Data

Water use across a catchment and effects on estuarine health and productivity: Little Swanport

Name: Water use across a catchment and effects on estuarine health and productivity: Little Swanport
Published: 2011

University of Tasmania, Australia

Crawford, Christine, Dr ; Ross, Jeff, Dr

Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]

ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/9b95eac0-011a-4a7b-b174-5b8a284600c2&rft.title=Water use across a catchment and effects on estuarine health and productivity: Little Swanport&rft.identifier=https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/9b95eac0-011a-4a7b-b174-5b8a284600c2&rft.description=The most recent field study of the Little Swanport estuary, Tasmania carried out by Crawford et al. (2006) collected monthly samples at sites throughout the estuary between January 2004 and January 2005. Measurements included water column nutrients, chlorophyll-a, dissolved oxygen, salinity, phytoplankton, zooplankton and oyster growth. This work demonstrated that freshwater flows had a significant effect on salinity, turbidity, dissolved oxygen and nutrient levels in the estuary. However, monthly sampling didn’t provide the temporal resolution necessary to detect potential flow-on effects on the biology (e.g. phytoplankton and zooplankton dynamics, oyster growth). To gainan improved understanding of the temporal dynamics of the estuary, including the response to freshwater flow, samples were collected weekly (chlorophyll-a), fortnightly (nutrients and zooplankton) and bimonthly (oysters) between March 2006 and June 2008 at a site in the lower estuary where the majority of oysters are farmedMaintenance and Update Frequency: notPlannedStatement: Samples were collected weekly (chlorophyll-a), fortnightly (nutrients and zooplankton) and bimonthly (oysters) between March 2006 and June 2008 at a site in the lower estuary where the majority of oysters are farmed. Duplicate water samples were collected from ~20 cm below the surface for analysis of ammonia, total oxidised inorganic nitrogen (nitrite + nitrate), phosphate and silicate. Nutrient analysis was conducted by Analytical Services Tasmania (AST) using the American Public Health Association (APHA) Method 4500 on a Lachat Instrument auto analyser. Duplicate water samples for chlorophyll-a were collected using an integrated sampler consisting of 3 m long, 2.5 cm diameter tubing which sampled the entire water column to a depth of ~3 m. The sample was then filtered through a Whatman GF/F glass microfibre filter, and the filtrate wrapped in aluminium foil and frozen. Chlorophyll-a concentrations were measured spectrometrically following 90% acetone extraction (Strickland & Parsons 1972). To ensure consistency with the units used in the ecosystem model (mg Nitrogen m-3), chlorophyll-a was converted to nitrogen using a ratio of 7 mg N mg Chl-a-1 (see Murray & Parslow 1997). Zooplankton was sampled using a 100 mm mesh, single conical plankton net that was 3 m long and 0.6 m in diameter, towed ~20–30 m behind a boat. An ocean flow meter suspended in the mouth of the net was used to calculate sample volume. Samples were immediately preserved using 4% buffered formalin in seawater and later sorted in a Bogorov tray under a dissecting microscope. When zooplankton abundances were very high, samples were split using a Folsom splitter. Zooplankton abundance was converted to biomass in milligrams of nitrogen per cubic metre (mg N m-3) using existing information on the average nitrogen content of the major