Discover the waterways of south-east Queensland: waterways health and catchment management of south-east Queensland, Australia

Marine viruses have been shown to affect phytoplankton productivity; however, there are no reports on the effect of viruses on benthic microalgae (microphytobenthos). Hence, this study investigated the effects of elevated concentrations of virus-like particles on the photosynthetic physiology and community composition of benthic microalgae and phytoplankton.

Effluent water from shrimp ponds typically contains elevated concentrations of dissolved nutrients and suspended particulates compared to influent water. Attempts to improve effluent water quality using filter feeding bivalves and macroalgae to reduce nutrients have previously been hampered by the high concentration of clay particles typically found in untreated pond effluent. These particles inhibit feeding in bivalves and reduce photosynthesis in macroalgae by increasing effluent turbidity.

Trace metal run-off associated with urban and industrial development poses potential threats to seagrasses in adjacent coastal ecosystems, Seagrass from the largest urban (Moreton Bay) and industrial (Port Curtis) coastal regions in Queensland, Australia were assessed for metal concentrations of iron (Fe), aluminium (Al), zinc (Zn), chromium (Cr) and copper (Cu), Trace metal concentrations in seagrass (Zostera capricorni) leaf and root-rhizome tissue had the following overall trend:

The impact and recovery from exposure to the herbicide diuron [DCMU; 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea] was assessed for three tropical seagrasses, maintained in outdoor aquaria over a 10-day period. Photosynthetic stress was detected using chlorophyll a fluorescence, measured with a Diving-PAM (pulse amplitude modulated fluorometer).

Several coastal areas in southeast Queensland, Australia have been affected by blooms of the cyanobacterium Lyngbya majuscula Gomont ("Mermaid hair"). Lyngbya majuscula blooms have caused respiratory irritation, eye inflammation and severe contact dermatitis in fisherman and swimmers as well as causing reduced fish catch, seagrass loss and localized inputs of nitrogen through nitrogen fixation.

Survival and recovery of the seagrass Halophiln ovalis (R.Br.) Hook during and after light deprivation was investigated to assist in the interpretation of recent losses of Halophiln spp. in Queensland, Australia. Light deprivation experiments were conducted in outdoor aquaria and in situ at two water depths. Halophiln ovalis plants were deprived of light for a maximum of 30 days, and recovery processes were investigated for up to 18 days following 15 days of light deprivation.

Rapid global expansion of the aquaculture industry has prompted the need for development of techniques for effective environmental management. In intensively farmed regions, aquaculture effluent has resulted in environmental degradation of receiving waters. The issues to be addressed include analysis of effluent water quality, determination of the ecological impact of effluent on the ecosystem, and development of remediation strategies to reduce these impacts.

Microbial nutrient cycling in seagrass sediments

Factors limiting phytoplankton biomass in the Brisbane River and Moreton Bay