The hydrology of the upper Swan River Estuary with focus on an artificial destratification trial

2001 ◽  
Vol 15 (13) ◽  
pp. 2465-2480 ◽  
Author(s):  
David P. Hamilton ◽  
Terence Chan ◽  
Malcolm S. Robb ◽  
Chari B. Pattiaratchi ◽  
Michael Herzfeld
Keyword(s):  
River Estuary ◽  
Artificial Destratification ◽  
Swan River

scholarly journals Artificially oxygenating the Swan River estuary increases dissolved oxygen concentrations in the water and at the sediment interface

2019 ◽  
Vol 128 ◽  
pp. 112-121 ◽  
Author(s):  
Sarah J. Larsen ◽  
Kieryn L. Kilminster ◽  
Alessandra Mantovanelli ◽  
Zoë J. Goss ◽  
Georgina C. Evans ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
River Estuary ◽  
Swan River ◽  
Sediment Interface ◽  
Oxygen Concentrations

Nutrient limitation of phytoplankton in the upper Swan River estuary, Western Australia

1996 ◽  
Vol 47 (4) ◽  
pp. 659 ◽  
Author(s):  
PA Thompson ◽  
W Hosja
Keyword(s):  
Nutrient Limitation ◽  
Chlorophyll A ◽  
Phytoplankton Community ◽  
River Estuary ◽  
Early Summer ◽  
Phosphate Silicate ◽  
Cell Densities ◽  
And Control ◽  
Swan River ◽  
Second Peak

During 1993-94 the phytoplankton community in the upper Swan River estuary had a peak chlorophyll a concentration of 57 mg m-3 during early summer (December 1993) and a second peak of 35 mg m-3 during late autumn (May 1994). Mid summer was characterized by low cell densities and low chlorophyll a concentrations. The potential of the phytoplankton community for nutrient limitation was assessed with dilution bioassays given nutrient mixes deficient in one of the following: nitrogen, phosphate, silicate, iron, trace metals, chelators, or vitamins. During the mid-summer period of low phytoplankton abundance, nitrogen was the nutrient with the greatest potential to limit algal biomass. During mid summer, ambient N:P ratios tended to be near unity and bioassays indicated that the available pool of N was up to 20 times more limiting to biomass development than was available P. Also during mid summer, bioassay treatments given no nitrogen and control treatments given no nutrients showed little growth, reaching chlorophyll a concentrations -1/30th of those given a full suite of nutrients. Chlorophyll a concentrations in the bioassay control treatments given no nutrients were correlated (r2 = 0.74) with measured surface nitrate concentrations; this suggested that nitrate inputs may be a major factor controlling phytoplankton biomass in this ecosystem. The correlation between surface nitrate concentration and rainfall (r2 = 0.69) further suggests that rainfall may be the most important mechanism supplying nitrate to the surface waters of this estuary.

Studies in Australian Estuarine Hydrology. II. The Swan River

1956 ◽  
Vol 7 (2) ◽  
pp. 193 ◽  
Author(s):  
RS Spencer
Keyword(s):  
Recovery Period ◽  
River Estuary ◽  
Barometric Pressure ◽  
Tidal Mixing ◽  
Lunar Tides ◽  
Eastern Australia ◽  
Mean Water Level ◽  
Tidal Characteristics ◽  
Basin Region ◽  
Swan River

The physiography of the Swan River is described, with particular reference to the drowned valley basin which is connected to the sea across a shallow sill. The climatological features of the region are discussed, together with the tidal characteristics of the basin. Drought conditions prevail during the summer, effective rainfall being confined to the winter months. Density stratification in the basin is intense and prolonged, because of the weakly developed tidal mixing. Changes in the mean water level of the basin are correlated with variations in barometric pressure; the amplitude of these changes sometimes exceeds that of the lunar tides. This fact has a significant bearing on hydrological conditions within the basin. The distribution and the seasonal cycles of temperature, chlorinity, and oxygen saturation are compared with those of a tidal-dominated estuary situated at the same latitude In eastern Australia. Most of the differences in these cycles can be attributed to the tidal regimes of the two systems. Nutrient cycles within the Swan River basin are discussed with particular reference to the recovery period following the development of stratification. In the later stages of the investigation this period was studied intensively, and from the information obtained several theories are advanced to explain the circulatory features of the basin region. An attempt is made to classify the Swan River estuary.

scholarly journals Diversity and abundance of epibiota on invasive and native estuarine gastropods depend on substratum and salinity

2015 ◽  
Vol 66 (12) ◽  
pp. 1191 ◽  
Author(s):  
Jakob Thyrring ◽  
Mads Solgaard Thomsen ◽  
Ane Kirstine Brunbjerg ◽  
Thomas Wernberg
Keyword(s):  
Environmental Factors ◽  
Native Species ◽  
Linear Models ◽  
River Estuary ◽  
Generalised Linear Models ◽  
Future Studies ◽  
Shell Type ◽  
Five Factors ◽  
Wide Scale ◽  
Swan River

