Nutrient and gilvin levels in waters of coastal-plain wetlands in an agricultural area of Western Australia

1988 ◽  
Vol 39 (5) ◽  
pp. 685 ◽  
Author(s):  
TJ Wrigley ◽  
JM Chambers ◽  
AJ McComb
Keyword(s):  
Coastal Plain ◽  
Phytoplankton Biomass ◽  
Particulate Material ◽  
Agricultural Activity ◽  
Estuarine System ◽  
Light Penetration ◽  
Phytoplankton Blooms ◽  
Consequent Reduction ◽  
Coastal Plain Wetlands ◽  
High Concentrations

The Peel-Harvey catchment lies on a sandy coastal plain, largely cleared for agriculture, and drains into a eutrophic estuarine system. Sixty-eight wetlands in the catchment had total phosphorus concentrations of 0.4-7.8 mg I-1, the high values being atrributed to agricultural activity. Conductivity was 150-8770 �S cm-1, pH 4.1-9.3. Waters contained high concentrations of gilvin, up to 262 g440 m-1 with a mean ratio of 6.2. Particulate material contributed little to light absorption at lower wavelengths (400-450 nm) but governed absorbance at 600-700 nm. Wetlands with the largest concen- trations of gilvin were located in the grey Bassendean sands, leachates from which had gilvin levels up to 748 g440 m-1. NO phytoplankton blooms were observed, and it is suggested that high gilvin levels and the consequent reduction in light penetration are important in maintaining low phytoplankton biomass in these lakes.

Limnological features of coastal-plain wetlands on the Gnangara Mound, Perth, Western Australia

1991 ◽  
Vol 42 (6) ◽  
pp. 761 ◽  
Author(s):  
TJ Wrigley ◽  
SW Rolls ◽  
JA Davis
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Coastal Plain ◽  
Nutrient Concentrations ◽  
The North ◽  
Large Numbers ◽  
High Nutrient ◽  
Consequent Reduction ◽  
Coastal Plain Wetlands ◽  
Urban Activity

The Gnangara Mound is an area of elevated sandy soil on the Swan Coastal Plain to the north of Perth. It constitutes a major groundwater resource for metropolitan Perth. Sixteen wetlands on the Mound had total phosphorus concentrations of 12-462�g L-1, the high values being attributed to agricultural and urban activity. Sediment concentrations of total phosphorus and total nitrogen were 61-954 and 1212-16739 �g g-1, respectively. Conductivities were 505-10270 �S cm-1, and pH values were 3.3-9.3. Only one wetland was highly coloured (79.9 8440 m-1), with an E4/E6 ratio of 4.6. Chlorophyll a concentrations were 0.01-130.8�g L-1; in wetlands with low gilvin concentrations, Myxophyceae dominated, whereas wetlands with higher gilvin concentrations had large numbers of diatoms and Chlorophyceae. The highly coloured wetland had the lowest chlorophyll a concentration despite high nutrient concentrations, supporting the hypothesis that the consequent reduction in light or other associated factors are important in maintaining low phytoplankton biomass in dystrophic wetlands of the region, particularly those on Bassendean sands.

Experimental culling of minnows suppresses cyanobacterial bloom under low-nutrient conditions

2019 ◽  
Vol 76 (11) ◽  
pp. 2102-2109 ◽  
Author(s):  
Blake R. Stuparyk ◽  
Mark Graham ◽  
Jenna Cook ◽  
Mitchell A. Johnsen ◽  
Karen K. Christensen-Dalsgaard ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Trophic Cascade ◽  
Phytoplankton Biomass ◽  
Management Practices ◽  
Phytoplankton Community ◽  
Cyanobacterial Bloom ◽  
Nutrient Status ◽  
Cyanobacterial Blooms ◽  
Phytoplankton Blooms ◽  
Cascade Effect

