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.

Thursday 26 April 2012

Experiencing the highs and lows of Welsh weather...


Monday- If you fail at first, try, try, try and TRY again!

The new calibration point
With the weather forecast promising a good weather window on Tuesday, Monday was a day of last minute preparations. The cliff observation team headed up along the coastal path with Felix to measure the calibration point for the theodolite as well as the position of the buoys marking the location of the PODs. While Marta and Winnie began measuring the position of the buoys, Felix and Gemma set off to measure the calibration point for the theodolite; a white MOD trailer located further down along the coast. Unfortunately, this expedition was soon met with complications; possibly because it is the property of the Ministry of Defence, Gemma and Felix could not get close enough to measure it. Not wanting to compromise national security but in desperate need of a measurable reference point that would allow us to calibrate the theodolite, the decision was made to choose a new point, a large corner fence post. Changing the reference point, however, meant that all buoy positions Winnie and Marta had been busy measuring, now could not be used anymore and that all measurements would need to be redone. Although initially frustrating, it was still a good exercise, allowing the cliff observation team to get familiar and comfortable in the use of the theodolite.

Later that day, it was still too rough to take the boat out but the team spent most of the afternoon preparing the Islander for the promised lull in the wind. The famous 'Culticave', was also allocated a permanent position on the boat and was successfully set up and secured on deck. Felix also used this time to measure the boat and array with the inertial measurement system which compensates for the rotation roll, pitch and angle of boat as well as measuring the angle to the north during acoustic recordings, this way we will be able to tell how the roadie bar is aligned at all times. However, these measurements had to be cut short due to the quickly rising tide. On dry land, once again, Winnie, Felix and Jens spent a long evening disentangling hydrophone cables, ensuring they were coiled separately and safely and ready to use the following day. After a long day, the team headed home, hoping for better weather for Tuesday.

Tuesday- All systems go!

Preparing the acoustics equipment
Tuesday was the big day, the window of opportunity we had all been waiting for! With the wind predicted to be at an all time low in the afternoon, there was an air of anticipation around the house as everyone did their bit to ensure that the first run with the full hydrophone array would be a success.
The array was assembled on the pier, and for the first time, the hydrophones attached! All electrical equipment, 2 laptops, batteries, the recording unit and amplifier, was assembled under the protective cover of the Culticave. Originally designed to be a greenhouse, it also very efficiently retains heat, which may prove to be a bonus on cold days, but was a bit of a concern in Tuesday's atypically sunny weather with not only all electronics but also Jens and Felix squeezed snugly under it's protective plastic roof! Finally, after breaking for a well deserved lunch in the sun (including home made cream tea courtesey of Hanna and Kati!), the cliff observation team, Marta, Winnie, Gemma and Katrin, set off to prepare the site while the boat team, Hanna, Luke, Felix, Jens and Kati, made last minute adjustments, ready to set off as soon as the last white caps disappeared from the horizon.

Calibrating the theodolite
Having had plenty of time to practice on the friendly neighbourhood cows, and encountered and resolved many error messages under the careful guidance of Felix, the cliff team confidently set up the theodolite- just to be set upon by error upon unknown error! Undeterred, they consulted the manual, made notes and tried the well known 'switch it off and back on again' technique, before resorting to calling Felix on the boat who swiftly resolved the issue once again. Calibrated, centred and ready to go, the team was now ready to record the positions of all the buoys marking PODs (all of which were present and intact despite the scare with Patricia!), as well as scanning for cetaceans and keeping an eye on the Islander.

Meanwhile on the boat, the first trial run with all hydrophones in the water was in full swing and although there were no animals in the vicinity to record, the boat team successfully recorded and located the echosounder using the acoustic array! Despite the limited practical application of this achievement, it was nevertheless a very important step forward, as it allowed the team to test whether the equipment was working correctly. They also had some time to attempt the first playback experiments; playing back sounds with the aim to study the likelihood of the static PODs picking up sounds at different volumes and distances. In the early evening, with storm clouds gathering overhead, the wind picking up again and the rumble of distant thunder in everyone's ears, both teams headed home after a successful day!

Islander as viewed from the cliff top observation point

Wednesday- Gone with the wind-again

All hopes of resuming boat or cliff based work were literally gone with the wind early on Wednesday morning. As gale force winds racked New Quay, there was little to do but to resign ourselves to the fact that we would be confined indoors for most of the day. However, as always there was plenty of odds and ends to do -such as updating the blog and replenishing our diminished food supplies as well as downloading data from the theodolite and working out the kinks in the electronic set up.

