NOAA Teacher at Sea
Aboard NOAA Ship Bell M. Shimada
August 11 – 26, 2017
Mission: Summer Hake Survey Leg IV
Geographic Area of Cruise: Pacific Ocean from Newport, OR to Port Angeles, WA
Latitude: 48.19 N
Longitude: 125.29 W
Wind Speed: 7.9 knots
Barometric Pressure: 1021.70 mBars
Air Temperature: 55.4 F
Weather Observations: Foggy
Science and Technology Log:
I am learning an unbelievable amount about marine biology! Today I will focus on hake because that is the main type of fish we are surveying on this voyage. Pacific hake are found in great abundance out here off the west coast of North America and Canada. Let me tell you a little bit about what we do.
The first thing we have to do before trawling for hake is find a good aggregation of them based on our acoustics. There is always a scientist in the acoustics lab watching the monitor outputs. The monitors show the acoustics from different frequencies: 18, 38, and 120 KHz. They can “see” when there are things between us and the ocean floor (see picture below). Based on the response of the acoustics to the objects in the water, the scientists make an educated guess about when we are over a hake aggregation. I’ve been learning a lot about how to read these monitors and how to see if we’re over rockfish, phytoplankton, or hake. I think it would be pretty cool to see something giant like a whale go underneath us, but that hasn’t happened. That’s probably for the best – I can’t imagine it’s super safe to have a whale under your ship.
Once the acoustic scientists decide we’re over hake, they radio up to the bridge to tell them it’s time to go fishing. The fishermen start getting the nets ready, and the scientists (that’s me!) go up for marine mammal watch. We have to make sure there aren’t any whales or dolphins nearby that might get caught in our nets. I really like marine mammal watch. I get super excited to see whales and dolphins, even though I guess that’s kind of bad because we might have to postpone our trawl. Seeing mammals when we’re not fishing is the most exciting. Today we saw two orcas by the side of our boat – now THAT is cool!
Once the net is fully deployed and well below the surface, the marine mammal watch ends. Then they fish through the sign they saw on the acoustics and bring the net up when they believe they caught an adequate sample. Then it’s time to process the trawl! What we want to see is a majority of hake, but that doesn’t always happen. We’ve had trawls with hundreds of hake, and we’ve had trawls with only seventeen. We sometimes catch a bunch of other stuff too, and we do different things with those creatures (I’ll save that for a different post).
Processing the trawl is pretty intensive. First we have to weigh all of them to get the mass of the entire trawl. Then we sex them to sort into male and female baskets. It’s tricky to tell the difference between males and females. We have to dissect them and find the gonads to be able to tell. Near as I can tell, the male gonads look like ramen noodles and the females look like peach jello. I think of it as, “I wonder what my husband is eating while I’m gone? Probably ramen noodles. Okay, ramen noodles means male.”
Once we have them all sorted, we take length measurements and start extracting the parts we need. The scientists are collecting and preserving the otoliths, gonads, stomachs, livers, and fin clips. We have a LOT of tubes of fish guts in our lab. I’m not entirely sure what scientists will be doing with all of this data, but perhaps I’ll interview our chief scientist about this and put it in a future post.
Everyone I’ve met on this ship has been so friendly! One of my favorite things about it is that these people seem so passionate about whatever they’re doing. You should have seen my friend Hilarie’s face today when we pulled up a trawl full of pyrosomes (that’s what she studies). Tracie showed me some of the phytoplankton she’s studying, and it was like she was a little kid at Christmas. Personally I’ve never been super interested in phytoplankton, but now I am. She makes it sound like it’s the most exciting subject on earth, and looking at her slides makes me believe her.
It’s not only the scientists who are passionate about their work. The chief steward, Larry, was so excited about his cauliflower soup today that he seemed personally offended when I didn’t take any. “Take some soup!” he said. “Seriously – it’s really good soup. You’re going to like it.” I took some just to be nice, but after one bite I said, “Larry, will this be out at dinner? Can this please be out at dinner? I LOVE IT.” It was seriously good. I need to learn how to make that.
Our chief scientist takes her job as chief very seriously too. She’s like the momma duck who takes care of all of us (thanks, Julia!). Also, she plans fun and goofy games every day where we can win prizes out of her “bag of goodies.” I haven’t won yet, but I hope I will before this is over. Today Hilarie won some awesome coral reef socks. I’m not sure how I’ve gotten this far in life without owning marine biology socks! It’s great to have Julia around because she makes time for all of us even though her own research is very absorbing and important. She’s a rock star.
Stay tuned for more info from Leg 4 – bye for now!