Water column nutrient concentrations are related to excretion by benthic invertebrates in Lake Taihu, China


Peng K., Qin B., Cai Y., Gong Z., Jeppesen E.

ENVIRONMENTAL POLLUTION, vol.261, 2020 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 261
  • Publication Date: 2020
  • Doi Number: 10.1016/j.envpol.2020.114161
  • Journal Name: ENVIRONMENTAL POLLUTION
  • Journal Indexes: Science Citation Index Expanded, Scopus, PASCAL, Aerospace Database, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chimica, Communication Abstracts, Compendex, EMBASE, Environment Index, Food Science & Technology Abstracts, Geobase, Greenfile, MEDLINE, Metadex, Pollution Abstracts, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Macroinvertebrates excretion, Internal release, Nutrient concentrations, PHOSPHORUS EXCRETION, AMMONIUM EXCRETION, DREISSENA-POLYMORPHA, SHALLOW LAKE, NITROGEN, SEDIMENT, RELEASE, MACROINVERTEBRATES, BLOOMS, RATES

Abstract

Internal release of nutrients is an important contributor to the nutrient dynamics in shallow eutrophic lakes. Zoobenthic organisms may contribute to this release by excreting nutrients to the overlaying water. Based on experiments and using results from previous experimental studies as well as field monitoring density data from 2007 to 2017, we calculated the annual and seasonal nutrient excretions of the two most common macroinvertebrates (Corbicula fluminea and Limnodrilus hoffmeisteri) in Lake Taihu, China. We compared these rates with the concentrations of NH4-N, total nitrogen (TN), PO4-P and total phosphorus (TP) in the lake water as well as with previous results of release rates from undisturbed sediments collected in the lake. The spatial distribution of nutrient excretion by the two invertebrate species varied markedly among sites and years. Regression analyses revealed significant relationships between total nutrient excretions by these two species and the concentrations of NH4-N, TN, PO4-P and TP in the lake, but with seasonal differences. The relationship was overall strongest in winter, followed by spring, and weakest in summer and autumn. The flux of NH4-N and PO4-P released by the two macroinvertebrate species were equivalent to as much as 50% and 66%, respectively, of the sediment release recorded in lab experiments under undisturbed conditions; however, the percentages would be somewhat lower under field conditions where the sediment is subjected to frequent wind-induced resuspension and fish disturbance, enhancing the release rates. The release declined during the study period due to a reduction in the density of macroinvertebrates, perhaps indicating increasing stocking of fish since 2007. Our results indicate that benthic invertebrates are important contributor to the internal loading in shallow eutrophic lakes. (C) 2020 Elsevier Ltd. All rights reserved.