Literature Review
Compiled by Leanne Sparrow and Kirsten Heimann
School of Marine and Tropical Biology, James Cook
University
ISBN 9781921359149
First Released June 2007
Published by RRRC September 2008
MTSRF Project 2.6.1 -
Indentification and impact of invasive pests in the Great Barrier
Reef
Abstract
Algal blooms are defined as
increased abundance, biomass or population growth. This review
reveals knowledge gaps regarding bloom initiation and nutrient
preferences and is divided into four parts.
Part one investigates
nutrient effects and challenges the paradigm of macroalgal growth
limitation by nitrogen in temperate – but phosphate in
tropical regions. Macroalgal nutrient preferences are
phyla-specific; diatoms are iron and nitrate co-limited;
preferences for other phytoplankton remain to be
determined.
Parts two and three
investigate global distributions of algal blooms. Macroalgal blooms
are restricted to tropical regions and associated with reduced
herbivory and disturbances, i.e. cyclones. Macroalgal succession
patterns indicate a potential role in reef recovery.
Since phytoplankton blooms
occur in all climatic zones, seasonality was included in part
three. Diatoms bloom in summer in the tropics but in spring and
autumn in all other regions. In contrast, dinoflagellates and other
harmful algae bloom in spring in the tropics and any season in
other regions, showing strong temperature dependence.
Part four shows that the colonial
bloom-forming microalga, Chrysocystis fragilis – a
new record for the Great Barrier Reef – exhibits some
macroalgal traits; blooms occur at high temperatures in
oligotrophic conditions, if coral cover is compromised by the
crown-of-thorns starfish or bleaching.
