Document of bibliographic reference 345400

BibliographicReference record

Type

Bibliographic resource

Type of document

Book/Monograph

Type of document

Dissertation

BibLvlCode

M

Title

Copepods dominate the mesozooplankton spring-summer community in a South Norwegian fjord

Abstract

In this study the seasonality of the mesozooplankton community in spring and summer of 2019 at Midtfjordsskjær (MFS), South Norway, was investigated. Zooplankton samples were collected using a fine mesh sized plankton net (60 μm) and zooplankton were identified by microscopy based on 5 ml subsamples. Total zooplankton abundance ranged from 754 – 1620 ind. M^-3 and peak abundance was found in May. Holoplankton dominated spring and summer communities at MFS constituting between 85,6 – 98,8% of total zooplankton. Copepods were the biggest contributors to the zooplankton community at MFS during spring and summer with abundance ranging between 707 – 1474 ind. m-3 (85,3 – 96,4%) of total zooplankton abundance. All copepod life stages were found in spring and summer and copepod nauplii were an important part of total copepod abundance and constituted between 21,4 – 74,7% in spring and summer. Cyclopoid copepods were the most abundant group in spring and were dominated by Oithona spp.. Calanoid copepods became more abundant among the copepods in summer and were dominated by Acartia spp. And Paracalanus/Pseudocalanus spp. copepodites. Microsetella spp. dominated among the harpacticoid copepods and was mostly found in spring. Meroplankton abundance was low throughout the study period and constituted maximum 14,4% of total zooplankton abundance. Polychaeta and Cirripedia dominated the meroplankton in spring, while Polychaeta and Gastropoda dominated in summer. A cluster analysis based on Bray-Curtis similarities among samples indicated a division of the zooplankton communities in three main periods; early spring (March), which corresponded to the pre-bloom phase in the phytoplankton community, spring (April – May) which corresponded to the bloom – late bloom phase of the phytoplankton community and summer (June – July) which represented a period of low algal biomass.

Bibliographic citation

Monrad, K. (2021). Copepods dominate the mesozooplankton spring-summer community in a South Norwegian fjord. MA Thesis. University of Agder: Kristiansand. 45 pp.