A review of feeding preference and deterrence in three faunal species associated with cyanobacterial blooms of Lyngbya majuscula in southeast Queensland, Australia

Abstract

Potentially harmful blooms of the benthic cyanobacterium Lyngbya majuscula have been occurring with increased frequency and longevity over the last several years in coastal regions of subtropical southeast Queensland, Australia. Biotic interactions associated with bloom proliferation and demise are poorly understood. Highly variable levels of secondary metabolites within L. majuscula blooms (both temporally and spatially) may lead to feeding deterrence in macro-and mesograzers. The rabbitfish Siganus fuscescens is a highly motile generalist herbivore, which has been known to feed upon L. majuscula. Speculation that over harvesting of this commercially important fish may have been a factor associated with bloom proliferation led to suggestions that captive-bred siganids could be a potential biocontrol agent for these blooms. Opisthobranch molluscs often have a 'boom-or-bust' relationship with L. majuscula blooms. The sea hares Stylocheilus striatus and Bursatella leachii are known consumers of L. majuscula and have also been suggested as potential candidates for biocontrol of these nuisance blooms.