Cliff Seery

Toxicant Impact on Macroalgae Populations


Cliff Seery In light of increased awareness of marine contamination and pollution, the Aquatic Photosynthesis Group (APG) of the University of Technology, Sydney (UTS) has joined the movement that seeks to develop toxicological procedures that easily and rapidly assess the environmental impact of xenobiotics on vulnerable coastal habitats. In doing this, the lab has moved away from its previous studies on physiological/morphological aspects of Hormosira banksii and has started to investigate the use of this species as a biological indicator as part of a SPIRT (Strategic Partnerships with Industry - Research and Training) PhD program. The APG is among the world leaders in Pulse Amplitude Modulated (PAM) Fluorescence techniques, as evidenced by the other pages associated with this site. Furthermore, the work currently being done with H. banksii is an exclusive world-first to UTS. While there have been ecotoxicological applications of PAM Fluorometry previously, this is the first time a standardised bioassay has been investigated for development. This research is being supported by and in collaboration with the Marine and Freshwater Research Institute of Victoria (MaFRI). This government research group have been involved in the development and extended use of H. banksii bioassays for a number of years. The bioassays used by MaFRI are based on morphological events in early life-stages; thus, the tests take a period of days before a result is obtained. From this, it has been concluded that there is a need for a rapid, sensitive method that can be performed over a shorter time span and give reliable results as to the impact of potentially harmful chemicals. Together, the APG of UTS and MaFRI, with their respective expertise, plan to develop a fluorescence-based bioassay with H. banksii that will fulfil this need. The bioassay will be based around the Walz (Germany) fluorometer dubbed ToxY-PAM. Preliminary results suggest that H. banksii eggs or fertilized gametes will be exposed to a given toxicant for a set period, after which the photosynthetic capacity of the eggs/gametes will be assessed against a control by the ToxY-PAM fluorometer. Thus giving an indication of egg/gamete health and the potential toxicity of the tested xenobiotic. While it is this fast, sensitive test that forms the main part of the study, we are hoping to expand upon this to include other facets of H. banksii related fluorometry. Another of Walz’s fluorometers will be used in this study, the Microscopy-PAM. This instrument is capable of fast kinetics fluorometry, whereby the initial rise seen following a saturating pulse is broken down further in what is known as the JIP-test. It is hoped that the JIP-test and further developments made by the ABG will allow for identification of a signature curve that is specific to a broad class of contaminant. This development would give a great deal more information than the standard laboratory toxicity tests currently being performed and would provide a powerful tool in the identification of unknown toxicants, or identification of the toxic component of an unknown mixture. In addition to defining protocols for the use of ToxY-PAM and Microscopy-PAM with H. banksii, this study will investigate the toxicokinetics of a range of environmental pollutants with H. banksii. That is, investigating the pathways and sites of action for chemicals that affect the viability of H. banksii gametes. Though this part of the study is considered to be secondary and has yet to be fully considered. For more information on any of the above topics, contact Cliff Seery via email or return to this site periodically to check for updates as the study progresses