National River Water Quality Network Database (Macro-invertebrates)

These macro-invertebrate data incorporate the results from the national river water quality network (NRWQN) from 66 sites throughout New Zealand for the purpose of monitoring long-term trends. The NRWQN was funded by the Foundation for Research, Science, & Technology through NIWA's Nationally Significant Database: Water Resources & Climate programme. Current funding (from July 2011) comes from the NIWA Environmental Information/Monitoring programme core funding.

The data are collected annually in summer, and data collection was initiated in January 1989.
(2010) . National River Water Quality Network Database (Macro-invertebrates). https://dc.niwa.co.nz:/niwa_dc/srv/api/records/8cf44974-57b4-4ce7-8c7e-2843d1fe603e
 

Simple

gmd:identificationInfo

Date ( publication )

pointOfContact

NIWA National Institute of Water & Atmospheric Research - Aslan Wright-Stow
Gate 10, Silverdale Road Hamilton 3216 New Zealand

+64 7 856 1785 +64 7 856 1051
  • macro-invertebrate freshwater FBIS
Other constraints

All data from this programme is freely available.

Subject to WQIS terms and conditions (https://secure.niwa.co.nz/wqis/terms.do).
Spatial representation type
vector
Metadata language used
eng
Topic category
  • biota
Description
New Zealand
N
S
E
W


Begin date
1989-01-01T00:00:00
End date
2008-12-31T00:00:00
Quality: Completeness
Quality: Attribute Accuracy
Quality: Logical Consistency
Quality: Positional Accuracy
Lineage

Raw data.

Collection Methods: Benthic invertebrates are sampled by collecting seven replicate Surber samples (0.1 m2, 250 µm mesh net). Cobble/gravel areas with depth <0.4 m and current velocity between 0.6 and 1 m/s are targeted. In the absence of these conditions, acceptable conditions included gravel substrate, depth < 0.7 m and current velocity > 0.2 m/s. The Surber sampler is positioned so that it faces into the current, then all cobbles in the sampling area are scrubbed (nylon bristled brush) then removed to a depth of approximately 10 cm. The remaining sediment is then stirred for 1 minute, while ensuring all animals are swept into the net. The seven samples are composited into one with any larger stones or wood cleaned of attached animals and removed. Invertebrates and organic material remaining in the net are then emptied into double plastic bags, using small quantities of water to remove any animals still attached. The samples are preserved immediately (10% formalin 1990-1995 or 70% isopropyl alcohol from 1996), labeled and stored in sealed buckets.The change in preservative was made for health and safety reasons - formalin is a potential carcinogen.

Lab processing: Macroinvertebrates are identified in the laboratory to the lowest practicable taxonomic level (usually species or genus) and counted. Consistent sub-sampling procedures are used to reduce processing time.The samples are split using a Folsom Plankton Splitter to the point where at least 100 individuals of the more common taxa are encountered. All other less common invertebrates in that fraction are also identified and counted.The next fraction (twice the concentration) is then counted and identified. Each time 100 individuals of one species is encounter, that invertebrates abundance is identified for the entire sub-sample, but then no longer counted in the subsequent sample fractions. Counts of these common taxa are converted to whole sample values by multiplying by the sample fraction examined.

Caveat: The change in sample preservation between 1995 and 1996 appears to have resulted in fewer numbers of at least two groups of soft bodied taxa (Oligochaetes and Platyhelminthes) in the post 1995 samples. Invertebrates with exoskeletons were not affected (insects, mollusca, crustacea etc ). The mean number of soft bodied taxa collected from 1990-1995 (Formalin) was an order of magnitude lower than 1996-2007 (IPA). ANOVA comparison of the data for key metrics by year showed significant differences (P < 0.05) between pre and post change in preservative for abundance, MCI, QMCI and %EPT, but not for Taxa Richness or EPT richness. This suggests that trend data for those metrics that are sensitive to preservative type should be done from 1996 not 1990, and/or that all trend analyses from 1990 -2007 should be treated with caution.
 
OnLine resource
Freshwater Biodiversity data, available through NIWA's Environmental Information Browser, contains fish, algae, aquatic plant and invertebrate data gathered from New Zealand's freshwater streams, rivers and lakes.

Freshwater Biodiversity data, available through NIWA's Environmental Information Browser, contains fish, algae, aquatic plant and invertebrate data gathered from New Zealand's freshwater streams, rivers and lakes.

Reference system identifier
LINZ Land Information New Zealand / NZMG New Zealand Map Grid
Reference system identifier
NZST/NZDT

gmd:MD_Metadata

File identifier
8cf44974-57b4-4ce7-8c7e-2843d1fe603e
Metadata language used
eng
Character set
utf8
Hierarchy level
Dataset
Date stamp
2010-07-15T12:03:24
Metadata standard name
ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata
Metadata standard version
1.1

custodian

NIWA National Institute of Water & Atmospheric Research - Data curator

 
 

 

 

         

 

 

Not available