NOAA Teacher At Sea
Aboard NOAA Ship Henry B Bigelow
May 2 -13, 2017
Mission: Spring Bottom Trawl Survey
Date: May 3, 2017
Latitude: 42 32.790N
Longitude: 070 01.210
Last night we passed through the Cape Cod Canal. It was exciting to go under the bridges I have traveled over many years for a summer vacation. It was a clear night with plenty of stars shining. We collected our first haul to survey just after arriving in the bay. I was surprised by the variety of fish that we sorted, weighed, measured and took samples. The scientists I am working with are a very dedicated, professional, hard working and friendly bunch. By the time we finished it was midnight and I was done with my day assignment.
I awoke to a view of Provincetown at the tip of Cape Cod in the distance. About two dozen right whales were spotted in the area. Later, I was able to observe the nets being lowered into the sea. The instruments placed along the opening of the net will measure the depth and opening area of the net. The nets are in the water for 20 minutes. The catch also included skates, lots of red hake, a few cod, lobsters of all sizes, a few star fish, alewife, mackerel and others I hope to learn more about. Sorting is done along a conveyor, 6 of us each at our stations. In my wet weather gear and rubber gloves, I place the fish in an array of buckets and baskets. I never would have imagined me holding a handful of small octopi! There must’ve been 8-10 of them!
Once the full catch is sorted, I assist alongside scientist Christine by recording the data she is collecting into the computer. We work with one species at a time, then onto the next basket or bucket.
The specimen that is mostly retained for further study is the otolith, a small bone within the fish’s ear. It determines the fish’s age much like the ring on a tree. The bone acquires a growth ring everyday for at least the first six months of the fish’s life. (The haddock otoliths I observed were between 1 – 2 cm, depending on the size/age of the particular haddock) (Image Compana Lab: http://www.uni.hi.is/compana/ )
“Why Age Fish?
“Once the ages are known for a sample of fish, scientists can measure the rates of various processes affecting these fish. For instance, data on fish size can be combined with age information to provide growth rates. Also, the decrease in abundance from one year (age) to the next gives a measure of mortality rates (due to the combination of fishing and natural causes). Finally, age data can be used to determine how long it takes individuals of a species to mature. Any of these vital rates may change over time, so it is important to examine age samples regularly.
Knowledge of fish age also allows scientists to learn more from capturing and measuring fewer fish. It is impossible to catch all the fish in the ocean. However, if a small portion of the fish are captured and aged, the relative abundance of fish at each age can be determined. These age data, with data from other sources, can then be expanded to estimate the total number of fish in the wild. Population models, using such data, enable scientists to monitor trends in the size of fish populations and to predict potential effects of fishing on those populations. The most detailed models include age-specific estimates of weight, mortality, and growth; this requires that larger numbers of fish be aged.” (1)
How did I hear about the Teacher At Sea Program?
Last summer, I was fortunate to attend the Maury Project, a summer teacher development program of the American Meteotological Society held at the Naval Academy in Annapolis, MD. A few other teachers in attendance had been Teachers at Sea and sang its praises. Teachers inspiring other teachers!
What a coincidence:
The Maury Project mentioned above is named for Matthew Fontaine Maury (1806- 1873) the Father of Oceanography and the NOAA ship I am aboard is the Henry B. Bigelow (1879-1987) named for the Modern Father of Oceanography.