eCite Digital Repository
Impact of canal development on intertidal microalgal productivity: Comparative assessment of Patterson Lakes and Ralphs Bay, South East Australia
Citation
Cook, SS and Roberts, JL and Hallegraeff, GM and McMinn, A, Impact of canal development on intertidal microalgal productivity: Comparative assessment of Patterson Lakes and Ralphs Bay, South East Australia, Journal of Coastal Conservation, 11, (3) pp. 171-181. ISSN 1400-0350 (2008) [Refereed Article]
![]() | PDF Not available 433Kb |
Copyright Statement
The original publication is available at www.springerlink.com
Official URL: http://www.springerlink.com
DOI: doi:10.1007/s11852-008-0020-0
Abstract
We assessed the potential impact of a proposed
canal development in an estuarine sandflat at Ralphs Bay,
Tasmania on intertidal microalgal productivity and species
composition, by comparing it over summer and winter
seasons with a well- established (30 year old) canal estate at
Patterson Lakes, Victoria. Pulse amplitude modulation
(PAM) fluorometry was used to generate a relative measure
of photosynthetic performance, which combined with
microalgal chlorophyll biomass and irradiance provides an
assessment of potential primary productivity. We present a
sophisticated mathematical model for calculating benthic
microalgal production and the contribution to total primary
production, taking into account sediment light attenuation
as estimated from sediment grain size. Ralphs Bay had a
total productive microalgal biomass of 44 mg chlorophyll a
m−2 which was six times higher than Patterson Lakes, while
the relative productivity of Ralphs Bay was four times
greater compared to Patterson Lakes where productivity
was virtually absent in the subtidal zone of the canal
waterway. Ralphs Bay exhibited a more or less homogeneous
spatial distribution of microphytobenthos biomass
but this was subject to some seasonal variation in species
composition, abundance and productivity. By contrast, at
Patterson Lakes biomass distribution, diversity and productivity
was highly spatially variable in the canal system in
both seasons. Patterson Lakes exhibited 60% lower microphytobenthos
species richness than Ralphs Bay but little
variation in species composition occurred between seasons
in the canal estate. This suggests that the dominant diatom
species in Patterson Lakes, Pinnularia yarrensis, Gyrosigma
balticum and Pleurosigma salinarum, are well
adapted to the disturbance regime within the canal estate.
The proposed canal development at Ralphs Bay is
estimated to cause a decrease in microalgal productivity
by both reducing available marine substrate (66% reduction)
and replacing productive intertidal phytobenthic
habitat with nonproductive canal substrate. These combine
to cause a decline in productivity of 92% with significant
flow-on effects predicted for higher trophic levels such as
migratory wading birds.
Item Details
Item Type: | Refereed Article |
---|---|
Keywords: | Primary productivity . Canal development . Microphytobenthos . Ecological impact assessment |
Research Division: | Environmental Sciences |
Research Group: | Environmental management |
Research Field: | Environmental assessment and monitoring |
Objective Division: | Environmental Management |
Objective Group: | Terrestrial systems and management |
Objective Field: | Assessment and management of terrestrial ecosystems |
UTAS Author: | Cook, SS (Dr Suellen Cook) |
UTAS Author: | Roberts, JL (Dr Jason Roberts) |
UTAS Author: | Hallegraeff, GM (Professor Gustaaf Hallegraeff) |
UTAS Author: | McMinn, A (Professor Andrew McMinn) |
ID Code: | 54355 |
Year Published: | 2008 |
Deposited By: | IASOS |
Deposited On: | 2009-02-18 |
Last Modified: | 2014-11-07 |
Downloads: | 3 View Download Statistics |
Repository Staff Only: item control page