Date and location accuracy

I’m quite new to iNaturalist (so, I’m still learning) and I was wondering about how acurate we need to be with date and location. There was some big sand dredging by the south-west coast of Spain many years ago that filled the beaches with an amazing volume of seashells, and, being the child of a biologist :rofl:, I spent two whole weeks collecting specimens that I cleaned, classified and kept. I was thinking about taking pictures of them so I could add them as new observations, but I can’t give an exact location (since I was moving along the beach) or date (the seashells were collected for two weeks).

Would it be wrong if I just add the observation at some random point of the beach (it’s maybe a mile long) and just pick a day of those two weeks, as if all were gathered on the same day?

Also, if there’s something I should know about taking pictures os seashells to make the observation more useful, please give me all the tips you know. Thank you!! :smile:

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Welcome to the forum! Yes this is generally accepted. I would put the pin midway down the beach and enlarge the accuracy circle to include the entire possible location. You can indicate the situation in the notes, including something like “date ± 1 week.”

As for photographing seashells, it’s always best to include multiple angles. For snails, it’s particularly good to have an aperture shot looking inside the shell. For clams, inside and outside of both shells are ideal. In both cases it’s good to photograph the shells head on and not at an angle. The easiest way to do this is lay them in your hand, which also provides an indication of scale. Not exactly your region, but this website is very good:
http://www.idscaro.net/sci/04_med/index.htm

7 Likes

Yes this is fine, just make the accuracy circle big enough on the location and add a comment for the date range; I can’t really think of a plausible science use case that would care about (or trust) the accuracy of the specific day a seashell washed up on the beach several years ago was picked up; if the location is obscured they can only see the month anyway, so often the specific date might not be available.

The exact specific date can matter more for things migratory birds, bug emergences, and plant phenology. But again all of those have to contend with date obscuration sometimes anyway.

4 Likes

Welcome!

There’s zero issue with the location accuracy - just make sure the accuracy circle is big enough that you are certain the true location is inside. You can pin a location so that you can easily use it for all your observations.

Date accuracy is a little trickier, since there isn’t a formal way to note uncertainty in the data (though I agree with @thomaseverest that adding this info in the notes is a good idea. For some observations, a week’s uncertainty might be important. However, in the case of shells from a sand dredge, there’s already little importance to the exact day, so I don’t think this would be an issue.

You could also consider writing up a short journal post with info about all these observations (dates, your process for finding them, what you know about the dredging), and then link to it. Or you could make a project for all the observations to group them and write the post for that project. Neither of those are “required” they might just be interesting things you could do if you are interested.

2 Likes

Thanks so much, to all of you!! I agree that some of the shells might’ve been buried in the sand for who knows how long, so knowing the exact day they were collected may be kinda unnecessary, but better safe than sorry.

I’ll follow your advices, and try to include as much information as I can.

Or you could add a brief (copypasta) note to the obs - about the dredging. To give identifiers context.