Welcome to the 2016 PODS Blog page! NOAA Fisheries scientists will be conducting a survey for 20 days aboard the NOAA ship Bell M. Shimada to help us understand where endangered Southen Resident killer whales go during the winter months, as well as to better understand their ecosystem. Follow us as we share interesting news and photos from our survey!
February 22, 2016
We all survived our first night at sea, very rough waters all through the night. On the hydrophones the acousticians heard lots of unidentifiable dolphins, most likely Pacific white sided dolphins and a faint sperm whale echolocating. During daylight hours, everyone was working overtime to spot either blows or to see dorsal fins of killer whales. Our crew on the bridge, observers on the flying bridge, and folks listing for clicks and calls in the acoustics lab were all maximizing their time and effort. My hat goes off to our acoustics staff who work 24 hours a day to track the locations of the whales. If they detect animals, they want to maximize as much information as they can from them. For instance, are the sounds echolocation clicks, calls, or whistles? Can they give us clues to which pods we are listening to? However, our oceans are never quiet. We hear our engines, other boats, echo sounders and a variety of other noises. Specifically, we are looking for pulsed calls, echolocation clicks and more importantly foraging clicks or click trains, and whistles. If we hear any of these, we immediately communicate with the bridge to possible change course, plus let the observers with high power binoculars know to keep their eyes out for the whales. Since our hydrophone array has multiple hydrophones and amps, if a whale calls that sound arrives at each of those hydrophones slightly at different times. We then have three programs inside our acoustics lab that computes the angles and detect if the signals are coming from which side of the array, hence localizing the sound. Ideally, of course. There are times when we know where a signal is coming from, we use a three different software programs to be able to localize those calls, but sometimes we can’t decipher if it is on the right or left side of the array. In those cases, we ask the captain to turn 30 degree and try to localize again. This often tells us which side of the boat to relay up to the bridge and our observers up on the fly bridge. Our lab is utilizing probably 7 computers at all times. We are recording, plotting, taking screen shots of good calls, and time stamping every encounter plus taking the latitude and longitude as well. Not only that we are constantly checking to see if the files are recording, batteries are charged, connections are still working, etc. Shout to all of these scientists who make it look so easy!