Survey of Posidonia sea grass under way

The first survey of Malta's Posidonia oceanica, the vulnerable sea grass which grows only in the Mediterranean, is being carried out in line with the EU's Habitats Directive.

The data collected will equip the Malta Environment and Planning Authority with the right tools to eventually set up a marine conservation area.

"Once we know exactly what we have, we will be in a position to protect it and ensure that development in the region of the Posidonia is controlled," MEPA environmental management unit manager Adrian Mallia said.

Mr Mallia and parliamentary secretary George Pullicino yesterday saw for themselves how the data is collected when they went on board a boat equipped to carry out the survey.

Mr Pullicino said the authority had commissioned Italian experts Geological Assistance & Services to carry out the survey, at a cost of Lm40,000.

GAS is a top company operating in Italy and abroad in the provision of positioning, geophysical, oceanographic services and offshore environmental studies.

The Habitats Directive lays down that Malta must produce this data.

"The results of the survey will allow for the full assessment of the implications of the provisions of the Habitats Directive with respect to the Maltese environment. This is an intrinsic part of the pre-accession process to join the EU," Mr Pullicino said.

However, this exercise was long overdue and the data was essential for the authority to designate sites as conservation areas. At the moment there are no official marine conservation areas, Mr Mallia said.

The Posidonia oceanica, which is also known as Neptune's sea grass, or alka in Maltese, is often regarded as a nuisance by swimmers.

"What is usually washed up on the shore are the dead leaves of the Posidonia. It is nothing like algae or seaweed; rather it's more like an underwater rainforest," explained Mr Mallia.

The Posidonia, a plant which only grows in the Mediterranean, grows fruit and is one of the few flowering plants growing submerged in the sea.

The plant is vital for biodiversity and is a breeding ground for sea creatures such as sea urchins and crustaceans. It is also a stopover for fish passing through the Mediterranean.

Another important function for it is to serve as a buffer against waves, to protect the coast and sandy beaches from erosion.

"Malta's Posidonia has been found at a record depth of 55 metres in the area off Benghajsa. Usually, it's found at a much lower depth," Mr Mallia said.

A lot of research on Posidonia has been carried out in France, Spain and Italy. However, Malta's Posidonia meadows seem to have a higher density.

"From studies that Maltese students have carried out and from impact assessments, we know that we have the deepest meadows in the Mediterranean."

The Posidonia is found mostly in the north-east of the island and along Hurd's Bank, 12 nautical miles off Zonqor Point.

The plant is highly susceptible to pollution and plants died off when the dredging work for the Marsa power station and Freeport was under way.

The rock-cutting of the Hilton's marina had also destroyed the Posidonia in the area and the developers had had to pay a penalty, Mr Mallia said.

"Once the plant dies it will not grow again. Attempts abroad to transplant it have proved practically unsuccessful."

The branch of the plant grows just one centimetre a year and Mr Mallia said that in certain areas it was being destroyed by the use of anchors on the seabed.

"Once we have the data from this survey we can establish that certain areas will be marked as a no-anchoring zone," Mr Mallia said.

The survey, which started three weeks ago, is split into two phases. The first is to be completed by next week, involving the use of a side scan sonar which is submerged in the sea to collate electronic data on the Posidonia's geographic position.

Dr Sabrina Melandri, environment and oceanography department manager of GAS, said the team was currently mapping the exact position of the plants.

In the second phase, five teams of two divers will go to 30 sites to verify the electronic data and assess the health of the meadows.

Mr Pullicino said the entire exercise should be over by the end of July or the first week of August, depending on weather conditions.

"The results of this survey are essential as they provide the baseline against which the future health of the marine environment, and consequently the viability of management plans, may be assessed through monitoring programmes," he said.