NOAA Teacher at Sea
Onboard U.S. Coast Guard Vessel Healy
July 1 – 30, 2008
Mission: Bering Sea Ecosystem Survey
Geographic Region: Bering Sea, Alaska
Date: July 15, 2008
For the past thirteen days I have predominantly been working with the MOCNESS team. These scientists have opened their nets to me, and I have entered a world of plankton, juvenile fish, copepods, jelly fish, crab larva, and even juvenile squid. There is though one member of our team who I have been remiss in mentioning, meet Ron! Ron Heinz is the head of the nutritional ecology lab for AFSC (Alaska Fisheries Science Center) in Juneau, Alaska. And well Ron collects samples of species and literally blows them up! Yes you heard me, he combusts his samples.
Ron has a quest, he wants to know how much energy is stored in a fish and how it is partitioned, specifically in either fat or protein. Basically juvenile fish want protein to help them grow muscle to avoid predators, they also want to store fat for the winter when there is nothing to eat.
The underlying question in Ron’s research is: what happens to juvenile fish as the climate warms and there is a “mis-hatch” between when the food is available and the fish, hatch. Ron’s current project is collecting fish, identifying the species, and saving samples for the lab in Juneau. He will freeze his samples for transport, and then the fun begins again.
To extract fat from juvenile fish the process is simple: -Grind up the sample. -Add solvents to the sample to dissolve the fat. (the fat is trapped in suspension with the solvent) -Filter the sample to remove all other “stuff.” -Evaporate the solvent and weigh the left over and voila, you have fat.
To extract protein we now need the other “stuff.” Nitrogen is found in protein, so simply put, burn the fish sample, remove the CO2 and you have Nitrogen. Multiply by 6.25 and voila, you have the amount of protein. To do this he… drum roll please, combusts the sample, torches it, and poof. Since there is not a lot of existing data on larval fish Ron is a forerunner in his field.
Basically Ron is developing nutritional labels for marine species. He finds out what the different species are made of and in turn can then figure out what would be considered a healthy ecosystem for that specific species. Right now the target species in his research are pollock, pacific cod, and arrow tooth flounder. Ron has also made nutritional labels for other species including a five foot sleeper shark. In a nutshell his “nutritional labels” tell of metabolic demand, and how who eats whom when and why is so important.
Right now the pollock we are collecting have approximately less than 1% body fat, in the fall it is hoped that they will have 3- 4% body fat so as to survive the winter. The diet of pollock is predominantly micro-zooplankton. And for those of you who do not know pollock, every time you eat a fish stick, you are eating pollock! So there you have it “Ron’s World.” It might be a small and microscopic world but in marine ecology it is very important!
Quote of the Day: The Earth, like the sun, like the air, belongs to everyone – and to no one. -Edward Abby
FOR MY STUDENTS: Can you find a quote about nature that inspires you?