Nutrient Pools of an Estuarine Ecosystem--The Blackwood River Estuary in South-Western Australia

1980 ◽  
Vol 68 (1) ◽  
pp. 287 ◽  
Author(s):  
R. A. Congdon ◽  
A. J. McComb
Keyword(s):  
Western Australia ◽  
River Estuary ◽  
Estuarine Ecosystem ◽  
Nutrient Pools

Creel census of amateur line fishermen in the Blackwood River estuary, Western Australia, during 1974-75

1976 ◽  
Vol 27 (4) ◽  
pp. 583 ◽  
Author(s):  
N Caputi
Keyword(s):  
Western Australia ◽  
River Estuary ◽  
Fishing Pressure ◽  
Swan Lake ◽  
Main Species ◽  
Lake Region ◽  
Black Bream ◽  
Major Species ◽  
Creel Census ◽  
Rate Of Success

A creel census was carried out from May 1974 to April 1975 on the amateur line fishermen of Blackwood River estuary, from the Swan Lakes and Deadwater to Alexandra Bridge. The estimated total fishing pressure was 76 149 fisherman hours which was mainly concentrated in the summer and autumn months. The rate of success averaged 3.86 fish per fisherman per hour fishing. The estimated harvest of fish was 287 300. In the Hardy Inlet and Swan Lake region, western sand whiting (Sillago schomburgkii) was the main species caught for most of the year, except for the autumn months when Australian herring (Arripis georgianus) was the major species. In the Blackwood River, black bream (Mylio butcheri) dominated the catch throughout the year.

Three-dimensional modelling of a Microcystis bloom event in the Swan River estuary, Western Australia

2004 ◽  
Vol 174 (1-2) ◽  
pp. 203-222 ◽  
Author(s):  
B.J. Robson ◽  
D.P. Hamilton
Keyword(s):  
Western Australia ◽  
Three Dimensional ◽  
River Estuary ◽  
Microcystis Bloom ◽  
Swan River

Factors influencing concentrations of polychlorinated biphenyls in organisms from an estuarine ecosystem

1982 ◽  
Vol 33 (6) ◽  
pp. 1057 ◽  
Author(s):  
GR Shaw ◽  
DW Connell
Keyword(s):  
Polychlorinated Biphenyls ◽  
Direct Relationship ◽  
Steric Effect ◽  
Laboratory Data ◽  
River Estuary ◽  
Sediment Concentration ◽  
Food Sources ◽  
Major Influence ◽  
Log P ◽  
Estuarine Ecosystem

Polychlorinated biphenyls (PCB's) were detected in both the abiotic and biotic components of the Brisbane River estuary. Maximum average concentrations were detected in the muscle tissue of pelican (8.2 mg kg-1), gull (2.6 mg kg-1) and catfish (2.1 mg kg-1). Biomagnification was shown not to be a significant factor controlling PCB concentrations in the organisms investigated except in pelicans and gulls. In these cases, estimates of uptake from food sources indicated that biomagnification could be the major process involved. Metabolism or excretion was also found to influence the observed PCB composition of these organisms. Field and laboratory data indicated that, with some benthic organisms, sediment concentrations were the major influence on body concentrations of PCB's and a direct relationship between body concentration and the log of sediment concentration was established. Further laboratory experiments indicated that the uptake of individual PCB's was influenced primarily by two factors: the partition coefficient of n-octanol to water (p) and stereochemical effects. A direct relationship between uptake and the product of log p and the steric effect coefficient was demonstrated. Thus, maximum uptake was found with penta- and hexachlorobiphenyls, predominant in Arochlor 1254. Comparatively less uptake was found with di-, tri- and tetrachlorobiphenyls (Arochlor 1242), which have lower values for log p, and hepta- and octachlorobiphenyls, predominant in Arochlor 1260, which have lower steric effect coefficients.

Waders and Other Aquatic Birds on the Swan River Estuary, Western Australia

1938 ◽  
Vol 38 (1) ◽  
pp. 18-29 ◽  
Author(s):  
D. L. Serventy
Keyword(s):  
Western Australia ◽  
River Estuary ◽  
Aquatic Birds ◽  
Swan River

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.

Modelling and mass balance assessments of nutrient retention in a seasonally-flowing estuary (Swan River Estuary, Western Australia)

2008 ◽  
Vol 76 (2) ◽  
pp. 282-292 ◽  
Author(s):  
Barbara J. Robson ◽  
Paul A. Bukaveckas ◽  
David P. Hamilton
Keyword(s):  
Mass Balance ◽  
Western Australia ◽  
River Estuary ◽  
Nutrient Retention ◽  
Swan River

scholarly journals Exploring Impacts of River Discharge on Forage Fish and Predators Using Ecopath With Ecosim

2021 ◽  
Vol 8 ◽  
Author(s):  
Dylan Sinnickson ◽  
David Chagaris ◽  
Micheal Allen
Keyword(s):  
Food Web ◽  
Functional Groups ◽  
River Estuary ◽  
Forage Fish ◽  
Ecopath With Ecosim ◽  
Short Term ◽  
Estuarine Ecosystem ◽  
Suwannee River ◽  
Freshwater Inputs ◽  
The Impact

