Strathprints Home | Open Access | Browse | Search | User area | Copyright | Help | Library Home | SUPrimo

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.

Item type: Article
ID code: 4579
Keywords: aquatic organisms, diffusion dispersal, drift, modeling, estuaries, tidal forcing, ecology, Human ecology. Anthropogeography, Probabilities. Mathematical statistics
Subjects: Geography. Anthropology. Recreation > Human ecology. Anthropogeography
Science > Mathematics > Probabilities. Mathematical statistics
Department: Faculty of Science > Mathematics and Statistics
Related URLs:
    Depositing user: Strathprints Administrator
    Date Deposited: 05 Nov 2007
    Last modified: 12 Mar 2012 10:41
    URI: http://strathprints.strath.ac.uk/id/eprint/4579

    Actions (login required)

    View Item