DIVERS have documented a rare sighting of a deep-water fish in the Port Coogee Marina.
The Stott’s goatfish was located by divers and marine scientists Glen Whisson and Alexandra Hoschke, who say the fish is not native to such a shallow environment like the marina and was a “highly unusual” sighting.
Mr Whisson says he “mistakenly” identified the Stott’s goatfish as the similar blue striped goatfish given how rare it is to see the former in such shallow waters.
“I thought it was that because very few people see [the Stott’s goatfish] as they’re deeper water fish,” Mr Whisson said.
“I only took one photo, and if I’d known, I would have stayed with it… in hindsight, it was special.”
• This Stott’s goatfish was a long way from its usual home.
Trawling
The Stott’s goatfish is typically found “in trawling grounds”, according to Mr Whisson, inaccessible to divers or snorklers which is why it is so rarely seen by the human eye.
“It’s been found quite deep out towards the near side of the continental shelf, but its depth range is documented as 30-60 metres,” Mr Whisson said.
“We spend thousands of hours in the water, and that’s the only time we’ve ever seen it… it was really exciting.”
Mr Whisson and Ms Hoschke conduct fish surveys of the Marina as part of their Aqua Research and Monitoring Services using transect lines scattered across the area, photographing any fish they see, unidentifiable or otherwise.
“If you could take an area like the marina, in the perfect world, you could shut it off from the ocean, drain it, and count, photograph, and identify every single fish that was there,” he said.
“We’ve got six transects of 100 metres each, and every three years we will swim those transects and we’re looking for any fish at all… we document everything through photography.
“The fun starts when you can dry off and download all of the photographs, and then we start the process of identifying what we’ve seen and categorising them.”
The information is then passed onto the City of Cockburn, but, as with ARMS’ other surveys, it’s also compiled into fish and marine species identification guides.
Mr Whisson “can’t definitively say” what caused the little goatfish to wander into shallower waters, but it could be interpreted as a sign of a biodiverse marine area.
“The fact that it’s a deep-water species coming into shallower water… there might have been a big weather event and lots of big swells,” he said.
“In the marina, we’ve seen lots of coral which is quite unusual, and we’ve logged not far off 100 species of fish and nearly 200 species of invertebrates… it’s great.
by KATHERINE KRAAYVANGER