NOAA Teacher at Sea
Onboard University of Miami Ship R/V Walton Smith
August 2 – 6, 2011
Mission: South Florida Bimonthly Regional Survey
Geographical Area: South Florida Coast and Gulf of Mexico
Date: August 3, 2011
Weather Data from the Bridge
Air Temperature: 29.5°C
Water Temperature: 31.59°C
Wind Direction: North
Wind Speed: 3 knots
Seawave Height: calm
Clouds: Partially cloudy (cumulos and cirrus)
Relative Humidity: 72%
Science and Technology Log
The oceanographic work on the boat can be divided into three categories: physical, chemical, and biological. In this log, I will explain a little bit about the part of the research related to the physics of light. Upcoming 5th graders – pay attention! We will be learning a lot about light in January/February and it all relates to this research project.
Brian and Maria are two PhD students who are working with the physical components. They are using several optical instruments: the SPECTRIX, the GER 1500, the Profiling Reflectance Radiometer (PRR), and the Profiling Ultraviolet Radiometer (PUV).
Brian and Maria take optic measurements with the SPECTRIX and GER 1500
The SPECTRIX is a type of spectroradiometer that measures the light coming out of the water in order to understand what is in the water. For example, we can measure the amount of green light that is reflected and red and blue light that is absorbed in order to get an idea about the amount of chlorophyll in the water. This is important because chlorophyll is the biggest part of phytoplankton and phytoplankton are tiny plant-like algae that form the base of the food chain on Earth.
Brian lowers PRR into the water
The PRR and the PUV measure light at different depths to also understand what is in the water and at what depth you will find each thing in the water. The light becomes less bright the further down you go in the water. Most of light is between 0-200 meters of depth. The light that hits the water also becomes less bright based upon what is in the water. For example, you might find that chlorophyll live at 10 meters below the surface. It is important to understand at what depth each thing is in the water because that tells you where the life is within the ocean. Most of the ocean is pitch-black because it is so deep that light cannot penetrate it. Anything that lives below the light level has to be able to either swim up to get food, or survive on “extras” that fall below to them.
These few days have been very fun and action-packed! I arrived on the ship on Sunday afternoon and helped Nelson and the crew get organized and set-up the stations for the cruise. Several other people had also arrived early – two graduate students who are studying the optics of the water as part of their PhD program, one college student and one observer from the Dominican Republic who are like me – trying to learn about what NOAA does and how scientists conduct experiments related to oceanography.
On Monday morning, we gathered for a team meeting to discuss the mission of the cruise, introduce ourselves, and get an updated report on the status of the Mississippi River water. It turns out that the water is going in a bit of a different direction than previously projected, so we will be changing the cruise path of the ship in order to try to intersect it and collect water samples.
I am helping lower the CTD into the water
Monday we all learned how to use the CTD (a machine that we use to collect samples of water from different depths of the ocean) and other stations at the first several stops. It was a bit confusing at the beginning because there is so much to learn and so many things to keep in mind in order to stay safe! We then ate lunch (delicious!) and had a long 4-hour ride to the next section of stops. When we arrived, it was low tide (only 2 ft. of water in some places) so we could not do the sampling that we wanted to do. We continued on to the next section of stops (another 3 hour ride away!), watched a safety presentation and ate another delicious meal. By this time, it was time for the night shift to start working and for the day shift to go to bed. Since I am in the day shift, I was able to sleep while the night shift worked all night long.
Today I woke up, took a shower in the very small shower and ate breakfast just as we arrived at another section of stops. I immediately started working with the CTD and on the water chemistry sampling. We drove through some sea grass and the optics team was excited to take optical measurements of the sea grass because it has a very similar optical profile to oil. The satellites from space see either oil or sea grass and report it as being the same thing. So scientists are working to better differentiate between the two so that we can tell sea grass from oil on the satellite images. The images that Maria and Brian took today are maybe some of the first images to be recorded! Everyone on the ship is very excited!
Several hours later, we came to a part of the open ocean within the Florida Current near Key West where we believe water from the Mississippi River has reached. Nelson and the scientific team believe this because the salinity (the amount of dissolved salt) of the surface water is much lower than it normally is at this time of year in these waters. Normally the salinity is about 36-36.5 PSUs in the first 20 meters and today we found it at 35.7 PSUs in the first 20 meters. This may not seem like a big difference, but it is.
The water from the Mississippi River is fresh water and the water in the Florida Keys is salt water. There is always a bit of fresh water mixing with the salt water, but usually it is not enough to really cause a change in the salinity. This time, there is enough fresh water entering the ocean to really change the salinity. This change can have an impact on the animals and other organisms that live in the Florida Keys.
Additionally, the water from the Mississippi River contains a lot of nutrients – for example, fertilizers that run off from farms and lawns into gutters and streams and rivers – and those nutrients also impact the sea life and the water in the area. Nelson says that this type of activity (fresh water from the Mississippi River entering the Florida Current) occurs so infrequently (only about ever 6 years), scientists are interested in documenting it so they can be prepared for any changes in the marine biology of the area.
For all of these reasons and more, we took a lot of extra samples at this station. And it took almost 2 hours to process them!
In the evening, we stopped outside of Key West and the director of this program for NOAA, Michelle Wood, took a small boat into the harbor because she cannot be with us for the entire cruise.
Sunset over Key West - a beautiful way to end the day
She asked me if I’d like to go along with the small boat to see Key West, since I have never been there before, and of course I agreed! I got some great pictures of the R/V Walton Smith from the water and we saw a great sunset on the way back to the ship after dropping her off with Jimmy Buffet blasting from the tourist boats on their own sunset cruises.
We will be in the Mississippi River plume for most of tonight. Everyone is very excited and things are pretty crazy with the CTD sampling because we are doing extra special tests while we are in the Mississippi River plume. We might not get much sleep tonight. I will explain in my next blog all about the chemistry sampling that we are doing with the CTD instrument and why it is so important.
Did you know?
On a ship, they call the kitchen the “galley,” the bathroom is the “head,” and the bedrooms are called “staterooms.”
One interesting thing about the ship is that it does not have regular toilets. The ship has a special marine toilet system that functions with a vacuum and very thin pipes. If one of the vacuums on one of the toilets is not closed, none of the toilets work!
Animals seen today…
- Zooplankton that live in the sargassum (a type of seaweed that usually floats on the water) –baby crab, baby shrimp, and other zooplankton. The sargassum is a great habitat for baby crab, baby shrimp, and baby sea turtles.
- Baby flying fish
- Two juvenile Triggerfish
We caught a young triggerfish in our tow net