Tamar Zohary

Chlorophyll distribution throughout the southeastern Mediterranean in relation to the physical structure of the water mass

The spatial distribution of chlorophyll was recorded throughout the southern part of the Levantine Basin of the eastern Mediterranean and was related to patterns of the physical structure and nutrient concentrations. Chlorophyll a concentration in the upper 200 m of the water column ranged from 9.2 to 423 ng l−1, with an overall mean of 126 ± 85.6 (SD) ng l−1. The pattern of vertical distribution of chlorophyll was close to uniform throughout the basin, with a prominent deep chlorophyll maximum (DCM) of ca. 250 ng l−1 at 90–110 m. The values we report fall at the lower end of ranges reported from other oligotrophic seas, in accordance with the ultra-oligotrophic nature of the eastern Mediterranean. n nThroughout the basin more than 90% of the chlorophyll at the surface was confined to particles < 10 μ in diameter and more than 60% was found in particles < 2 μ. The proportion of chlorophyll in < 2 μ particles increased with depth between the surface and the DCM, as was also confirmed by flow cytometric analysis. n nDiscontinuities of physical and chemical features were mostly confined to depths greater than 200 m, and had little impact on the distribution of chlorophyll. An exception was an anti cyclonic eddy south of Crete, within which chlorophyll (mostly > 100 μg l−1) was more evenly distributed with depth over the upper 200 m.

Impacts of climate change on biodiversity in Israel: an expert assessment approach

The Mediterranean region is both a global biodiversity hot spot and one of the biomes most strongly affected by human activities. Ecologists and land managers are increasingly required to advise on threats to biodiversity under foreseeable climate change. We used expert surveys to evaluate current understanding and uncertainties regarding climate change impacts on biodiversity in terrestrial, inland freshwater, and marine ecosystems of Israel. Finally, we propose a response strategy toward minimizing these changes. The surveys and the published literature indicated that the main climate change impacts in Israel include ongoing deterioration of freshwater habitats, decline of shrubland and woodland areas, and increased frequency and severity of forest fires. For the Mediterranean Sea, the surveys predict further introduction and establishment of invasive species from the Red Sea, accelerated erosion of coastal rocky habitat, and collapse of coastal rocky platforms. In the Gulf of Aqaba, Red Sea, corals may be resilient to foreseen climate change due to their high tolerance for rising water temperatures. Despite these predictions, science-based knowledge regarding the contribution of management toward minimizing climate change impacts on biodiversity is still lacking. Habitat loss, degradation, and fragmentation are presently the primary and immediate threats to natural ecosystems in Israel. Protection of natural ecosystems, including local refugia, must be intensified to maintain existing biodiversity under pressure from mounting urban development and climate change. This protection policy should include ecological corridors to minimize the consequences of fragmentation of existing natural habitats for species survival. A longer-term strategy should mandate connectivity across environmental and climatic gradients to maintain natural resilience by allowing reorganization of natural ecosystems facing climate change.