In the other 90%: phytoplankton responses to enhanced nutrient availability in the Great Barrier Reef Lagoon
In the other 90%: phytoplankton responses to enhanced nutrient availability in the Great Barrier Reef Lagoon
复制标题
DOI：
10.1016/j.marpolbul.2004.11.010
复制
发表时间：
2005-01-01
影响因子：
5.8
通讯作者：
Brodie, J
中科院分区：
文献类型：
--
作者：
Furnas, M;Mitchell, A;Brodie, J
我们对水质如何影响大堡礁生态系统的看法主要是根据大型底栖生物（珊瑚、藻类、海草）对珊瑚礁沃茨中溶解营养物、沉积物和其他污染物水平提高的观察或预期反应而定的。然而，就营养物而言，底栖生物和群落主要是对以微藻（浮游植物）、原生动物、鞭毛虫和细菌为主的海洋生物群落循环和转化的物质作出反应。由于GBR沃茨的特点是高的环境光强度和水温，输入的营养物质从内部和外部来源迅速采取和转化为有机物的珊瑚礁间沃茨。浮游植物的生长、浮游生物的摄食和再矿化速度都非常快。GBR沃茨中的优势浮游植物种类具有每天近似1至数倍的原位生长速率。初步估计，浮游植物群落及其营养成分含量每天都在变化。溶解的营养物质的相对丰度强烈表明新的生物量形成的N限制。直接（N-15）和间接（C-14）的浮游植物N需求量的估计表明，溶解无机氮池周转时间的顺序小时到天。水体中无机磷的周转时间从数小时到数周不等。由于浮游生物群落对营养物质的迅速吸收，底栖生物群落对水质变化的生物反应更可能（在几个生态层面上）是由来自浮游生物初级生产的有机物而不是仅由溶解的营养物质所驱动的。皇冠版权所有（c）2004年出版的爱思唯尔有限公司保留所有权利。
Our view of how water quality effects ecosystems of the Great Barrier Reef (GBR) is largely framed by observed or expected responses of large benthic organisms (corals, algae, seagrasses) to enhanced levels of dissolved nutrients, sediments and other pollutants in reef waters. In the case of nutrients, however, benthic organisms and communities are largely responding to materials which have cycled through and been transformed by pelagic communities dominated by micro-algae (phytoplankton), protozoa, flagellates and bacteria. Because GBR waters are characterised by high ambient light intensities and water temperatures, inputs of nutrients from both internal and external sources are rapidly taken up and converted to organic matter in inter-reefal waters. Phytoplankton growth, pelagic grazing and remineralisation rates are very rapid. Dominant phytoplankton species in GBR waters have in situ growth rates which range from similar to 1 to several doublings per day. To a first approximation, phytoplankton communities and their constituent nutrient content turn over on a daily basis. Relative abundances of dissolved nutrient species strongly indicate N limitation of new biomass formation. Direct (N-15) and indirect (C-14) estimates of N demand by phytoplankton indicate dissolved inorganic N pools have turnover times on the order of hours to days. Turnover times for inorganic phosphorus in the water column range from hours to weeks. Because of the rapid assimilation of nutrients by plankton communities, biological responses in benthic communities to changed water quality are more likely driven (at several ecological levels) by organic matter derived from pelagic primary production than by dissolved nutrient stocks alone. Crown Copyright (c) 2004 Published by Elsevier Ltd. All rights reserved.