New Zealand CPR Survey
Karen Robinson - Plankton Analyst, NIWA
The New Zealand CPR Survey is being managed by the National
Institute of Water and Atmospheric Research (NIWA). Currently two
regular CPR routes are being sampled which are providing data for
areas previously under-sampled.
Analysis is carried out in the NIWA laboratory in Christchurch
with a Phytoplankton Colour Index score being recorded as a measure
of phytoplankton biomass, and all plankton in five nautical mile
segments being identified to species level where possible. These
data are combined with environmental parameters collected by the
ship's underway monitoring equipment during the tows to provide an
overall view of plankton ecology and dynamics.
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Map showing the Chatham Rise CPR survey routes
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The Chatham Rise Survey
The Chatham Rise is a relatively shallow underwater plateau
located to the east of New Zealand. This area is oceanographically
complex, being a dynamic frontal zone between subtropical and
subantarctic surface water masses. As a result it is a highly
productive area that has been extensively studied, and has two
permanent biophysical moorings situated north (subtropical water),
and south (subantarctic water), of the Rise which record in situ
environmental parameters.
The first dedicated CPR tow across the Chatham Rise was carried
out in 2007 as an addition to an existing long term research
program carried out by NIWA with funding from the Ministry of
Science and Innovation (MSI). This research provides the
opportunity for repeatable runs on a regular basis, and also
produces detailed data on biological and environmental variables
between the moorings. Population dynamics within the convergence
zone have been shown to be complex and the CPR Survey should add
valuable data on species variability.
Two routes have now been established (see map below) . Sampling
occurs twice a year in spring and autumn. Analysis of these surveys
is in the initial stages, with three out of nine sets of silks
completed. Data obtained from the CPR will contribute to the GACS
database, and will provide a benchmark for surveys in this
region.
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Map showing the Southern Ocean CPR survey
routes
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The Southern Ocean Survey
The Southern Ocean Survey was established in 2008 through
funding from the Ministry of Fisheries, (MFISH) and Land
Information New Zealand (LINZ) in order to map the changes in the
quantitative distribution of epipelagic plankton in NZ's Economic
Exclusion Zone, transiting to the Ross Sea, Antarctica. This survey
carries out annual tows between 44°S and 70°S during the Austral
summer. The Survey was set up for a period of five years and
utilises a commercial fishing vessel, the San Aotea II, run by
Sanford Ltd. The route will provide valuable data on the spatial
and temporal changes in plankton communities in an area sensitive
to global climate change, and will extend the range of data
currently available in the Southern Ocean region which is
concentrated south of Australia. The data from this Survey will
contribute to the SCAR SO - CPR Survey overseen by the Australian
Antarctic Division and also the CCAMLR's Ecosystem Monitoring
Program C-EMP.
To date, three years of sampling have been carried out.
Twenty two tows have been collect with 12 silks processed and
analysis on the latest set of tows is about to begin. Preparation
is currently underway to ready the CPR for the 2011-2012 summer
sampling run.
As the NZ-CPR Survey is still in the early stages of CPR
collection and analysis, few trends can be presented. However for
the Chatham Rise, results have already shown distinct changes in
populations directly attributed to the position of the frontal
zones, as well in timing and positions of blooms. The Southern
Ocean Survey has also provided evidence of zonal population changes
as well as population diversities similar to that recorded by other
SO-CPR sections.