Melissa George: Crossing the Line, July 25, 2013

Latitude:  58° 30.5′ N
Longitude: 148° 47.7′ W

How can you determine the population size of species?  You could count every member of the population.  This would be the most accurate method, but what if the individuals in the population move around a lot? What if the population is enormous and requires too much time to count each individual?   For example, krill is a small crustacean (usually between 1 and 6 cm long) that accounts for 400-500 million metric tons of biomass in the world’s oceans.  Would you want to count all of the krill in the Gulf of Alaska?

Often, ocean populations of animals are just too large to count.  Sampling, or collecting a manageable subset of the population and using the information gathered from it to make inferences about the entire population, is a technique that ocean scientists use.   There are a variety of ways to sample.

One method is called mark and recapture.   In this method,  one catches individuals from the population, tags them, and releases them in a certain area.  After a set amount of time, an attempt is made to recapture individuals.  Data are compiled from the recaptures and the population is mathematically calculated.  Tuna populations in some areas are monitored this way;  fishermen are required to report any fish that are recaptured.  (Photo courtesy of Western Fishboat Owners’ Association)

Another method is quadrat sampling.  The organisms in a subset area (quadrat) are counted and then the overall population in the entire area is calculated.  For example, in the picture below, one quadrat would be randomly selected and the organisms counted.  From this count the overall population would be extrapolated.  (Photo courtesy of BBC Bitesize Biology)

In his 1943 paper “A Theory of Human Motivation,” Abraham Maslow, a developmental psychologist, proposed a hierarchy of needs which focus on describing the stages of growth in humans.  The largest, most fundamental needs are at the bottom, and as those are satisfied, individuals are able to progress up the pyramid.  So, I am going to use this diagram (somewhat tongue-in-cheek) to discuss how  basic needs are met on the ship.  In today’s blog, I will begin the discussion at the bottom level (where else?).

Water

Water is needed for in several capacities on the ship.  The staff on the ship needs potable water to drink and to cook with.  Additionally,  water is needed for washing dishes, bathing, flushing toilets and doing laundry.

To get clean drinking water, we pump the salt water from the ocean into a desalination unit (a distiller). The distilled water is then sent to a 10,000 gallon holding tank. When water is needed, it is pressurized so that it will move to the faucets, drinking fountains, showers, and so on.

Water is also needed on the ship in the lab and on the deck to clean up after the catch is hauled in and processed.   The water used here is salt water and is pumped onto the boat directly from the ocean.

Rest

Half of the staff on the ship is working around the clock; the other half is resting.   For the science staff, there are two shifts, a morning shift (4 am to 4 pm) and an evening shift (4 pm to 4 am).  The shifts are staggered at these hours so that the evening shift will be able to share two meals with the rest of the staff (usually lunch and dinner).  In most cases, two people share a stateroom:  one works days and the other works nights.  Because the quarters are close on a ship, this gives each person some time alone in the room to sleep, bathe, and take care of other personal needs.  A stateroom consists of a bunk bed, a desk, two lockers, and a bathroom/shower.  Below are some photos of the stateroom that I share with my roommate, Abby.  (Note:  Because rooms are small and space is shared, it is not advisable to bring a large purple suitcase that won’t fit inside one’s locker.)

Exercise

There are two workout areas on the ship.  One workout area has a treadmill, an elliptical machine, a bike, and a yoga mat; the other has a treadmill, a rowing machine, and some free weights.  There are limited walking spaces on the ship, so these machines provide a way to stretch one’s legs, so to speak.

With a bachelor’s degree in science, math, or engineering and a 6 month training program at the US Coast Guard Academy in New London, CT, one can serve the United States as a member of the National Oceanic and Atmospheric Administration’s Commissioned Officer Corps (NOAA Corps).  Members of the NOAA Corps serve as operational experts, taking researchers to sea and helping to generate environmental intelligence.  My roommate, Abby, serves as a member of the NOAA Corps.

This is Abby’s second cruise with the NOAA Corps.  She has a bachelor’s degree in chemistry and just completed her NOAA officer basic training.  One of her tasks is to be ready to deploy specific measures in case of a fire on board.  Below, she is reviewing all of the locations on the Oscar Dyson with fire response equipment.  For more information on NOAA Corps, click on the link.

Knowing geography is essential to various positions on the ships such as scientific exploration and navigation.  Many types of maps are seen on board, for example, computer generated bathymetric maps show the contour and depth of the ocean.  Equally valuable are the “old school” tools (paper maps, compasses, straight edges, and pencils) used to plot the ship’s course.

Fun Fact

Etymology is the study of the origin of words.  Many of the words in science originate from ancient languages such as Greek or Latin.   For example, the word etymology comes to us from two Greek words: etymon meaning “the true sense of a word“ combined with  logia meaning “doctrine, study.” Combining these two roots gives us “the study of the true sense of words,” which can be said to be the meaning of the word etymology.

Here are some root words I came across today all originating from Greek words:

zoo-from zoion meaning “animal”

phyto-from phyto meaning “plant”

plankton-from planktos meaning “drifting” or “wandering”

vorous-from vorous meaning “eating”

In the blogs thus far, I have discussed two species:  walleye pollock and one of their prey, krill.  Krill are classified as zooplankton, literally “animals that drift. ” Krill eat phytoplankton, or “animals that drift.”  Pollock are considered to be zooplanktivorous, or “drifting animal eaters.”  An award winning short video explaining The Secret Life of Plankton can be viewed by clicking on the link.