Sunday, 29 April 2012

Just Push Play

The ring of alarm of alarm bells marked the begin of Thursday morning at the C-CATS base in New Quay. Roused at 4:30 AM, there was just enough time for a direly needed cup of coffee before the team split up to take advantage of calm seas. While Gemma, Winnie and Katrin scaled the coastal path up to the cliff with only head torches illuminating their path, Hanna, Luke, Katie and Marta made their way down to the harbour to prepare the boat for a morning of playback experiments.

An early start for the C-CATS team: New Quay before dawn

On the cliff, the practice sessions with the theodolite paid off and the equipment on the cliff was set up just as the sun rose and the Islander arrived at the grid of PODs. It was not long before the cliff observation team could put their experience to the test; a group of six bottlenose dolphins, including two calves, appeared at 7 AM and delighted the cliff team (or C-team) with their high energy displays; breaching, tail slapping and lunging for fish at the surface. They stayed in the area for over 2 hours and were successfully tracked with the theodolite throughout that time. Not having anticipated such a long encounter, however, meant that there was now a shortage of forms and Gemma had to call for reinforcement from the home base. Jens gallantly volunteered to trek up the cliff with the forms himself but unfortunately missed the last dolphins of the day, a pair of adults travelling swiftly through the grid, by about five minutes.

Panoramic view of the cliff observation site
Directional transducer for playback
Excitement was also at an all time high on the Islander. After days and days of preparations, the calm seas finally allowed for systematic playback experiments. During these experiments, the team aimed to play artificial and real porpoise sounds to a specific set of PODs to determine factors that may affect the likelihood of PODs detecting the animal. For this purpose, in addition to the existing deployed PODs a special 'triPOD' was designed; a set of three C-PODs set in a triangular wooden frame, lovingly named 'Jemima'. The team deployed Jemima within the existing grid of C-PODs and then proceeded to play back artificial porpoise sounds at varying distances and volumes. They used two different type of playbacks, omnidirectional, broadcasting sound 360 degrees from the source, and then directional, using a specific setup to direct the sound towards the C-POD in a way that more closely resembles the narrow echolocation beam of a porpoise. Although the weather was an improvement on previous days, the winds did pick up significantly throughout the day and by early afternoon, the crew had to battle choppy waters while trying to stay put during playbacks. Nevertheless, they were not deterred, determined to make the most of brief window of opportunity and successfully conducted both directional and omnidirectional playbacks at 3 separate stations - all without any seasickness casualties!

Playback from the 'Culticave'
In the early afternoon however, the boat team was forced to return to New Quay harbour to pick up a spare battery to power the laptop from which the playbacks were conducted. Having exchanged the battery and a couple of crew members, everyone was ready to get back to work. Apart from the Islander. As Luke tried to start the engines it became apparent something was very wrong. One of them was not starting at all. After a preliminary look to see if any superficial problems could be spotted, Hanna called New Quay's lifeboat mechanic who came down to have a look. While the problem itself turned out not to be serious, the next supplier stocking the required part was located a 4 hour roundtrip from New Quay. Frustrated after being stopped short in our tracks after such a successful day, we decided to call it a day. There was only one problem. Jemima was still out there and with the winds picking up, leaving her to her fate could have meant losing her -and all the data- permanently. While everyone else headed home to get some dinner, Luke and Hanna stayed with the Islander, discussing our options. Finally, the decision was made that we would attempt to retrieve Jemima. On empty stomachs and over 12 hours at sea, Luke and Hanna manoeuvred the Islander through stormy New Quay waters on just one engine and Marta's support. Despite the fading daylight and crashing waves, Jemima was successfully retrieved and her safe return- and of course Hanna's, Luke's and Marta's as well- came as a great relief to everyone.

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