An Atlantic partnership is acceptable if the European cultural, linguistic, social and economic diversities are preserved. And yet, Europe feels a threat through the now Globalisation which is so often seen as a form or aspect of Americanisation. The European Union is weak but not drifting away. If the Union do wants to behave as “a global power in the Economic, Social, Environmental governance of the world” (Josaiane Tercinet), it must talk as a united power. This short overview of the period 1945-2006, made by an historian who is aware of the long term influence, shows that it is European integration that has recreated the conditions of the European renewal. Of course, Atlantic economic integration represents a mighty trend ever since 1944. But the Atlantic economic and financial interactions do not necessarily create the political unity of action between the two sides of the Atlantic ocean. It seems that trouble between the two banks of Atlantic is rising because the political, even mental, position of now US leaders and not because economic or commercial tensions. However, it doesn’t only depend on the short term situation. We will conclude on the specificity of the two sides of Atlantic. Beyond an economic integration which seems inevitable in an open world and which will spread to another part of industrial countries, beyond the necessary bilateral cooperation due to the old friendship, to hope overcoming the political and cultural differences between the two is both an unrealizable dream and a mistake.

Keywords: Atlantic partnership, European diversities, European Union, European integration, economic integration, European power

The high productivity and diversity of giant kelp forests have long attracted the attention of biologists. After observing the kelp forests of Tierra del Fuego, Charles Darwin (1860, p. 227-229) wrote: "There is one marine production, which from its importance is worthy of a particular history. It is the kelp, or Macrocystis pyrifera…The number of living creatures of all Orders, whose existence intimately depends on the kelp, is wonderful…I can only compare these great aquatic forests of the southern hemisphere, with the terrestrial ones in the intertropical regions. Yet if in any country a forest was destroyed, I do not believe nearly so many species of animals would perish as would here, from the destruction of the kelp."

Along the coast of California, forests of giant kelp also harbor rich and complex communities of marine plants and animals. The environmental conditions and species composition of these forests vary, but they all have one factor in common: the dominating presence of the giant kelp, Macrocystis sp. In what ways are the organisms associated with this plant influenced by it and dependent on it?

Macrocystis plays a major role in determining the physical structure of the kelp forest community. It not only substantially increases the total substrate area (Clendenning, 1960, in North, 1971a), but also extends that substrate vertically through the water column to the sea surface. The morphological heterogeneity of the plant itself provides a diversity of habitats (North, 197la; Pearse and Gerard, in press). The influence of Macrocystis on the physical structure of the forest is comparable to that of the trees in a terrestrial forest and of the hermatypic corals in a tropical reef community.

Macrocystis also influences the trophic structure of the forest community as the dominant primary producer, outweighing and outproducing the other benthic algae and phytoplankton (Clendenning, 1971; North, 197la). The magnitude and fate of the kelp production and its role as a food base within the forest community are the major concerns of this thesis.

In the first chapter, I investigate the dynamics of the attached kelp population, and examine the magnitude and mechanisms of drift kelp production and its importance, relative to grazing and detritus formation, as a pathway of primary production within and out of the kelp forest. The formation of drift kelp influences the availability of kelp production to and its utilization by members of the forest community. This trophic pathway is discussed in the second chapter, in which I consider benthic drift plant material as a resource within the forest. Finally, in the third chapter, I test my hypotheses on the role of benthic drift algae and seagrasses as a trophic pathway by study­ing the feeding habits of the drift consumer, Patiria miniata. The dependence of this asteroid on the drift plant resource may provide insight into the dependence of other kelp forest inhabitants on the productivity of Macrocystis.