Posted by: Alison Cawood | August 6, 2009

SEAPLEX Day 5 Part 1

Today’s first post is from Josh Jones, who works in the Scripps Whale Acoustics Laboratory.

Josh writes:

8/5/09
32°13.461´N
129°01.780´W
Heading: 269.7 T
Speed: 9.42 N

Hello readers. My name is Josh Jones and I am the marine mammal observer on board the New Horizon during the SEAPLEX cruise.  I work in the Whale Acoustics Laboratory at Scripps and I’ve been following whales around one part of the ocean or another for the past 14 years.  On board the New Horizon, it’s my job to use all available means to find, identify, and record any whales and dolphins that we encounter along the way during this expedition. The goal is to give an idea of what species of marine mammals might be utilizing the area of the Pacific where the science team will be studying the plastics that have collected on the surface. I’ll be using two methods to accomplish this: one very old and a new one that uses state of the art technology and some cool equipment. While we’re out here I’ll be writing three short pieces in order to keep you updated on what whales we’re finding and how we’re finding them. I’ll also share a few sea stories on aspects of the expedition that stand out for me personally.

Whales live their lives mostly underwater. Seems like an obvious statement, but this fact becomes significant if you want to find them and to learn about how they live their lives. Up until 20 years ago, the primary way that people who study whales or who just want to go out and see them could find whales at sea was to go out and look for them breathing at the surface. Think of old-time whalers and the cry of “Thar she blows!” We still rely on this as an important method of identifying whales and observing their behavior. Often, a sighting is determined through faint evidence like a splash in the far distance, a sparkle of sunlight off its back, or a cloud-like blow hovering above the animal after it exhales and takes another breath.

Today, we and many other scientists also use a technology that allows us to extend our senses below the surface of the water and much farther away from the boat than we can see with our eyes. We use underwater microphones, or hydrophones, to listen to the sounds that whales make when we can’t see them at the surface. During this cruise, I’ll be towing several of these hydrophones behind the boat on a 300-meter-long cable. The whole thing is called an acoustic array and it’s my specialty. This system will allow me and the others on board to hear what’s going on in the ocean around us and, hopefully, to detect and record the sounds that whales within hearing range are making as we pass by. I also use several computer programs written by my friend Doug Gillespie for the International Fund for Animal Welfare to help with the detection and identification of the sounds, even to tell what direction the sounds are coming from. More about this later, but I can tell you that it’s like the coolest video game ever.

It’s about 7 a.m. right now. The sun has just come up above the horizon and I’ll be putting the array into the water soon to start the day’s search. Who knows what we’ll find? For me, the fun is in the searching. This trip’s is exploratory in every sense. I’ll look forward to reporting back to you next week with more on what we’ve seen and heard.

So long for now,
Josh

cruise-track-Aug 2-5

The SEAPLEX voyage on the research vessel New Horizon makes its way across the Pacific Ocean.

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Responses

  1. On the same day that I read about your expedition in the SD Union, there was also an article about Blue Whales being closer to the coast of San Diego this year. Do you think there is a correlation between this and the gyre? Since the diet is krill, are they encountering more plastic mixed with the krill, the further out to sea they are? Is this something you’re investigating? We’re curious in the science class! Mrs. AB

    • These things probably aren’t connected. As blue whales need a huge amount of food, they tend to focus on large swarms of krill. In general, these swarms are associated with productive areas of the ocean. The gyre is characterized by very low productivity. The krill are more likely moving because of some change in weather patterns and/or water temperatures than plastics.

      • Thanks for the responses. My students will be checking the blog this weekend, and should be posting some questions that they came up with in class! Interesting stuff!

  2. Thanks for the post Josh. Very interesting. We’ll be anxious to hear what you are hearing and seeing! Amazing that you can hear anything over the roar of your engines! Good luck! Rob

    • That is why there such a long array! There are 300 meters of cable which allow the hydrophones to be pretty far from the ship’s engines.

      • Incredibly enough, the array still picked up the engines but most of the time, I think Josh was able to work around it.

      • Your answer shows real intleligecne.

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  3. […] Titmus (left) and Josh Jones work together to locate dolphins detected by an acoustical array in the […]

  4. Josh,
    I enjoyed reading your description of your job during the expedition. I look forward to reading about your findings. I hesitate to ask this but do marine mammals sleep at night – and if not, will you be doing any sampling with the array during some nights?

    • For most whales and dolphins, it is believed that one hemisphere of their brains sleeps at a time because they have to be at least partially conscience in order to come to the surface to breathe. However, we can’t see very well at night, so that makes is less effective to do the marine mammal work. A big part of Josh’s work is to try to associate the sounds the whales make with the whales themselves. Scientists are still learning which sounds are associated with which species, so we need to be able to look for whales when we hear a sound.


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