Onion Trevally - another new record for Sydney Harbour

According to the Australian Faunal Directory, the Onion Trevally occurs in tropical waters from off Exmouth Gulf, Western Australia (22º05´S) to off Newcastle, New South Wales (32º52´S).
For this reason, we were surprised to see John Sear's observation of an individual at Clifton Gardens. This is the first known observation of the species from Sydney Harbour. It's also the 7th time a species has been observed in the harbour for the first time since the 2022 publication of the Sydney Harbour fishes paper by DiBattista and colleagues.
When asked about his observation, John stated, "It was right at the end of my dive. I was heading towards the shore in about 2m of water when I came across three of them. I realised immediately that it was a trevally I wasn't familiar with due to body shape and fin size. With very little air left I only had a few minutes to get a shot and they weren't keen to have their photographs taken. To overcome backscatter in silty water I try to get as close as possible to the subject, but it's easy to overexpose the shot with trevally as strobe light reflects back from the silver body. To fix that I either reduce the strobe output, or point the strobes outwards."
We are delighted that John managed to take such excellent photos despite starting to run out of air and the inherent challenges of photographing trevallies. Thanks John for adding yet another species to the steadily growing Sydney Harbour fish list.
Joseph D. DiBattista, Tanika C. Shalders, Sally Reader, Amanda Hay, Kerryn Parkinson, Robert J. Williams, Jemina Stuart-Smith and Mark McGrouther, 2022. A comprehensive analysis of all known fishes from Sydney Harbour. Marine Pollution Bulletin 185. pp 1-13. View paper
PS. In different publications the species is sometimes referred to as Carangoides caeruleopinnatus or Turrum coeruleopinnatum.
Publicado el junio 1, 2023 12:38 MAÑANA por markmcg markmcg


@johnsear Great observation also a great photo considering all the strobe setting changes you had to make quickly before they took off & running low on air also, well done. Ken

Publicado por ken_flan hace alrededor de 1 año

Question: is this observation a result of Climate Change and water warming?

Publicado por muffy hace alrededor de 1 año

Hi @muffy. Many people think that these southern sightings are due to warming waters and climate change. I am one of them. Having said that, we can't be 100% sure. The Australasian Fishes Project contributes to Redmap. You may find this report of interest. https://www.redmap.org.au/article/report-card/. Thanks for your interest. :)

Publicado por markmcg hace alrededor de 1 año

That's a great find and photo!

Publicado por biniek-io hace alrededor de 1 año

What a valuable sighting!

Publicado por anagaisiner hace alrededor de 1 año

Thanks for your comment @anagaisiner. We really need to track down some Siphamia for you!

Publicado por markmcg hace alrededor de 1 año

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