Tag Archives: Porpoise

No excitement November?

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Greetings extensive readership!

In the midst of the summer and early fall when I was traveling a bunch and doing field work, I remember thinking how nice the term would be to be in one place for a while and get some analysis/other work done. What I didn’t realize was how unexciting my life would be for blog posts….

I guess excitement depends on your interests, though, because for me there have been SOME exciting moments standing in front of my computer. I’ve spent the last month putting my master’s on hold, instead analyzing acoustic data collected from one of our gliders that was deployed back in March, and then deploying and analyzing another glider all within the month of October. Want to see what I found? Good. I was going to put in the images anyway.

Here's a Stejneger's beaked whale click.
Here’s a Stejneger’s beaked whale click. The top image is a long term spectrogram, or LTSA, that shows 15 minutes. All the little bits around 50 kHz are beaked whale clicks. The middle spectrogram just shows one click during a fraction of a second, and the bottom shows the wave form, or the amplitude of the click.

From the March deployment, the excitement came in the form of TONS of beaked whales. Like so many. Like all the time. Including the super weird looking Stejneger’s beaked whale (Mesoplodon stejnegeri). I can tell the species by what frequency the click is at, how much time there is between clicks (inter click interval, aka ICI fyi), and the duration of the click. They are all unique features for this species of beaked whale, which I know thanks to other people confirming that by combining visual and acoustic data like was done by theses lovely folks at Scripps.

 

Here's two porpoise species detected together - Dall's porpoise and harbor porpoise
Here’s two porpoise species detected together – harbor porpoise (the two higher frequency red specs) and Dall’s porpoise (the middle, slightly lower frequency). All together a bunch of those clicks make up that light blue section in the LTSA on the top.

The March deployment also brought excitement through porpoise recordings! Did I mention that glider was the first of its kind to record ultra high frequencies? We used a 394 kHz sampling rate, which means we could detect vocalizations up to 196 kHz, which is where porpoise and a few other odontocetes (toothed whales) vocalize. Most equipment doesn’t sample that high (memory gets filled too fast) so this was pretty neat-o. I’m a big fan of looking for these ultra high frequency encounters because they are so obvious in the upper part of the LTSA, far above the background noise.

And like I mentioned, I did go out in the field one day. We deployed one of our new gliders for a few days just outside of Newport in early October, and I went out on the recovery. I took this one super exciting picture of these gulls on the back of the ship. You’re welcome.

Piper helped Holger and Alex prep Will the glider before he got deployed in early October.
Piper helped Holger and Alex prep Will the glider before he got deployed in early October.
These gulls agree with "no excitement November". Until I threw pistachio shells over the side. Sadly this is the only picture I took of the whole glider deployment.
These gulls agree with “no excitement November”. Until I threw pistachio shells over the side. Sadly this is the only picture I took of the whole glider recovery.

First Successful DMON Deployment!

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Last Thursday marked our labs first successful DMON (Digital Acoustic Monitor) deployment of the spring! The DMON is a passive acoustic instrument that is capable of recording and processing audio in real-time. Friday, May 16th, a single DMON was deployed off the coast of central Oregon to target the acoustic signatures and monitor the occurrence of several high frequency odontocetes (specifically porpoise and dolphin), for frequencies up to 150Khz. Although abundant in the coastal environment of the central Oregon coast, because of their skittish nature, little is known on the behavior of harbor porpoise. Passive acoustic monitoring is an ideal method for collecting information on their presence and vocalization behavior with little habitat disturbance. In light of the planned development for wave energy converter (WEC) testing at the south energy test site (SETS) as part of the Northwest National Marine Renewable Energy Center’s (NMREC) grid connected full scale facility off South Beach, OR, this project is focused on gathering baseline data on high frequency odontocetes using the area. With this information we plan to assess the impact of WEC testing activities as the SETS facility is brought on line.

Pretty Cool Stuff! Fortunately, I will be deploying and analyzing data all summer alongside with Joe Haxel, who is a Research Associate for the Cooperative Institute for Marine Resources Studies at Oregon State University and the NOAA /Pacific Marine Environmental Laboratory Acoustics Program.

IMG_0077 IMG_0079 Dmon device!  

While a full-depth analysis of last week’s data hasn’t yet been accomplished, I was able to take a quick peek and MAN IT LOOKS GOOD! Both harbor porpoise and killer whale vocalizations were identified – sound bites and spectrograms will be coming soon!

Finally, All of this wouldn’t be accomplished without our friendly Newport neighbors, Marine Discovery Tours, who offer narrated ocean and bay cruises with naturalist guides and have the finest accommodations for viewing whales and other sea life.

Memory storage capacity on the high frequency DMON mooring is limited by the high sample rate (~480 Khz) and we therefore record on a 10% duty cycle which simply means “deploy, leave for 7 days, recover, charge, and redeploy” schedule.

Without the help of Marine Discovery Tours, we would not be able to deploy and recover so frequently! So if you plan on taking a trip or a visit to the Oregon Coast, you might want check out what trips are available to see our beloved Oregon marine life, and you never know, if you’re lucky you might just book the trip with all the DMON action and see it first hand!

Some assistance from the Marine Discovery crew!

I’ll be back with a full update on what the ORCAA lab has discovered from our DMONS in August! In the meantime, make sure you follow ORCAALab on Twitter for updates!