Kimberly Gogan: Night Crew Oceanography! More than just a Bongo! April 29, 2014

NOAA Teacher at Sea
Kim Gogan
Aboard NOAA Ship Gordon Gunter
 April 7 – May 1, 2014

MissionAMAPPS & Turtle Abundance SurveyEcosystem Monitoring
Geographical area of cruise:  North Atlantic Ocean
Date: April 29, 2014

Weather Data from the Bridge
Air Temp: 15.5  Degrees Celsius
ind Speed: 7 – 12 Knots
Water Temp: 8.8  Degrees Celsius
Water Depth: 10 Meters

Science and Technology Log

As I mentioned in my previous blogs, there are many layers of science that are happening simultaneously that support the AMAPPS project (see April 9th blog). One of these layers is monitoring the ecosystem with oceanography. In the April 9th blog I explained all about the Bongo Nets, and in April 15th blog I explained about the VPR and it’s plankton picture data. While the rest of the ship slept, the night time oceanography team – Betsy Broughton (scientist from NEFSC in Woods Hole), John Rosendale (lab technician from NOAA Fisheries Howard Labratory in Sandy Hook) and Brian Dennis (volunteer) were busy conducting Benthic science with the Beam Trawl and Van Veen Grab Sampler.

Although  this equipment was not used every night, I was lucky enough to have stayed up some of the night to see these two in action. The Benthic Zone, in a body of water, like the ocean refers to the very bottom of that aquatic ecosystem. The night time science team use a Beam Trawl or a bottom fishing net that is towed along the bottom of the ocean to take a sample of the organisms that live there. The Beam Trawl is attached to a winch that is on the stern of the boat, that one is much larger than the winch that is used to lower the Bongo Nets. The trawl is lowered down until it touches the bottom and then towed along the bottom picking up whatever is in its path. The trawl is then brought to the surface and the sample is sorted in the wet lab and preserved in formaldehyde just like the other samples. The Van Veen Grab Sampler is lowered into the water by the same smaller winch that is used for the Bongo Nets along the port side of the ship. The grab is rigged so that when it touches the bottom of the ocean, two arms open up and grab a large sample of the sediment at the bottom of the ocean. To me it looked just like the suffer muck I know as “clam flats.” Once the Van Veen Grab is brought up to the surface, the arms of the grab are released and the sediment is dropped into a bucket. From there the soil is washed over and over using several sized sieves until all of the muck is washed away and just the organisms, shells and assorted bottom treasures are left. This sample, once cleaned, is also brought back to the chemistry lab for processing in formaldehyde.  The scientists worked at a much faster pace to get all the sediment removed and the  samples processed. It was fun to be able to watch and help out.

Betsy teaching me how to run the computer software for the CTD.

Betsy teaching me how to run the computer software for the CTD.

Personal Log:

For most of the trip, my “assigned” task has been to work with Jerry Prezioso as the day Oceanography team. Jerry and I are in charge of the mid-day Bongo Nets (see April 9th blog). Sometimes we are up early and timing is such that our morning Bongo Net overlapped with night crew’s scheduled time. Sometimes they would start the morning Bongo and Jerry and I would take over and finish the work, or we would just all work together to get it done twice as fast.  Since there were more people to help in the morning, Betsy Broughton (see April 15th blog) was available to help teach me how to run the computer software that was attached to the Bongo called a CTD Sensor.

The graph on the computer software of the  Conductivity, Temperature and density data the CTD collects as the Bongo drops to it's lowest depth.

The graph on the computer software of the Conductivity, Temperature and density data the CTD collects as the Bongo drops to its lowest depth.

CTD stands for Conductivity, Temperature and Depth and it sits above the Bongo Net collecting this data that it sends back to the computers. Generally one scientist is in charge of running the software that turns on the CTD and gets it to start collecting data as it is dropped down into the deep water. The person on the computer is in charge of knowing how deep the Bongo Net should go and telling the winch operator when to pull the Bongo Net back up to the surface. They are also responsible for letting the NOAA Corps officer on the Bridge know when the equipment is ready and telling the winch operator the speed at which the Bongo should be dropped. If this information is not relayed correctly the Bongo Net could go crashing into the bottom of the ocean. It took a couple of days of Betsy overseeing what I was doing, but in no time at all, Jerry felt confident enough in me to leave me at the helm and let me run the software on my own. From net washer to computer software operator, I was moving up!

Thomas Ward, September 13, 2010

NOAA Teacher At Sea: Thomas Ward
Aboard NOAA Ship Miller Freeman

Mission: Fisheries Surveys
Geographical Area of Cruise: Eastern Bering Sea
Date: September 13, 2010

The Procedure

The way that we collect data is done by three methods. They are the beam trawl, the benthic sled and the benthic grab. The beam trawl is a metal beam supported by a cable on the ship. Hanging from the beam is a net that when dragged behind the ship opens up. The trawl is pulled behind the ship for a specific amount of time.

The benthic sled is a piece of equipment that looks like it would be right at home on the snowy slopes of Central New York. It is a sled that gets dragged on the bottom and collects plankton (look out Eugene). The net is a finer mesh than the one used on the beam trawl. At the end of the net is a container that collects the plankton, we call it a cod end.  At the opening of the net is a device called the flow meter which looks like a little hand held fan. This performs the function of measuring the amount of water or flow that is going through the net. The meter has a counter on it and needs to be read and reset at each sampling station. This instrument gives the scientists a sense of the volume of water flowing into the net.

Flow Meter

Benthic Sled

The last device we are using is the benthic grab.  This device and the wet bulb on the bridge are instruments closest to my curriculum, Earth Science.  In fact, while on the bridge one officer asked another for the wet bulb temperature, very cool, I almost pulled out my sling psychrometer and compared data.  Any how, the grab is opened up and set and then lowered into the water.  When the grab hits the bottom, the weight and the downward force of the grab forces it shut, and into the bottom, scooping up sediment as it closes.  Of course because of the nature of this scientific expedition we are more concerned with organic matter than sediment.  I will have to say the scientist that I am working with have a natural curiosity toward all of Earth’s wonders.

These devices are deployed one at a time.  After each piece returns to the surface the crew maneuvers the ship so that subsequent samplings are performed at the same area.

I was going to write about life on board but the seas have gotten rougher and I am sea sick.