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EK80 Water Column Sonar Data Collected During PC2406 Leg1
The Ecosystem Monitoring surveys contribute to stock assessments, protected species assessments, ecosystem assessments, and climate assessments. As such, the surveys are multi-objective. Ichthyoplankton and hydrographic data are collected for stock assessments. A range of ecosystem observations are made, from nutrients and ocean acidification to marine mammals, and these measurements are used in NEFSC ecosystem assessment products. The ocean acidification and hydrographic measurements are incorporated into the regionâs climate assessments. This survey is multidisciplinary and as such will integrate all these operations. The cruise plan will evolve with input from scientists as well as the officers and crew of Pisces. A post-cruise meeting will focus on lessons learned and improvements to make for subsequent The survey consists of 120 random-stratified and 42 fixed stations in the Middle Atlantic Bight, Southern New England, Georges Bank and the Gulf of Maine (Figure 1). These stations are distributed at varying distances, and as such there is no fixed expectation of number to be covered each day. Rather, the progress of the survey will depend on transit time, sea state, and water depth of the stations, with deeper stations requiring more time to complete operations. Some stations will also have more complex operations scheduled, such as a water cast and a bongo tow, which will increase the amount of time spent on-station. All station locations and a detailed cruise track will be provided to the vessel prior to sailing to allow the navigation officer ample time to load this information into the navigation systems. The Mid-Atlantic Bight, Southern New England, Georges Bank, and western Gulf of Maine stations will be prioritized for sampling. A cruise track will be planned to best sample these regions. All of this is dependent on weather conditions and may be altered by the vessel command in coordination with the Chief Scientist. The Commanding Officer and Chief Scientist will jointly modify the track during the cruise as weather conditions and time constraints vary to best achieve the cruise objectives. Highest reasonable cruising speeds should be employed to improve the potential to complete the cruise missions. Supplemental sampling may be added to the cruise track if essential cruise objectives will be completed before the scheduled return date. Potential areas of interest include the central Gulf of Maine, warm core eddies along the northeast shelf-break, and regions near wind energy lease areas. The Commanding Officer and Chief Scientist will jointly modify the track during the cruise to add supplemental science sampling if cruise objectives are met and the cruise can continue to provide valuable science for NOAA. The deployments of the Seabird 19+ (with and without bongos) and 911+ CTD units will use the two hydrographic winches and a CTD computer located in the dry lab. (A) Random Plankton Stations: A Seabird CTD profiler attached to an array of two bongo nets (61 and 20 cm diameters) will be deployed at 120 randomly selected stations, time permitting (Figure 2). In addition, a Seabird CTD 19+ profiler will be deployed alone to collect seawater for salinity calibrations, at deep stations (>205 m), following the bongo tow, which only goes to a maximum depth of 200 m depth (B) Fixed Oceanography Stations: A Seabird 911+ CTD will be deployed on a rosette frame with a carousel water sampling system (SBE32) and 12 10-liter Niskin bottles at 35 of the fixed stations (Figure 3). This package will collect profiles of water temperature, salinity, chlorophyll-a and oxygen levels to within 5 meters of the bottom, or to a maximum depth of 500 meters. Water samples collected by the Niskin sampling bottles at multiple depths along the upcast will be processed for nutrients, dissolved inorganic carbon (DIC) analysis, a water filtered for chlorophyll analysis. A sub-set of stations, approximately 18, will also conduct a bongo tow. (C)