08/19/2024 | News release | Distributed by Public on 08/19/2024 13:25
Where Science and Technology Meet
While I'm on the trawl team, I have been able to interact and ask lots of questions of the acousticians, and let me tell you, it's really amazing what they do! The ship is equipped with scientific echosounders that transmit sound pulses that reflect off objects in the water column, like fish, small invertebrates, and the seabed. During the day, we transit along predetermined acoustic transects oriented perpendicular to the coast to map echoes (or backscatter) produced by fish schools. We return to these areas at night to collect information about the species and size composition of fish that produced those echoes. The acousticians then direct the trawl team to sample in the locations of larger objects, which out here are typically schools of coastal pelagic species. Finally, catches from nighttime trawls are used to partition backscatter to the various species present. We repeat this each day and night as we proceed northward along the coast.
Each day, we analyze data using customized code to visualize preliminary results, correct errors, and optimize sampling. This allows data errors such as incorrect weight or length to be identified and fixed while still out at sea. Also, scientists ensure enough biological samples, such as otoliths, are collected across each species' size range. This saves time by preventing us from oversampling the more common size ranges and prioritizing the collection of others. I was blown away by the timeliness of the data analysis and how much work went into creating the code to drive the next day of sampling.
The methods for this survey are greatly different from the East Coast surveys I've been a part of, offering a great learning opportunity. This is mainly because of the different target species and geographic features. On the East Coast, I've primarily been involved in sampling benthic (bottom-dwelling) reef fish, which tend to aggregate just over rocky outcroppings on the ocean floor. Based on previous seafloor mapping, scientists predetermine sampling sites each year, allowing for greater planning of timing and locations of sites. On this expedition, all the fish we are targeting are pelagic fish that occur across open areas of the ocean while feeding. So the team ensures trawling occurs soon after the echosounders identify schools of fish for sampling to produce the most accurate and precise estimates of biomass, or weight.
Bingo Night
Spending weeks at sea and working hard to collect samples each day and night can be exhausting. Thankfully, the crew gets creative with ways to keep everyone's spirits up and increase team-building opportunities for those on board. Two weeks into the mission, the officers held a bingo night for everyone on the ship, and it quickly got competitive! Using customized bingo cards with science-related words, there were lots of laughs shared with all involved. Winners had their choice of candies, lab-related stickers, patches, and coins. One of the funniest parts was how long it took me and Ensign Miles Litzmann to finally win a round, which happened to occur on the same word. We were the last two to win out of 15 participants, and everyone was cheering us on once we won. It was a huge morale booster and appreciated by all participants.
Life at Sea for 3 Weeks
Three weeks is by far the longest I've stayed out at sea during a survey. I often participate in the Southeast Fishery Independent Survey expeditions, which are typically 10-12 days long. I can happily say that the NOAA Ship Reuben Laskerhas plenty of space and amenities to keep us comfortable, even in rougher seas (I'm fortunately not prone to seasickness).
I share my stateroom with another trawl biologist. It consists of a bunk, a desk, a pair of lockers, a fridge, and our own bathroom. In rougher seas, showers can be a bit tricky, but we can still get it done! The ship also has laundry facilities for us to use, a workout room (I get all the exercise just walking around in higher seas), and food and drinks available 24 hours a day (including an ice cream freezer!). Even on the night shift, I can request meals be saved for me to eat during my "lunch" break at around 1-2 a.m. The only meal I'm typically awake for is breakfast-and who doesn't like breakfast for dinner?!
One of the perks of working nights is the ability to watch the Olympics live during our work breaks, which has been one of our favorite things to do to pass the time. The Internet is stellar, too, with the recent addition of a dual advanced satellite internet system, enabling "normal" work to continue as needed (and blogs to be written!).The Reuben Laskeris the first in the Office of Marine and Aviation Operation's fleet to have this technology installed, and this summer is the first time we are using it. This allows us to send data (primarily acoustics) back to shore for quick processing.
The best part of living in close quarters is the chance to meet new people and get to know them. I'm amazed at the background of a lot of the folks, both scientists and crew alike. More than a few laughs have been shared over late night sorting or meals. The geography and weather here on the West Coast are completely different than I expected and needless to say, I didn't pack warm enough!
A Few More Firsts
At this point in the cruise, we have done more than 40 trawls and they start to blend together. However, a few stick out because of their unique catches. One trawl brought in a tennis ball squid, which are really cool looking because they are so odd looking-picture a rough gelatin-looking ball with small tentacles coming off! One other experience that has been impactful is witnessing the deployment of a conductivity-temperature-depth profiler, known as a CTD, in 2,000 meters of water. It took a solid hour to send it down and haul it back up! On the east Coast surveys I've participated in, the deepest I've ever been is 65 meters.
Author's note: A huge shout out to Dr. Kevin Stierhoff from the Southwest Fisheries Science Center who helped edit this blog for accuracy!