From May 26 to June 2nd I was aboard the NOAA research vessel the Reuben Lasker to help out with NOAA’s Pre-Recruit survey to help with federal fishery research and to collect samples for my own research. Below is a description of the cruise and a daily log of my time on the cruise)

The Pre-Recruit Survey is part of the National Marine Fisheries Service’s (NMFS) effort to improve stock assessment estimates of rockfish recruitment. Let’s see if I can break this down. Federal fisheries scientists (who work for NMFS) are tasked with tracking commercially harvested fish stocks and determining the appropriate amount that fisherman should catch in a given year to ensure the population persists and produces fish in future years. To give fisherman an accurate number, NMFS scientists need to be able to predict how their specific fish populations will change in size from year to year. Most commercially harvested fishes produce prodigious numbers of young every year, with relatively few surviving to adulthood.

• I’ll define recruits as fish that survive to adulthood
• I’ll define recruitment as the total number of fish that survive to adulthood from a cohort born in a given year.

Recruitment can be high or low for a given year depending on survival of the early life stages. The Pre-Recruit Survey collects Pre-Recruit rockfishes (a.k.a. young rockfishes that haven’t reached adulthood, but have passed through most of the gauntlet of high mortality associated with the larval stages) so stock assessment scientists can try to get a sneak preview of what recruitment in a given year will look like. Otherwise, stock assessment scientists have to wait several years for these fish to mature to adulthood and then be caught by fishermen (or fishery independent fish surveys) to know how many survived (isn’t it weird that fish have to be caught for scientists to know that they lived? Some groups are working on using remotely operated vehicles and other camera systems to get non-destructive estimates of fish abundance).

I am on this cruise to help sort fishes and will be using juvenile rockfishes collected in the cruise as part of my PhD research. My work aims to give us a better understanding of how environmental conditions (water temperature, food availability, and patterns of water movement) affect survival of the young life stages of rockfish.

Sea-date 1 :

Today I boarded the NOAA Research Vessel Reuben Lasker. To get to the ship was quite a trip. I drove from Newport, OR to Eureka, CA where I met up with another NOAA scientist, Paul Chittaro, who was going on the cruise. Paul and I have been on several research cruises together and are pumped for this cruise.

To get to the ship, we had to get picked up at the docks of the Eureka Harbor on a small skiff and cruise out to meet the Lasker. Every other time I’ve been on a research cruise, I’ve met the vessel at the dock, but this year to save time (it takes a full day to bring a large vessel into a port to load and offload passengers) the ship’s commanding officer decided to do an at sea transfer.
The weather and sea conditions were pretty exciting. The waves crossing the bar at the mouth of the harbor were a good 6-10 feet tall and outside the harbor the seas had been whipped up by some storm winds creating crisscrossing swells.

Approaching the RV Lasker from their transfer skiff. Photo: Will Fennie

This made an already exciting boat ride almost too exciting when we got picked up by the Lasker. The Lasker has a device much like a claw that slides down the side of the ship to pick up its skiff. Our boat driver had to maneuver the skiff alongside the Lasker and hold it in position, in choppy seas, so the ship’s claw could grab the skiff and pull it onboard. I am having trouble describing how weird it felt to be in a boat, lifted out of the water, and land on a larger ship, but anyway I’m on board and ready to start catching fishes.

Unfortunately the weather off Eureka wasn’t conducive to sampling, so the chief scientist decided to steam up to Newport Oregon where the weather was better. My first day aboard consisted of eating, and trying to adjust my sleep schedule over to the night shift. Juvenile fishes spend the daytime in deep water and come closer to the surface at night to feed. It is much easier to collect juvenile fish at nighttime because they are concentrated near layers of zooplankton (tiny planktonic animals) that they feed on, so all my work occurs from 9pm to 6am. “Adjusting” my sleep schedule to get used to the night shift really means that I spent most of the first day trying to sleep in my bunk and battling nausea.

