Variability of Stable Isotope Ratios of Glassfish(Ambassis jacksoniensis) from Mangrove/SaltmarshEnvironments in Southeast Australiaand Implications for Choosing Sample Size

摘要

Stable isotopes offer an accurate and cost-effective way to understand critical pathways ofenergy, and their use has application where aquatic habitats have been degraded.Isotope ratios can offer insights into appropriate conservation and rehabilitationtechniques to manage these valuable resources. To date, the literature shows littleattention to spatial and temporal variation in isotope signatures of samples taken fromestuarine environments. This study reports on an investigation of sample size by whichto determine isotopic signatures within a single species of fish, Ambassis jacksoniensis.Provided are two ways by which to determine how many samples are needed, and theresults imply that care may be needed in interpreting previous studies based on smallsample size. A minimum of five individuals would appear necessary in some cases.