The Occurrence of "Green Tides" - a Review
17
increased pollution leading to an increase in a number of tolerant species
such as Hypnea musciformis. Grenager (1957), in a study of the inner
polluted harbour of Oslofjord, Norway, observed no macroscopic
Phaeophyceae with the vegetation only represented by a few Rhodophyceae
(Bangia juscopurpurea, Ceramium strictum), Chlorophyceae (Enteromorpha intestinalis, E. crinita and Urospora penicilliformis) and a cover of
Cyanophyceae.
In general, the great majority of reports refer to an increase in the
number of green algae associated with eutrophicated waters (Wilkinson
1963; Subbaramaiah and Parekh 1966; Ehrhardt 1968; Smyth 1968;
Borowitzka 1972; Buttermore 1977; Bellan and Bellan-Santini 1972; Munda
1974; Littler and Murray 1975; Sfriso 1987; Sfriso et al. 1987; Wennberg 1987;
Raffaelli et al. 1989; Wilson et al. 1990; Jeffreyet al. 1992; Munda 1993), this
usually being at the expense of red algae (particularly fleshy reds) (North
1963; Munda 1974; Sfriso 1987) and brown algae (Munda 1974). Particularly
common green algae include species of the genera Enteromorpha, Ulva,
Chaetomorpha and Cladophora. Commonly recorded brown algae, however,
include species of the genera Ectocarpus (Wilson et al. 1990; Jeffrey 1993) and
Pilayella (Wilce et al. 1982), whilst frequently recorded red algae include
species of the genera Gracilaria, Gracilariopsis, Corallina, Ceramium,
Gelidium and Bangia. More recently, Sfriso (1987) recorded 95 species in the
polluted Venice Lagoon compared to 141 and 104 recorded by Schiffner and
Vatova (1938) and Pignatti (1962) in the 1930s and 1960s respectively. This
represented a 2% increase in the Chlorophyta and a 65-51 % decrease in the
Rhodophyta. Occasionally, however, there are reports oflarge red algae (e.g.
Furcellaria lumbricata and Phycodrys rubens increasing in abundance as a
result of eutrophication (Baden et al. 1990). The Cyanophyceae, or bluegreen algae, are also well represented, particularly in regions of high pollution
and during the warmer summer months (Nasr and Aleem 1948; Grenager
1957; Littler and Murray 1974; Munda 1974, 1993; Murray and Littler 1974,
1983). Table 1.1 lists some of the genera and species of marine macro algae
described for sewage-polluted waters.
Many of these algae, especially the green algae, are often described by
authors as annual, ephemeral, fast growing and opportunistic (Littler and
Murray 1974; Murray and Littler 1974; Bokn et al. 1977; Smith et al. 1981;
Kangas et al. 1982; HaIlfors et al.1987; Wennberg 1987, 1992; Elmgren 1989;
Isaksson and Pihl 1990; Rosenberg et al. 1990; Vogt and Schramm 1991;
Kautsky et al. 1992) and are well known as pioneering organisms on
recently exposed or denuded surfaces. Essentially, the 'polluted' environment maintains an immature community characteristic of an early seral
stage (referred to as a 'dis climax' community by Littler and Murray 1974).
Such a simple, low turfforming, non-complex, unstratified community is
17
increased pollution leading to an increase in a number of tolerant species
such as Hypnea musciformis. Grenager (1957), in a study of the inner
polluted harbour of Oslofjord, Norway, observed no macroscopic
Phaeophyceae with the vegetation only represented by a few Rhodophyceae
(Bangia juscopurpurea, Ceramium strictum), Chlorophyceae (Enteromorpha intestinalis, E. crinita and Urospora penicilliformis) and a cover of
Cyanophyceae.
In general, the great majority of reports refer to an increase in the
number of green algae associated with eutrophicated waters (Wilkinson
1963; Subbaramaiah and Parekh 1966; Ehrhardt 1968; Smyth 1968;
Borowitzka 1972; Buttermore 1977; Bellan and Bellan-Santini 1972; Munda
1974; Littler and Murray 1975; Sfriso 1987; Sfriso et al. 1987; Wennberg 1987;
Raffaelli et al. 1989; Wilson et al. 1990; Jeffreyet al. 1992; Munda 1993), this
usually being at the expense of red algae (particularly fleshy reds) (North
1963; Munda 1974; Sfriso 1987) and brown algae (Munda 1974). Particularly
common green algae include species of the genera Enteromorpha, Ulva,
Chaetomorpha and Cladophora. Commonly recorded brown algae, however,
include species of the genera Ectocarpus (Wilson et al. 1990; Jeffrey 1993) and
Pilayella (Wilce et al. 1982), whilst frequently recorded red algae include
species of the genera Gracilaria, Gracilariopsis, Corallina, Ceramium,
Gelidium and Bangia. More recently, Sfriso (1987) recorded 95 species in the
polluted Venice Lagoon compared to 141 and 104 recorded by Schiffner and
Vatova (1938) and Pignatti (1962) in the 1930s and 1960s respectively. This
represented a 2% increase in the Chlorophyta and a 65-51 % decrease in the
Rhodophyta. Occasionally, however, there are reports oflarge red algae (e.g.
Furcellaria lumbricata and Phycodrys rubens increasing in abundance as a
result of eutrophication (Baden et al. 1990). The Cyanophyceae, or bluegreen algae, are also well represented, particularly in regions of high pollution
and during the warmer summer months (Nasr and Aleem 1948; Grenager
1957; Littler and Murray 1974; Munda 1974, 1993; Murray and Littler 1974,
1983). Table 1.1 lists some of the genera and species of marine macro algae
described for sewage-polluted waters.
Many of these algae, especially the green algae, are often described by
authors as annual, ephemeral, fast growing and opportunistic (Littler and
Murray 1974; Murray and Littler 1974; Bokn et al. 1977; Smith et al. 1981;
Kangas et al. 1982; HaIlfors et al.1987; Wennberg 1987, 1992; Elmgren 1989;
Isaksson and Pihl 1990; Rosenberg et al. 1990; Vogt and Schramm 1991;
Kautsky et al. 1992) and are well known as pioneering organisms on
recently exposed or denuded surfaces. Essentially, the 'polluted' environment maintains an immature community characteristic of an early seral
stage (referred to as a 'dis climax' community by Littler and Murray 1974).
Such a simple, low turfforming, non-complex, unstratified community is