Fluctuation of the zooplankton community in Lake Biwa during the 20th century: A paleolimnological analysis

Narumi Tsugeki, Hirotaka Oda, Jotaro Urabe

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)

Abstract

Detailed zooplankton records from a 26-cm sediment core with a time resolution of approximately 3-10 years were obtained from Lake Biwa, Japan, to examine the historical variations in the zooplankton community during the 20th century. In the sediments, selected zooplankton remains have fluctuated over the years, Daphnia - large zooplankton herbivores - did not occur from 1900 to 1920, and formed a very minor component of the zooplankton community in the following 30 years, while Bosmina - small zooplankton herbivores - were common during this period. In the mid-1960s, however, when eutrophication was noticeable in this lake, Daphnia numbers increased dramatically and became the dominant zooplankton thereafter. In contrast, Difflugia brevicolla and D. biwae, two amoeboid protozoans that live in connection with the lake bottom environment, occurred abundantly until the late 1950s, but gradually decreased after the mid-1960s. In particular, D. biwae, a species peculiar to this lake, was not found in sediment dated after 1980, suggesting its extinction. These results indicate that the zooplankton community structure changed greatly in the 1960s, and suggest that the eutrophication occurring at this time altered the relative strength of top-down and bottom-up forces on the zooplankton community in Lake Biwa.

Original languageEnglish
Pages (from-to)101-107
Number of pages7
JournalLimnology
Volume4
Issue number2
DOIs
Publication statusPublished - 2003 Aug 1
Externally publishedYes

Keywords

  • Daphnia
  • Difflugia
  • Lake Biwa
  • Long-term changes
  • Zooplankton

ASJC Scopus subject areas

  • Ecology
  • Aquatic Science
  • Water Science and Technology

Fingerprint Dive into the research topics of 'Fluctuation of the zooplankton community in Lake Biwa during the 20th century: A paleolimnological analysis'. Together they form a unique fingerprint.

Cite this