanker or a system connected to the main sewage system
    • if fuel stations that dispense fuel to boats could likewise provide a similar facility

    The benefits:

    • Besides reducing the pollution of the sea, enabling sustainable tourism, the PR benefits would be considerable and improve Croatia’s standing as a Tourist destination with an eco conscience.
    • The provision of this service can be an income generator for the provider as has been proved throughout Europe, USA and Canada. The installation costs need not be prohibitive and there are a wide range of systems to suit most budgets and needs

    For information and guidance only please see


    which will give you an idea of the equipment available.


    Hopefully the above information will provide an indication of my thoughts and obviously I would be happy to discuss the subject further if it is of potential interest.


    Kind regards,

    John Nash


    Marina Facility Solutions Ltd

    tel/fax : +385 (0) 21 797 301
    mobile: +385 (0) 98 942 7143

  • Jakov on December 11th, 2007 10:13 pm

    John, I know what you mean, I live in a coastal croatian town, and everyone here dumps their septic tank into the sea.


    I remember well from my childhood, there were rocks by the sea covered in green slipperly algae, now its all gone and the rocks are bare, there were also sea horses you could catch with your hands, but I haven’t seen any for years.


    My mother also tells me of a time when there was a “sea-lettuce” everywhere on the sea floor, but its all gone because it only grows in clean sea.


    Even though, when you look at the sea, it seems very clear and clean, I’m sure no tourist realises how polluted it is, because on the surface it looks nice


    But you have to understand us, we don’t have a lot of money, tourist seasons are getting worse and worse, we simply have no money to spare for making this sewage system.


    I guess its a similar situation in south america (but not as drastic), the people there have a choice of cutting down the rainforest to grow food… or starve.


    I’m not saying we would starve if we did this, but we have the same thoughts, in a choice between ourselves and the environment, I’d choose myself every time.


    I don’t think this situation would ever change unless a larger body helps, a charity agency or something, but all their money is going to Africa.


    I dont know who said this, but it shows what I mean very well, “In hard times, the milk of human kindness does not flow as freely”



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