Nl. Andrew et Rm. Viejo, EFFECTS OF WAVE EXPOSURE AND INTRASPECIFIC DENSITY ON THE GROWTH AND SURVIVORSHIP OF SARGASSUM-MUTICUM (SARGASSACEAE, PHAEOPHYTA), European journal of phycology, 33(3), 1998, pp. 251-258
In this paper we quantify the interactive effects of wave exposure and
intraspecific density on the survivorship and growth of Sargassum mut
icum in northern Spain. Juveniles settled onto slate plates were exper
imentally thinned to two densities and transplanted to exposed and she
ltered shores. Initially, plants grew faster at the exposed sites but
final lengths were similar between exposures after 5 months, largely b
ecause of breakages at the top of the main primary lateral of plants a
t exposed sites. Mean weights of plants did not significantly differ b
etween exposures. The results indicate that S. muticum juveniles growi
ng at high density were longer and thinner but similar in weight to th
ose at low density. Patterns of growth of larger plants transplanted b
etween sheltered sites similarly suggested changes in morphology of S.
muticum in response to differences in density. Survivorship of juveni
les did not differ between exposures but was significantly poorer at t
he higher density irrespective of wave exposure. The results of this a
nd previous studies suggest that the abundance of S. muticum in the lo
w intertidal area of exposed shores in northern Spain is limited at se
veral life-history stages. The relative importance of these potential
bottlenecks compared with the availability of propagules remains unkno
wn.