Adam,
I'm not familiar with that area, but with that water temp most fish will shut down. Did you try around the gladesville bridge? Have heard of a few Jew been pulled from there! The bait is spot on, so might have been the water or just an unlucky day for you! Try middle harbour or port stephens, the Jew are firing up this way! Good luck! Hopefully someone else can add some info.
Cheers scratchie!!!