NOAA Teacher at Sea
Elizabeth Bullock
Aboard R/V Walton Smith
December 11-15, 2011
Mission: South Florida Bimonthly Regional Survey
Geographical Area: South Florida Coast and Gulf of Mexico
Date: December 11, 2011
Weather Data from the Bridge
Time: 2:30pm
Air Temperature: 24.5 degrees C (76 degrees F)
Wind Direction: 65.9 degrees east northeast
Wind Speed: 15.8 knots
Relative Humidity: 78%
Science and Technology Log
Today is the first day of the research cruise. The R/V Walton Smith left its home port in Miami, FL this morning at about 7:30am. After a delicious breakfast, the crew and scientific party received a safety briefing from Dave, the Marine Tech. We learned about the importance of shipboard drills and we were shown the location of all the safety gear we might need in case of an emergency. This ship works like a self-contained community. The crew of the ship must also be the policemen and firemen (or policewomen and firewomen).
After our safety briefing, the science party went outside to our first station of the day. The first piece of equipment we put into the water was a CTD. The CTD is named after the three factors the equipment measures: conductivity, temperature, and depth. The CTD will be deployed at precise locations along our route. Since they conduct this research cruise twice a month, they can see if conditions are changing or staying the same over time.
Question for students: What is the relationship between salt and electrical conductivity? If the salt content in the water increases, will it conduct electricity better or worse?
The next piece of equipment we deployed was the Neuston Net. This net sits at the water line and skims organisms off the surface of the ocean. The net is in the water for 30 minutes at a time. After bringing the net onto the deck, the fun part starts – examining the contents! Our Neuston Net had two main species: moon jelly (Aurelia) and sargassum. The term sargassum actually describes many species, so the scientists on board will study it carefully in order to classify which kinds they caught in the net. Sargassum is an amazing thing! It is planktonic (which means that it floats with the current) and it serves as a habitat for bacteria and small organisms. Since it is such a thriving habitat, it is also a great feeding ground for many different species of fish.
Once we emptied the contents of the Neuston Net, Lindsey and Rachel, two of the scientists on board, began to measure the quantity of each species they caught. In order to measure the weight of the moon jellies, they used the displacement method. This is because we can’t use regular scales onboard. Here are the steps we took to measure the moon jellies:
1) We poured water into a graduated cylinder and recorded the water level. For example, let’s say that we poured in 100ml of water.
2) We put a moon jelly into the graduated cylinder and recorded the new water level. For example, let’s say that the new water level read 700ml.
3) We subtracted the old water level from the new, and we could tell the volume of the moon jelly we had caught. For example, based on the numbers above, we would have caught a 600ml moon jelly!
Both the CTD and the Neuston Net will be deployed many times over the course of the cruise.
Personal Log
Despite a bit of seasickness, I am having a wonderful time! Everyone on board is very welcoming and happy to answer my questions. Everyone is so busy! It seems like they have all been working nonstop since we arrived on board yesterday.
Answers to your questions
First, let me just say that these are great questions! Good job, Green Acres. Here are some answers, below.
1) How do the currents make a difference in the water temp? The currents play a major role in water temperature. In the Northern Hemisphere, currents on the east coast of a continent bring water up from the equator. For example, the Gulf Stream (which is a very important current down here in Florida) brings warm water from the tropics up the east coast of the United States. This not only keeps the water temperature warm, but it also affects the air temperature as well.
2) How does the current affect the different algae populations? Currents regulate the flow of nutrients (which phytoplankton needs to survive). Strong currents can also create turbidity, which means that it stirs up the water and makes it harder for light to penetrate the water column. As you know, phytoplankton rely on sunlight to grow, so if less light is available, the phytoplankton will suffer. I’m told by Sharein (one of the phytoplankton researchers) that algae are hearty creatures. This means that as long as the turbid conditions are temporary, algae should be able to thrive.
Do you get stung by the jelly fish when you measure them? Ben,Taylor and Josh
Hi Ben, Taylor, and Josh! We actually all had gloves on, so we were protected from the jelly fish.
Hi again. I found out today that moon jellies have such a mild sting, that we wouldn’t be hurt if we touched them. Since we didn’t know what else we would find in the neutson net, we wore gloves as a precaution. Safety first!
If there is algae growing on the surface how long does it take for the plankton to die underneath?
