The south coast of Western Australia is isolated from the major population centres of the world, but it is still subject to the impact of marine plastic. The many islands of the coast are home to a variety of sea bird species, including the Flesh Footed-Shearwaters (Ardenna carneipes). This species over winters in the Bay of Bengal and the North Pacific and then breeds on the Australian islands during the austral summer. During the breeding season these birds can be caught in nets as bycatch by the local pilchard industry where they compete for the fish during the last stages of chick rearing in April/May. However this provides the opportunity to routinely estimate the plastics load of this species. In October 2017 there was an unusual wreck of this species allowing us to compare the plastic load at the beginning and end of the breeding seasons in 2017. The Frequency of Occurrence of plastic for October was 60% compared to 20% in April/May. The processes that affect the plastic loads of birds may differ at the beginning and end of the breeding season. The birds may have imported plastic during their migration or consumed large amounts on arrival, while at the end of the season the local oceanography may reduce the availability of plastic. This research indicated that plastic – bird phenology is required to fully understand the interaction between fauna and plastic.