Is conscientious beachcombing the key to 'unlock' marine plastic pollution trends through citizen science? A case study from Cockburn Sound, Western Australia.

Despite the global implementation of plastic waste reduction policies and bans on single use plastics (SuPs), their effectiveness for protecting marine ecosystems remains unclear. Frequent monitoring could confirm policy effectiveness, but this is difficult due to resourcing and logistic constraints. This study tested a 'beach litter' beachcombing citizen science approach that could overcome some constraints. Between November 2018 and January 2021, 168 beach visits led to the collection of 12,659 pieces of litter from a beach in Western Australia. Litter was predominantly plastic (87%) and mostly associated with fishing/boating (34%). Significant reductions in six types of litter, including fishing/boating items, balloons, and straws were detected and four coincided with local government waste mitigation measures. We show potential to harness conscientious beachcombers as citizen scientists to help evaluate plastic policy impact. Furthermore, we propose how to harness this effort and increase spatial and temporal coverage of marine plastic pollution monitoring.

Microcystins associated with Microcystis dominated blooms in the Southwest wetlands, Western Australia.

Potentially toxic cyanobacterial blooms are becoming common in the freshwater wetlands on the Swan Coastal Plain, Western Australia. During summer the dominant bloom-causing species belong to the genera Microcystis and Anabaena and to a lesser extent Aphanizomenon and Nodularia. Although toxic cyanobacteria have been recorded in the Swan-Canning and Peel-Harvey estuaries in Western Australia, very little is known about the blooms in the surrounding freshwater lakes. In this study, a total of 32 natural bloom samples representing 13 lakes were analyzed by HPLC for microcystin (MC)-LR, -RR, and -YR. Twenty-eight samples proved to be toxic. The highest total microcystin concentration ranged from 1645 to 8428.6 microg L(-1), and the lowest concentrations were less than 10 microg L(-1) with some below the detection limit (< 0.05 microg L(-1)). MC-LR (100%) was the predominant microcystin, followed by MC-YR (71.4%) and MC-RR (60.7%). The presence of a Nodularia spumigena bloom in the freshwater Lake Yangebup was associated with the detection of nodularins (1664 microg L(-1)). This is the first study to demonstrate the presence of microcystins and nodularins in urban lakes on the Swan Coastal Plain, Western Australia.

Interesting biological activities from plants traditionally used by Native Australians.

Four plants routinely used for medicinal purposes by Native Australians were screened for various biological activities. Methanol extracts of Eremophila maculata, Acacia auriculoformis and Acacia bivenosa exhibited antibiotic effects, while Eremophila alternifolia yielded an extract that induced significant changes to the heart activity of spontaneously hypertensive rats. We report on these biological activities.