Nutrient bioindicators are increasi

Nutrient bioindicators are increasingly being recognised as a diagnostic tool for nutrient enrichment of
estuarine and marine ecosystems. Few studies, however, have focused on field translocation of bioindicator
organisms to detect nutrient discharge from industrial waste. The brown macroalgae, Sargassum
flavicans, was investigated as a potential bioindicator of nutrient-enriched industrial effluent originating
from a nickel refinery in tropical north-eastern Australia. S. flavicans was translocated to a number of
nutrient enriched creek and oceanic sites over two seasons and assessed for changes in stable isotope
ratios of 15N and 13C within the plant tissue in comparison to reference sites. Nutrient uptake in macroalgae,
translocated to the nutrient enriched sites adjacent to the refinery, increased 3–4-fold in d15N,
compared to reference sites. Using d15N of translocated S. flavicans proved to be a successful method
for monitoring time-integrated uptake of nitrogen, given the current lack of passive sampler technology
for nutrient monitoring