In the afternoon, Felix, Luke and Katrin headed back down to the Islander to complete the inertial measurements during low tide. Waiting patiently for the waves to retreat, the flooded 'Culticave' was dried out and the electrical equipment set up while further storm clouds gathered overhead. Slightly concerned about this development, as some of the measuring equipment is sensitive to water, the team checked the time to gauge how much time they had to complete the measurements- only to find that low tide had come and gone and at no time had Islander been completely on dry land! Unfortunate as this development was, we resigned ourselves to the fact that the weather and tides were not under our control and headed back home.
Waiting for the low tide that never was! 

Meanwhile, Hanna had checked the weather and discovered a brief good weather window early on Thursday morning- however just how early 'early' was remained a matter of mystery and much discussion for a while. We did not have long to dwell on this somewhat ominous announcement as Jens commanded all our attention for a pre-dinner talk on TOAD; Time of Arrival Difference, the method used to localise vocalising animals using a hydrophone array. After dinner the real meaning of 'early' was finally revealed and we headed straight to bed to be awake- bright and 'early' the following morning!  

Wednesday 25 April 2012

One Stormy Night...


After attaching the array bar to the boat on Friday afternoon, it was taken out for its first test drive that evening. This proved very useful, as it identified that extra strapping was needed to keep the bar steady while the boat was moving.

Test driving at sunset

The next morning the cliff observation team (Gemma, Marta, Katrin and Winnie) headed up to the lookout point to practise setting up and using the theodolite; as we arrived the heavens opened and the torential rains started, this quickly turned to hail, but luckily this didn't last too long. A dolphin foraging just off the coast made an excellent target for us to track.

The Cliff team fully kitted up in waterproofs through the hail and rain
Equipment was sorted and in the afternoon final adjustments were made to the array system. Hanna, Marta and Katy changed into their drysuits to run more straps under the boat to secure the bar in place on the side of the boat.

Changing into drysuits- the tricky bit!
Overseeing the final adjustments of the array bar on 'Islander'
With a busy day (and week) behind us, the team headed into New Quay for some fish and chips in the evening, as we were coming down the hill and into the centre of the town, a huge ship could be seen offshore, instantly we were very worried about all the PODs and bouys deployed off New Quay head. Hanna phoned the coastgaurd to find out what was going on, they told us that this 86 x 13m ship, named 'Patricia', was in the area carrying out checks on all the lighthouses; a RIB was launched from it, and as there was no radio on board, or any way we could communicate with them directly, we stood on edge of the pier waving frantically, trying to get their attnetion so they could come to shore and we could warn them about all the moorings in the water. However this didn't work, and after they had done a large loop, the RIB returned to the ship, which continued on it's travels. We called the coastgaurd again, who let us know that the boat was now travelling North.

The huge ship 'Patricia' just off New Quay head!
The next morning we set to work tracking the boats movements to see if it had travelled through our grid of bouys. From comparing the tracks it looked like it had! And with the sea being too rough to take the boat out or see the bouys from the cliff, we were not sure if 'Patricia' had caused any damage to our project- Sunday was an anxious day.

The route taken by 'Patricia'- right off New Quay head

POD and mooring positions

With a slight lul in the weather we took the boat out on Sunday evening, to test if the hydrophone array bar was secured- the extra strapping appeared to make a large difference, and held the bar very steady. Then with some desperation to see if the bouys were stilll in place we searched for the grid; however with the wind and waves rapidly picking up and the light fading, we had to turn back for harbour without completing the search.

Friday 20 April 2012

Success!


With gale force winds still battering the New Quay coast, we were all confined to land, but there was plenty of work to keep us busy.

Marta, Katrin and Winnie set to work writing out the theodolite set-up and use protocol, cliff observation forms and maps for tracking porpoise movements. All equipment for the cliff observations was prepared and sorted into (many) appropriate bags ready for use when the weather calms.

Meanwhile, Felix and Jens set up the hydrophone array with the help of Luke and Gemma. As we couldn't measure the whole attachment at once we have to go step by step. First step was to measure the array on land (i.e not attached to the boat). The second step will be to connect this to the boat on a different day. Our measurements involved the positions of all 15 hydrophones and some points on the bar as a reference for further measurements. Using the accurate positions of each of the hydrophones and calculating the time differences in arrival we will be able to calculate the angle and distances of the animal.

