The Okeanos Explorer sailed on a sunny Saturday morning, August 24, from Davisville, RI, to start the August Ecosystem Monitoring Cruise. It made its way through the busy waters of Narragansett Bay to an anchorage across from the Newport Naval Station where Mike Jech and his small team calibrated the EK60 acoustic system.
This was completed in just over a couple of hours, after which they were ferried to the Newport Naval Station by small boat.
We then proceeded south of Martha’s Vineyard and past Nantucket Shoals onto Georges Bankwhere we are now, as of Monday evening. We are sampling with a variety of bongo net diameters and mesh sizes to sample plankton, and larval and juvenile fish. A CTD 911 rosette equipped with ten-liter bottles will be used for hydrographic and nutrient sampling. The first plankton samples were dominated by hordes of gammarid amphipods, but those have dropped off and been replaced by salps in our most recent tows south of the shoal area of Georges. Numerous juvenile and larval fish were seen in the samples taken just east of Great South Channel.
This is a first for this vessel, undertaking a fisheries ecosystem monitoring survey such as ours. Normally the Okeanos would be on missions of exploration, using ROV’s and camera sleds to study sea bottom features and shipwrecks. This will be an exploration of a different sort, and although bongo plankton nets may seem pretty low-tech compared to the hardware normally deployed from this vessel, we do have some techier gear on board, in the form of two Imaging Flow Cytobot units from Woods Hole Oceanographic Institution, that capture images of plankton pumped in from the scientific seawater flow through system.
Our rosette is equipped with a submersible fluorometer that can help us to identify different phytoplanktonic organisms, based on their fluorescence features and a Laser In-Situ Scattering and Transmissometry (LISST) unit to measure the size frequency distribution of particles in the water column. We’ll also be doing a few mid-water trawls near puffin breeding areas to learn what types of fish they may be capturing to feed their young, and we’ll be mapping the sea-floor topography of the Schoodic Ridge and Wilkinson Basin areas. It will be a very busy thirteen days!
EX 13-05 Ecosystem Monitoring Survey