Western Channel Observatory

NERC National Capability of the Plymouth Marine Laboratory and Marine Biological Association


L4 Zooplankton time-series

Ongoing zooplankton research at the Plymouth Marine Laboratory has established a time series of zooplankton species since 1988 at L4, a coastal station off Plymouth. Samples were collected by vertical net hauls (WP2 net, mesh 200 µm; UNESCO 1968) from the sea floor (approximately 55m) to the surface and stored in 5% formalin. Much of the zooplankton analysis has been to the level of "major taxonomic groups" only, and a number of different analysts have participated over the years. The level of expertise has generally been consistent, but the user should be aware that levels of taxonomic discrimination may vary during the course of the data-set.

The dominant calanoid copepods are generally well discriminated to species throughout. Calanus has not been routinely examined for species determination, the assumption being that the local population is entirely composed of Calanus helgolandicus. In certain years there has been a particular interest in Temora stylifera, Centropages cherchiae and other species reflected in the data-set. The lack of records in other previous years does not necessarily reflect species absence. Similarly, particular interest in Appendicularia species in some years has lead to good species discrimination (Acuña et al, 1995) . In other years, the species probably were present, but not identified.

We view it as essential for all users of L4 plankton data to establish and maintain contact with the nominated current data originators as well as fully consulting the metadata. While not impinging on free data access, this ensures that this large, species-rich but slightly complex species database is being used in the correct way, and any potential issues with the data are clarified. Furthermore, a proper dialogue with these local experts on the time series will enable where appropriate the most recent sampling timepoints to be used.

The data can be downloaded from BODC website. To access the entire dataset please contact Dr. Angus Atkinson (aat@pml.ac.uk) in the first instance. The taxonomic list can be downloaded from here

The entire set of zooplankton samples is stored at the Plymouth Marine Laboratory in 5% buffered formalin, and may be available for further taxonomic analysis on request.

Total zooplankton abundance

About Us

The WCO is a partnership between the Plymouth Marine Laboratory and the Marine Biological Association.

How are we funded?

The core work of the WCO is funded as part of the UK Natural Environment Research Council's National Capability.

Contact Information

For more details about the WCO please contact:

Dr Tim Smyth
Western Channel Observatory
Plymouth Marine Laboratory
Prospect Place
email: tjsm@pml.ac.uk