390
LM. Munda
in patches at these levels. The biomass was notably lower at 7 m, where
crustose floristic elements dominate.
In a moderately polluted habitat from the same area (Fig. 16.9C), the
biomass was higher at the two intermediate depths of 1 and 3 m.
Halopythis incurvus contributed a great proportion to the total biomass.
Cystoseira species were better represented here than in the heavily eutrophicated locality. In the eulittoral and at 7 m depth, differences between the transects were less conspicuous.
A scheme of the average percentage species composition of the fresh
weight biomass is given in Fig. 16.10 (Munda 1993b). In the eulittoral,
Fucus virsoides dominated in undisturbed sites, with a small proportion
of the green algal component. With increasing pollution the proportion
of the green algae within the Fucus settlements increased and turflike mats of Gelidium pusillum became notable. In moderately polluted
sites, these Gelidium mats may contribute the greater part to the total
biomass (60%), while the rest are green algae (Blidingia minima, Ulva
rigida, Enteromorpha spp. and Cladophora species) Green algae could be
predominant in the biomass of some sites. In heavily polluted sites the
eulittoral slopes were covered by diverse spring annuals, but the bulk of
the biomass consisted of nearly 100% of either Blidingia minima or
Cladophora species.
In undisturbed sites, the level of the eulittorallsublittoral junction was
covered by either Ceramium or Polysiphonia species, each of them contributing 100% to the total biomass of the transects investigated.
In moderately polluted sites, the algal biomass was dominated by
Scytosiphon lomentaria and green algae (Ulva rigida, Enteromorpha spp.)
occurring in different proportions. In heavily polluted sites, this level was
usually occupied by Mytilus galloprovincialis. Ulva rigida, attached to it,
formed only a negligible proportion of the total biomass.
In the upper sublittoral, Cystoseira species dominated (c. compressa,
C. barbata), with a small proportion of Corallin a officinalis and locally
also Dictyota dichotoma in the fresh weight biomass. In moderately
polluted sites, this level was occupied by mixed populations, dominated
either by Halopteris scoparia or Dictyota dichotoma. Other components
contributing to the biomass could be Halopythis incurvus, green algae
and Cystoseira species, which were, however, in the minority. Locally,
Ulva rigida also contributed to the total biomass.
It is noteworthy that Pterocladia capillacea and Padina pavonica
occurred, in terms of fresh weight biomass, in negligible quantities and
were not included in the measurements.
In heavily polluted sites, the biomass was negligible due to grazing by
sea urchins, crustose corallines being the only remnants of the previous
LM. Munda
in patches at these levels. The biomass was notably lower at 7 m, where
crustose floristic elements dominate.
In a moderately polluted habitat from the same area (Fig. 16.9C), the
biomass was higher at the two intermediate depths of 1 and 3 m.
Halopythis incurvus contributed a great proportion to the total biomass.
Cystoseira species were better represented here than in the heavily eutrophicated locality. In the eulittoral and at 7 m depth, differences between the transects were less conspicuous.
A scheme of the average percentage species composition of the fresh
weight biomass is given in Fig. 16.10 (Munda 1993b). In the eulittoral,
Fucus virsoides dominated in undisturbed sites, with a small proportion
of the green algal component. With increasing pollution the proportion
of the green algae within the Fucus settlements increased and turflike mats of Gelidium pusillum became notable. In moderately polluted
sites, these Gelidium mats may contribute the greater part to the total
biomass (60%), while the rest are green algae (Blidingia minima, Ulva
rigida, Enteromorpha spp. and Cladophora species) Green algae could be
predominant in the biomass of some sites. In heavily polluted sites the
eulittoral slopes were covered by diverse spring annuals, but the bulk of
the biomass consisted of nearly 100% of either Blidingia minima or
Cladophora species.
In undisturbed sites, the level of the eulittorallsublittoral junction was
covered by either Ceramium or Polysiphonia species, each of them contributing 100% to the total biomass of the transects investigated.
In moderately polluted sites, the algal biomass was dominated by
Scytosiphon lomentaria and green algae (Ulva rigida, Enteromorpha spp.)
occurring in different proportions. In heavily polluted sites, this level was
usually occupied by Mytilus galloprovincialis. Ulva rigida, attached to it,
formed only a negligible proportion of the total biomass.
In the upper sublittoral, Cystoseira species dominated (c. compressa,
C. barbata), with a small proportion of Corallin a officinalis and locally
also Dictyota dichotoma in the fresh weight biomass. In moderately
polluted sites, this level was occupied by mixed populations, dominated
either by Halopteris scoparia or Dictyota dichotoma. Other components
contributing to the biomass could be Halopythis incurvus, green algae
and Cystoseira species, which were, however, in the minority. Locally,
Ulva rigida also contributed to the total biomass.
It is noteworthy that Pterocladia capillacea and Padina pavonica
occurred, in terms of fresh weight biomass, in negligible quantities and
were not included in the measurements.
In heavily polluted sites, the biomass was negligible due to grazing by
sea urchins, crustose corallines being the only remnants of the previous