US GLOBEC: Maintenance of Pseudocalanus spp. Populations in Georges Bank

美国GLOBEC：太子鱼的维护乔治斯银行的种群Ann Bucklin和Dennis J.McGillicuddy浮游的桡足类兄弟种--Pseudocalanus mortoni和P.Newmani，在乔治斯海岸的春夏两季交配出现。尽管它们在形态上有明显的相似之处，但它们在生态的许多方面都不同，包括：分布和丰度的模式；首选栖息地；以及繁殖的季节性时机。与P.Newmani相比，P.mortoni在60米等深线内的乔治海岸混合良好的顶部上更加丰富(Bucklin等人，1998，Mar.Biol.，在印刷中)。我们假设，在乔治斯浅滩，莫尔托尼螺旋藻的种群是通过本地繁殖和补充来维持的，并且该物种通过与物理过程(潮汐混合锋的动力学)有关的行为(垂直分布)而不同地保留在沿60m等深线的潮汐混合锋内。这一假说将通过描述与环流模式(基于1999年1月至6月收集的大尺度调查样本)和与潮汐混合锋区平流和混合有关的三维小尺度分布(建议于1999年5月和6月进行的现场试验期间)与环流模式(基于1999年1月至6月收集的大尺度调查样本)有关的岸宽、特定阶段的分布和丰度来检验。这项工作的目标是了解梅尔托尼氏杆菌如何在乔治斯浅滩复杂多变的流场中持续和繁殖。技术方法将是使用物种特定的竞争性聚合酶链式反应来识别莫尔托尼螺旋体的所有生活期，并利用在已知物理场中观察到的分布进行数值模拟实验。该项目的意义在于了解种群动态和海洋过程之间的相互作用，以确定乔治斯浅滩浮游动物组合的重要成员的分布和丰度。

U.S. GLOBEC: Maintenance of Pseudocalanus spp. populations on Georges BankAnn Bucklin and Dennis J. McGillicuddy The planktonic copepod sibling species, Pseudocalanus moultoni and P. newmani, occur sympatrically during the spring and summer on Georges Bank. Despite their marked morphological similarity, the species differ in many aspects of their ecology, including: patterns of distribution and abundance; preferred habitat; and seasonal timing of reproduction. In comparison to P. newmani, P. moultoni is more abundant on the well-mixed crest of Georges Bank within the 60 m isobath (Bucklin et al., 1998, Mar. Biol., in press). We hypothesize that populations of P. moultoni are maintained on Georges Bank by local reproduction and recruitment, and that the species is differentially retained within the tidal-mixing front located along the 60 m isobath by behavior (vertical distribution) in relation to physical processes (dynamics of the tidal-mixing front). This hypothesis will be tested by characterization of Bank-wide, stage-specific distribution and abundance of P. moultoni and P. newmani in relation to circulation patterns (based on Broadscale Survey samples collected from January to June, 1999) and three-dimensional small-scale distributions in relation to advection and mixing in the tidal-mixing front (during field experiments proposed for May and June, 1999). The goal of this work is to understand how P. moultoni may persist and proliferate in the complex and variable flow field over Georges Bank. The technical approach will be to identify all life stages of P. moultoni using species-specific competitive PCR, and to perform numerical modeling experiments using observed distributions in a known physical field. The significance of this project is to understand the interplay between population dynamics and ocean processes in determining the distribution and abundance of important members of the Georges Bank zooplankton assemblage.