Kick sampling is a standard and widely used method for sampling the invertebrates living on the bed of a stream or river. It involves placing a net in the direction of flow, with open net mouth facing upstream. The biologist kicks the substrate in front of the net for a standard period of time and the dislodged organisms are carried into the net for counting and analysis.
This technique became established in the mid 1970’s, with organisations such as the Institute of Biology and the US Environmental Protection Agency adopting its use. Today kick-sampling is the accepted standard around the world for collecting comparable samples from stream beds.
However working in the early part of the 1900’s Kathleen Carpenter, a pioneering freshwater ecologist in Wales, carried out an extensive survey of the rivers around Aberystwyth. It is evident from her papers archived in the National Library of Wales that she was a very thorough fieldworker. Here is the description of the sampling strategy she developed before kick-sampling.
“The method adopted is as follows: first , as large a number as possible of stones in the bed of the stream are turned over and any Molluscs, Insect-larvae etc. adhering to them are picked off. Next, water is squirted over the surface of the stone into a jar, to wash off any smaller forms.
Samples of mud from the bed and edges of the stream are then taken, and the roots of any submerged vegetation are well scraped with the sharp edge of a collecting- net, to dislodge individuals which may be sheltering among them.
Masses of the weed are brought away, and are subsequently well shaken in water, and, finally, weed, mud and water are looked over carefully with first a hand lens and then a binocular dissecting microscope, lest any small species should escape observation.
A small silken tow-net is also dragged along the surface of the water to collect Copepoda etc.
When all these precautions have been taken, an afternoon’s collecting may yield the harvest of a dozen species – except in one of the richest streams, that is to say! ”
Kathleen Carpenter used these samples to produce simple lists of species and to compare the differences in biodiversity between rivers polluted by metal mine water and more pristine river systems. There is no indication given in her papers that she was assisted in the field so what other practical precautions would a woman pioneering ecologist have to take when contemplating climbing into a stream? Although after World War One women were able to adopt more practical work clothes, including trousers, we do not know what Kathleen Carpenter wore. Clearly it would be difficult and potentially dangerous to kick sample in a long skirt! Our early women aquatic biologists coped with some exceptional social challenges including what to wear.
You are invited to come hear more about the life of Kathleen Carpenter at my International Women’s Day public lecture at Aberystwyth University on the evening of 7th March 2016 – details here.