Benthic Dinoflagellate Migration (BenDiM): Occurrence and Processes

标准化鞭毛藻垂直迁移（DVM）假说的大多数应用考虑了白天的表面目标和夜间的地下营养目标，因为表面华的可见性。然而，地下的营养来源可能是如此之深，以致鞭毛藻在12小时的上升过程中无法到达地表。至少有三篇文献报告记录了另一种DVM模式的沉积物导向表达，其特征是大陆边界更宽，更缓倾斜的大陆架，可以产生高生物量，近底部的鞭毛藻聚集。目标鞭毛藻生态位，这里称为“底栖鞭毛藻迁移”或“BenDiM”，受光和营养梯度的影响，但其独特之处在于，在沉积物-海洋界面附近或附近的营养源与支持种群规模净增长的较低光强区之间存在一个DVM。该项目具体处理：1)在5月至11月期间，占据巴拿马市外大陆架60米至20米等高线之间BenDiM生态位的不同鞭毛藻物种；2) BenDiM生态位中不同鞭毛藻物种的光适应、养分吸收能力和行为模式；3)具有代表性的水体物理运动对不同BenDiM鞭毛类种群形成、迁移和命运的影响。研究包括：1)在2008年5月至10月和2009年7月至8月的不同月份进行3次为期7天的远洋/底栖实地考察；2) BenDiM鞭毛藻的光、营养和行为特征的实验室研究，使其能够与近底浮游硅藻和微底栖植物成功竞争；3)物理-生物模型研究，以规划、整合和扩展现场和实验室结果。巡航计划应用标准UNOLS船舶能力，扩展仪器包括：1)一个Acrobat波动系统，配备了SeaBird - o2系统、Biospherical PAR、SeaPoint叶绿素和CDOM荧光计、SeaPoint浊度计、satatic ISUS硝酸盐传感器、brokeseas激光光学浮游生物计数器和通用海洋流量计，集成了GPS和回声探测定位系统，并能实时显示收集到的数据；2)FlowCAM; 3)自主垂直剖面仪（AVP）。实验室的努力应用了一个经过验证的运动分析系统来研究鞭毛动物的行为，以及一个发达的中游能力来研究鞭毛动物的生理、生物化学和行为。建模工作建立在现有的、生物强度建模方法的基础上，该方法结合了鞭毛藻生理学、生物化学和代表性物理领域行为的参数化。这种智力优势直接适用于“隐形”爆发，因为发展中的BenDiM生物质通常是看不见的，因为它发生在卫星探测的第一光学深度以下。BenDiM还涉及到碳输出的改进估计，因为在常规的生光带调查中可能会遗漏这种生物量，并且在营养关系中，因为这种生物量可能对食草动物有利或有害，这取决于在给定地点和时间内主导生态位的鞭毛类物种。更广泛的影响包括：NCSU和UNCW的研究生和本科教育；高中教师教育通过COSEE；在国家/国际会议上向同事传递信息；并通过COSEE的DVD向公众传递有关邮轮工作的信息。

Most applications of the standardized dinoflagellate diel vertical migration (DVM) hypothesis consider a surface goal in daylight and a subsurface nutrient goal at night because of the visibility of surface blooms. The sub-surface nutrient source, however, can be so deep that dinoflagellates are unable to reach the surface during a 12 h ascent. At least three literature reports document a sediment-oriented expression of an alternative DVM pattern characteristic of continental boundaries with wider, more gently sloping shelves that can yield high biomass, near-bottom dinoflagellate accumulations. The targeted dinoflagellate niche, here termed ''Benthic Dinoflagellate Migration'' or ''BenDiM'', is influenced by light and nutrient gradients but is unique in that a DVM exists between a nutrient source near or at the sediment-sea interface and a light intensity in the lower euphotic zone that supports a net increase in population size. The project specifically deal with: 1) the different dinoflagellate species that occupy the BenDiM niche on the continental shelf off Panama City, FL between the 60 m and 20 m contours between May and Nov; 2) the light acclimation, the nutrient uptake capabilities, and the behavioral patterns required of different dinoflagellate species that occupy the BenDiM niche; and, 3) the effect of representative physical water motion on the formation, transport and fate of the different BenDiM dinoflagellate species populations. The study includes: 1) a pelagic/benthic field program with three 7-day cruises during different months between May and Oct in 2008 and Jul-Aug 2009; 2) laboratory studies on the light, nutrient, and behavioral characteristics of BenDiM dinoflagellates that allow successful competition with near-bottom pelagic diatoms and the microphytobenthos; and 3) a physical-biological modeling study to plan, integrate and extend the field and laboratory results. The cruise program applies standard UNOLS ship capabilities extended with instrumentation that includes: 1) an Acrobat undulating system instrumented with SeaBird CTD-O2 system, Biospherical PAR, SeaPoint Chlorophyll and CDOM Fluorometers, Seapoint Turbidity, Satlantic ISUS Nitrate Sensor, Brooke-Oceans Laser Optical Plankton Counter, and General Oceanics Flow Meter with integrated GPS and echo sounding location system and a real-time graphical display of the collected data, 2) the FlowCAM, and 3) the autonomous vertical profiler (AVP). The laboratory effort applies a proven motion analysis system for studying dinoflagellate behavior and a well-developed mesocosm capability for studying dinoflagellate physiology, biochemistry, and behavior. The modeling effort builds on an existing, biologically intense modeling approach that incorporates parameterization of dinoflagellate physiology, biochemistry and behavior in a representative physical field. The intellectual merit directly applies to "stealthy" bloom initiation since the developing BenDiM biomass generally is unseen because it occurs below the first optical depth of satellite detection. BenDiM also is implicated in improved estimates of carbon export since this biomass may be missed during routine euphotic zone surveys and in trophic relationships since this biomass may benefit or harm grazers depending on the dinoflagellate species that dominates the niche at a given place and time. The broader impacts include: NCSU and UNCW graduate and undergraduate education; high school teacher education through COSEE; information transfer to colleagues at national/international meetings; and, information transfer to the public through a COSEE facilitated DVD on the cruise effort.