Missions Accomplished, We’re Heading Home

The Delaware II completed sampling operations on Georges Bank at 11 p.m. Monday night and continued westward along our planned cruise track towards Southern New England to do as much plankton and hydrographic sampling as possible in this area before returning to the NEFSC dock in Woods Hole on Wednesday, September 1. We have completed 83 stations up until this point, and we are scheduled to sample seven more before our time is up. A total of 90 stations for this cruise is quite a respectable accomplishment in light of the weather and unscheduled Coast Guard rendezvous for personnel transfer.

In addition to the primary mission of Ecosystem Monitoring, this cruise has had three other missions, all of them successful. The deployment of the In Situ Ichthyoplankton Imaging System (ISIIS) on Stellwagen Bank and Georges Bank by researchers Cedric Guigand and Adam Greer of the University of Miami’s Rosenstiel School of Marine and Atmospheric Science (RSMAS) has illustrated a different way of looking at planktonic organisms. For example, many gelatinous creatures, such as salps, comb jellies and medusae, come out of our bongo nets looking like gobs of mush, but captured on camera, in situ, they are intricate and marvelously complex organisms. This was illustrated for us first hand on this cruise as salps were very abundant at many stations! By conducting comparison bongo tows along the ISIIS transects we will learn more about the comparability between these two sampling methods.

salp

A salp photographed by the ISIIS towed camera, showing anatomical details. (Photo by Cedric Gigand and Adam Greer, RSMAS).

Jerry shows mashed salp from net

Salps captured in the bongo plankton net appear as a mass of mashed jelly. (Photo by Scott Sperber)

Another mission has been the observation of marine mammals and birds by our two observers, Marie Martin and Tim White from the City University of New York (CUNY) Graduate Center. Ironically, they saw large numbers of humpback whales and white-sided dolphins in the vicinity of the Chatham shoreline, an area that was not on the original cruise track but was visited for the personnel transfer that took place on Saturday. Humpbacks were also observed near the Great South Channel. Fin and minke whales were seen near the Gardner and Lydonia Canyons on the southern flank of Georges Bank, and Common and Roseate Terns on Stellwagen Bank. A couple of right whales were sighted off of Nova Scotia, along with large numbers of phalaropes and greater shearwaters near large floating mats of rockweed. Alternating with each other during the daylight hours (weather permitting) along most of our entire cruise track, Marie and Tim have logged over 1,000 miles of observing, identifying and enumerating marine birds and mammals. These observations were entered into a waterproof laptop from their observation post on the flying bridge.

Observers with binoculars look for marine mammals and birds

Observers Marie Martin and Tim White on the Delaware II flying bridge, with their waterproof laptop to log observations. (Photo by Jerry Prezioso, NOAA)

Our third mission has been to have a science teacher join us on this trip who, as he is helping us, is also learning about the marine ecosystem. Scott Sperber, our middle school science teacher from the Sherman Oaks Center for Enriched Studies in Tarzana, California, has been using his onboard observations to develop lesson plans and projects to occupy his class this fall. His launching of a radio equipped drifter buoy on the fourth day of the cruise south of Nova Scotia will provide his students with a unique opportunity to study ocean currents and surface temperatures as their buoy (#44554) meanders its way across the Atlantic. We have been observing its movement on the NOAA website, http://www.aoml.noaa.gov/phod/trinanes/xbt.html . It is currently directly in the projected path of Hurricane Earl, which should provide some very interesting data on on the movement of surface waters from effects of a hurricane.

Scott and Jerry hold decorated buoy

Science teacher Scott Sperber, in green hardhat, and Jerry Prezioso launch a NOAA radio-equipped drifter buoy for his class to track. (Photo by Anthony Gomes)

To accomplish all of these missions we have had the unflagging support of the officers and crew of the Delaware II. None of the science accomplished would have happened without their truly 24/7 support. In addition to tweaking our cruise track for maximum efficiency, and deploying our instruments so they go over the side and return intact, they also keep us sheltered, fed and healthy while we are out here as part of this floating community. A meeting of all department heads is convened every morning to determine if there are any safety or habitability issues that need to be addressed. All this support not only led to successful science, but made this cruise a pleasure to be a part of as well!

Jerry Prezioso
Chief Scientist

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