CHAPTER XI 



MARINE ECOLOGY 



The algae of the rocky coasts have attracted more investigators 

 than those of the salt-marsh coast, probably because of the greater 

 abundance of species, the greater ease in identifying the component 

 members of the flora, and the v^ell-marked zonation which is so 

 characteristic of most rocky shores. In spite of these numerous 

 investigations v^e are still very far from understanding how the 

 zonation is secured and maintained, nor is there sufficient data 

 about the environmental factors because most workers have simply 

 contented themselves with describing zonations in particular areas 

 and only suggesting possible controlling factors. Furthermore, our 

 knowledge of recolonization on the sea-shore is very rudimentary,* 

 and it is highly desirable that more information should be obtained 



Table XII. Algal associatiot 



Dover 



Endoderma 

 Rividaria- Colo thrix 



Schizothrix Fritschii 

 Enteromorpha- Urospora- 



Codiolum 

 Chrysophyceae-Endoderma- 



Lyngbya 

 Chrysotila stipitata 



Fucus spp. 



Gelidium-Polysiphonia 

 Rcdfsia 



Enteromorpha-Porphyra 

 Chalk-boring algae 



Rhizoclonium- Vaucheria 

 Pylaiella littoralis 



Enteromorpha intestinalis 

 Rhizoclonium riparium 



Isle of Wight 



Peveril Point 

 (Dorset) 



Wembury 

 (Dorset) 



Rivularia-Calothrix — 



SUBLITTORAL 



Sheltered coasts 



Fucus ceranoides Fucus spiralis 



Ascophyllum Fucus vesiculosus 



Fucus vesiculosus — 



Fucus serratus Fucus serratus 



— Porphyra 



Ulva 



Laurencia- 

 Corallina 



Pelvetia 

 Fucus spiralis 



Ascophyllum 

 Fucus serratus 



Lomentaria \ 

 Gigartina J 



Halidrys 



Laminaria 



Laminaria 



Laminaria 



Chondrus 



Lough Ine (Ireland) 



Lichina 



Hildenbrandtia- Verrucaru 



Ralfsia 

 Upper Chlorophyceae 



Fucus spiralis 



Fucus vesiculosus var. 



evesiculosus 

 Ascophyllum 

 Fucus serratus 



Porphyra 

 Bangia- Urospora 



Lomentaria 

 Laurencia 



Gigartina 



Callithamnion-Ceramium 



Nemalion 



Himanthalia 



Corallina-Lithothamnion 



Laminaria 



Sublittoral Rhodophyceac 



Alaria 



Plumaria- Ceramium 

 Laurencia- Gelidium 

 Chondrus 



Cladophora rupestris 

 Lower Chlorophyceae. 

 {Enteromorpha spp.) 



* Cf. Rees (1940) upon recolonization. 



