This may
prove to be very useful in designing integrated effluent treatment
systems which remediate and recirculate or release pond discharges
in an environmentally responsible way. Preliminary work undertaken
in this area (DEEDI unpublished data) suggests that the sand bed
filtrate is ideally suited to the culture of macrophytes such as
Enteromorpha sp. and Ulva sp., which offer a sink for dissolved
nutrients, and several economic advantages to farming operations
including useful natural feeds (Palmer et al., 2009). This is because the
sand beds help mediate several factors which have previously created
difficulties for seaweed culture systems using untreated prawn pond
water (eg. suspended solids which foul foliage and block light: Jones
et al., 2002; phytoplankton which compete for available nutrients,
and proliferation of herbivorous invertebrates like amphipods:
Palmer, 2005). A further ability to deliver a pulse of concentrated
dissolved nutrients (which may have been fortuitously demonstrated
in this study and is the subject of ongoing investigations) may further
aid in the development of integrated macrophyte culture systems for
nutrient recovery in the future.