NOAA Teacher at Sea
Aboard NOAA Ship Reuben Lasker
May 31 – June 11, 2018
Mission: Rockfish recruitment and ecosystem assessment survey
Geographic Range: California Coast
Date: June 10, 2018
Data from the Bridge
Latitude: 36° 39.980′ N
Longitude: 122° 33.640′ W
Wind: 30.87 Knots from the SE
Air Temperature: 12° C
Waves: 2-3 feet with 6-8 foot swells
As you may have gathered from my previous blogs, I spent my time working with the night scientists. However, there was a lot happening during the daylight hours that I would like to highlight. There was a separate team assigned to the day shift. Some of their tasks included analyzing water samples, fishing, and surveying marine mammals and seabirds.
Catching fish during the day allowed them to see what prey were available to diurnal predators, and they could also compare their daytime catch to the evening catches. They used a different net called a MIK Net, which is a smaller net used for catching smaller and younger fish.
The day shift is also the best time for spotting seabirds and marine mammals. Some of the bird species spotted included brown pelican, common murre, terns, black-footed albatross, shearwaters, and at least 1 brown booby. The marine mammals we spotted included humpback whales, fin whales, blue whales, common dolphins, and sea lions.
I had an opportunity to speak with Whitney Friedman, a postdoctoral researcher with NOAA, and she explained to me some of the goals of their marine mammal survey. Many may recall that there was a time when whale populations, especially humpback whales, were in significant decline. Today, humpback whales are considered a success story because of rebounded populations. The concern now is monitoring the success of their food sources. Humpback whales feed on krill and fish like anchovies. However, it is possible that when these sources are less available or as competition increases, they may feed on something else. The question is, what is that something else? During this survey, one goal was to collect whale scat for analysis. Studies have found that some seabirds feed on juvenile salmon incidentally when their preferred local prey is limited, and they move inshore to feed on anchovy. Is it possible that whales might do the same? What else might they be foraging on? Unfortunately, we did not have much luck catching whale scat this time around, but they will try again in the future, and hopefully will find the answers they are looking for.
As previously mentioned, we also did water quality tests and took water samples using the Conductivity, Temperature, and Depth (CTD) Rosette. This instrument has multiple functions. As the initials suggest, it detects conductivity (the measure of how well a solution conducts electricity) and temperature at any given depth. Salinity (the amount of dissolved salts and other minerals) and conductivity are directly related. By knowing the salinity and temperature, one can determine the density. Density is one of the key factors that drives the ocean currents. Many species depend on the ocean currents to bring in nutrients and food. It all comes full circle.
When we lowered the CTD we could also take water samples at any given depth. This allowed scientist to test for various parameters. For example, we filtered various water samples to determine the amount of chlorophyll at certain depths. This can help scientists estimate the growth rates of algae, which in the open ocean are called phytoplankton. One of the scientists collected water to analyze for environmental DNA (eDNA). This is DNA that might be left in the air, soil, or water from feces, mucus, or even shed skin of an organism. In her case, she was trying to find a way to analyze the water samples for sea turtle DNA.
I’ve heard of eDNA, but I have never actually understood how they collected and analyzed samples for this information. My understanding is that it can be used to detect at least the presence of an extant species. However, when collecting these samples, it is likely to find more than one species. Scientists can use previously determined DNA libraries to compare to the DNA found in their samples.
We started trawling again on the evening of June 7th. By then we settled ourselves into the protection of the Monterey Bay due to the weather getting bad. While we still had some off-shore stations, we tried our best to stay close to the bay because of the wind and swells. We had some interesting and challenging trawls in this area: lots of jellyfish. Some of the trawls were so full we had to actually drop the catch and abort the trawl. If not, we risked tearing the net. We tried to mitigate the overwhelming presence of jellies by reducing our trawls to 5 minutes instead of 15 minutes, and we still had similar results. One night, we had to cancel the final trawl to sew up the net. I’ve been told that sewing a fish net is an art form. Our deck hands and lead fisherman knew exactly what to do.
Let me tell you my experience with jellyfish during the survey. As you may recall, someone must be on watch for marine mammals on the bridge. This is the ship’s control room that sits on the 5th level above water.
From here you can see the surface of the water quite well, which makes it a great spot for the marine mammal watch. It was also great for watching hundreds of moon jellies and sea nettles float right by. It was one of the coolest things to watch. It was somewhat peaceful, especially hanging your head out of the window, the cool air blowing against your face, and the occasional mist of sea spray as the ship’s hull crashes against some of the larger swells. However, that same peaceful state disappears the moment you realize, “I’m gonna have to lift, count, and sort all those jellies!” I wasn’t too concerned about being stung; we had gloves for the sea nettles and the moon jellies were no real threat. However, the sea nettles (Chrysaora fuscenscens) smelled AWFUL, and the moon jellies (Aurelia spp.) are quite large and heavy. I’m honestly not sure how much they weighed; we did measure up to 20 per haul, some of them measuring over 400 mm. Even if they weighed about 5 pounds, lifting 50-60 of them consecutively until the count is complete is enough to get the muscles burning and the heart rate elevated. It was a workout to say the least. I was literally elbows deep in jellyfish. I also wore my hair in a ponytail most of the time. Anyone that knows me knows well enough that my hair is long, and definitely spent some time dipping into the gelatinous goop. I smelled so bad! HAHAHAHA! Nonetheless, it was still one of the most intriguing experiences I’ve had. Even though the jelly hauls proved to be hard work, I enjoyed it.
In those last few days, I felt like I became integrated into the team of scientists, and I felt comfortable with living out at sea. I had a few moments of nausea, but never really got sea sick. I still couldn’t walk straight when the ship rocked, but even the experts wobbled when the ship hit the big swells. Then, that was it for me. By the time I got the hang of it all, it was time to leave. I wish there were more hours in the day, so I could have experienced more of the day time activities, but I still got to see more than I thought I would, and for that I am grateful.
Did you know…
NOAA offers many career options. As a scientist, here are some things one might study:
- track and forecast severe storms like hurricanes and tornadoes; monitor global weather and climatic patterns
- Research coastal ecosystems to determine their health, to monitor fish populations, and to create policies that promote sustainable fisheries
- Charting coastal regions and gathering navigational data to protect the ship from entering unsafe waters
NOAA Corps allows one to serve as a uniformed officer, commanding a ship or piloting aircraft. On NOAA Ships, they need engineers, technicians, IT specialists, deck hands, fishermen, and even cooks (The Reuben Lasker had two of the best, Kathy (Chief Steward) and Susan (second cook)). There are many opportunities available through NOAA, and there is a longer list of amazing experiences one can have working for this organization. If you want to explore in more detail, visit http://www.careers.noaa.gov/index.html