Setting up the hydrophone array bars and measuring them

Hanna and Kati took on the very important job of cutting out displays to notify other boat traffic that our vessel had limited manoeuvrability while the array is attached. The CultiCave was set up in the living room of the house to make sure all equipment that needed to be inside, along with Felix and Jens could fit.

After careful monitoring of the weather, there was finally a break on Thursday night, meaning it was all systems go! GPS positions were printed out, logistics were discussed and Kati prepared all the C-PODS and T-PODS ready for deployment in the early hours of the following morning.

We were up with the first light, knowing that this was our chance to finish deploying all the PODS. Hanna expertly navigated the boat to the beach with the help of Kati who donned her drysuit and had waded up to her shoulders to guide the boat in the shallows. With all of the team pitching in the weights were quickly loaded, and it was round to the slip way to collect the moorings, buoys and PODS. With all equipment loaded and each person's role assigned, Islander left the harbour with it's crew of Jens, Kati, Gemma, Marta and skipper Hanna, and headed out onto the calm sea. However this was not to last; as the wind picked up and conditions worsened three out of the five man crew were struck with sea-sickness, however our team soldiered on, letting nothing affect their work! And after only a few hours with an extremely efficient system now in place, the last nine PODS were deployed, completing the static acoustic monitoring (SAM) set-up. YAY!!

Early morning in New Quay harbour.

Jens, Hanna, Kati and Marta ready for a morning of deploying the last PODS

In the afternoon, the hydrophone array was carried down to the boat, assembled on the shore as per the measurements yesterday. We then held the bars in place while they were levelled and securely attached to the boat, cutting a layer of foam to put between it and the boat for protection of both. As the tide was coming in, Kati and Winnie swiftly changed into drysuits to finish attaching the array bar in place, running ratchet straps from the bar under the boat and fastening it to the opposite side. With the last tightening of the strap the array bar was fixed meaning it is now ready for poles containing multiple hydrophones to be suspended down into the water from; and with this the first test-run of this system, a very exciting prospect for us all!

Carrying all the pieces of the array bar down the many steps and onto the beach

Array bars to the boat
Fastening the bar to 'Islander'
Array bar attached to the boat! YAY!

Winnie and Kati in their drysuits ready to attach the last strap, fixing the array bar to the boat!


Thursday 19 April 2012

Project C-CATS!

Sunday marked the official start of Project C-CATS, a unique approach to acoustic monitoring that will be the first of it's kind to be conducted. Although there have been comprehensive echolocation studies in captive cetaceans, relatively little is known about their wild counterparts. Static acoustic monitoring is often used to detect vocalisations of wild cetaceans, such as clicks and buzzes, but there is limited knowledge of the extent to which various factors such as the animal's distance from the data logger and mooring depth affect the detectability of these sounds. C-CATS will be attempting to monitor harbour porpoises and bottlenose dolphins by simultaneously employing a hydrophone array and static PODs; this will allow us not only to localise and track individual animals through the water column but also to calculate detection ranges for C-PODs.

With calm seas forecast for Monday, there was no time to lose and it was all hands on deck from the very start; on their arrival Winnie, Marta and Katrin, the three research assistants, were swiftly roped in to assist Hanna, the project coordinator, and Luke, the skipper, to prepare the moorings and buoys for the PODS, measuring, knotting, marking and coiling lengths upon lengths of rope. The boat, Islander, also needed some finishing touches to prepare it for it's duty as a research vessel and with the help of Luke, Winnie and it's owners, Hanna and Brett, the seats usually reserved for paying passengers were removed to make space for PODs and other acoustic equipment. In the late evening, Kati, Felix and Jens arrived in New Quay at 10 PM after an arduous two day journey from Germany, joining the rest of the team- just in time for an enormous portion of Chilli!
We were off to an early start on Monday, setting out at 4 AM to deploy 5 pairs of vertical C-PODS, each comprised of one surface and one bottom POD, for a project run by Nik Tregenza, who has agreed to share his data with us. With the moon still high in the sky, we carried the equipment down to the beach which was when we realised that the boat would most likely ground if we drove it onto the beach and loaded it with the weights for the moorings. Not deterred by this unforeseen complication, Kati and Hanna bravely donned their dry suits, while Luke and Winnie brought the boat closer to the beach and the rest of us waded out in wellingtons to pass the weights and other equipment to them so that they could pass it up into the boat.
4am at the harbour, ready to load up the equipment for a days work of deploying C-PODS and T-PODS


