There is considerable variation in the objectives and methods of biological sampling projects, which generally makes it impractical to set a standard price for processing samples. Below is a list of factors that influence the cost of processing a macroinvertebrate sample; there are similar considerations for periphyton, plankton and fish samples.
Probably the most important factor in determining the effort required, and therefore the cost, of processing a macroinvertebrate sample is taxonomic effort (resolution). Generally the higher the taxonomic resolution, the greater the cost (family vs. genus vs. species). Adding specialized groups, (i.e. Chironomidae, Oligochaeta) also increases cost. Most bioassessment protocols call for genus/species level identifications. In the past, chironomids were often left at family, but identification to at least genus is becoming more routine. In impacted systems, where a large portion of your taxa richness is in chironomids and worms, identification of both those groups to the lowest possible level may be important.
100, 200, 300, 500 counts, complete sorts, 1/4 samples, 1/2 samples… The second most important factor in determining cost is subsample size. The more invertebrates we have to look at, the greater the cost. Fixed count methods are generally less expensive than proportional subsampling as we can more easily predict the effort that will be necessary to process the sample. Full (complete) sorts are the most unpredictable and therefore usually the most expensive. For these samples we often bill hourly, or bill on a sliding scale, depending on the final number of individuals processed.
Other less influential, but still important, factors affecting sample price are the mesh size used to collect the samples (e.g. 250, 500 micron), habitat from which they were collected (e.g. riffles, depositional zone, etc.), type of water body (river, lake, stream, etc.), area of benthos sampled, preservative used (we have to charge extra for dealing with formalin), and season in which the samples were collected.
A final, non protocol based factor involved in price is the required turn-around time. Normally projects are processed on a first come, first served basis so TAT is largely a factor of how busy we are. However, if it absolutely must be done now, we offer an express service which moves your samples to the front of the line, but does involve an increase in price.