​The data we collected at Ogden Point were quite good and we captured fish on both the hydrophones and the video cameras. As expected, the vessel noise was quite important though. So now we are ready to move on to a new location with different fish species and hopefully less noise.

In my list of potential good places to deploy the XAV array was the wreck of the Lord Jim near Mill Bay. The Lord Jim was an old tugboat that sank accidentally many years ago while on anchor. The wreck of the boat is still there and acts as a nice artificial reef. It is supposedly a nice diving spot with lots of fish. It is also in an area with much less boat traffic than Ogden Point.

Before deploying the array and mobilizing all the diving team, I wanted to make sure that it was a good location. So, I went to check it out with my small inflatable boat and the Trident underwater drone. I was not alone this time. Jean-Baptiste, my brother in law, and Helene, his girlfriend, were visiting us from France, so I took them with me to give them a little taste of beautiful British Columbia. The place was absolutely gorgeous and we found many different species of fish including pile perch, stripped perch, yellowtail rockfish, brown rockfish, copper rockfish and spiny dogfish (i.e. little sharks). Definitely a good spot to deploy the XAV array!

Once upon a time while deploying instruments at Ogden Point:

• Brian: "Hey Xav, did you give a name to your hydrophone and camera array ?"
• Me (Xavier): "No, I have not really thought about it, but Morgan said we should call it the Xav array."

 
(laughs)

• Brian: "Well, you know, the A and the V could stand for Audio/Video. Not sure about the X though..."
• Me: "Hum.. that is kind of cool."
• Stan: "What about eXperimental for the X ?"
• Everyone: "Uhhh nice!"

​
That's it, we now have a name! It is now the eXperimental Audio Video array, aka the XAV array ;-)

Team work!

Given the success of the exploratory dive at Ogden Point, it was clear that if was a great spot to deploy the audio and video array. There are many different fish in the area and it is also easily accessible. The only issue with this location is the intense boat traffic. It is close to the cruise ships terminal and is on the main channel leading to the Victoria inner harbor. This is not an issue for the deployment operations and the instrumentation per se, but mostly for the elevated the noise from the boat traffic that could mask the fish sounds we are interested in. Nevertheless, it looked like a great location to get started and a great way to get all of us more comfortable with the deployment/recovery operations and gain confidence with the equipment.

So, we deployed twice off the breakwater at Ogden Point. Once in May and once in June. Both deployments lasted for 10 days. The first deployment had only one camera at the top of the array, while for the second deployment I had built a second camera and placed it on the side of the array to get an additional angle of view and thus facilitate the fish identification.

Despite some windstorms, the array held up very well in place. As the array was deployed close to the breakwater, it was easy for me to go check that everything was fine from land with the Trident (and I did that often…very often). I am happy to report that all instruments worked correctly and that we recorded many fish swimming through the array with the video cameras. Despite being a very noisy environment, we were able to capture fish sounds on the hydrophones and localize them in 3D.

I can’t tell you how much of a relief it is… FINALLY! I am finally collecting the data I was hoping to get many months ago! It took a long time, but it is finally happening. This very encouraging and now we are already planning to deploy the array at other places around Vancouver Island. Hopefully somewhere quieter.

Ogden Point deployments team:

• Skippers: Nick Bohlender, Morgan Black, Jesse Macleod.
• Divers: Kieran Cox, Morgan Black, Brian Timmer, Desiree Bulger, Sean Dimoff, Kristina Tietjen, Niallan O'Brien.
• Dive tenders: Hailey Davies, Garth Covernton.