Algae can actually be considered a type of plankton. However, there are many types of plankton that are not algae. Plankton and algae both live in the top few feet of the water. They don’t sink farther than the light can penetrate. Since they float with the current (that’s what the word plankton means – floating) they will move around a lot. The different species might compete with each other, but it’s not generally enough to make an entire species die off.
The salt in the water improves the flow of electricity because the charges let the electricity go through. Anil
Good job, Anil! There are many different ions in salt water. That’s why we are able to measure conductivity.
What does the Sargassum have in it. Is it like the zooplankton?
The sargassum has many epiphytes (a plant that grows on another plant) that use the sargassum as a habitat. There are also many species of bacteria in the sargassum. When the sargassum forms large mats, small fish can actually live in it too! Check out this website about it: http://oceanexplorer.noaa.gov/explorations/03edge/background/sargassum/sargassum.html
How do you navigate the ship?? Do you use a GNSS receiver? If so, what type of receiver? Do you use a compass and stars? That would be rad….
Inquiring minds would like to know
~Peter
Hi Peter! Captain tells me that they use a SeaMap charting system, as well as a Nobeltec charting software to back up the SeaMap. They can also use Nobeltec for voyage planning. They have 5 global positioning systems (GPSs) on the boat. The AIS (automatic identification system) they have is required on some vessels. They are also required to have paper nautical charts and a magnetic compass. For those students out there who are interested in ship navigation, learning how to use a GPS is important, but knowing how to use paper nautical charts and a compass is also crucial.
When salt is added to electrical conductivity it increases, so you should get out of the water even faster if lightning strike the ocean compared to lightning striking the pool.
Here is an answer to your question:
When more salt is added to water, the electrical conductivity rises because the salt dissolves into both positively and negatively charged ions which are then attracted to their oppositely charged electrical current. Also, if more salt is added in the water, the electrical conductivity will become more electrical which can cause preoblems.
I also have a question for you:
Is there a specific time when the electrical conductivity is at its highest point in an ocean or sea?
Hi Hannah,
If the conductivity is highest, that means the salinity is highest. Surface water is most saline when it is hot, because the freshwater evaporates off the surface. For example, in the Chesapeake Bay, the water is its most saline in the summer months (especially if it hasn’t rained in a while). On a global scale, hot places such as right along the equator have the most saline surface water.
What is the relationship between salt and electrical conductivity?
Water is made up out of two elements that are hydrogen and oxygen. Distilled water is pure and has no salts, making it very poor conductor of electricity. If you add just original table salt to the distilled water it truns into an electrolyte solution, making available to conduct electricity. How long have you been studying this topic?
Hi Lily,
Since I am a member of the Teacher at Sea program, I am just visiting on this particular 5-day mission. The scientists from AOML (Atlantic Oceanographic and Meteorological Laboratory) have been conducting this same research cruise since the 1990’s. If you go to this website, you can see the data they have collected over the years: http://www.aoml.noaa.gov/phod/sfp/data/index.php
Water is made up of two elements called hydrogen and oxygen. Pure water that is free of salt is called distilled water. That is why it is a poor conductor of electricity. An electrolyte soluction can condct electricity. This happens by adding origional table salt and distilled water.
Were you interested in this subject when you were a kid? If not what did you want to be?
How did it gorw into being your carrer?
Distill water does not have any salt in it. If distill water does not have salt then it is a very poor conductor of electricity. If someone was to add table salt to distill water then it wwill bbe able to conduct electricity. Ionic compounds such as salt water, conduct electricity when they disolve in water. When did you decide that you wanted to do this?
Water is ,made up of two elements: hydrogen and oxygene. Pure water that does not contain salts is called distilled water. Therfore, its not the best conductor of electricity. Only an electrolyte solution can conduct electricity. This activates by mixing original table salt and distilled water.
Hi Andrea and Hannah,
I’ve always been really interested in the environment. I went to college and studied International Development. I was really interested in how developing nations manage resources like water and oil. Afterwards, I went to graduate school and studied Environmental Science and Policy. I became very interested in environmental education and I discovered the Teacher at Sea program, which educates teachers through research experiences. I had no idea what I wanted to be, but I knew what I was interested in and I pursued it in school. When I was younger I was convinced I was going to be a famous actress 🙂
I would suggest working hard in school and pursuing what you love.