Seds, bugs and rocks that roll: faunal drivers of fluvial sediment dynamics Seminar

Bugs and other animals that live in rivers inhabit an environment shaped by physical processes of sediment erosion and deposition. The resulting habitat is a primary determinant of the biological health of river ecosystems. However, the opposite is also true – river plants and animals help to create their own habitat by modifying physical processes. For example, river animals affect sediment movements in rivers - bugs make rocks roll. The two-way interaction between biota and geomorphological processes was understood by Charles Darwin who's 'other' great book was about the zoogeomorphic agency of myriad earthworms. His perspective is now largely forgotten and replaced by a one-way view of the interaction in which habitat is seen as a simple determinant of ecological success; a view that is neatly captured by Kevin Costner’s mantra in the movie Field of Dreams, that “If you build it (the habitat), they (the animals) will come”. The engineering of rivers by wild animals is ignored in current explanations of sediment mobility, landform development and river restoration. This is an unfortunate omission, because sediment dynamics affect water quality, pollutant transfers, flood risk and the breeding success of iconic species like salmon. Developing a full understanding of the role of animals in the river sediment cascade would improve our ability to manage and restore rivers effectively. This argument will be illustrated using recent research investigating the role of invertebrates, crustaceans and fish in fluvial sediment dynamics.

 

 

pre-seminar excursion to the Chilworth flumes

14:15 – 15:45 Visit and tour of the Chilworth facilities – sign up!

Prior to Professor Rice's talk, Southampton University’s Earth Surface Dynamics research group (ESD) offers a tour of the Chilworth facilities. The visit will provide a glimpse of the cutting-edge of experimentation in aquatic sciences, and will allow plenty of discussion about future opportunities.

Ongoing work at Chilworth includes Hal Voepel’s flume experiments that investigate how particle scale structure affects river scale morphology. This work is part of an international NERC-funded research project on gravel bed streams by Dr. Julian Leyland (ESD), Dr. R. Hodges (Durham), David Sear, prof. S. Rice (Loughborough), prof. Kleinhans (Utrecht). In addition, Jack Bloomer’s PhD research at the Chilworth facility investigates the ecological and biological effects of exposure of salmonid embryos to different levels of hypoxia. The tour will highlight these ongoing studies as well as the wider technical capabilities of the facility.

There are a limited number of places on this tour, so sign up with Arjan Reesink soon! Email: a.j.reesink@soton.ac.uk