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Peralta-Maraver, I*; Reiss, J; Robertson, A: An overview of the hypoTRAIN network topics: hydrology, secondary production and the bioreactor ability of the hyporheic zone
Poster, SIL 2016, Torino, Italy: 2016-07-31 - 2016-08-05

Abstract:
The hypoTRAIN network is a multidisciplinary, international team of scientists who want to elucidate the importance of the hyporheic zone (HZ). Hyporheic zones are dynamic and complex transition regions between rivers and aquifers and they are characterized by the simultaneous occurrence of multiple physical, biological and chemical processes. Turnover and degradation of nutrients and pollutants are among the prominent ecological services the hyporheic zone provides. Here, we summarise current knowledge on the three main topics hypoTRAIN will tackle over the next three years. [1] Hydrology methods: Hydrology and substratum characteristics have great influence on the ecological processes and assemblage of organisms (hyporheos) in the hyporheic zone and therefore assessing these hyporheic features is critical in hyporheic ecology. Here we summarize and describe some of the most popular techniques used to assess hydraulic exchange and flow paths thorough the HZ, most of which have been almost exclusively used in the field of hydrology and engineering. [2] Secondary production: Although one of the main ecological processes of the hyporheos is their contribution to the production of the whole system, quantifying this production and comparing it with other river compartments is very rare. We conducted a literature search in order to compare invertebrate secondary production in benthic vs hyporheic zones (< 10 cm sediment depth) in different streams. We found that hyporheic zones contribute substantially (16-50%) to total invertebrate production in the channel. This supports previous studies which have stressed the importance of quantifying hyporheic secondary production and its potential role in the Allen paradox. [3] Bioreactor ability: Finally, it has also been proposed that productive and active communities maintain the bioreactor ability of the HZ to attenuate nutrient and pollutant concentration in freshwater ecosystems. Although the underlying mechanisms that result in this attenuation are still unknown, it is broadly accepted that bacterial activity plays a key role in this process. Concern over rising concentrations of organic micropollutants (such as pharmaceutical and personal care products) in streams and rivers has increased in recent years. We present a list of identified bacteria with the potential capacity to remove these micropollutants in the HZ and discuss how invertebrates and nutrient supply are involved in this process.

last modified 2016-11-23