families (K Swadling, unpub data). To gain an improved understanding of the dynamics of oyster growth in the estuary, particularly the response to environmental flows, the growth and change in condition of oysters was measured bimonthly. The start samples consisted of 280 oysters, approximately 50–60 mm in length, selected from the farm, with 240 placed back on the farm; 60 per basket in each of two units (each unit has two baskets). The remaining 40 oysters were measured in the laboratory to provide an estimate of initial size and condition. After two months all of the oysters were collected and 20 oysters from each basket were measured in the laboratory. This cycle was repeated with a new batch of oysters every two months. To estimate oyster growth, shell length, width and depth were measured to the nearest millimetre using Vernier calipers and the whole live weight of the oysters was measured to the nearest milligram. To calculate oyster condition, tissue dry weight (60°C for 48 h) and shucked shell dry weight (60°C for 48 h) were measured and used to estimate the Crosby Gale Index (1990): Crosby and Gale Index (1990) = tissue dry weight (g) x 1000/ internal shell cavity capacity(g) where internal shell cavity capacity = whole live weight (g) – dry shell weight (g).&rft.creator=Crawford, Christine, Dr &rft.creator=Ross, Jeff, Dr &rft.date=2011&rft.coverage=westlimit=147.94; southlimit=-42.34; eastlimit=148.02; northlimit=-42.31&rft.coverage=westlimit=147.94; southlimit=-42.34; eastlimit=148.02; northlimit=-42.31&rft.coverage=uplimit=3; downlimit=0&rft.coverage=uplimit=3; downlimit=0&rft_rights=Creative Commons Attribution 2.5 Australia License http://creativecommons.org/licenses/by/2.5/au/&rft_rights=The citation in a list of references is: citation author name/s (year metadata published), metadata title. Citation author organisation/s. File identifier and Data accessed at (add http link).&rft_rights=Please contact J. Ross for access to the data.&rft_rights=The data described in this record are the intellectual property of the University of Tasmania through the Tasmanian Aquaculture and Fisheries Institute.&rft_subject=oceans&rft_subject=AQUACULTURE&rft_subject=EARTH SCIENCE&rft_subject=AGRICULTURE&rft_subject=AGRICULTURAL AQUATIC SCIENCES&rft_subject=WATER MANAGEMENT&rft_subject=HUMAN DIMENSIONS&rft_subject=ENVIRONMENTAL GOVERNANCE/MANAGEMENT&rft_subject=ESTUARINE HABITAT&rft_subject=BIOSPHERE&rft_subject=AQUATIC ECOSYSTEMS&rft_subject=BENTHIC HABITAT&rft_subject=INTERTIDAL ZONE&rft_subject=OCEANS&rft_subject=COASTAL PROCESSES&rft_subject=NUTRIENTS&rft_subject=OCEAN CHEMISTRY&rft_subject=CHLOROPHYLL&rft_subject=ZOOPLANKTON&rft_subject=PLANKTON&rft_subject=Oyster aquaculture&rft_subject=Catchments&rft_subject=Environmental flows&rft_subject=Estuarine health&rft_subject=Aquatic Ecosystem Studies and Stock Assessment&rft_subject=AGRICULTURAL AND VETERINARY SCIENCES&rft_subject=FISHERIES SCIENCES&rft_subject=Natural Resource Management&rft_subject=ENVIRONMENTAL SCIENCES&rft_subject=ENVIRONMENTAL SCIENCE AND MANAGEMENT&rft_subject=Marine and Estuarine Ecology (incl. Marine Ichthyology)&rft_subject=BIOLOGICAL SCIENCES&rft_subject=ECOLOGY&rft_subject=Ammonia&rft_subject=Nitrate plus Nitrite&rft_subject=Phosphate&rft_subject=Silicate&rft_subject=Chlorophyll a&rft_subject=Abundance - zooplankton&rft_subject=Shell length - oyster&rft_subject=Shell width - oyster&rft_subject=Shell depth - oyster&rft_subject=Live weight - oyster&rft_subject=Dry weight - oyster&rft.type=dataset&rft.language=English Access the data

