Waikato Coastal Database
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NIWA Whitianga terrestrial sediment experiment

1. Identification information

Status
Complete
Data Collection Date
2000
Summary
A field experiment was conducted over 212 days to assess the impact of terrestrial sediment deposits at six sites on the intertidal flats of Whitianga Harbour. Macrofaunal communities and sediment characteristics were sampled over time to determine recovery rates. Purpose: Determining the rate of recovery of the macrobenthic community and understanding how physical and biological processes influence the recovery rate in different locations.
Content
Samples from 6 sites within the Whitianga Harbour provide infauna, mud crab density, particle size, salinity, chla, wave climate, conductivity, penetrability and bed shear stress data.
Study Types
  • Scientific Study
Categories
  • Benthic Communities (including shellfish)
  • Sediments
  • Benthic Communities (including shellfish)

2. Contact information

Commissioning Agencies
  • Foundation for Research Science and Technology
Contact Organisations
  • NIWA (Hamilton)

3. Spatial information

Geographic Coverage
Whitianga Harbour
Grid Coordinates
Whitianga Harbour – E2750534 N6477849, NZMG, 1:50000, AREA
Locations
  • Name
    Whitianga
    NZMG Easting
    2750531
    NZMG Northing
    6477852
    Location
    Whitianga Harbour
    East Coast

4. Data acquisition information

Collection Date
February – September 2000
Methodology
Sites were established at two tidal elevations (high and low) at three harbour locations (outer/mid/upper harbour). 5 experimental plots of introduced terrigenous sediment were established at each site. Macrofaunal density was assessed by collecting two cores (13cm diam x 15 cm deep) from each plot. Core samples are sieved through a 0.5 mm mesh. Thickness of the terrestrial sediment layer, its position down the sediment column and the thickness of any estuarine sediment deposited on the terrestrial sediment layer was measured. Sediment cores (1. cm diameter x 2 cm deep) were also taken for analysis of organic content, benthic chlorophyll a, and particle size. Surficial sediment geotechnical properties were measured at three places in each plot using a mechanical shear vane and penetrometer. Density of burrowing crabs was estimated by photographing and excavating nine 0.25 m2 x 8 cm deep quadrats which were sieved through 4 mm mesh. At each site a DOBIE wave gauge with a conductivity probe was deployed.Site OL could not be sampled on days 29 and 107 due to insufficiently low tides. Frequency of collection: One off experiment. Sampling undertaken on days 7, 29,50,107 and 212.

5. Data quality information

Known Limitations
Not reported Gaps in collection: Site OL could not be sampled on days 29 and 107 due to insufficiently low tides. Data quality: Standard coring and sieving techniques used. Attribute accuracy: Not reported. Standard coring and sieving techniques used. Completeness: Not reported

6. Distribution information

Format
report, graphs, electronic
Applications
Availability
See NIWA Sensitivity/Confidentiality: See NIWA

7. Status information

Data Status
Finished

8. Metadata information

General Notes
Related Links
Publications
  • Thrush, S.F., Hewitt, J.E., Norkko, A., Cummings, Funnell, G.A., 2003: Macrobenthic recovery processes following catastrophic sedimentation on estuarine sandflats. Ecological Applications Vol. 13(5), p. 1433-1455.
Related Publications
  • Hewitt, J.E., Cummings, V.J., Ellis, F.I., Funnell, G., Norkko, A., Talley, T.S., Thrush, S.F., 2003: The role of waves in the colonisation of terrestrial sediments deposited in the marine environment. J. Exp. Mar. Bio. Eco. 290: 19-47.
  • Norkko, A., Thrush, S.F., Hewitt, J.E., Cummings, Norkko, J., Ellis, J.I., Funnell, G.A., Schultz, D., MacDonald, I., 2002: Smothering of estuarine sandflats by terrigenous clay: the role of wind-wave disturbance and bioturbation in site-dependent macrofaunal recovery. Marine Ecology Progress Series 234: 23 - 41.
  • Cummings, V.J., Pridmore, R.D., Thrush, S.F., Hewitt, J.E., 1995: Post-settlement movement by intertidal benthic macroinvertebrates: do common New Zealand species drift in the water column? NZJMFR 29: 59-67.
  • Cummings, V.J., Thrush, S.F., Hewitt, J.E., Norkko, A., Pickmere, S., in press: Terrestrial sediment deposits in marine soft-sediments: sediment characteristics as indicators of habitat suitability for recolonising macrofauna. Marine Ecology Progress Series.
  • Norkko, A., Cummings, V.J., Thrush, S.F., Hewitt, J.E., Hume, T.H., 2001: Local dispersal of juvenile bivalves: implications for sandflat ecology. Marine Ecology Progress Series 212: 131-144.
  • Thrush, S.F., Hewitt, J.E., Cummings, V.J., Green, M.O., Funnell, G.A. & Wilkinson, M.R. 2000: Improving the generality of field experiments: the interaction of processes operating over different spatial scales on intertidal sandflats. Ecology 81:399-415.
Related Datasets

9. Related files

No files have been attached to this dataset

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