Thank you Javier,

But if it possible only macrobenthos not in meiofauna, i may right?

AFDW we loss the specimens also

yes, i work only on the macro benthos and I use Ash-free Dry Weight, but you're right, it destroys the sample. It is therefore definitely validate the determination to make the biomass. Nonetheless a reference collection can be realized, for further verification.

Yes, indeed, it destroys the sample. You can use AFDW for macrobenthic fauna. For meiofauna I have seen other authors using conversions such as that proposed by Widborn (1984):

Widbom, B., 1984. Determination of average individual dry weights and ash-free dry weights in different sieve fractions of marine meiofauna. Mar. Ecol. Prog. Ser. 75, 101–109.

That should solve the problem.

Good luck!

If you want to keep the specimen(s) then blotted wet weight is what to use. There are papers with conversion factors for AFDW, or you could do some tests and make your own conversion factors. Usually for biomass, AFDW is used after removal of carbonate by physical or acid methods as appropriate.

I think that it depends the objetive of your research, the samples amount and the scale considered. I mean if you are studing production, ash free dry weight or dry weight I think that it is the best way to do that. However, if you are studing community structure of a lot of species maybe with % of surface, wet weigh, biovolume or categorized abundance (e.g. Braun-Blanquet scale) is enough, because if you transform the data or a very precise value is not representative, it can be a waste of time.

Biomass and productivity of mobile invertebrates communities can be estimated by washing samples through a series of sieves (for example, 8, 5.6, 4, 2.8, 2, 1.4, 1, 0.71, and 0.5 mm mesh sizes), then using the general equations of Edgar (1990), which predict individual biomass as a function of sieve mesh size, and production as a function of individual biomass and water temperature.

Edgar GJ 1990. The use of the size structure of benthic macrofaunal communities to estimate faunal biomass and secondary production. Journal of Experimental Marine Biology and Ecology 137(3): 195-214.

Yah, ash-free dry wight

Yes Mehrnoosh Darya,

If my doubt is if it possible in Macrofaunal organisms while what about meiofaunal organisms particularly in nematodes

I hope that this paper can be helpful for you. All the best Kapuli!

Good afternoon, Cai and Lizhe report a equivalences in their paper, we have the oportunity to compare linear and nonlinear estimation and ignition method with the concordance coefficient correlation to evaluate reproducibility, and the equivalences showed the highest values.

The nematodes could be biomass values if they have high density, or you have an analytical balance with precision of 0.0001.

Have a nice week

I agree with Ian above, the methods of Edgar are very efficient for macrofaunal samples, however note that for the largest sieve specimens still must be measured by hand and individual length/ weight relationships thus developed.

Would you consider a surogate such as ATP? (still a destructive test).

see Holm‐Hansen, O. (1969). Determination of microbial biomass in ocean profiles 1. Limnology and Oceanography, 14(5), 740-747.

As others have stated, it depends on the objective of the study.