Ch. Lucas et al., PLANKTON DYNAMICS AND AURELIA-AURITA PRODUCTION IN 2 CONTRASTING ECOSYSTEMS - COMPARISONS AND CONSEQUENCES, Estuarine, coastal and shelf science, 45(2), 1997, pp. 209-219
The population dynamics and production of the Scyphomedusa Aurelia aur
ita (Lam.) were examined within two contrasting ecosystems on the sout
h coast of England; Southampton Water, an open productive estuary, and
Horsea Lake, an enclosed, brackish, man-made body of water. Annual A.
aurita production in Southampton Water ranged between 31 and 58 mg C
m(-3) year(-1) in different years (1990-94); while at Horsea Lake, ann
ual production was 76 mg year(-1) in 1994. The potential impact of A.
aurita on the mesozooplankton communities was estimated through C m(-3
) measurements of in situ secondary production and transfer efficiency
between the two populations. Using literature-based estimates for mes
ozooplankton production, the annual transfer efficiency between the me
sozooplankton and A. aurita populations in Southampton Water ranged be
tween 9 and 26% in different years, and in Horsea Lake was 73% in 1994
. These data imply that the abundant A. aurita population may have a s
ignificant impact on the mesozooplankton community of Horsea Lake, and
in turn, the very small A. aurita sizes observed indicate a severely
food limited population. The ecological role of A. aurita in Horsea La
ke is discussed in View of the very low chi a and mesozooplankton numb
ers present. (C) 1997 Academic Press Limited.