Cyanobacterial blooms in lakes of low nutrient status are recent ecological surprises. Culling of planktivorous fish may help suppress phytoplankton blooms via a trophic cascade effect. To test this hypothesis, we conducted a 90-day experiment adjacent to a shallow oligomesotrophic lake increasingly beset by midsummer cyanobacterial blooms in the presence of high abundances of minnows and sparse herbivorous zooplankton. The single-factor (± three spottail shiners, Notropis hudsonius) experimental design was replicated 10 times for a total of twenty 1200 L capacity mesocosms. Contrary to the trophic cascade hypothesis, minnow removal decreased the abundance of bosminids capable of grazing cyanobacteria. Nevertheless, removal of the minnows significantly both suppressed phytoplankton biomass and offset the development of cyanobacteria, such as Gloeotrichia echinulata. Lower concentrations of phosphorus and nitrogen in the fishless relative to stocked mesocosms best explained these differences in the phytoplankton community. Our findings highlight how fisheries management practices that enhance minnow populations in lakes of low productivity may inadvertently contribute to cyanobacterial blooms through increased nutrient cycling.

scholarly journals Effect of Tidal Stage on Sediment Concentrations and Turbulence by Vessel Wake in a Coastal Plain Saltmarsh

2019 ◽  
Vol 7 (6) ◽  
pp. 192
Author(s):  
Richard Styles ◽  
Michael A. Hartman
Keyword(s):  
Coastal Plain ◽  
Habitat Structure ◽  
Sediment Concentration ◽  
Small Scale ◽  
Characteristic Time Scale ◽  
Suspended Material ◽  
Turbulent Fluctuations ◽  
High Concentrations ◽  
Tidal Stage ◽  
Water Elevation

Vessel generated waves can impact shoreline stability and habitat structure in many waterways. Sheltered regions, such as coastal plain saltmarshes, support fragile ecosystems and can be particularly vulnerable to the effects of unregulated vessel operations. Instruments for measuring currents and sediment concentration were deployed in a coastal plain saltmarsh to examine the small-scale physical characteristics of the vessel wake generated by recreational craft typical of this environment. The response to vessel wake varied sharply depending upon the stage of the tide. At low tide, waves breaking on the exposed bank produced high concentrations of suspended material that were transported offshore through turbulent diffusion. When the water elevation exceeded the toe of the marsh scarp, the concentration and turbulent kinetic energy exhibited less of a statistically significant variation in response to vessel passage. For the most energetic flows, the vessel orbital velocities were dwarfed by turbulent fluctuations generated by the sheared tidal boundary layer. While further research is required, preliminary findings indicate that the dissipation of vessel wake energy may stimulate or enhance shear generated turbulence if the characteristic wave period is similar to the characteristic time scale of the energy containing eddies.

Phosphorus export from coastal plain drainage into the Peel-Harvey estuarine system of Western Australia

1982 ◽  
Vol 33 (1) ◽  
pp. 23 ◽  
Author(s):  
PB Birch
Keyword(s):  
Western Australia ◽  
Coastal Plain ◽  
Dairy Farms ◽  
Dairy Farming ◽  
Benthic Alga ◽  
Clay Soils ◽  
Estuarine System ◽  
Phosphorus Export ◽  
Alluvial Clay

Excessive growth of the benthic alga Cladophora aff. albida in the Peel-Harvey estuarine system has coincided with greatly increased inputs of phosphorus from rivers over the last 20-25 years. At present, about 90%, of phosphorus input is derived from rural coastal plain catchments, where use of superphosphate increased fourfold over the period 1945-1975. The present export of phosphorus from these catchments was found to be positively correlated with rates of superphosphate application, dairy farming, and presence of alluvial clay soils, and negatively correlated with beef farming. Reduction of phosphorus input to the estuary from the coastal plain, therefore, could be achieved by reducing or modifying the present use of superphosphate, and reducing runoff from dairy farms into waterways.

scholarly journals The influence of the Guadalquivir river on spatio-temporal variability in the pelagic ecosystem of the eastern Gulf of Cádiz

2014 ◽  
Vol 15 (4) ◽  
pp. 721 ◽  
Author(s):  
I. CABALLERO ◽  
E. P. MORRIS ◽  
L. PIETRO ◽  
G. NAVARRO
Keyword(s):  
Temporal Variability ◽  
Phytoplankton Biomass ◽  
Phytoplankton Bloom ◽  
Light Limitation ◽  
Gulf Of Cadiz ◽  
Phytoplankton Blooms ◽  
Pelagic Ecosystem ◽  
Guadalquivir Estuary ◽  
Gulf Of Cádiz ◽  
Spatio Temporal

