Angelo Coast Range Reserve

21 Jul, 02 PM - 18 Aug, 06 AM

Larval members of the caddisfly genus Glossosoma, and most other members of the benthic stream community, prefer a certain flow regime and have physiological or life history adaptations specialized for their microhabitat. In many cases the signature flow for specific organisms has yet to be quantified and the nascent theories addressing why they prefer a certain near-bed flow regime found in current literature are largely speculative. This study explores the different scales at which patterns arise in Glossosoma distribution, and is an attempt to progress in the description of where and why Glossosomatid caddisfly larvae live where they do. Methods and principles applied here are generalizeable to many members of the benthic community. Spatial stream velocity and turbulence patterns are shown to correlate with grazer distribution on the centimeter to meter scale, defining more specifically accepted patterns in Glossosoma distribution (they prefer riffles (stream reach scale), and can dominate streams when conditions are right in watersheds with drainage areas >2km (watershed scale? McNeely and Power, 2008)). This study also outlines the pros and cons of using various types of acoustic Doppler velocimeters and field deployed PIV instrumentation to quantify relevant flow parameters at different depths over a square meter in a stream riffle, and proposes experimental methodology useful for obtaining field ADV profiles and surface PIV imagery. Describing preferred flow regime lends direction to the investigation of why caddisfly larvae only inhabit certain locations in rivers, which is currently recognized opportunity for further research (Galbraith et al., 2008). The data obtained will hopefully lead to better understanding and perhaps predictive ability for armored grazer success in a stream reach based on either surface, depth averaged, or near-bed dimensionless flow parameter (Froude number, Reynolds number based on shear velocity, etc...) patterns.

Visit #15762 @Angelo Coast Range Reserve

Approved

Under Project # 8203 | Research

Influence of local fluid flow on larval caddisfly distribution and behavior

graduate_student - University of Minnesota

Reservation Members(s)

Mark Morris Jul 21 - Aug 18, 2008 (29 days)

Reserve Resources(s) | Create Invoice

Computer lab 1 Jul 21 - Aug 18, 2008
Fox Creek Lodge 1 Jul 21 - Aug 18, 2008
Lab 1 Jul 21 - Aug 18, 2008