Here are the current results from our invertebrate monitoring programme as they stand at the end of August 2015. Surveys will continue all year round as there are no fish present this far up the watercourse so we do not need to worry about disturbing their breeding cycle. This page should be regularly updated, probably around every four to five weeks, weather permitting. Updates will be posted on the blog with a link back to this page.


Regarding the data presented in the charts below, the Angler's Score Index (ASI), is intended to give an overall view of the health of the watercourse. It is a simple measure of the diversity of invertebrate life and the relative numbers present. It is not intended to be a definitive or thorough investigation, as the aim is to provide a quick means of assessing whether or not there is a problem that needs dealing with.


The first chart is for the current cycle of monitoring, beginning April 2015, so it will take a while to populate with data. The second chart down shows the results for the previous year. Results prior to that, can be accessed via the links at the bottom of the page (as they become available).


 Click on each chart to open it fullsize in a new window





We believe it is possible that there may have been a pollution event occurring during October and November last year. We will have a better idea of whether or not this is true once we have another years’ worth of data and can see whether a similar pattern in results emerges or not. We still don’t think that we can completely discount the possibility that the commencement of work on the Reap’s Moss Windfarm access road may have been a contributing factor.

It is also possible that the poor results at these times are as a result of heavy rainfall and increased flow in Midgelden Brook, washing much of the looser material on the bed downstream, taking many of the invertebrates with it.

Samples have been difficult to obtain due to large variations in the amount of flow higher up along Midgelden Brook.

Calderdale Council’s planned programme of drainage improvements along Bacup Road is well underway and we would be interested to note whether there is any associated effect on invertebrate life, as the new drains being installed will discharge into Midgelden Brook.