The British Isles
231
southeast Scotland and northeast England (Bellamy and Whittick 1968;
Bellamyet al. 1969, 1972). These authors also showed that polluted ecosystems are dominated by suspension feeders with a great reduction in all
other trophic groups. Polluted/ silted waters have also been held responsible for smaller kelp blades (Burrows and Pybus 1970, 1971), inhibiting
germling development in several algae (Burrows and Pybus 1971; Moss
et al. 1973; Wilkinson and Tittley 1979) and the increased abundance of
some turf-forming algae such as Rhodochorton floridulum (Edwards 1975).
8.S Marine Benthic Algae
Associated with "Eutrophicated" Waters
Whilst a small increase in the nutrient loading of coastal waters can
probably be considered beneficial, and indeed is likely to pass unnoticed
in many situations (e.g. Edwards 1972, 1973 reported very little difference in the marine benthic flora of the nutrient-polluted Tyne Estuary
and the relatively unpolluted Wear Estuary), when in excess and given
the right hydrological conditions, the nutrients can cause quite marked
ecological changes. They can, for example, considerably increase the
productivity of algae and this was particularly well demonstrated by
Raymont (1947) when he artificially fertilized a sea loch in Scotland
(Loch Craiglin) during the summer and produced heavy growths of
seaweed and Zostera. More notably, however, the excess inputs of anthropogenic sources of nutrients have been attributed with both an overall reduction in species diversity and an enlarged productivity of a relatively small number of species. Table 8.5 lists examples of marine benthic
algae reported to be characteristic of eutrophicated waters, especially
those contaminated by sewage, in the British Isles. In agreement with
Edwards (1975), an ideal way to determine pollution effects is to compare the flora prior to and following the advent of pollution. Such historical comparisons like those of Johnston (1971172), Price and Tittley
(1972), Edwards (1975) and Wilkinson and Tittley (1979) are either rare
or lacking even for a relatively well-known flora like that of the British
Isles and, like the other examples given, do not always distinguish
between the different sources of pollutants. However, Johnston's study
does relate to sewage pollution and is worth mentioning here. Johnston
compared the marine flora and its distribution in the Firth of Forth,
Scotland, with data obtained by Traill (1886) in the late 19th century. He
recorded a 41.6% reduction in species at Joppa in the inner regions of
231
southeast Scotland and northeast England (Bellamy and Whittick 1968;
Bellamyet al. 1969, 1972). These authors also showed that polluted ecosystems are dominated by suspension feeders with a great reduction in all
other trophic groups. Polluted/ silted waters have also been held responsible for smaller kelp blades (Burrows and Pybus 1970, 1971), inhibiting
germling development in several algae (Burrows and Pybus 1971; Moss
et al. 1973; Wilkinson and Tittley 1979) and the increased abundance of
some turf-forming algae such as Rhodochorton floridulum (Edwards 1975).
8.S Marine Benthic Algae
Associated with "Eutrophicated" Waters
Whilst a small increase in the nutrient loading of coastal waters can
probably be considered beneficial, and indeed is likely to pass unnoticed
in many situations (e.g. Edwards 1972, 1973 reported very little difference in the marine benthic flora of the nutrient-polluted Tyne Estuary
and the relatively unpolluted Wear Estuary), when in excess and given
the right hydrological conditions, the nutrients can cause quite marked
ecological changes. They can, for example, considerably increase the
productivity of algae and this was particularly well demonstrated by
Raymont (1947) when he artificially fertilized a sea loch in Scotland
(Loch Craiglin) during the summer and produced heavy growths of
seaweed and Zostera. More notably, however, the excess inputs of anthropogenic sources of nutrients have been attributed with both an overall reduction in species diversity and an enlarged productivity of a relatively small number of species. Table 8.5 lists examples of marine benthic
algae reported to be characteristic of eutrophicated waters, especially
those contaminated by sewage, in the British Isles. In agreement with
Edwards (1975), an ideal way to determine pollution effects is to compare the flora prior to and following the advent of pollution. Such historical comparisons like those of Johnston (1971172), Price and Tittley
(1972), Edwards (1975) and Wilkinson and Tittley (1979) are either rare
or lacking even for a relatively well-known flora like that of the British
Isles and, like the other examples given, do not always distinguish
between the different sources of pollutants. However, Johnston's study
does relate to sewage pollution and is worth mentioning here. Johnston
compared the marine flora and its distribution in the Firth of Forth,
Scotland, with data obtained by Traill (1886) in the late 19th century. He
recorded a 41.6% reduction in species at Joppa in the inner regions of