Population-Dynamics And Production Of Euphausiids .2. Thysanoessa-Inermis And Thysanoessa-Raschi In The North-Sea And American Coastal Waters

Results from the Continuous Plankton Recorder (CPR) survey for 1966 and 1967 are used to describe seasonal changes in abundance, size and aspects of the population structure of Thysanoessa inermis (Krøyer) and T. raschi (M. Sars) at a depth of 10 m in the North Sea and in American coastal waters from the Grand Banks to the Gulf of Maine. Production and dry weight were estimated from these data. Two year-groups were usually present in the breeding population, the proportion surviving into a second year being higher in American waters than in the North Sea. Annual production for each species was within the range 0.69 to 4.66 mg m-3 and the ratio between production and biomass (P:B) was between 1.3 and 4.2; values outside these ranges were obtained only for American coastal waters in 1967, when the frequency of sampling was low.

Filtration Unit For Use With Continuous Autoanalytical Systems Applied To Highly Turbid Waters

A simple unit for filtration prior to continuous autoanalysis of highly turbid waters is described. Seawater can be supplied at a rate of 10 ml min−1, after filtration through a 0.45 μm pore-sized membrane filter (47 mm diameter), for at least 45 min from sea water containing 1000 parts/106 of suspended solids.