Our understanding of variation in epibiota communities remains incomplete. This study relates such variability to multiple concurrent environmental factors. Specifically we determined the relative importance of salinity, depth, wave exposure, habitat and ‘shell type’ (shell type combined species, size, morphology and mobility traits) for community structure of sessile epibiota on gastropods in the Swan River Estuary, Australia. We quantified distribution, biofouling patterns, and detailed epibiota community structures on gastropod species in the estuary – the native Nassarius pauperatus and Bedeva paiva and the invasive Batillaria australis. The invasive Batillaria was much more abundant, and more biofouled, than any of the native species, thereby supporting orders of magnitude more epibiota in the estuary. Generalised linear models were used to partition variation in richness and abundance of epibiota among the above listed factors. Of the five factors were only shell type and salinity significant in 9 of 14 models. These results highlight (1) that a single invasive species can alter epibiota communities on a large system-wide scale, (2) an overwhelming importance of shell type and salinity in explaining estuarine epibiota communities, and (3) that additional environmental factors need to be included in future studies to improve predictive models of distribution for epibiota communities.

scholarly journals Reproductive biology of Rhabdosargus sarba (Sparidae) in Western Australian waters, in which it is a rudimentary hermaphrodite

2003 ◽  
Vol 83 (6) ◽  
pp. 1333-1346 ◽  
Author(s):  
S. Alex Hesp ◽  
Ian C. Potter
Keyword(s):  
Reproductive Biology ◽  
Western Australia ◽  
River Estuary ◽  
Marine Waters ◽  
Spawning Period ◽  
Shark Bay ◽  
Males And Females ◽  
First Maturity ◽  
Swan River ◽  
Western Australian

The reproductive biology of the tarwhine Rhabdosargus sarba has been studied in three very different environments in Western Australia, namely the lower reaches of the Swan River Estuary and marine waters at the same latitude, i.e. ≈32°S, and a large subtropical marine embayment (Shark Bay) approximately 800 km further north. A macroscopic and histological examination of the gonads demonstrated that R. sarba is typically a rudimentary hermaphrodite in Western Australian waters, i.e. the juveniles develop into either a male or female in which the ovarian and testicular zones of the gonads, respectively, are macroscopically undetectable. This contrasts with the situation in the waters off Hong Kong and South Africa where R. sarba is reported to be a protandrous hermaphrodite. Although R. sarba spawns between mid-late winter and late spring in each water body, the onset of spawning in the estuary is delayed until salinities have risen well above their winter minima. Although males and females attain sexual maturity at very similar lengths in the Swan River Estuary and Shark Bay, i.e. each L50 for first maturity lies between 170 and 177 mm total length (TL), they typically reach maturity at an earlier age in the former environment, i.e. 2 vs 3 years old. During the spawning period, only 25 and 12% of the males and females, respectively, that were caught between 180 and 260 mm TL in nearshore marine waters were mature, whereas 94 and 92% of the males and females, respectively, that were collected in this length-range over reefs, were mature. This indicates that R. sarba tends to move offshore when it has become ‘physiologically’ ready to mature. The L50s at first maturity indicate that the minimum legal length in Western Australia (230 mm TL) is appropriate for managing this species.

Arthur James McComb 1936–2017

2018 ◽  
Vol 29 (2) ◽  
pp. 184
Author(s):  
Jen McComb
Keyword(s):  
Plant Growth ◽  
State Government ◽  
River Estuary ◽  
Ecosystem Approach ◽  
Aquatic Systems ◽  
Nutrient Analysis ◽  
Plant Growth Hormones ◽  
Shark Bay ◽  
Consulting Firms ◽  
Swan River

Professor Arthur McComb conducted pioneer research on the occurrence and mode of action of the plant growth hormones gibberellins for fifteen years. He then applied his experimental skills and physiological knowledge to develop a whole ecosystem approach to the study of aquatic systems. He was passionate in wanting to improve the state of environmental management, based on rational, logical and well-founded biological principles. He and his team focused primarily on the mechanisms controlling plant growth and productivity in aquatic environments, and especially the effects of nutrient enrichment and its consequences, eutrophication. He became a leader in nutrient analysis of water systems, with innovations in how to determine nutrient pathways into waterways and strategies for fixing these issues. This important research has informed the long-term management of several important aquatic systems in Western Australia: the Blackwood River Estuary, the Peel Harvey Estuary, and the protection of seagrasses in Shark Bay, the Swan River and Cockburn Sound. Arthur McComb had a seminal influence on a generation of researchers. Thirty-nine students completed their higher degrees under his supervision and they are spread internationally and throughout Australia in universities, state government departments and consulting firms, confirming his influence on driving our understanding and management of marine, estuarine and freshwater systems.

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