Sources of chitin, estimated from new data on chitin biomass and production

On the basis of recent quantitative data on chitin biomass and production, marine surface zooplankton, mainly Copepods and Cladocerane, appears as a valuable source of chitin. Its mean chitin production of about 1g m-2 year-1 is much higher than krill chitin production. Marine benthic communities growing on naked substrates sometimes exhibit similar chitin production, but chitin proportion with respect to calcified and organic weight of this biological material is far much lower than in krill and zooplankton. Chitin production is the highest in eutrophic freshwaters ; the development of Bryozoan colonies in organopolluted waters seems to offer interersting possibilities, chitin production values of about 20g m-2 year -1 being recorded in some cases.