A Quantitative Comparison of Two Zooplankton Sampling Methods, a Plankton Trap and a Towed Net, in the Baltic

✍ Scribed by Paula Kankaala

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 629 KB
• Volume: 69
• Category: Article
• ISSN: 1434-2944
• DOI: 10.1002/iroh.19840690218

✦ Synopsis

A coniparison between a large plankt,on trap with a capacity of 33 litres and a modern towecl net was made in the course of zooplankton production studies in the Balt,ic. On the average, the net efficiency was 75 U#, of that, of the trap. Both methods were equally efficient in catching naapliar stages of oopepods. The net efficiency was especially low during the zooplankton maximum for adult copepods and eladocerans (41 and 51 "/". respectively), probably due to the act,ive avoidance of the net by fast swimming species. The net was only about 66 ' \ !o as efficient as the t m p for catching rotifers. This difference is probably caused by the loss of sinall and softbodied fornis through the mesh. Only about 65 ";,, of the total zooplankton biomass ret,ained in the t,rap IVRS collected by the net. Net sampling is not recommended for quantitative zooplankton studies.