Sea-date 2:

Bucket o’ pyrosomes. We had to rinse the pyrosomes in seawater to clean off any fish or other important organisms from the pyrosomes to figure out what else was in the water. Photo: Will Fennie

We arrived on station just south of Newport this afternoon and began our first night of sampling. Our sampling plan is to run transects of midwater trawls at specific location along Oregon’s coast. We starting sampling our shallow depth/nearshore stations at the beginning of the night, and move offshore to
deeper water as the night progresses. The idea is to get a long-term view of fish communities and see how they vary with distance from shore (bottom depth) and latitude. We use a mid-water trawl to get density estimates of fish and other organisms.
There is pretty high variability in the abundance and composition of our catches from year to year, but this year is pretty weird. Normally we catch lots of juvenile rockfishes (yellowtail, widow, shortbelly,

Sorting fish and krill from the pyrosomes. Looks like we caught some myctophids (lantern fish) and a king of the salmon (the long, skinny, red and silvery fish in the bottom right).

canary, dark blotched, bocaccio, blue, and black rockfishes), Pacific hake, several species of lantern fish, quite a few species of larval flat fishes, and some adult anchovy.
Tonight we mainly caught gelatinous zooplankton and in particular colonial tunicates called pyrosomes. Pyrosomes are typically found in more tropical waters, but with the warm blob in 2015 and the el Niño of 2016, waters off Oregon have been unusually warm and many tropical species are showing up far north or their normal ranges. While pyrosomes are pretty cool to see in the water, they are bioluminescent, they are a real bummer to sort through and have almost broken are net!

Sea-date 3:

We sampled off of the Columbia River mouth tonight. This is an interesting place because there is a huge source of freshwater that dramatically affects the oceanographic conditions for hundreds of miles. Freshwater is much less dense than salt water, so it sits on top of it (think oil and water, but less dense water and denser water…). As the Columbia River empties into the Pacific Ocean it punches through the surrounding saltwater creating a wedge in the ocean. Oceanic water moving towards shore smashes into this freshwater wedge and sinks beneath it (like a tectonic subduction zone). This concentrates plankton at the interface between these two types of water, which attracts zooplankton, then juvenile fishes, then larger fishes and birds, then marine mammals and so on. The marine mammal and bird observer on the ship said he saw more birds in that area than he has seen almost anywhere else (this observer has been on research cruises for 30+ years all around the globe).

This is Paul who is pumped for our huge catch of pyrosomes. We lost a little enthusiasm when we learned that this catch had ripped the net. (Photo: Will Fennie)

Last year we caught hundreds of rockfishes along this transect, so I was very excited to see what we caught this year. Unfortunately for me, our nearshore station was dominated by adult anchovies, many of which were pregnant females, and there were very few rockfishes. Our second station was so full of pyrosomes that it ripped the net (see attached image of our net almost bursting with pyrosomes). We cancelled our furthest offshore station because we were afraid that we wouldn’t get any fish and needed time to repair the net.

Sea-date 4

Tonight we sampled off the Tillamook line. We had decent rockfish catches here last year, but like the Columbia River line, pyrosomes dominated this year’s catch. I am starting to get sick of wading through buckets of those things. However, we did collect several rockfishes. I wasn’t quick enough to take a picture of them, but we caught a couple of species: yellowtail rockfish (S. flavidus), shortbelly (Sebastes jordani), bocaccio (S. paucispinis), canary (S. pinniger), and widow rockfish (S. entomelas). At least this cruise is starting to live up to its name (Rockfish Pre-Recruit Survey)!

Sea-date 5

Tonight was our last night of fishing. We managed to catch quite a few rockfishes! We didn’t collect nearly as many as I was hoping, but certainly better than catching zero. I also saw a salmon shark while we were collecting larval fishes (click the link to
view, sorry it isn’t the best quality video!): https://media.oregonstate.edu/media/t/0_94ypdre8

While we didn’t catch as many rockfish as I hoped for, we still
found some, and it made the cruise worthwhile. I am looking forward to planning the next steps in my research which involve free diving and SCUBA diving to collect juvenile rockfishes that have moved from their offshore life stage (the one being sampled in this cruise) to their nearshore benthic stage where they grow up to become the adults that everyone loves to fish for.