The distribution, abundance and ecology of mixotrophic algae in marine and freshwater plankton communities
type: CreativeWork
description: Mixotrophic algae are algae that combine photosynthesis with phagotrophy to satisfy nutritional requirements. Mixotrophic algae have been found to dominate the nanoplankton assemblage in some aquatic environments, and algal phagotrophy can account for a significant fraction of total bacterivory on occasion. The distribution and abundance of mixotrophic algae have not been widely characterized, however, and the factors that control their abundances and phagotrophic activity in aquatic environments are poorly understood. The vertical distribution and abundance of mixotrophic nanoplankton was therefore documented in a variety of aquatic environments including the oligotrophic open ocean (Sargasso Sea), nine freshwater seepage ponds (Adirondack Mountains, NY) and three coastal salt ponds (Falmouth, MA) using epifluorescence microscopy and fluorescently labeled prey to trace ingestion by algae. Field experiments designed to examine the influence of prey density, nutrient availability and light intensity on mixotrophic nanoplankton abundances and their phagotrophic activity were also carried out to examine the adaptive significance of phagotrophy for mixotrophic algae in surface waters of the Sargasso Sea and in the epilimnion of one freshwater seepage pond. Mixotrophic nanoplankton abundances in the Sargasso Sea ranged from less than a few cells mi-l to more than 140 cells mi-l, and they were more abundant in surface waters. On two occasions rnixotrophic algae comprised more than 50% of the total algal nanoplankton assemblage in surface waters. The results of field experiments indicate that phagotrophy may provide mixotrophic algae in surface waters of the Sargasso Sea with major nutrients and may enable them to compete with purely phototrophic algae during periods of low nutrient concentrations. Mixotrophic nanoplankton abundances comprised a small fraction of the total algal nanoplankton ( <5%) in most of the freshwater seepage ponds and in all three coastal salt ponds…
abstract: Mixotrophic algae are algae that combine photosynthesis with phagotrophy to satisfy nutritional requirements. Mixotrophic algae have been found to dominate the nanoplankton assemblage in some aquatic environments, and algal phagotrophy can account for a significant fraction of total bacterivory on occasion. The distribution and abundance of mixotrophic algae have not been widely characterized, however, and the factors that control their abundances and phagotrophic activity in aquatic environments are poorly understood. The vertical distribution and abundance of mixotrophic nanoplankton was therefore documented in a variety of aquatic environments including the oligotrophic open ocean (Sargasso Sea), nine freshwater seepage ponds (Adirondack Mountains, NY) and three coastal salt ponds (Falmouth, MA) using epifluorescence microscopy and fluorescently labeled prey to trace ingestion by algae. Field experiments designed to examine the influence of prey density, nutrient availability and light intensity on mixotrophic nanoplankton abundances and their phagotrophic activity were also carried out to examine the adaptive significance of phagotrophy for mixotrophic algae in surface waters of the Sargasso Sea and in the epilimnion of one freshwater seepage pond. Mixotrophic nanoplankton abundances in the Sargasso Sea ranged from less than a few cells mi-l to more than 140 cells mi-l, and they were more abundant in surface waters. On two occasions rnixotrophic algae comprised more than 50% of the total algal nanoplankton assemblage in surface waters. The results of field experiments indicate that phagotrophy may provide mixotrophic algae in surface waters of the Sargasso Sea with major nutrients and may enable them to compete with purely phototrophic algae during periods of low nutrient concentrations. Mixotrophic nanoplankton abundances comprised a small fraction of the total algal nanoplankton ( <5%) in most of the freshwater seepage ponds and in all three coastal salt ponds…
author: Arenovski, Andrea L.
language: en_US
keywords: Marine algae, Phytoplankton, Endeavor (Ship: 1976-) Cruise EN234
date published: 1994-09
date modified: 2026-07-27T22:05:06Z
provider: Woods Hole Oceanographic Institute
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massachusetts Institute of Technology and Woods Hole Oceanographic Institution

PropertyValue
property ID: Handle
value: https://hdl.handle.net/1912/5582

PropertyValue
property ID: DOI
value: 10.1575/1912/5582