NOAA Teacher at Sea
Onboard R/V Savannah
June 24 – July 1, 2011
NOAA Teacher at Sea: John Taylor-Lehman
Ship: R/V Savannah
Mission: Fisheries Survey
Geographical area of the cruise: Continental Shelf off of Florida
Date: Wednesday, 29 June 2011
Weather Data from the Bridge
Barometric pressure 32.00
Depth 47.7 m
Winds S,SW 26 knots
Science and Technology Log
We continue to bait and deploy traps during the daylight hours. Three sets of 6 traps are typically deployed at one location. On Tuesday, 4 sets were deployed because of the low number of fish caught on the previous 3 sets.
There is an art to selecting sites and retrieving traps. Some traps can get hung-up on the ledges they were meant to be resting upon. Our Chief Scientist, Nate Bacheler, must communicate with the winch operator and captain with gestures to subtly move the tether in the hopes of freeing the trap. In rare events, a trap can be lost.
Mounted on each trap are 2 video cameras. They record the habitat and activity in the vicinity of the trap. The resolution on the videos is remarkable! During the winter months the films will be viewed and the fish species identified and counted.
What Happens to the Data?
The data collected on these cruises allows scientists to create an “index of abundance” for each species of interest. This information is combined with information from other sources and in-put to an existing assessment (population) model. The South Atlantic Fisheries Management Council then looks at the output from the model to decide on management regulations. They’ll decide on loosening or strengthening harvesting rules for each species.
So What Happens Once the Fish Are Caught?
There is a great deal of information collected on each fish caught. For example: site location, weight, species, total length, length to fork in tail, and length before the tail. Select fish are later dissected to collect their otoliths (a bone in the head that can be used to determine age) and gonads (for maturity and sex determination). All fish are kept on ice in a large cooler until they are processed. Some of the fish are filleted, wrapped and frozen to ultimately be given away to charity.
I no longer see the placid Atlantic under the ship. Strong winds (40 knots) have been blowing and stirring up the surface, creating 3-4 ft. waves and at times 4-5 ft. My stomach has noticed the change in conditions so I have been trying to keep busy and my mind distracted. Tried chewing some ginger, a remedy many people have suggested. Later, as the seas calmed and/or the ginger took effect, my stomach settled.
The weather conditions have stimulated much discussion among the science staff and crew. It was decided that conditions were ok to deploy the traps but too “sketchy” to retrieve them safely.
The chief scientist seems to have many contingency plans for when the weather does not cooperate. Decisions can be made at a moment’s notice to head to another site or cancel the trap drops. The fall back plans maximize the productivity of the research with the limited time at sea. The “down” time has given me some extra time to interview the science staff and crew. They are all very interesting people.
Zeb , David and Nate, members of the science crew
New animal sightings: (birds) brown boobies, yellow-throated warbler, Wilson’s storm-petrel, royal terns, (fish) reticulated moray eel, purplemouth moray, and red porgy.