The seasonality of invertebrates across the sandy beach-dune ecotone

Coastal ecosystems support simply structured food webs, involving threatened shorebirds who rely on invertebrates for food. Moulting and breeding cycles observed in an obligate shorebird (hooded plovers) are suspected to be induced by winter food shortages, however evidence to support this assertion is currently lacking. How terrestrial invertebrates vary in abundance across both beach/dune habitats and seasons is poorly understood in Australia, and globally. This study examines and characterises seasonal patterns in invertebrates of sandy dune and beach habitats by measuring and indexing their abundance, diversity, and assemblage composition in a known hooded plover breeding site, Venus Bay in Victoria, Australia. Insects were found to dominate summer, spring and autumn assemblages compared to crustaceans which dominated winter assemblages. Morphospecies richness was lowest in winter, and constantly lower in dunes compared to beaches across all seasons. Abundance differed significantly such that both winter and summer, differed to autumn and spring, with abundance peaking in summer in the dunes and in winter on beaches. There were no distinct shortages of invertebrate abundance throughout the seasons, suggesting that at this location, there?s an unlikely winter food restriction for hooded plovers. A series of future research areas are highlighted to address the limitations presented in this study. If addressed, generalisability of the seasonal patterns reported here would be confirmed.