Looking to sample net spinning caddisflies in deep water but also want to look at colonisation at different depths. I am thinking of using a pole eg 5 m with multiple Hester-Dendy attached along its length.
Thanks in advance.
This is a hard question to answer without a little more information, specifically depth, the number of substrate samplers on any particular pole/line (drag), channel velocity at the sampling location, anchoring mechanisms, and the amount of potential debris that could damage the suite of samplers.
I have seen networks of samplers deployed on relatively low-gradient rivers, they tend to be attached to high tensile lines attached to trees and submerged 1 to 5 m depending on river stage. Using a line allows for some flexibility for debris impacts (large wood) but makes getting a precise depth reading difficult if not impossible (except for the bottom sampler). Without knowing your river system I would recommend trying out a few different techniques and see which will work best in terms of recoverability, repeatability, and statistical design.
We have used hester dendy samplers in a large river situation using anchors and large bouys with the samplers suspended from a separate, weighted line off the bouy. The bouys and sampler lines were monitored for debris on a weekly basis and were cleared as needed.
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