NOAA Teacher at Sea
Kate Schafer
Aboard NOAA Ship Oregon II
September 17 – 30, 2017
Mission: Shark/Red Snapper Longline Survey
Geographic Area of Cruise: Gulf of Mexico
Date: September 21, 2017
Weather Data from the Bridge:
Latitude: 27o 15.5’ N
Longitude: 97o 01.3’ W
Haze
Visibility 6 nautical miles
Wind SE 15 knots
Sea wave height 3-4 feet
Sea Temperature: 29.6o Celsius
Note: Just a month ago Hurricane Harvey was bringing 20 foot seas to this area, but today we’re enjoying the 3-4 foot swell.
Science and Technology Log:
Well, we’ve gotten to the fishing grounds, and we’ve gone from waiting to very busy! We put out the first lines starting at around 8 pm on Tuesday evening. The process involves first baiting 100 hooks with Atlantic mackerel. When it’s time for the line to be deployed, first there is a tall buoy with a light and radar beacon (called a high flyer) on it that gets set into the water, attached to the monofilament fishing line. Then there’s a weight, so the line sinks to the bottom, a series of 50 baited hooks then get clipped onto the line as the monofilament is being fed out.
Those 50 hooks are referred to as a “skate”. This confused me last night when I was logging our progress on the computer. I kept thinking that there was going to be some kind of flat, triangular shaped object clipped on to help the line move through the water…not really sure what I was imagining. Anyway, Lisa Jones, the field party chief and fisheries biologist extraordinaire, has so kindly humored all my questions and explained that skate is just a term for some set unit of baited hooks. In this case, the unit is 50, and we’ll be deploying two skates each time.
After the first skate comes another weight, the second skate, another weight and then the last high flyer. Then the line is set loose and we wait. It’s easy to locate the line again, even at night, because of the radar beacons on the high flyers.
Why are we collecting this data?
As mentioned in my previous post, one of the tasks of NOAA, especially the National Marine Fisheries Service Line Office, is to collect data that will help with effective fisheries management and assist with setting things like catch quotas and so forth. A catch quota refers to the amount of a particular species that can be harvested in a particular year. Fisheries management is incredibly complicated, but the basic idea is that you don’t want to use up the resource faster than it is replenishing itself. In order to know if you are succeeding in this regard, you must go out and take a look at how things are going. Therefore, the Oregon II goes out each year in the fall and samples roughly 200 sites over about eight weeks. The precise locations of the sampling sites change each year but are spread out along the SE Atlantic Coast and throughout the U.S. waters in the Gulf of Mexico.
We’ve put out three long lines so far. Last night, we caught a single fish, but it was a really cool one. It’s called the Golden Tilefish but has an even better species name: Lopholatilus chamealeonticeps. As Lisa was explaining that they dig burrows in the sea floor, I realized that I had seen their cousins while snorkeling around coral reefs but would never have made the connection that they were related. This guy was big!
This afternoon, things got really hectic. Of our 100 hooks, 67 had a fish on it, and 60 of those were sharks. As we were pulling in the last bit of line, we pull on a shark that was missing its back half! Another had a bite taken out of it. And then on hook number 100, was a bull shark. This shark had been snacking along the line and got caught in the process.
And I haven’t even mentioned the red snappers. I will save them for another post, but they are absolutely beautiful creatures.
Personal Log:
I definitely continue to feel out of my element at times, especially as we were pulling in all these hooks with sharks on them, and I could barely keep up with my little job of tracking when a fish came on the boat. All the sharks started running together in my mind, and it was definitely a bit stressful. Overall, I feel like I’ve adjusted to the cadence of the boat rocking and have been sleeping a lot more soundly. I continue to marvel at how amazing it is that we’re relatively close to shore but, except for a few songbirds desperate for a rest, there is no evidence of land that my untrained eyes can detect. Lastly, I’ve realized that a 12-hour sampling shift is long. I have a lot of respect for the scientists and crew that do this for months on end each year with just a few days break every now and then. Well, it time to pull in another line. Next time, we’ll talk snapper.
Do you release all the catch?
We release the sharks. The snappers are kept so their otoliths (ear bones) and gonads can be collected. These are used to age the fish and to assess their reproductive status. These are both important to know about the population when setting harvesting regulations and are used in lots of research by NOAA scientists and others.
Such beautiful animals, Kate! Amazing photos, considering your simultaneous “little job of tracking…fish.” And I’m off to look up the origins of “skate.” : )
Yes, it has been challenging finding a moment to snap a quick shot or two. I’ve seen so many things that I’ve just captured in my mind.
We release the sharks. The snappers are kept so their otoliths (ear bones) and gonads can be collected. These are used to age the fish and to assess their reproductive status. These are both important to know about the population when setting harvesting regulations and are used in lots of research by NOAA scientists and others.