Problem 3.

Three different environmental studies are briefly described below. For each, indicate the type of study done (Study Guide: Figure 1.4), the kind of impact which was studied (Study Guide: Figure 1.5) and the aspect(s) of the system which were monitored (Study Guide: Figure 1.6).

a) In 2003, work started on building an LNG plant at Wickham Point in Darwin Harbour. For the plant to proceed, some parts of the sea floor in Darwin Harbour, near Wickham Point, had to be dredged to be deeper. One effect of this is the disturbance of the mud and a consequent increase in turbidity. One part of the environmental monitoring program was done by surveying coral in the harbour for bleaching events: events where the functioning of the coral’s symbiotic algae is disrupted, due, in this case, to decreased light levels. The corals were surveyed: the critical information recorded was the percentage of the coral in an area showing bleaching. This information was collected while dredging was occurring. (Once a certain level of bleaching occurs, dredging must stop.)

b) A fish farm is releasing effluent with high levels of nutrients into streams feeding into mangrove forests. Monitoring started some years before the first release and continues so long as the farm is operating. Several things are measured and recorded on a number of plots in the forest: (i) the growth of mangrove seedlings, in height (cm); (ii) the number of mangrove seedlings (in the plot); and (iii) the percentage cover of algae (in the plot).

c) INPEX, as part of its Ichthys Project, is building a LNG processing plant atBladydin Point in Darwin Harbour. INPEX is required to do regular monitoring during the construction phase to check for environmental impacts. One of these monitoring programs involves measuring the number, survival and growth of mangrove seedlings in permanent study plots at various locations around the harbour.