NEFSC Passive Acoustic Research Group Multi-Recorder Deployment and Recovery Cruise on the R/V Connecticut

NEFSC Cruise Participants: Eric Matzen and Annamaria Izzi

4/18/2016

harps_on_deck

Top: R/V Connecticut‘s deck loaded with 5 HARPs to be deployed. Bottom: Sunset at Avery Point, CT. Photos by Annamaria Izzi, NEFSC/NOAA

After days of preparation, of making sure we crossed our t’s and dotted our i’s, we left Avery Point, Connecticut at 1800 with overcast skies but calm seas. The goal of our trip is to deploy 5 HARPs (High-frequency Acoustic Recording Packages from SCRIPPS), recover 3, and recover, refurbish, and redeploy a noise reference station (NRS, PMEL and Oregon State University). All recorders are off the shelf break, from New Jersey up to the tip of Georges Bank. The HARPS are capable of recording sound from many species including baleen whales, sperm whales, beaked whales, and dolphins. The five that we will be deploying, as well as the three that were out, are part of the Shelf Break Acoustic Ecology project, which includes a total of 8 HARPs spanning Georges Bank to Florida. This is a combined effort of the Northeast and Southeast Fisheries Science Centers to understand biological activity along the shelf break before the planned seismic exploration starts off the United States’ eastern seaboard. The NRS serves a slightly different purpose, to listen to and characterize the ambient noise in the deep ocean. It is part of a larger project that is being conducted by NOAA Fisheries, NOAA Sanctuaries, and the National Park Service, to compare ocean noise throughout a number of sites within U.S. waters on both coasts and the Gulf of Mexico.

4/19/2016

harp_deployment

Top left: HARP in the Big Apple.  Top right: HARP at the Brooklyn Bridge and the Empire State Building. Bottom left: Eric Matzen getting the first HARP ready to be deployed. Bottom right: Eric launching the HARP with the crew of the R/V Connecticut.  Photos by Annamaria Izzi, NEFSC/NOAA

By 0600 we were sailing through NYC. Skyscrapers, the Brooklyn Bridge, and the Statue of Liberty all greeted us and bade us farewell as we made our way out of New York Harbor. We had traveled down Long Island Sound, hugging the coast for as long as possible before making our way offshore. Today was a day of planning, of outlining how things were going to happen and where we wanted to deploy our units as we made our way full-steam down to the southernmost deployment site. We arrived at the site in the late evening with perfect seas, and dropped it off right where we wanted it without a hitch. Then it was full steam ahead to the next site.

4/20/2016

The sea gods were a bit rough with us at the start. Waves slopping on deck, boat rocking back and forth, a few of us fell prey to the rough conditions. But there were enough of us that despite what the weather threw at us, we still managed to get the second HARP out easily. Later on in the day the winds died down, and with it the whitecaps.  We even managed to find a few pods of common dolphins, which took the opportunity to bow-ride our vessel, as well as some ocean sunfish sunbathing.

4/21/2016

floating_harddrive_removal

Top: HARP floating at the surface after being released from the ocean floor. Bottom: Eric extracting the hard drive data from the recovered HARP. Photos by Annamaria Izzi, NEFSC/NOAA

Today was the first day in which we had to recover an existing HARP, and replace it with a new one. There was an air of excitement (and nervousness) about the vessel as there always is when calling out to an instrument that has been underwater for a year. In order to get the unit to surface, a burn signal is sent that when the release “hears” it, acknowledges and scuttles the weights, allowing the unit to rise to the surface. We all didn’t know how long it would take, and were surprised to see it at the surface in a mere 15 minutes. The unit had been down around 1000 m in depth! We carefully extracted the unit from the water and quickly deployed the new one that was to take its place. With the unit we recovered, we cleaned and pulled its guts out, taking the precious data collected on the hard drives and storing them in static-free bags to be analyzed once back at the lab. If that wasn’t enough of an interesting day, we also came across three sperm whales in which one raised its flukes to go on a deep foraging dive, and the other two were logging at the surface and traveling. Bottlenose dolphins kept us company for most of the day, and we also found a few puffins! The sun was high in the sky, temperatures were warm, the sea state was great, and some of the crew could be found on the deck enjoying the nice weather. Definitely a much needed reprieve from the weather the day before!

4/22/2016

nrs_recovery.jpg

Top left: The crew of the R/V Connecticut spotting the NRS buoy at the surface after its release from the seafloor. Top right and bottom left: Capturing the NRS mooring and bringing it on deck. Bottom right: All of the crew assisting Eric and Annamaria in recovering the 1.67-mile mooring. Photos by Annamaria Izzi, NEFSC/NOAA

The day started out much like the previous one did. We had taken the night to steam up to our northernmost HARP site to arrive just after daybreak for retrieval, which went without a hitch. However that was not the case for the deployment. The HARP that we had selected did not pass the deck tests we conduct before dropping it over; luckily we still had one other HARP on deck. We prepped that one and launched it right where the old one was. We tried to troubleshoot the problematic HARP, but ran out of time as we started to prepare for the NRS mooring that was to be recovered later on that afternoon. That mooring had been like an uneasy weight on everyone’s minds this past week, as it had 1.67 miles of line, not including the hydrophone, float, acoustic release, and anchor. We all referred to it as the “monster buoy”. Due to the skill of the crew and many recovery planning meetings, the entire mooring was up in 5 hours and went so smoothly, even with the building swells! By the time we were done, it was well into dark so we strapped it all down securely on deck to be deployed first thing the following morning. We spent the rest of the night replacing shackles and any other parts that looked to have some wear to make less work for the morning.

4/23/2016

nrs_deployment.jpg

Top left: The newly refurbished NRS mooring. Top right: Annamaria and Eric letting out 1.67 miles of line with assistance from the crew. Bottom left: Annamaria and Eric just before releasing the NRS anchor. Bottom right: cutting the last ropes holding the anchor. Photos by Annamaria Izzi, NEFSC/NOAA

Today was our first overcast day of the trip, but the seas were essentially the same as they had been. We conducted many deployment meetings to make sure that everyone knew what task they needed to perform, and how it was all going to work. By 0700 we were ready to deploy and despite everyone’s trepidation, the deployment went very smoothly, even with towing 1.67 miles of mooring for 5 miles. Including the time it took to tow the mooring behind us, the entire process took half the time it took to recover it. After the deployment, we set to work to ascertain just what was wrong with the last HARP. After a few phone calls to the manufacturers on the West Coast and completely taking apart the internal frame, we were able to solve the problem and get the unit working again. Things were back on schedule to do the recovery of the last HARP that had been in the water, and swapping it with the newly fixed HARP. But the weather kicked up and things weren’t looking very optimistic, which put a damper on our spirits. We decided to hold off the final decision of whether to recover the unit at the bottom until we actually made it to the HARP site. Once there, after a brief planning meeting, and weather check, we decided to go for it. And the decision paid off. We were able to recover and deploy our HARPs, fully completing our mission. By 1800 we were heading home.

 

 

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