Amphipods fail to suppress the accumulation of Ulva lactuca biomass in eutrophic Yundang Lagoon

作     者：ZHENG Xinqing HUANG Lingfeng WANG Qian LIN Rongcheng 

作者机构：Third Institute of OceanographyState Oceanic Administration Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems Xiamen University College of the Environment and Ecology Xiamen University China Ocean Press 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2014年第33卷第12期

页      面：155-162页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 071004[理学-水生生物学] 

基　　金：The Natural Science Foundation of Fujian Province under contract No.2014J01127 the Public Science and Technology Research Funds Projects of Ocean under contract Nos 201205009-3 and 201105012 

主　　题：amphipods Ampithoe valida consumption gross growth efficiency secondary production,Ulva lactuca 

摘      要：The Gross growth efficiency （GGE） is defined as the amount of consumer carbon produced relative to the amount of prey ingested in a given time interval. In population ecology, it can be considered as an index for the ability of a consumer to convert the biomass of food into its population production. In this study, it was firstly applied to estimate the role of amphipods grazing in the biomass dynamics of macroalgae （Ulva lactuca） in Yundang Lagoon （a subtropical eutrophic coastal lagoon, Xiamen City, China）. It was found that amphipods were the dominant group （82.2%-98.7%） in the benthic assemblage, in which five amphipod species （Corophium uenoi, Ampithoe valida, Grandidierella japonica, Grammaropsis laevipalmata andCa-prella panantis） were observed in the lagoon. However, onlyA. valida significantly consumedU. lactuca among these amphipod species. A series of experiments were conducted to estimate the consumption of U. lactuca byA. valida. It was suggested that the monthly secondary production （P） ofA. valida using size frequency method ranged from 2.39 to 13.68 g/***. valida exponentially reduced with body size and was closely associated with water temperature. Therefore,GGE equation for different months using the temperature recorded during the field investigation was fitted. The monthly consumption ofU. lactuca was figured out to be 86.7-1 549.0 g/m2 by the sum of consumption （P/GGE） byA. valida at different size, ac-counting for 2.0%-37.5% ofU. lactucaproduction. It indicates that the grazing effect ofA. valida did play a role in reducingthe accumulation ofU. lactucabiomass whenA. valida was abundant, but it finally fails to limit the U. lactucagrowth in Yundang Lagoon. Low abundance of A. valida and high nutrient loading may be two major reasons for the outbreak ofU. lactuca bloom in the lagoon.