Eastern Hulafish (Trachinops taeniatus), Blue Groper (Achoerodus viridis)

As the clean-up continues on the Northern Beaches, water temperatures have dropped to 18 degrees in the aquatic reserve and only the most committed divers are venturing into the murky waters. Very few of our tropical visitors can survive temperatures below 19 degrees and so as the variety of fish life wanes for the next 6 months we can look forward to seeing the locals.

Schools of small Eastern Hulafish populate the reefs around the bay in large numbers, and the large Blue groper will be patrolling their rocky territories too. The Blue Groper is actually the biggest representative of the Wrasse family to be found in Cabbage Tree Bay. Born as brown coloured females the largest can perform an amazing change of sex to the blue male form, often when the dominant male is displaced from its territory.


A reminder from before the storm

The storms that hit the northern beaches last week have left waters murky, and the walkway between Shelly beach and Manly is in pieces. Concrete slabs have been lifted, the toilet block washed away and the bronze statue on the pool snapped. It will be interesting to see what tropical fish, if any have survived, as most of them linger in the shallows of what became an impact zone for 5m waves pounding relentlessly for two days.

Here are a few photos from Cabbage Tree Bay Aquatic Reserve (CTBAR) – do you know which ones are locals and which ones are summer visitors?


Black Bar Filefish (Pervagor janthinosoma)

This secretive fish is a tropical visitor often found within the aquatic reserve, hiding amongst cunjevoi and seaweed on the rocks. They dislike bright lights making it hard to get a good photograph. They often hang around in pairs and if you see them in the open they have gorgeous hues of the rainbows, rich blue lines in the ventral region turning to green, yellow and orange towards the tail. One of my favourite fish to find in CTBAR.