Prior to 2010 weedy seadragons could still be found in reasonable numbers within CTBAR, then they disappeared suddenly. Whilst water temperatures may have appeared to have increased slightly the annual fluctuations between 14-23 degrees is typical for their range. Their food source, mysid shrimps, remain in abundance, so what caused their rapid decline. They are now extremely rare within the reserve, whilst still common in other areas of Sydney. Having spent close to 20 hours diving systematically looking specifically for this species I have only found 3 individuals, whereas previously you could almost guarantee seeing several in certain locations on a single dive.
Was it disease, or illegal collecting, or maybe some other condition such as water quality that caused their demise?