What fishes live at my dive site?

Let’s say you dive or fish regularly at a particular location. One of the terrific features of iNaturalist that may be of interest to you is the ability to produce a list of the fishes that have been observed at that location, or indeed any location. To give you a quick example, let’s take the Kurnell region in Sydney. Just enter “Kurnell” in the Location search box (see red ellipse on the left image above) and over 1800 observations of 153 species are retrieved. You can view these observations as a grid of photographs, a list of species, or as points on a map (see orange ellipse). The data can be easily downloaded as an excel file by clicking on the Filters button then choosing Download.
Retrieving observations by locality and displaying a grid of individual species photographs can make identifying a fish much easier. Again, an example would be instructive. Suppose you have photographed a butterflyfish you didn’t recognise while diving at Lord Howe Island. Simply enter “butterflyfishes” in the Species search box and “Lord Howe Island” in the Location search box (right image above), then click the orange Go button. Finally click on the species tab which will display a gallery showing an image of each butterflyfish species observed at Lord Howe Island. Of course, this gallery only shows butterflyfish species for with the Australasian Fishes Project has observations. Your photograph might show a species that has not been recorded from the region, in which case please upload it. 😊
A powerful feature of iNaturalist that you may not be aware of is the ability to create your own ‘Places’. Many Australasian Fishes Project members regularly upload observations of fishes washed up on particular beaches. They might find it useful to define their own places on which they can search. To do this, first check that your area of interest doesn’t already exist by typing the name of your place of interest into the Location search box. If it doesn’t appear, you can define your own place by clicking on “Places” (see left image below), then clicking on the "Add a New Place" button. Finally, draw a polygon that encloses your area of interest and give it a name. The right image below shows a polygon drawn around Exmouth Gulf, Western Australia. Feel free to set up your own personal places, perhaps for your favourite dive location, angling spot or even your research locality.
Posted by markmcg markmcg, June 17, 2021 04:57


One important thing/tip for places that some people might not know about. If I search for all fishes in Australia (https://www.inaturalist.org/observations?place_id=6744&taxon_id=47178), I get 90,394 observations (as of my search at this exact second). However, as Mark would know, this doesn't include all Australian observations! The borders for the iNat place 'Australia' end pretty shortly after going past the coastline, and include very little coastal waters. This means a lot of observations from small, remote offshore tropical islands, fishing trawlers, etc, don't get captured. Instead, they fall under a place called 'Australia Exclusive Economic Zone'. So you can search Australia and the AEEZ simultaneously (https://www.inaturalist.org/observations?place_id=6744,118147&taxon_id=47178), which now bumps me up to 98,408 observations (and indeed bumps up the species count from 1957 to 2268).

Posted by thebeachcomber 4 months ago (Flag)

One potential bias is that people tend to only report the unusual, or species that they can't identify. I know I often only photograph the uncommon species, and the bias also exists in museum collections. Often the only way around this is to extrapolate from the extreme records (e.g. southern-most and northern-most), and assume that a given species occurs in suitable habitat inbetween those extremes. That's a reasonable conclusion, but isn't an ideal approach, and the common species would not turn up in iNaturalist report-based checklists. Just something to be aware of.

Posted by anthonygill 4 months ago (Flag)

Thank you for your comments @thebeachcomber and @anthonygill. :) I was going to mention in the journal post that when defining an area it's important to 'be generous' with the polygon. If the place is too tightly defined, observations that have a vaguely defined locality (ie a big circle on the map) won't be retrieved in a search because part of the locality falls outside the defined place. For the sake of brevity I didn't include this information but am delighted to be able to mention it in response to your comment. With regard to the issue of bias towards uncommon fishes, I agree that this occurs and could be an issue if someone regards the search results for an area to be truly indicative of the species mix. That's why when I take photos, I try to shoot all species present. :)

Posted by markmcg 4 months ago (Flag)

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