13 April 2018 Captain Kent Sheasley R/V Neil Armstrong, Voyage #AR-29 Woods Hole Oceanographic Institution Mail Stop #27 Woods Hole, MA 02543 Dear Captain Sheasley: On or about 16 April 2018, your vessel being ready for sea and weather permitting, you will depart Woods Hole, MA on Voyage #AR-29. Upon completion of science activities, the vessel shall return to the port of Woods Hole, MA. You may return to the port of Woods Hole, MA on or about 29 April 2018. Science Objectives The continental shelf break of the Middle Atlantic Bight supports a productive and diverse ecosystem. Current paradigms suggest that this productivity is driven by several upwelling mechanisms at the shelf break front. This upwelling supplies nutrients that stimulate primary production by phytoplankton, which in turn leads to enhanced production at higher trophic levels. Although local enhancement of phytoplankton biomass has been observed in some synoptic measurements, such a feature is curiously absent from time-averaged measurements, both remotely sensed and in situ. Why would there not be a mean enhancement in phytoplankton biomass as a result of the upwelling? One hypothesis is that grazing by zooplankton prevents accumulation of biomass on seasonal and longer time scales, transferring the excess production to higher trophic levels and thereby contributing to the overall productivity of the ecosystem. However, another possibility is that the net impact of these highly intermittent processes is not adequately represented in long-term means of the observations, because of the relatively low resolution of the in situ data and the fact that the frontal enhancement can take place below the depth observable by satellite. Science Activities To obtain cross-shelf sections of physical, chemical, and biological properties within the Pioneer Array. Nutrient distributions will be assayed together with hydrography to detect the signature of frontal upwelling and associated nutrient supply. It is expected that enhanced nutrient supply will lead to changes in the phytoplankton assemblage, which will be quantified with conventional flow cytometry, imaging flow cytometry (Imaging FlowCytobot, IFCB), in situ optical imaging (Video Plankton Recorder--VPR), traditional microscopic methods, and HPLC pigments. Zooplankton will be measured in size classes ranging from micro- to mesozooplankton with the IFCB and VPR, respectively, and also with microscopic analysis. Biological responses to upwelling will be assessed by measuring rates of primary productivity, zooplankton grazing, and net community production. These observations will be synthesized in the context of a coupled physical-biological model to test the two hypotheses that can potentially explain prior observations: (1) grazer-mediated control and (2) undersampling. Hindcast simulations will also be used to diagnose the relative importance of the various mechanisms of upwelling. R/V Neil Armstrong Voyage #AR-29 16 April 2018 – 29 April 2018 Woods Hole, MA – Woods Hole, MA Scientific personnel participating on this cruise under the direction of Dr. Dennis McGillicuddy, Woods Hole Oceanographic Institution will be: Dr. Dennis McGillicuddy, Woods Hole Oceanographic Institution Dr. Heidi Sosik, Woods Hole Oceanographic Institution Mr. Weifeng Zhang, Woods Hole Oceanographic Institution Dr. Walker Smith, VA Institute of Marine Science, College of William & Mary Dr. Jefferson Turner, University of Massachusetts, Dartmouth Dr. Christian Petitpas, University of Massachusetts, Dartmouth Mr. Daniel Brinkhuis, ScienceMedia.nl Ms. Saskia Madlener, ScienceMedia.nl Ms. Meredith Meyer, Virginia Institute of Marine Science Dr. Zuchuan Li, Woods Hole Oceanographic Institution Ms. Zoe Sandwith, Woods Hole Oceanographic Institution Ms. Jaclyn Friedman, Virginia Institute of Marine Science Ms. Elizabeth Larson, UMass Dartmouth Ms. Melissa Campbell, Division of Marine Fisheries Mr. Philip Alatalo, Woods Hole Oceanographic Institution Mr. Joshua Eaton, Woods Hole Oceanographic Instituion Ms. Melissa Brennan, Woods Hole Oceanographic Institution Ms. Taylor Crockford, Woods Hole Oceanographic Institution Ms. Bethany Fowler, Woods Hole Oceanographic Institution Mr. Kevin Archibald, Woods Hole Oceanographic Institution Dr. Zhen Cheng, Woods Hole Oceanographic Institution Ms. Emily Shimada, MATE Intern Mr. Cris T Seaton, Woods Hole Oceanographic Institution Mr. Joseph McCabe, Woods Hole Oceanographic Institution The ship’s agent in Woods Hole, MA will be: Master R/V Neil Armstrong Attn: Dr. Dennis McGillicuddy Voyage #AR-29 c/o WHOI 266 Woods Hole Rd. Woods Hole, MA 02543 Contact: Sarah Fuller Phone: (508) 289-3811 Email: sfuller@whoi.edu Please note: At the completion of this voyage, the Captain should complete a Post-Cruise Assessment form online at the following web site: http://strs.unols.org/Public/diu_faq_view.aspx?short=HowdoIsubmitaPCAR Please advise the Port Office of all personnel changes prior to departure and maintain the daily SITREP via INMARSAT C or other means as required. Please advise the Port Office of all significant expenses incurred, particularly the quantity, price and source of fuel oil. Also, at each port stop, please advise the Port Office the gallons of fuel on board stating the date the inventory was taken. I wish you a pleasant and successful voyage. Very truly yours, Robert Munier Vice President for Marine Facilities and Operations RM/kar