NOAA Teacher at Sea
Jenna Cloninger
Aboard Bell M. Shimada
June 11 – June 26, 2025
Mission: Integrated West Coast Pelagics Survey (Leg 1)
Geographic Area of Cruise: Pacific Ocean, California Coast
Today’s Date: June 17, 2025
Track the Ship: Bell M. Shimada
Weather Data Snapshot: 12:23pm, Pacific Daylight Time
Currently, the air temperature is 63°F (17°C) with a wind speed of 14 knots and a wave height of 8 feet. The seas have been rough lately, but at least the sun is shining! I wandered onto the back deck earlier to combat some seasickness, and it was quite chilly with the strong wind.
Science and Technology Log
I am amazed at how quickly conditions change while at sea. One minute, I forget I’m even on a moving vessel. The next, I’m bumping into walls and feeling like gravity isn’t following its own rules anymore. And getting work done? That’s a whole other challenge!
Two days ago, the seas were relatively calm, and we had a ton of work to do in the science lab. My teammates extracted 150 otoliths from various fish specimens, and I must have measured and weighed at least 100 more fish. We had an amazing set of trawls that brought us samples of each of our target species: anchovy, sardine, and mackerel. We are studying these species to estimate their biomass and better understand their population dynamics and life cycles. I had already seen plenty of anchovy and some small mackerel. However, this was my first time seeing such large mackerel – and this isn’t even their full size!
According to NOAA, Pacific mackerel are a smart seafood choice for consumers in the United States because they are harvested sustainably; their nets are selective and therefore reduce bycatch; and they are caught using surface trawls instead of bottom trawls, which can destroy sensitive habitat. (Click here to see if some of your favorite seafood is harvested sustainably, or if you should make a different choice at the grocery store or at your favorite restaurant.)
Let me explain some keywords related to seafood sustainability:
Sustainable fishing means catching just enough fish for people to eat without hurting fish populations to the point that they can’t grow and stay healthy for the future. It also means protecting the ocean environment and other species that share the habitat. This helps make sure there are fish for people to catch and eat for many generations.
Bycatch is when fishers accidentally catch animals they weren’t trying to catch, like turtles, dolphins, or other fish. These animals are often thrown back into the ocean, but some may be injured or die in the process. Reducing bycatch helps protect ocean ecosystems and endangered species.
Bottom trawling is when a fishing net is dragged along the ocean floor to catch fish or shellfish that live near the bottom, like shrimp. Surface trawling, also called pelagic trawling, uses nets that are pulled through the open water to catch fish that swim near the surface, like the anchovy, mackerel, and sardines that we are targeting.
The surface trawling net on NOAA ship Bell M. Shimada is also equipped with a marine mammal excluder device, which is a special apparatus built into the net that prevents large mammals such as dolphins or sea lions from becoming trapped. If these animals do happen to swim into our net, they can escape through the excluder device. This reduces bycatch of other large animals as well, such as sea turtles and sharks.
Going back to the changing conditions at sea, yesterday was a rough day! Our trawling operations were cut short due to a tangled net, so we finished our work early. That was a very good thing for me, because I had time to catch up on this blog, do some laundry, and even take a break to try and combat some seasickness. I am taking Dramamine every single day, but when the waves are rough, there’s not much you can do except step outside for some fresh air and hope you don’t lose your lunch. (Or breakfast, in my case.) The sea was so rough that afternoon that instead of being rocked to sleep, I was awake for most of my sleeping hours, which left me feeling exhausted when I woke for my next shift.
Personal Log
I need to take a minute to give a shout-out to the incredible team of human beings that I have been working with on this cruise. Honestly, everyone here has been so friendly, helpful, and supportive in every way. While I interact with many people on the ship throughout the day, I am part of a specific night shift of individuals that work alongside each other during the midnight to noon hours. Melissa, Kelsey, Bryan, and Elias have been so much fun to work with, and I am learning new things from them every day. They hold a variety of positions: a fish biologist and project coordinator, a research fish biologist, a fisheries biologist, and an affiliated data analyst.
Did You Know?
Part of our job as scientists is to conduct a marine mammal watch before every trawl to ensure that we avoid marine mammals that may be swimming within range of our net. This is another way that we work to reduce bycatch and keep marine mammals safe while we conduct our trawling operations. We conduct these watches during daylight and nighttime hours in all kinds of weather, because you never know when you might spot a marine mammal. I took this picture of the moonlight reflecting on the ocean’s surface during one of my late-night marine mammal watches.
Thank you for the information about the mackerel. That’s news to me.