Maintenance and conservation of laggon habitat

The lagoon of the Fajã de Santo Cristo is an internationally recognized location of environmental importance for biodiversity, and for ecosystems services.

The lagoon is natural nursery for different fish species and is also the only place in Azores that has a commercial exploration of clams (Ruditapes decussatus). But, due to climate and human pressures the lagoon has been changing its hydrodynamics, oxygenation and redox potential, affecting the clam production which also serves as food for several species of fish and resident and migratory birds.

There is a vast expanse of decomposing algae at the bottom of the lagoon. These algae entered the lagoon channel and sank. It is now decomposing, creating dense layers of sludge. This phenomenon alters the physical and chemical parameters of the sediments, making them unfavorable to life. There are also banks/margins of the lagoon that previously produced clams and are now so compacted that there is no longer any life in these sediments, only black mud and a foul smell.

The objective of the action would be habitat conservation and maintenance, analyzing the current problems with technical assistance and technical analysis, cleaning the decomposing macroalgae from bottom of the lagoon, and in the banks/margins loosen compacted areas and add suitable sediments. The expected results are the increase of oxygenation and redox potential, increase of organism that live in the sediment as polychaetas, detritivores, and increase clam production favoring a balanced habitat.