Running only slightly behind schedule, we loaded the remaining equipment -and the deployment team consisting of Hanna, Nik Treganza, Luke, Winnie and Katrin- at New Quay pier at about 6 AM and headed out into the bay. The extensive knotting practice from the previous day paid off as stopper knot after stopper knot joined buoys to moorings and moorings to PODs, allowing us to deploy the PODs quickly at their allocated spots under the careful guidance of our experienced team leaders, Luke and Hanna. We were even joined by a pod of dolphins that stayed with us for most of the morning, hopefully providing the first set of recordings! 
Out on the water, Ready to deploy C-PODS

We returned to New Quay in time for an early lunch and a well deserved rest. As the weather was set to turn the following day, however, Hanna and Luke only got a brief respite before heading back down to the harbour with Jens, Felix and Kati to deploy another 6 pairs of horizontal T-/C-PODs, both PODs suspended 2m above the seabed and at least 5m apart, which took the best part of the afternoon and the early evening.

Deploying T-PODS and C-PODs
 
The deployment of 22 PODs in a day was considered a great start to the project by everyone involved and we decided that we had earned the right to celebrate- by having a very early night.


Tuesday the predicted gale force winds hit New Quay. Confined to dry land, we built the array on land for the first time on Tuesday and realised just how big it was (7m long and 6m wide) and set about discussing the best methods of attaching it to the Islander, an 8m aluminium boat- preferably without causing lasting damage to either boat or equipment. This required a lot of quick thinking, in the truest sense of the word, as it was only feasible to attempt attachment when the boat was fully out of the water, which is only for about 2 hours every day during low tide. After initial frustration and with the tide lapping at our heels, we decided to reconvene the next day and trial a decidedly low tech solution to attach the high tech equipment securely to the boat: ratchet straps.  
Building the hydrophone array to be mounted on 'Islander'


The afternoon provided a real taste of the infamous British weather, sunshine interspersed generously with heavy showers. Jens, Kati and Felix made the best out of a bad situation by staying in the house and setting up the acoustic and GPS equipment so that once the weather turns in our favour, we will be ready to head out on the boat. Meanwhile, Winnie, Marta and Katrin were preparing for their role as cliff observations team. Together with Gemma, another research assistant, they will be responsible for tracking cetaceans near the PODs and the research vessel using a theodolite and keeping the boat team updated of animal positions at all times. Armed with copious amounts of rain gear- and a giant pair of garden shears- Marta, Winnie and Katrin used the afternoon to familiarise themselves with the observation site. Located on the picturesque Ceredigion coastal path, a steep 5 minute climb from New Quay, the site is nestled in between ruins of the old coast guard look out and a large amount of gorse bushes conveniently overlooking the grid of PODs.

The howling winds woke us up several times Tuesday night and by Wednesday morning we were all fairly sure there was no way we were getting out on the water. Instead, Felix spent most of the morning training the cliff observations team, Gemma, Winnie, Marta and Katrin, in the correct set up of the theodolite, or 'total station' while Kati and Jens continued to work on setting up the acoustic equipment in the dining room.
Getting a lesson from Felix in the use of Theodolites
In the afternoon, most other things came to a stop as most of the team made their way back down to the beach to try to attach the array to the boat again. With the help of several styrofoam blocks and a good amount of ratchet straps, we eventually arrived at a satisfactory solution that would allow us to safely attach the equipment, minimise movement of the gear and safeguard the boat as well. Now that we had managed to attach the array, we had time to tackle another problem, keeping expensive electronic equipment safe and dry on a small boat. The answer was simple; the Culticave. A small, fully, collapsable greenhouse which fits neatly on the deck of the Islander, keeps the rain out, the heat in and is also fully see through, making it slightly less of an obstacle for Luke to navigate!

The 'CultiCave'
 
The afternoon was spent tracking a variety of objects from the front garden (starting with drainpipes, before graduating to cows) - involuntarily also trialling their full outdoor gear in the strong Northerly winds- while the acoustic team was also hard at work fine tuning their equipment.