As we enter the mouth of the River Orwell bound for SOTW’s berth back in Ipswich, the team are excited at the prospect of stepping ashore after several weeks at sea, and looking forward to a well deserved pint of beer.
The survey has been a great success; with the best weather we could have hoped for at this time of year, allowing us to cover the entire proposed set of track lines. There have also been plenty of sightings including 13 harbour porpoise sightings, several grey seals, a sighting of 3 minke whales and a whole day accompanied by white-beaked dolphins. Acoustic detections of porpoises from the hydrophone have, however, far exceeded sightings. Although, the weather has been unexpectedly good for the time of year, the very calm sea states required for optimal porpoise observations were rare, and it is under these conditions that the acoustic survey methodology comes into its own, with a preliminary analysis suggesting, at least 250 detections – approximately 20 times as many acoustic as visual detections.
Now the task of analysing the acoustic dataset in detail will begin, the presence and distribution of harbour porpoises examined and reports and papers written up. The survey team all go their separate ways tomorrow, back to Scotland, Wales, Germany and the Netherlands, and the R/V Song of the Whale will be readied for forthcoming projects beginning in 2012.