Nitrate and phosphate uptake characteristics of three species of brown algae cultured at low salinity.

Nitrate and phosphate uptake mechanisms have been characterised under conditions of 100 and 50% seawater in 3 common brown algae of NW Europe: Fucus vesiculosus, F. serratus and Laminaria digitata. Under low salinity, the growth rate and internal nitrate accumulation of F. serratus significantly increased (20 and 48%, respectively), but no significant changes were observed for F. vesiculosus and L. digitata. However, nitrate uptake rates were reduced in L. digitata, so that this species was less adaptable to low salinity than the Fucus species. Both F. vesiculosus and F. serratus reached a steady-state uptake rate after acclimation regardless of the salinity treatment. All 3 species had a high capacity for storing inorganic N and P intracellularly. The results for F. serratus pointed to a dual mechanism of adaptation to the special characteristics of the intertidal environment where it grows. Non-saturating (low affinity) nitrate uptake and biphasic (double Michaelis-Menten curve) phosphate uptake are adaptations to high nutrient concentrations. Temporal partition of cellular energy for carbon metabolism and nutrient uptake is also suggested as an adaptation to the transient nutrient inputs occurring in these environments.

Crisis Management in the Eastern Mediterranean (Implications for Policymakers)

This article examines Greek-Turkish crisis behaviour in the Eastern Mediterranean over the past two decades. Crises are first defined and classified, after which a number of common misperceptions are then addressed in light of recent experience. Three broad categories of foreign policy crises are analyzed: 1) those involving ethnically related minorities across the border; 2) those with 'alien' minorities within borders; and 3) those with third countries involving territories and resources. The article examines whether crises are simply elite-driven or partly endorsed and motivated by mass publics in both countries, and whether Greek-Turkish crisis behaviour reflects enduring ethnic rivalries, 'genuine' security interests, or domestic political needs and norms. The article draws upon the Greek-Turkish experience of the past two decades to illuminate contemporary dilemmas and issues which policymakers face in this region.