JPR Advance Access originally published online on September 10, 2004
Journal of Plankton Research 2004 26(10):1135-1145; doi:10.1093/plankt/fbh095
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The next generation of Optical Plankton Counter: the Laser-OPC
Bedford Institute of Oceanography, Department of Fisheries & Oceans, 1 Challenger Drive, Dartmouth, NS, Canada B2Y 4A2
Corresponding Author: hermana{at}mar.dfo-mpo.gc.ca
Received on December 17, 2003; accepted in principle April 7, 2004; accepted for publication May 6, 2004; published online September 10, 2004
Optical Plankton Counters (OPCs) have been in operation for 
12 years and while there have been considerable research studies by the user community, some operational issues have emerged over this time, such as its operational limitations in high densities, the lack of accompanying flow measurements and other measurement limitations. Reported here is the next generation of this device, the Laser-Optical Plankton Counter or LOPC which was designed at the Bedford Institute of Oceanography to address the future needs of optical plankton counting. Using a narrow laser beam and new sampling geometry, the LOPC is now capable of working in plankton densities of 106 m–3, nearly 100 times greater than its predecessor, the OPC, and is also capable of providing shape profiles of plankton >1.5 mm. Other new features include (i) the measurement of flow speeds through the sampling tunnel by making statistical estimates of the particle time-of-transit, (ii) a lower detection limit of 100 µm, (iii) high speed towing up to 8 m s–1, and (iv) overall smaller physical size relative to the OPC. Data are presented from an LOPC mounted on the inside of a 0.5 m plankton net (75 µm mesh size) showing linear correlation between net samples (e.g. counts of copepod eggs, nauplii) and LOPC counts. The LOPC-measured shape profiles from the same LOPC/net tows clearly show copepods and appendages and, in some cases, euphausiids. By increasing the tunnel width relative to the original OPC, the volume sampled by the LOPC can be increased by 5x. Other towing platforms that have been tested to date are the Batfish vehicle towed at 8 knots and the Moving Vessel Profiler (MVP) towed at 12–14 knots.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  S. L. Basedow, K. S. Tande, and M. Zhou Biovolume spectrum theories applied: spatial patterns of trophic levels within a mesozooplankton community at the polar front J. Plankton Res., November 13, 2009; (2009) fbp110v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. O. Peterson and W. T. Peterson Influence of the Columbia River plume (USA) on the vertical and horizontal distribution of mesozooplankton over the Washington and Oregon shelf ICES J. Mar. Sci., April 1, 2008; 65(3): 477 - 483. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Zhou What determines the slope of a plankton biomass spectrum? J. Plankton Res., May 1, 2006; 28(5): 437 - 448. [Abstract] [Full Text] [PDF]
|
|