Picture of person typing on laptop with programming code visible on the laptop screen

World class computing and information science research at Strathclyde...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including by researchers from the Department of Computer & Information Sciences involved in mathematically structured programming, similarity and metric search, computer security, software systems, combinatronics and digital health.

The Department also includes the iSchool Research Group, which performs leading research into socio-technical phenomena and topics such as information retrieval and information seeking behaviour.

Explore

Population persistence in rivers and estuaries

Speirs, D. and Gurney, W.S.C. (2001) Population persistence in rivers and estuaries. Ecology, 82 (5). pp. 1219-1237. ISSN 0012-9658

Full text not available in this repository. Request a copy from the Strathclyde author

Abstract

A wide variety of organisms inhabit streams, rivers, and estuaries where they are continually subjected to downstream drift. It is well known that when this is the only transport process, extinction is inevitable (the "drift paradox"). Using a series of analytical and numerical models, representing a range of hydrodynamic scenarios, we demonstrate that the action of diffusive dispersal can permit persistence in an advective environment. The mechanism underlying this phenomenon is that diffusive dispersal can allow a proportion of the population to reproduce close to their natal location. For well- and poorly mixed non-tidal systems we establish approximate analytic conditions for diffusion-mediated persistence both throughout the water column and in a benthic boundary layer. Although tidal forcing results in residual landward flow near the base of the water column, we find that this has little effect on persistence, which is respectably approximated by our analytic results. We apply these analytic results to four hydrodynamically disparate systems: a stream (Broadstone Stream [UK]), a river (Christiana Creek [USA]), a shallow estuary (Ythan [UK]) and a deep fast-flowing estuary (Saco River [USA]). Using parameters derived from published studies we examine the persistence of a number of real and hypothetical organisms in these systems and identify those for which diffusively mediated persistence is a realistic possibility. We note that such persistence is only likely when advection is low or horizontal dispersal is high.