CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Marine & Freshwater Research   
Marine & Freshwater Research
Journal Banner
  Advances in the Aquatic Sciences
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Board
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Sample Issue
For Authors
General Information
Instructions to Authors
Submit Article
Open Access
For Referees
General Information
Review Article
Referee Guidelines
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter youtube

 

 Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.


Benthic algal assemblage changes following environmental flow releases and unregulated tributary flows downstream of a major storage

Alec Davie, Simon Mitrovic

Abstract

A large dam reducing the magnitude of flows regulates the Severn River, Australia. Environmental flows (EFs) designed to increase the magnitude of flow and improve ecological outcomes such as reducing filamentous algal biomass and re-setting algal succession. The effectiveness of EF releases to alter benthic algae assemblages is poorly understood. We examined benthic algal biomass and assemblage structure at two cobble dominated riffle sites downstream of Pindari Dam before and after two EFs. Both EFs had discharges of ~11.6 m3s-1 (velocity of ~0.9 ms-1). Neither EF reduced benthic algal biomass but sometimes led to increases, with some filamentous algae density increasing (Stigeoclonium and Leptolyngbya). An unregulated flow from a tributary between the two sites increased discharge to 25.2 m3s-1 (velocity of ~1.2 ms-1), decreasing biomass and filamentous algal density. The similarity in flow velocities between scouring and non-scouring events suggests that thresholds may exist and/or suspended sediments carried from unregulated tributaries may contribute to reduce algal biomass. Identifying velocities needed to reduce algal biomass are useful. Accordingly, EFs with flow velocities ~1.2 ms-1 may achieve this in river cobble dominated riffle sections dominated by filamentous algae. Lower flow velocities <0.9 ms-1 may result in no change or an increase in filamentous algae.

MF13225  Accepted 23 March 2014
 
© CSIRO 2014



Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2014