NOAA Teacher at Sea
Aboard NOAA Ship Oregon II
September 15-October 2, 2019
Mission: Shark/Red Snapper Longline Survey
Geographic Area of Cruise: Gulf of Mexico
Weather Data from the Bridge
Wind Speeds: E 5 mph
Science and Technology Log
Retrieving the Longline
One hour after the last highflyer is entered into the water it is time to retrieve the longline. The ship pulls alongside the first highflyer and brings it on board. Two people carry the highflyer to the stern of the ship. The longline is then re-attached to a large reel so that the mainline can be spooled back onto the ship. As the line comes back on board one scientist takes the gangion removes the tag and coils it back into the barrel. The bait condition and/or catch are added into the computer system by a second scientist. If there is a fish on the hook then it is determined if the fish can be brought on board by hand or if the cradle needs to be lowered into the water to bring up the species.
Protective eye wear must be worn at all times, but if a shark is being brought up in the cradle we must all also put on hard hats due to the crane being used to move the cradle. Once a fish is on board two scientists are responsible for weighing and taking three measurements: pre-caudal, fork, and total length in mm. Often, a small fin clip is taken for genetics and if it is a shark, depending on the size, a dart or rototag is inserted into the shark either at the base of the dorsal fin or on the fin itself. The shark tag is recorded and the species is then put back into the ocean. Once all 100 gangions, weights and highflyers are brought on board it is time to cleanup and properly store the samples.
Fish Data: Some species of snapper, grouper and tile fish that are brought on board will have their otoliths removed for ageing, a gonad sample taken for reproduction studies and a muscle sample for feeding studies and genetics. These are stored and sent back to the lab for further processing.
It has been a busy last few days. We have caught some really cool species like king snake eels (Ophichthus rex), gulper sharks (Centrophorus granulosus), yellow edge grouper (Hyporthodus flavolimbatus) and golden tile fish (Lopholaatilus chamaeleontiiceps). There have been thousands of moon jelly fish (Aurelia aurita) the size of dinner plates and larger all around the boat when we are setting and retrieving the longline. They look so peaceful and gentle just floating along with the current. When we were by the Florida-Alabama line there were so many oil rigs out in the distant. It was very interesting learning about them and seeing their lights glowing. One of them actually had a real fire to burn off the gases. There were also a couple sharks that swam by in our ship lights last night. One of the best things we got to witness was a huge leatherback sea turtle (Dermochelys coriacea) that came up for a breath of air about 50 feet from the ship.