No, I don't think so. There's not really a universal standard for sampling time when collecting benthic macroinvertebrates across microhabitats. It varies quite a bit depending on protocol and purpose. The key is consistency. Whatever time you choose, document it clearly and apply it uniformly across all your sampling locations.

If you're designing a new protocol, I'd suggest doing pilot samples to determine the minimum time needed to capture representative diversity in your specific microhabitats.

What specific ecosystem are you working in?

Lorenzo Ricolfi : thank you for your help. It means a lot. My work is focusing on macroinvertebrate in river ecosystem.

If u don't mind, I'd ask the following questions regarding that:

If I do replication at each of my sampling locations, is there a standard about distance between replication 1, replication 2, and other replications?

How the best way to design it so that the distance between each replications is representative enough of the existing environmental conditions but not heterogeneous because it could be that I am sampling too close between replications.

Are there any standard about that? Or do you have any suggestion regarding that?

There is an ISO standard for sampling benthic organisms: ISO 1983: Water quality -Methods of biological sampling - handnet sampling of aquatic benthic macroinvertebrates: International Organization for Standardization ISO/DP 8689 I don't have the standard at hand, but I bought a copy several years ago... The standard describes the shape of the net, and the method for taking kick samples. I think it was about 15 min/sample and 3 parallels at each station.

Arne Andersen Thank you for your suggestion.

If u don't mind, I'd ask the following questions regarding that:

If I do replication at each of my sampling locations, is there a standard about distance between replication 1, replication 2, and other replications?

How the best way to design it so that the distance between each replications is representative enough of the existing environmental conditions but not heterogeneous because it could be that I am sampling too close between replications.

Are there any standard about that? Or do you have any suggestion regarding that?

I don't remember if I've seen any "standard" distance. Personally, I use three parallels at each station, where the samples are taken with "meters" distance. Three samples on the same substrate. To cover an entire watercourse, I take samples at different stations. Placed so that they cover the variation in the watercourse. See example on map:

Arne Andersen Thank you for the new insight. It means a lot.

Maybe my last question is:

For example I want to try sampling in 2 different locations, like main stream and tributary. But when I did preliminary sampling before I only took samples in the main stream, not in the other location.

So I don't have an idea where I will determine the location point of the tributary that I will take samples when I do Main Sampling later in the future.

Any suggestions related to that?

I think it is an advantage to take samples in tributaries at a distance where they are not affected by the main stream. Another thing is that you can take samples in the main stream before and after tributaries, to see what the input means. "Forking" is a method for finding unknown inputs: Take samples at the top, in the middle and at the bottom. If the upper part is negative, you can do a new test between the middle and the bottom. Or vice versa, if the upper part is positive. In this way, you can reduce the area where the source is searched. (Such orienteering surveys should of course be as simple as possible.)