The anoxic Butrint Lagoon, SW Albania

Butrint Lagoon, which displays anoxic conditions for the last 300 years at least, constitutes part of the Butrint coastal system that also incorporates the adjacent Butrint Bay and the shallow Vivari Channel (depth < 6 m), which connects the lagoon with the open sea. For the investigation of the Butrint coastal system, three surveys were carried out in 2003, 2004, and 2012. These included conductivity–temperature versus depth casts, grain size, and mineralogical analyses of surface sediment samples, side-scan imaging, and bathymetric measurements. The synthesis of the obtained data (1) showed that sedimentation processes in the deeper part of the lagoon rather have not changed for the time span 2003–2012, (2) verified the long-term establishment of anoxia in the deeper parts (depth > 8 m) of the lagoon, and (3) allowed the determination of anoxic, hypoxic, and oxic sediment provinces. In addition to some noteworthy bedforms (i.e., sediment ripples and sand barriers) in the shallow parts of Butrint Lagoon (depth < 3 m) and Vivari Channel, side-scan imaging also revealed the existence of ruins of potential historic significance.