Tuesday, September 21, 2010

It's Getting Serious

The weather turned from sunny and calm to windy and wet once the vollies started arriving over the weekend (not sure if the two phenomena are correlated). They’re probably wondering why this stretch of coastline is called Sunshine Beach. I’ve had a few very fun surf sessions with the staff at the river mouth in Noosa, but lately the lack of swell and increased winds have effectively killed any decent waves that may have been trying to reach the beach. So of course my attention has now shifted to birding since there’s no surf to think about. While doing some bino (binocular) 101 training up on the balcony of base station, I spotted a few Scaly-breasted Lorikeets (all green with yellow scales and a bright red bill). Apparently they’re seen all over eastern Australia, but I’ve had little evidence of it until yesterday.


As mentioned in the title, things are starting to get pretty serious around here. We are scheduled to start collecting real data next Thursday I believe, so we need to work out all of the kinks and get everyone trained and on the same page before then. I haven’t been too involved with the training, partly because the Straddie people have already learned most of the skills required, and mainly because the techy (Trevor) has requested help constructing the buoys that will support the hydrophones for the acoustic monitoring. Zeus, Drew, and I have been duct tapping, zip tying, and gluing bits and pieces to the PVC piping that will house all the necessary electronics and batters for the hydrophones.

The study is very complicated, and has never been attempted before in such a large scale. Here’s what will be happening in a condensed version, I just realized that it won’t make much since without illustrations so I won’t go into much detail. There will be 8 main platforms for data collection. Three land based stations for tracking whales visually; either from compass and reticule binoculars or with the theodolite (basically what we did in Straddie). These observations will then be plotted in the Cyclopes software developed by Uncle Eric. We will need to plot all whale sightings in the study sight, along with every behavior of a focal follow pod (A pod that has been tagged).

To compliment the visual obs, there will also be 2 acoustic platforms; one to record the social sounds and song of humpbacks, and the other to use simple geometry to acoustically determine the location of the sound source(based on the varying arrival times of the sound to each hydrophone in the array). The sounds will be streaming back to base station in real time via a radio transmitter from 5 hydrophones moored a few hundred meters off the beach in a “T” formation. This will allow us to actually see the position of a singing whale, and watch how it changes in real time. We can also layer on top of this the visual observations from the 3 land based platforms. The acoustic tracking allows us to follow the whale’s position when it’s not available at the surface for visual obs.

The last 3 are vessel platforms. Two of the vessels will be attempting and hopefully succeeding in placing suction cup tags on the backs of humpbacks, to track their fine scale movements through the study site. This is most likely where I’ll be spending most of my time. They are called D-tags, and can record the pitch, roll, depth, water temp, and GPS position; along with recording any sounds the whale is making. The data is stored in an internal hard drive, so the tag has to be retrieved in order to upload the data. The tag is programmed to pop off after a certain period and broadcast its position again using a radio transmitter. The other vessel will be towing an air gun (a canister with highly compressed air, when the air is released it makes a loud sound). They are basically a high powered echo sounder used to explore for oil reserves under the seafloor. We will only be using 1, while the industry uses up to 70 I think. There’s more to it than this, but it is just too much to explain.

When it all said and done, they hope to learn how humpbacks respond to the sounds of air guns (based on all of the tracking and playback data), in order to make better policy recommendations for how seismic activity should be managed around whales.

In other news: Dave has given me the option to start work in Western Australia after this project, on an offshore island called Barrow. I would be stationed on dredging ships this time instead of a coal trestle, and will live on the boats for 4 weeks at a time, with a 4 week break in between. I was planning on flying over to NZ for the Hector’s Dolphin study (by the way mom the dolphin was named after some dude named Hector apparently, they’re just a small dolphin species), but the opportunity to make money for school is just too tempting. I may be able to fit in the study during my time off from MMOing, and there will most definitely be more studies coming online. I still want to do some work with seabirds instead of these bloody whales.

I’ve posted of photo of the hydrophone buoys. You can see the radio antennas and the flasher to alert vessels of their position at night. The rest of the equipment is all internal (for obvious reasons). The hydrophone however will be suspended in the water column, the sounds are sent through a long cable from the hydrophone to the buoy, then from the buoy to base.

2 comments:

  1. This study sounds REALLY friggin cool, I am pretty jealous, although Daniela and I are starting some exciting new work that I will tell you about later.
    The dredging thing sounds like it could be interesting, at minimum a change in scenery from the east...you are very lucky to have all these opportunities coming your way, I really hope you take advantage of them all and don't feel like you have to rush to start grad school. Maybe we could do the Hector's internship together next year after all? (submitted everything yesterday but I'm sure I'll get it)

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  2. The study sounds complicated, but interesting! Hope everything works out as planned. Thanks for clarifying the Hector dolphin study (hah!)

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