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The citation in a list of references is: citation author name/s (year metadata published), metadata title. Citation author organisation/s. File identifier and Data accessed at (add http link).

Please contact J. Ross for access to the data.

The data described in this record are the intellectual property of the University of Tasmania through the Tasmanian Aquaculture and Fisheries Institute.

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Full description

The most recent field study of the Little Swanport estuary, Tasmania carried out by Crawford et al. (2006) collected monthly samples at sites throughout the estuary between January 2004 and January 2005. Measurements included water column nutrients, chlorophyll-a, dissolved oxygen, salinity, phytoplankton, zooplankton and oyster growth. This work demonstrated that freshwater flows had a significant effect on salinity, turbidity, dissolved oxygen and nutrient levels in the estuary. However, monthly sampling didn’t provide the temporal resolution necessary to detect potential flow-on effects on the biology (e.g. phytoplankton and zooplankton dynamics, oyster growth). To gain
an improved understanding of the temporal dynamics of the estuary, including the response to freshwater flow, samples were collected weekly (chlorophyll-a), fortnightly (nutrients and zooplankton) and bimonthly (oysters) between March 2006 and June 2008 at a site in the lower estuary where the majority of oysters are farmed

Lineage

Maintenance and Update Frequency: notPlanned

Statement: Samples were collected weekly (chlorophyll-a), fortnightly (nutrients and zooplankton) and bimonthly (oysters) between March 2006 and June 2008 at a site in the lower estuary where the majority of oysters are farmed. Duplicate water samples were collected from ~20 cm below the surface for analysis of ammonia, total oxidised inorganic nitrogen (nitrite + nitrate), phosphate and silicate. Nutrient analysis was conducted by Analytical Services Tasmania (AST) using the American Public Health Association (APHA) Method 4500 on a Lachat Instrument auto analyser. Duplicate water samples for chlorophyll-a were collected using an integrated sampler consisting of 3 m long, 2.5 cm diameter tubing which sampled the entire water column to a depth of ~3 m. The sample was then filtered through a Whatman GF/F glass microfibre filter, and the filtrate wrapped in aluminium foil and frozen. Chlorophyll-a concentrations were measured spectrometrically following 90% acetone extraction (Strickland & Parsons 1972). To ensure consistency with the units used in the ecosystem model (mg Nitrogen m-3), chlorophyll-a was converted to nitrogen using a ratio of 7 mg N mg Chl-a-1 (see Murray & Parslow 1997). Zooplankton was sampled using a 100 mm mesh, single conical plankton net that was 3 m long and 0.6 m in diameter, towed ~20–30 m behind a boat. An ocean flow meter suspended in the mouth of the net was used to calculate sample volume. Samples were immediately preserved using 4% buffered formalin in seawater and later sorted in a Bogorov tray under a dissecting microscope. When zooplankton abundances were very high, samples were split using a Folsom splitter. Zooplankton abundance was converted to biomass in milligrams of nitrogen per cubic metre (mg N m-3) using existing information on the average nitrogen content of the major families (K Swadling, unpub data). To gain an improved understanding of the dynamics of oyster growth in the estuary, particularly the response to environmental flows, the growth and change in condition of oysters was measured bimonthly. The start samples consisted of 280 oysters, approximately 50–60 mm in length, selected from the farm, with 240 placed back on the farm; 60 per basket in each of two units (each unit has two baskets). The remaining 40 oysters were measured in the laboratory to provide an estimate of initial size and condition. After two months all of the oysters were collected and 20 oysters from each basket were measured in the laboratory. This cycle was repeated with a new batch of oysters every two months. To estimate oyster growth, shell length, width and depth were measured to the nearest millimetre using Vernier calipers and the whole live weight of the oysters was measured to the nearest milligram. To calculate oyster condition, tissue dry weight (60°C for 48 h) and shucked shell dry weight (60°C for 48 h) were measured and used to estimate the Crosby Gale Index (1990): Crosby and Gale Index (1990) = tissue dry weight (g) x 1000/ internal shell cavity capacity(g) where internal shell cavity capacity = whole live weight (g) – dry shell weight (g).

Notes

Credit
Fisheries Research and Development Corporation (FRDC): 2005/072

Credit
Natural Resource Management (NRM) South

Purpose
To complete an investigation of environmental flow regimes required to maintain the health and production of oysters from the Little Swanport estuary through continued collection of environmental data under different flows and by the development of an estuarine model to predict the effects of different flow regimes.

Created: 22 11 2011

Data time period: 03 2006 to 30 06 2008

This dataset is part of a larger collection

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text: westlimit=147.94; southlimit=-42.34; eastlimit=148.02; northlimit=-42.31

text: uplimit=3; downlimit=0

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(REPORT - Project Report [direct download])

url : https://data.imas.utas.edu.au/attachments/9b95eac0-011a-4a7b-b174-5b8a284600c2/FRDC_Report_2005_0721.pdf External Link

Identifiers

global : 9b95eac0-011a-4a7b-b174-5b8a284600c2