This is the fourth and last in a series of articles on the sharks detected by our listening station off Stanwell Park for the period June 2022 to May 2023 (12-month period since the station was installed).

Each shark has its own unique number. During the sampling period, 11 different animals visited Stanwell Park of which 7 visited only once. Sharks 795 and 953 visited on four separate occasions in December of 2022 but the frequent visitor award goes to Shark 778 which visited on seven occasions in January to March of this year.

The earliest a detected shark was first tagged was in 2016 and the rest were tagged in either 2019 or 2021. The majority were tagged in various stations in Sydney Harbour and the Whitsundays (Queensland). One was caught in the Manning River and one at Evans Head. Curiously it was two of the sharks that visited most often (778 and 795) that were first tagged in the Whitsundays.

Prior to being detected by our listening station bull sharks were detected in Wollongong, Maroubra, Cronulla, North Steyne and Kiama. This may reflect the fact that they are very coastal and even though most are tagged in northern NSW and they move along the coast a lot, we have not yet had any detections of fish that have missed listening stations before getting to Stanwell Park.

Bull sharks favour warm water, being more common when the water is above 20°C.

We got our first detection in December 2022 and the last one in April 2023, which certainly fits this research result. The graph shows the average water temperatures for Sydney by month (www.seatemperature.info). I could not get the specific monthly averages by month for 2022/23.

Listening stations were only installed in the Wollongong area in 2022 and drumlines were installed in March of that year, so it will be in the 2022/23 reporting year that we will get some better data that may help interpret what we are seeing.

Next year I will do an update as there will be two years of data and, hopefully, the background information from the DPI.