A key characteristic of the EMS is the very low concentration of dissolved nutrients present in the water column. University of Haifa had purchased and put into operation a very high sensitivity automated nutrient analyzer, specifically to enable us to understand the nutrient cycling processes on the Israeli shelf.

A key characteristic of the EMS is the very low concentration of dissolved nutrients present in the water column. University of Haifa had purchased and put into operation a very high sensitivity automated nutrient analyzer, specifically to enable us to understand the nutrient cycling processes on the Israeli shelf.

Our results of the Israeli coastal shelf found an inverse relationship between the total oxidized Nitrogen concentration values and those of Phosphate  and Silicate.  This unexpected relationship needs further investigation to understand the possible causes. An example of this is shown in the Sdot-Yam Rocky reef LTER nutrient results (below plots), depicting average May/June concentrations of Phosphate and Nitrate+Nitrite.

Figure 1: Average Phosphate concentrations in the months of May/June between 2016-2019 at the rocky sites of Sdot-Yam.

Figure 2: Average Nitrate+Nitrite concentrations in the months of May/June between 2016-2019 at the rocky sites of Sdot-Yam.

Figures 1  and 2 show nutrient distribution from shallow waters above a rocky substrate on a transect off Sdot Yam. In May-June there is higher P concentration at 45m and towards the bottom suggesting that there was a coastal supply of P and possibly also sediment supply likely to be from adjacent areas since rocky substrates are not expected to produce any nutrients directly. By contrast the distribution of Nitrate+Nitrite is below detection limit close to shore and increases at the 45m sampling station.