A team led by Carlos Duarte of the University of Western Australia in Perth sequenced the DNA of Posidonia oceanica at 40 sites spanning 3500 kilometres of seafloor, from Cyprus to Spain. An area of the seagrass off the island of Formentera in the Balearics was found to be identical over 15 kilometres.
Posidonia oceanica reproduces by cloning, so meadows spanning many kilometres are genetically identical and considered to be one giant organism. Given the plant's annual growth rate Duarte’s team calculated that the Formentera meadow must be between 80,000 and 200,000 years old, making it the oldest living organism on Earth.
Despite its longevity, Posidonia oceanica is in decline by around 5 per cent per annum due to the effects of climate change, as the Mediterranean Sea is warming three times faster than the world average.
In one bay being studied by the Kenna Eco Diving team of divers, volunteering with the Silmar Project, there has been an estimated 25 per cent loss of Posidonia beds over the past decade, mainly as a result of careless anchoring.
Since Posidonia oceanica is unique to the Mediterranean we must step up our efforts to preserve it and protect it from the many threats to its survival. Towards this end Kenna Eco Diving is launching Design a Posidonia Poster Competition. Entrants are asked to design a graphical poster/flyer aimed at raising awareness amongst boat users about the severe damage caused by anchoring in the seagrass beds.
Voluntary coordinator, Gaynor Rosier, stated
“This is a vital habitat that hundreds of marine creatures depend on throughout their life-cycles. For example, the Posidonia pipefish, Syngnathus typhle, has evolved to perfectly resemble a blade of seagrass and cannot survive anywhere else. It is heart-breaking to be a daily witness, whilst diving during the summer months, to the careless destruction of hundreds of years’ worth of growth caused by anchors being dragged throught the Posidonia meadows.”
Kenna Eco Diving is launching an awareness campaign aimed at the boat users of many nationalities that come to enjoy our coast. A graphical design is needed to get the message across that we must RESPECT & PROTECT this *priority habitat.
*Posidonia oceanica is a Priority Habitat under the EU's Habitats Directive (Dir 92/43/CEE).
Win a guided scuba dive or snorkel in the Costa Brava Posidonia oceanica seagrass meadows.
At Kenna Eco Diving we have been carrying out conservation research into the seagrass Posidonia oceanica for the past decade. Posidonia oceanica is a habitat unique to the Mediterranean Sea in which a myriad of species find food and shelter, in fact up to 700 different species have been counted within a square meter of seagrass. It is also an important breeding ground and nursery for many animals including the rare Posidonia pipefish and several commercial fish species.
This amazing species of seagrass provides other services such as protecting the coastline from erosion, clarifying the water by catching suspended particles, absorbing vast amounts of carbon dioxide and releasing oxygen.
Catalunya banned otter-trawling over Posidonia beds many years ago. However, it still faces many avoidable threats to its survival, the most obvious destruction coming from unregulated pleasure boat anchoring.
As the Posidonia meadows are being destroyed the Posidonia pipefish, relative of the seahorse which is perfectly adapted to this habitat, is becoming harder to find. Now we are lucky to spot one or two per dive season whilst Eco Diving. Where there were once lush meadows of Posidonia teaming with marine life, we now see barren sediment, often littered with trash from tourist boats.
The key messages are:
More information on Posidonia oceanica can be found on our websites:
The closing date is 1st September 2012, and judging will take place during European Fish Week by a panel of judges appointed by Kenna Eco Diving. The winner will be the design that best relays the key messages aimed at deterring boat users from anchoring in the Posidonia oceanica beds. The judges’ decision is final.
The competition is free to enter and is open to anyone aged 15 years and over. (Parental permission and completion of a medical questionnaire will be required for a prize winner under 16 to take the scuba dive.)
The prize – the choice of a guided scuba dive or snorkel over the seagrass meadows – is to be taken during August to September 2012. The prize is non-transferrable and there is no cash alternative.
By entering the competition entrants agree that the design becomes the property of Kenna Eco Diving and may be adapted and shared on the internet and reproduced as a poster/flyer for the purpose of raising awareness of the threat to Posidonia oceanica from careless anchoring.