The ecology of estuaries is shaped significantly by the extent of freshwater discharge which regulates abiotic processes and influences overall biological productivity. The Suwannee River Estuary of Florida’s Big Bend Coastline has historically been a productive and diverse estuarine ecosystem supported by significant freshwater inputs from the Suwannee River. In recent years, significant changes in land use and climatic conditions have resulted in lower discharges from the Suwannee. Our objectives were to explore the impact of freshwater inputs from the Suwannee River on the estuarine forage fish and sportfish communities downstream. We built a trophic-dynamic food web model in Ecopath with Ecosim to simulate different levels of discharge and evaluate how changes in discharge (drought and floods) would influence the trophic structure of the food web. Using the fitted model, we applied a series of different short-term and long-term flow projections under different climatic scenarios to evaluate impacts on fish functional groups and sportfish biomass. Simulations suggested that ecological production was more influenced by drought conditions than flood conditions. In our short-term scenarios, the drought simulations produced biomass changes that were approximately twice as substantial as the flood scenarios. When making comparisons to other published EwE models, we generally observed smaller changes in biomass production. Although this model focused on the influence of bottom-up effects, we observed strong top-down control of snook (Centropomus undecimalis) on the system. Several functional groups were particularly sensitive to changes in snook abundance which included spotted seatrout (Cynoscion nebulosus), sand seatrout (C. arenarius), and other members of the family Sciaenidae. Because snook have recently colonized the estuary, likely as a result of warmer winter temperatures, this finding has implications for climate change and natural resource management.

scholarly journals New Insight to Niche Partitioning and Ecological Function of Ammonia Oxidizing Archaea in Subtropical Estuarine Ecosystem

2020 ◽  
Author(s):  
Yanhong Lu ◽  
Shunyan Cheung ◽  
Ling Chen ◽  
Shuh-Ji Kao ◽  
Xiaomin Xia ◽  
...  
Keyword(s):  
Ammonia Oxidation ◽  
Marine Ecosystem ◽  
Niche Partitioning ◽  
River Estuary ◽  
Amoa Gene ◽  
Pearl River Estuary ◽  
Nitrification Rate ◽  
Distributional Pattern ◽  
Estuarine Ecosystem ◽  
Ammonia Oxidizing Archaea

Abstract. Nitrification plays a central role in estuarine nitrogen cycle. Previous studies in estuary mainly focused on the niche-partition between ammonia-oxidizing archaea (AOA) and bacteria (AOB), while the diversity, activity, biogeography and ecophysiology of different AOA groups remained unclear. Here, we first time reported niche partitioning as well as differentially distributed active populations among diverse AOA (inferred from amoA gene) in a typical subtropical estuary–Pearl River estuary (PRE). In the water column of PRE, the AOA communities mainly consisted of WCA and SCM1-like sublineages. Surprisingly, we observed a strong disagreement of AOA communities at DNA and RNA levels. In DNA samples, WCA generally dominated the AOA community, and the distributional pattern indicated that WCA I and WCA II sublineages preferred oceanic and coastal conditions, respectively. In contrast, diverse SCM1-like sublineages were identified and outnumbering WCA at RNA level, in which SCM1-like-III was limited to freshwater while the rest sublineages were widely distributed in the estuary. The SCM1-like sublineages strongly correlated with nitrification rate indicated their important contribution to ammonia oxidation. Furthermore, intense nitrification contributed significantly to hypoxia conditions (nitrification contributed averaged 15.30 % of oxygen consumption) in the estuary. These results unraveled different ammonia-oxidizing activities and niche partitioning among different AOA sublineages in estuarine water, which was unexplored in previous DNA and clone library-based studies. The ecological significance and functioning of the diverse AOA should be further explored in the marine ecosystem.

scholarly journals New insight to niche partitioning and ecological function of ammonia oxidizing archaea in subtropical estuarine ecosystem

2020 ◽  
Vol 17 (23) ◽  
pp. 6017-6032
Author(s):  
Yanhong Lu ◽  
Shunyan Cheung ◽  
Ling Chen ◽  
Shuh-Ji Kao ◽  
Xiaomin Xia ◽  
...  
Keyword(s):  
Water Column ◽  
Ammonia Oxidation ◽  
Marine Ecosystem ◽  
Niche Partitioning ◽  
River Estuary ◽  
Amoa Gene ◽  
Nitrification Rate ◽  
Distributional Pattern ◽  
Estuarine Ecosystem ◽  
Ammonia Oxidizing Archaea

Abstract. Nitrification plays a central role in the estuarine nitrogen cycle. Previous studies in estuary mainly focused on the niche partition between ammonia-oxidizing archaea (AOA) and bacteria (AOB), while the diversity, activity, biogeography, and ecophysiology of different AOA groups remained unclear. Here, we for the first time report on niche partitioning and differentially distributed active populations among diverse AOA (inferred from amoA gene) in a typical subtropical estuary – Pearl River estuary (PRE). In the water column of the PRE, the AOA communities mainly consisted of water column A (WCA) and SCM1-like (Nitrosopumilus maritimus-like) sublineages. Surprisingly, we observed a strong disagreement in AOA communities at DNA and RNA levels. In DNA samples, WCA generally dominated the AOA community, and the distributional pattern indicated that WCA I and WCA II sublineages preferred oceanic and coastal conditions, respectively. In contrast, diverse SCM1-like sublineages were identified, and outnumbered WCA at RNA level, in which SCM1-like-III was limited to freshwater, while the rest of the sublineages were widely distributed in the estuary. The SCM1-like sublineages strongly correlated with nitrification rate, which indicated their important contribution to ammonia oxidation. Furthermore, intense nitrification contributed significantly to hypoxia conditions (nitrification contributed averaged 12.18 % of oxygen consumption) in the estuary. These results revealed different ammonia-oxidizing activities and niche partitioning among different AOA sublineages in estuarine water, which was unexplored in previous DNA and clone library-based studies. The ecological significance and functioning of the diverse AOA should be further explored in the marine ecosystem.

Sign in / Sign up

Export Citation Format

Share Document