Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-22T18:27:23.647Z Has data issue: false hasContentIssue false

Consistency of Towing Speed and Sampling Depth for the Continuous Plankton Recorder

Published online by Cambridge University Press:  11 May 2009

G. C. Hays
Affiliation:
The Sir Alister Hardy Foundation for Ocean Science, The Laboratory, Citadel Hill, Plymouth, PL1 2PB
A. J. Warner
Affiliation:
The Sir Alister Hardy Foundation for Ocean Science, The Laboratory, Citadel Hill, Plymouth, PL1 2PB

Extract

The mean annual towing speed of the Continuous Plankton Recorder (CPR) varied systematically between 1946 and 1991. By mounting a pressure transducer on the CPR to record towing depth, it was shown, however, that changes in towing speed did not cause a significant change in towing depth, although the mean towing depth (6–7 m, SD=l-7 m, N=77) was shallower than the previously assumed towing depth of 10 m. Thus the observed changes in towing speed are unlikely to have caused discontinuities in the CPR time-series by affecting sampling depth.

Long-term data sets play an important role in attempts to understand the causes of fluctua- tions in plankton abundance. The Continuous Plankton Recorder (CPR) survey provides multi- decadal information on plankton abundance in the North Sea and North Atlantic (McGowan, 1990), and is one of the longest standing marine plankton abundance time-series. However, while the CPR time-series has great potential, as with all other data sets spanning many years, questions may be asked regarding the consistency with which the data have been collected and hence the true continuity of the time-series.

Type
Short Communications
Copyright
Copyright © Marine Biological Association of the United Kingdom 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Colebrook, J.M., 1975. The Continuous Plankton Recorder survey: computer simulation studies of some aspects of design of the survey. Bulletin of Marine Ecology, 8, 143166.Google Scholar
Colebrook, J.M., 1986. Environmental influences on long-term variability in marine plankton. Hydrobiologia, 142, 309325.CrossRefGoogle Scholar
Mcgowan, J.A., 1990. Climate and change in oceanic ecosystems: the value of time-series data. Trends in Ecology and Evolution, 5, 293299.CrossRefGoogle ScholarPubMed
Raymont, J.E.G., 1963. Plankton and productivity in the oceans. London: Pergamon Press.Google Scholar