Predation effect on copepods by the giant jellyfish Nemopilema nomurai during the early occurrence stage in May in the northern East China Sea and southern Yellow Sea, China. (January 2023)

• Record Type: Journal Article
• Authors: Wang, Peng-peng; Zhang, Fang; Sun, Song
• Is Part Of: Marine pollution bulletin. Volume 186(2023)
• Publication Date: 2023-01
• Subjects: Jellyfish bloom -- Scyphomedusae -- Predation pressure -- Zooplankton -- Diet -- Prey competition; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2022.114462
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Massive blooms of Nemopilema nomurai have occurred recently across East Asian waters. They are potentially important as zooplankton predators, as well as being competitors for prey with zooplanktivorous fish. Few studies have estimated the predation effects on zooplankton by N. nomurai in situ. To quantify the natural diets and feeding rates and estimate the predation effects, N. nomurai medusae were collected in the northern East China Sea and southern Yellow Sea, one of the principal nursery grounds of this jellyfish, during May 2019. The gut contents indicated that copepods were an important food source for N. nomurai ; copepods <1000 μm represented the bulk of total prey intake in number (> 99 %). Linear regression analyses showed that the copepods number in the gut contents was significantly influenced by medusa diameter and prey abundance. Calculations using the above data indicated that one medusa (mean diameter: 26.06 ± 9.73 cm) consumed approximately 5248 ± 2768 of copepods daily. However, even the maximum predation pressure was <0.1 % of the total copepods standing stock daily due to the small diameter and low density/biomass of N. nomurai medusae in May 2019. The data presented here suggested that the predation effects of N. nomurai on copepods were low and might not reduce prey availability to fish with diets consisting mainly of copepods during the early occurrence stage of the N. nomurai population. Highlights: Copepods were an important food source for Nemopilema nomurai population in the northern East China Sea and southern Yellow Sea. The copepod number in the gut content was significantly influenced by medusa diameter and prey abundance. The predation effects of N. nomurai population on copepods were low during the early occurrence stage.