Marsalforn coastal defence project threatens protected seagrass

The construction of two gigantic breakwaters and submerged groynes to strengthen coastal defences and replenish the depleted Marsalforn beach, will pose a threat to protected seagrasses, a screening report by the Environment Resources Authority warns.

Seagrasses like Posidonia meadows have a fundamental role in oxygenating the sea and are protected by EU law.

One of the proposed breakwaters at il-Ponta ta’ Santa Marija will extend out from the coast across 400sq.m. The other breakwater located at il-Menqa will attach to the existing jetty on the eastern side of the bay, extending its the footprint by 1,000sq.m.

Two groynes will be located on either side of the Marsalforn valley mouth, extending 37m out in the bay, covering a total area of 900sq.m. 700cb.m of material will have to be dredged out to place the groynes. Following their placement, a beach replenishment will extend the beach by 3,000sq.m.

The beach project will result in the physical loss of marine seabed habitats and the deterioration of the protected Natura 2000 site, which includes protected habitats populated by Posidonia oceanica. “The likely loss of Posidonia oceanica is of concern and considered to be likely significant,” the ERA has warned, requesting benthic studies on the impact on the marine species.

The proposal could even result in increased erosion caused by potential changes in wave reflection patterns.

Dredging is expected to generate some 23,000cb.m of waste silt and rock, which means the project will not require an Environment Impact Assessment.

The project is being justified as a way of protecting the bay from severe storms and flooding that have become synonymous with the area in adverse weather conditions. The town is highly exposed to strong north, north-west and northeast winds, which are rather common. Being located the mouth of a valley, Marsalforn homes along the coastline are subjected to flooding during storms due to large volumes of run-off passing from the valley to the sea. The flooding is worsened by the waves from the low-lying shore, exposing all buildings along the coastline.

The original breakwater was constructed in the 1960s but since then has endured substantial physical damage, leading to the collapse of entire sections of the structure in 2005 and 2009.

The new coastal defence system makes the replenishment of the beach viable, which at present is just 48m in length due to intensive erosion.