Copepod communities related to water masses in the southwest East China Sea

Abstract

The East China Sea is characterized by a complex hydrographic regime and high biological productivity and diversity. This environmental setting in particular challenged a case study on the use of mesozooplankton community parameters as indicators of water masses. In order to reveal spatial patterns of zooplankton communities during summer, a large scale oceanic transect study was conducted. Two transects were taken in the southwest East China Sea region, covering for the Wrst time the China shelf, slope, and the estuaries of the Yangtze river and of the Minjiang river, the northern Taiwan Strait, and the Kuroshio Current region. A total of 77 copepod species were quantiWed. Copepod abundance was signiWcantly higher in the estuary of the Yangtze River runoV mixture waters and lowest at the Kuroshio Current Region. The calanoid Parvocalanus crassirostris was the most frequently occurring and abundant species retrieved from 27 samples of a total of 39 samples. The use of multivariate cluster analysis separated the Mainland China Shelf from the northern Taiwan Strait and the Kuroshio Current Region at the Wrst hierarchical level. The use of an indicator value method (IndVal) associated with each cluster of stations revealed characteristic species assemblages. Two hierarchical levels deWned 4 assemblages within geographical sectors representing copepod assemblages of the Kuroshio Current Region, of the northern Taiwan Strait and the southern China Shelf near the estuary of the Minjiang River and northern stations near the estuary of the Yangtze River. Overall, there was a strong correspondence between the distribution of certain copepod species and water masses. DiVerences between the Mainland China shelf, the northern Taiwan Strait and the Kuroshio Current Region were characterized by diVerences in species composition and abundance. Water mass boundaries in the study area were exclusively indicated by distinct diVerences in species composition, emphasizing a correlation between copepod communities and water masses of the southwest East China Sea in summer.

Copepod feeding study in the upper layer of the tropical South China Sea

“…Planktonic copepods are key organisms in aquatic ecosystems, because they are the most important link between the primary productivity of microalgae and the production of many fish species in the oceans (Irigoien et al 2002;Tseng et al 2008a). This has a qualitative and a quantitative dimension.…”

“…However, different zooplankton taxa play different roles with different impact. Copepods are probably the most abundant metazoans in the ocean (Schminke 2007) and constitute [90% of the total zooplankton abundance in the Taiwan Strait (Lo et al 2004), in the northeastern South China Sea (SCS) (Tseng et al 2008a) and other parts of the world's oceans (Froneman et al 2000).…”

Patterns of Zooplankton Distribution as Related to Water Masses in the Korea Strait during Winter and Summer

“…높은 종다양도 지수를 보이는 것은 일반화된 현상이다 (Tseng et al 2008). 특히, 난류를 따라 유입되는 요각류의 외양성 난류성 종에는 Eucalanus, Euchaeta, Undinula 속 …”

Trophic structure of the pelagic food web in the East China Sea

“…Extensive studies have investigated the spatiotemporal variation in the abundance or composition of larval fish (Okazaki and Nakata 2007;Hsieh et al 2011;Lefébure et al 2013), zooplankton (e.g., Liao et al 2006;Lan et al 2008;Tseng et al 2008), and phytoplankton (e.g., Gong et al 2006;Liu et al 2010;Gong et al 2011) in the ECS. Many of these previous studies used the abundance of neighboring trophic levels to explain the variation of the focal study group, but the multi-level trophic interactions and the factors regulating them remained to be investigated.…”