Diving into the past…

Despite being a year where many people couldn’t get on, and in, the water as often as they may like, 2020 saw the Australasian Fishes project continue to grow in both the number of observations and the total number of species. Nearly 27,000 observations were added to the project in the last year, 4000 more than 2019, taking the total to over 100,000 observations (Figure 1). Approximately 1,400 species were observed in 2020 by Australasian Fishes users, including 97 previously unrecorded, increasing the total number of species in Australasian Fishes database to nearly 2,500 (Figure 2).
Figure 1: Number of Australasian Fishes observations per year between 1962 and 2020 excluding years with no observations.
Figure 2: Number of fish species observed per year (green bars) and the total number of species recorded by the Australasian Fishes project (black line) between 1962 and 2020.
One of the most striking trends from these graphs is that there are relatively few observations and species prior to 2018. This is hardly surprising, given the Australasian Fishes project started at the end of 2016, however, it highlights the huge potential for increasing the Australasian Fishes database through the addition of older observations.
We know the underwater world is a very dynamic environment. Reefs are constantly changing, species disappear, and new ones arrive in their place. Rocks are cleared of algae and sponges by big storms, and even whole new reefs can appear from the beneath the sand before eventually being buried again. Many Australasian Fishes contributors may have observed such changes, having visited the same sites over years or even decades.
Chris Roberts (@cj_roberts) is a PhD candidate at UNSW Sydney researching how underwater photos and videos can be used as an alternative data source to monitor reefs. The research is also looking at whether old photos can be used to document how reefs and the species inhabiting them have changed through time. In addition to fish, this research will also be looking at changes in mobile invertebrates, as well as the reef attached organisms such as algae and sponges. The main reason for the creation of a separate project to Australasian Fishes is to gather underwater observations of ALL marine life in one place.
To gather old underwater observations for this research we have set up an iNaturalist project called In Bygone Dives (https://www.inaturalist.org/projects/in-bygone-dives). If you have older underwater photos, you can assist this research by joining the In Bygone Dives project and upload some of your older observations (but don’t forget to also add your old fish observations to the Australasian Fishes project). If digging through your archives to find and upload your old photos seems like a daunting task, we would encourage you to start with your oldest photos, as these will be relatively more valuable as historical data simply due to their being less observations further back in time (although all observations are extremely valuable!). If you already have older observations on iNaturalist, you could also add them to the In Bygone Dives project (to add observations already on iNaturalist to new projects in bulk/batches, message @cj_roberts for instructions).
If you’re thinking ‘I don’t have old dive photos’, well, we all know ‘old’ is relative, and this research is looking at change through time using photos from pioneer diving days through to more recent years. So, you can enjoy looking back at diving memories, and by adding them to In Bygone Dives, you’ll also be helping our reefs and how we conserve and manage them in the future.
For more info about the project visit www.inbygonedives.com or message @cj_roberts directly on iNaturalist.
This journal post was written by Australasian Fishes member, Chris Roberts.
Posted by markmcg markmcg, February 09, 2021 00:52



What I find impressive is that the cumulative number of species continues to rise with hardly any tailing-off (so far). Surely this can't last much longer??

Posted by nyoni-pete 3 months ago (Flag)

@nyoni-pete I agree that there will come a time when the species numbers slow down. The reason it hasn't happened so far is the increasing number of contributions from new members and also, I suspect, because we recently loaded a 'data sets' of trawled fishes from deep water.

Posted by markmcg 3 months ago (Flag)

Great project @cj_roberts I look forward to hearing about what you find.

Posted by amandahay 3 months ago (Flag)

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