Collaborative Research: THE BENTHIC MICROALGAL SUBSIDY IN ESTUARINE ECOSYSTEMS

河口是许多具有商业和娱乐价值的物种的重要栖息地。这些系统中食物网的基础由水柱(浮游植物)和沉积物(底栖微藻)中的微藻初级生产提供。本项目的重点是量化底栖微藻对南卡罗来纳州北入海口总生态系统初级生产力的贡献。然后使用沿海拔梯度(低潮至高潮区)的底栖微藻产量估计值来评估对即将到来的海平面上升的反应。这一结果对河口生态系统的湿地评估、碳信用、营养动力学和碳储存具有重要意义。这项研究具有变革性，因为它首次全面衡量潮间带、生态系统级别的底栖微藻对总净初级生产力的贡献，以评估生物多样性对河口生态系统过程和功能的生态重要性。研究结果可能会重塑我们对河口能量流动和循环过程的理解和现有范式。除了研究活动，该项目还包括对研究生和本科生的指导，努力从历史上代表性不足的群体中招收学生；将研究结果纳入教师和K-12学生的教材；以及与国家河口研究保护区合作的社区科学计划。我们目前对东南部河口生态系统净初级生产力的理解缺乏一个基本组成部分，实际上，它可能提供高达三分之一的固定碳，从而助长上层营养水平的高生物量。以底栖微藻为基础的主要补贴的概念与传统观点相矛盾，即浮游植物和以碎屑为基础的食物网是大多数东南部河口的唯一能源。该项目通过刻画BMA NPP的时空变异性来定量确定BMA的相对贡献，以估算年度生态系统水平对整个系统NPP的贡献。主要目标是测量河口潮间带生物量、生物量、群落组成和相关的环境变量(营养物质、颗粒大小、孔隙度等)。沿着从平均低水位到平均高水位跨越潮间带海拔梯度的固定横断面，将这些结果合并到地理信息系统数字高程模型中，以计算生态系统级别的BMA NPP。此外，地理信息系统模型预测了不同海平面上升情景导致的BMA NPP的等级和空间分布的变化。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Estuaries are nurseries that are critical habitat for many commercially and recreationally important species. The base of the food web in these systems is supplied by microalgal primary production in both the water column (phytoplankton) and the sediments (benthic microalgae). This project focuses on quantifying the contribution of benthic microalgae to total ecosystem primary production in the North Inlet Estuary, SC. Benthic microalgal production estimates along an elevational gradient (low to high tide region) are then used to assess responses to the impending sea level rise. The results have implications for wetlands valuation, carbon credits, trophodynamics, and carbon storage in estuarine ecosystems. This research is transformative in that it provides the first ever comprehensive measures of intertidal, ecosystem-level benthic microalgal contributions to total net primary production to evaluate the ecological importance of BMA for estuarine ecosystem processes and functions. The research results will likely restructure our understanding and current paradigms of energy flow and cycling processes in estuaries. In addition to the research activities, the project involves the mentorship of graduate students and undergraduates, with efforts to recruit students from historically underrepresented groups; incorporation of findings into educational materials for teachers and K-12 students; and a community science program in collaboration with the National Estuarine Research Reserve.Our current understanding of ecosystem net primary production in southeastern estuaries is missing a fundamental component that may, in fact, provide as much as a third of the fixed C fueling the high biomass of upper trophic levels. The concept of a major benthic microalgal-based subsidy contradicts the traditional views that phytoplankton and detritus-based food webs are the only energy sources for most southeastern estuaries. This project quantitatively determines the relative BMA contribution by characterizing the spatiotemporal variability in BMA NPP to estimate the annual ecosystem-level contribution to total system NPP. The primary objective is the measurement of estuarine intertidal BMA NPP, biomass, community composition, and relevant environmental variables (nutrients, grain size, porosity, etc.) along fixed transects that span the intertidal elevational gradient from mean low water to mean high water and incorporate these results in a GIS DEM to calculate ecosystem-level BMA NPP. Furthermore, the GIS model predicts shifts in the magnitude and spatial distribution of BMA NPP resulting from various sea-level rise scenarios.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.