This study examines the spatio-temporal variability of the turbidity plume and phytoplankton biomass (in terms of chlorophyll) in the marine region influenced by the Guadalquivir estuary using ocean colour images over a period of 11 years (2003-2013). The area of the turbidity plume was calculated using water-leaving radiance at 555 nm (nLw555). Climatologic and monthly averages showed recurrent high nLw555 levels in winter and high chlorophyll in spring. Similar variability was confirmed by Empirical Orthogonal Function (EOF) analysis of 8-day composite images, illustrating the existence of different regions with similar behavior. The first EOF mode explained 60.7% and 31% of the variability in nLw555 and chlorophyll, respectively, and was associated with enhanced Total Suspended Solids (TSS) in autumn-winter and phytoplankton blooms in winter-spring periods. The results confirmed that the development of the turbidity plume and subsequent phytoplankton blooms were strongly regulated by river discharges and precipitation. Indeed, interannual variation in nLw555 was consistent with changes in the large-scale climate index, the North Atlantic Oscillation, a proxy for regional rainfall patterns. In the case of phytoplankton biomass, the second EOF mode revealed differentiation between offshore and nearshore areas, the latter characterized by delayed development of phytoplankton bloom due to light limitation by high TSS. This suggests that the stability of the water column, via its influence on phytoplankton light-limitation, influenced also the timing and magnitude of phytoplankton bloom events. The dynamic of the Guadalquivir estuary turbidity plume is a crucial factor for the pelagic ecosystem of the Eastern Gulf of Cadiz, governing phytoplankton productivity.

scholarly journals In situ phytoplankton distributions in the Amundsen Sea Polynya measured by autonomous gliders

Elem Sci Anth ◽  
2015 ◽  
Vol 3 ◽  
Author(s):  
Oscar Schofield ◽  
Travis Miles ◽  
Anne-Carlijn Alderkamp ◽  
SangHoon Lee ◽  
Christina Haskins ◽  
...  
Keyword(s):  
Mixed Layer ◽  
Phytoplankton Biomass ◽  
Austral Summer ◽  
Euphotic Zone ◽  
Optical Data ◽  
Phytoplankton Blooms ◽  
Amundsen Sea ◽  
Water Column Stability ◽  
Upper Mixed Layer

Abstract The Amundsen Sea Polynya is characterized by large phytoplankton blooms, which makes this region disproportionately important relative to its size for the biogeochemistry of the Southern Ocean. In situ data on phytoplankton are limited, which is problematic given recent reports of sustained change in the Amundsen Sea. During two field expeditions to the Amundsen Sea during austral summer 2010–2011 and 2014, we collected physical and bio-optical data from ships and autonomous underwater gliders. Gliders documented large phytoplankton blooms associated with Antarctic Surface Waters with low salinity surface water and shallow upper mixed layers (< 50 m). High biomass was not always associated with a specific water mass, suggesting the importance of upper mixed depth and light in influencing phytoplankton biomass. Spectral optical backscatter and ship pigment data suggested that the composition of phytoplankton was spatially heterogeneous, with the large blooms dominated by Phaeocystis and non-bloom waters dominated by diatoms. Phytoplankton growth rates estimated from field data (≤ 0.10 day−1) were at the lower end of the range measured during ship-based incubations, reflecting both in situ nutrient and light limitations. In the bloom waters, phytoplankton biomass was high throughout the 50-m thick upper mixed layer. Those biomass levels, along with the presence of colored dissolved organic matter and detritus, resulted in a euphotic zone that was often < 10 m deep. The net result was that the majority of phytoplankton were light-limited, suggesting that mixing rates within the upper mixed layer were critical to determining the overall productivity; however, regional productivity will ultimately be controlled by water column stability and the depth of the upper mixed layer, which may be enhanced with continued ice melt in the Amundsen Sea Polynya.

scholarly journals Hydrochemical Characterisation of Groundwater Quality: Merdja Plain (Tebessa Town, Algeria)

