Date of Award

2009

Degree Type

Thesis

Degree Name

M.Sc.

Department

Great Lakes Institute for Environmental Research

First Advisor

Haffner, G.D. (GLIER Environmental Science)

Keywords

Health Sciences, Toxicology.

Rights

CC BY-NC-ND 4.0

Abstract

Factors regulating composition and relative abundance in phytoplankton communities were investigated in an ancient lake with a highly endemic food web. Lake Matano has genera diversity (21) similar to tropical lakes, but low phytoplankton biomass (0.0162 ug/L). Vertical mixing physically limits primary production (42% Zeu:Zm); phytoplankton are moved below the euphotic zone. Macronutrient concentrations (0.30 umol/L N, 0.13 umol/L P) are low. Nutrient bioassays used N and P (30-320 umol/L individually, 60:5-1920:160 umol/L N:P combined). After 16 days, no significant (p > 0.05) changes in relative abundance and no biologically significant changes in phytoplankton biomass occurred. CHU-10 growth media cultivation, however, significantly increased chl-a. Analysis identified Cr (0.14 umol/L) above a threshold to restrict algal growth (0.12 umol/L) and Mo (0.0005 umol/L) below requirements by most aquatic life (0.008 umol/L). Therefore, physical (mixing) and chemical (toxicity, micronutrient) factors are concluded to limit composition and relative abundance of phytoplankton in Matano.

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