July 22, 2007
Today I met Dr. Chris Melrose of the National Oceanic & Atmospheric Administration (NOAA) Northeast Fisheries Science Center, Narragansett Laboratories. This facility is up the hill from the MERL labs. Chris and his team conduct a set of monthly cruises around the east and west passages of Narragansett Bay, as well as Rhode Island Sound, Mount Hope Bay and the Providence River. Today I would be joining them along with ARMADA teacher Christine Kirch who was working at the NOAA labs for the summer.
We would be aboard the R/V John H. Chaffee, a fifty foot diesel vessel docked at the Department of Environmental Management's Marine Fisheries Laboratory at Fort Wetherill in Jamestown. This vessel was built in Southwest Harbor, Maine and commissioned in June of 2004. Her major role would be to continue and expand the monthly and seasonal fish trawl surveys first begun in the Bay in 1979. Additionally, she would tow scientific data collection equipment in order to monitor conditions in Narragansett Bay. In reading over her specs, I found it amazing that the hull of the John H. Chaffee is made of Kevlar.
Today's cruise would be towing NOAA's "undulating towed body sampler" more commonly called a sled, that was designed specifically for monitoring conditions in Narragansett Bay. This data would also be used in Leslie's hypoxia studies.
The sled was unloaded from the back of the pickup truck and stowed on the stern deck. Before getting underway, the cables were connected that sent the data back to the on-board lap top computers. Once underway, the sled was swung over the stern and slowly lowered into the water. It was a little tricky getting the sled into the water as the boat rolled on the waves, but this experienced crew made short work of the task. Christine even lent a hand shoving the sled out over the water.
The data Chris was collecting would be used as part of the Bay Window Program that monitors and assesses the water quality, ecology and changing fisheries yields in Narragansett Bay. This program is a joint venture between the Rhode Island Department of Environmental Management, NOAA Fisheries, the Narragansett Bay National Estuarine Research Reserve, the University of Rhode Island, and Roger Williams University.
The sled was controlled by a bank of three computers that set the course or "flight" for sampling, recorded dissolved oxygen and CTD readings, and recorded plankton counts. The flight of the sled was controlled by changing the angle of the top fins thus controlling the depth. A course was plotted that would have the sled rising and falling within the water column as it was sampling and sending data back to the ship-board computers.
At first glance, the computer displayed a very colorful set of graphs showing the many parameters that the sled was measuring. After explaining how the graphs were inter-related, a profile of the physical and chemical characteristics of the Bay could be seen. Chris explained that the Bay was comparatively shallow so even small changes in oxygen levels could have very far reaching effects on the entire ecosystem.
Once the sled was deployed, the Chaffee would tow the sled at a speed of 8 knots. Chris and the Captain had to carefully watch the bottom depth in order to change the path of the sled as we progressed on our course. The bottom of the Bay went from a shallow 5 meters to a depth of 20 meters with many obstacles in between. It certainly wouldn't be good if the sled hit the bottom or got hung up on a lobster pot.
As part of the study procedure, three calibration stations were set up to use as comparisons with the data collected from the electronic sensors on the sled. Elaine Caldarone, a biochemist from NOAA, would collect water samples using the Niskin bottle at the beginning of the cruise, at the mouth of the Providence River, and at the end of the cruise. At each calibration station the sled would be stopped and suspended just at the surface while the Niskin bottle was set out and retrieved. From these samples temperature, salinity, dissolved oxygen and chlorophyll concentration would be determined when we returned to the lab and compared to the sensor data at the same positions.
As we followed the cruise track, during lulls in the action, Christine and I had time to chat about her ARMADA experiences. She had just returned from Norway where she was on the R/V G.O. Sars. Here she was part of a project that was exploring hydrothermal vents using remote operated vehicles. As this was Christine's second ARMADA experience, she had some great stories to tell. She also had some helpful hints on how to put together my journal entries.
There were a few anxious moments when the sled stopped sending data to the computers. As we hadn't hit anything, Chris hoped it was just a connection problem that could be easily remedied. The sled had to be hauled in and all of the connections tested. Chris and Jack worked quickly to clean and reseal the connectors. They had no way of knowing if the problem was fixed until they re-deployed the sled and checked the computers If this didn't worked, we would have to return to Jamestown without data for this cruise. The equipment problem would have to be identified and another cruise scheduled so that this month's data would not be lost. Luckily, all systems were in communication again so we could continue on our track.
Today was a beautiful day for a cruise on the Bay. As we circled the Bay, I saw parts of Rhode Island I could never have seen on my own. We even circled up the Mount Hope Bay as far as Fall River, Massachusetts. It was amazing to see the mountain of coal that had just been off loaded from a barge at the Brayton Point Power Plant. Here the water temperature rose significantly most likely due to the outflow of the cooling water from the power plant.
This was the final part of my research experience. We had set out at 8:00 AM in the morning and returned at 4:45 PM. The people I have met and worked with for this short time are truly dedicated and remarkable people. Their commitment to what they do and the health and well being of Narragansett Bay was incredible. I truly fell privileged to have been a small part of their work for these few days in July. Thank you ARMADA for providing this research connection. I know that my chemistry students will certainly benefit from this real life application of some of the concepts and lab experiences we will be doing in the coming year.