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Hello Marin, > As some of you know, I am by training a fish ecologist, but I am also > greatly interested in cephalopods (octopus, cuttlefish, squid, Nautilus) > because of their ecological similarities to fish. No cephalopods exist in > freshwaters, but I was wondering if anyone had any evidence of estuarine > occurrence. I have heard of octopus being entrained at power station > intakes in mid-estuary areas (salinity 8-25), but have not seen any myself. > Are cephalopods limited by their osmoregulatory abilities to be only > adventitious species in estuaries, or are there other more important factors > perhaps involved as well? We regularly caught cephalopods in samples from West Thurrock power station on the Thames estuary, particularly in autumn when flows were generally lowes (the maximum salinity here is about 20 PSU - mid-tide corrected - but we generally sampled over low tide when the salinity was lower). Most of the specimens were small individuals of either the squid Alloteuthis subulata or the cuttlefish Sepiola atlantica. However, occassional large Sepia officianalis were also caught here. Rifling through my records the maximum abundances in any one catch (500 million litres of water screened) were: Alloteuthis: 15 Sepiola: 9 So they must be about in the mid-estuary in fairly high number. Hope this is of some interest Martin ____________________________________________ Dr. Martin Attrill Benthic Ecology Research Group Plymouth Environmental Research Centre University of Plymouth Drake Circus Plymouth. PL4 8AA. Tel: 01752 232916 Fax: 01752 232970 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%