2020 ◽  
Vol 6 (2) ◽  
pp. 318-325 ◽  
Author(s):  
Baazi Houria ◽  
Kalla Mahdi ◽  
Tebbi Fatima Zohra
Keyword(s):  
Groundwater Quality ◽  
Principal Component ◽  
Anthropogenic Factors ◽  
Agricultural Activity ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
High Concentrations ◽  
Geological Formations

The objective of this work is to evaluate the physico-chemical quality of the groundwater of the Merdja plain and to determine the sources of mineralization. This quality is influenced by several environmental and anthropogenic factors such as geological context, climate, precipitation and interaction between groundwater and aquifers and human activities.  A Principal Component Analysis (PCA) on samples taken from several wells spread over the entire Tebessa plain (Merdja) allowed us to detect two axes that explain 73.4% of the information. The first axis describes the variables related to mineralisation and the second one describes those related to agricultural activity. Multidimensional Positioning (MDS) confirmed the interaction of physico-chemical parameters between them and their influence on groundwater quality by highlighting three groups of wells according to their physico-chemical characteristics, particularly those containing high concentrations of nitrates. This contamination is mainly the result of spreading the fertilisers and wastes that are dumped into the plain without treatment. Salinization is the result of long-term interactions between groundwater and geological formations.

scholarly journals The Potential Long-Term Impacts of Climate Change on the Hydrologic Regimes of North Carolina’s Coastal Plain Non-Riverine Wetlands

2019 ◽  
Vol 62 (6) ◽  
pp. 1591-1606
Author(s):  
J. Jack Kurki-Fox ◽  
Michael R. Burchell ◽  
Brock J. Kamrath
Keyword(s):  
Climate Change ◽  
North Carolina ◽  
Ecosystem Services ◽  
Water Table ◽  
Coastal Plain ◽  
Hydrologic Model ◽  
Hydrologic Regimes ◽  
Coastal Plain Wetlands ◽  
Impacts Of Climate Change

HighlightsBased on current emissions, mean water table decline in these wetlands will likely range from 25 to 65 cm by 2100.Projected changes could lead to a decline or loss of the important ecosystem services that wetlands provide to society.Results indicate a potential need to allocate more resources to developing strategies for managing wetlands.Abstract. Wetlands are especially at risk from climate change because of their intermediate landscape position (i.e., transition between upland and aquatic environments), where small changes in precipitation and/or evapotranspiration can have substantial impacts on wetland hydrology. Because hydrology is the primary factor influencing wetland structure and function, the important ecosystem services that wetlands provide may be altered or lost as a result of climate change. While a great deal of uncertainty is associated with the projected impacts of climate change on wetlands, hydrologic models and downscaled climate model projections provide tools to reduce this uncertainty. DRAINMOD is one such process-based hydrologic model that has been successfully adapted to simulate the daily water level fluctuations in natural wetlands. The objective of this project was to determine the range of possible impacts of climate change on the hydrologic regimes of non-riverine, non-tidal Coastal Plain wetlands in North Carolina. DRAINMOD models were calibrated and validated for two minimally disturbed, natural wetland sites using observed water table and local weather data. Two representative concentration pathway (RCP) scenarios were evaluated: RCP4.5 and RCP8.5. Nine models were selected from an ensemble of 32 climate models to represent the range of possible changes in mean precipitation and temperature. Downscaled climate projections were obtained from the U.S. Bureau of Reclamation. Simulations were run from 1986 to 2099, and results were evaluated by comparing the projected mean water table levels between the base period (1986-2015) and two future evaluation periods: 2040-2069 and 2070-2099. The model simulation results indicated that the projected mean water table level may decline by as much as 25 to 84 cm by the end of this century (2070-2099) for the RCP8.5 scenario and may decline by 4 to 61 cm for the RCP4.5 scenario. In Coastal Plain wetlands, declines in water tables can lead to the subsidence of organic soils, which can lead to the loss of stored carbon and increased risk of peat fires. Lower mean water levels can also lead to shifts in vegetation community composition and loss of habitat functions for wetland-dependent fauna. These results provide an overview of the potential impacts of climate change on North Carolina wetlands, and they provide a range of scenarios to inform and guide possible changes to water management strategies in wetland ecosystems that can be implemented now to limit the loss of ecosystem services over the long term. Keywords: Climate change, DRAINMOD, Hydrology, Modeling, North Carolina, Wetlands.

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