Water quality

Parc National d'Ichkuel & Lake Bizerte, Tunisia

The Ichkeul - Bizerte Basin is located in the northern part of Tunisia covers an area ~ 3084 km², with the Ichkeul lake linked to the Bizerte Lagoon by the Tinja Canal. The Basin was demarcated as a biosphere reserve in 1977, a UNESCO World Heritage site in 1979, and as a RAMSAR site in 1980.

The Ichkeul National Park is the most important area in North Africa for the migratory Palaearctic waterfowl with peak winter records of up to 100,000–200,000 birds. Anthropogenic activities ( e.g. burning of coal, oil, gasoline, trash, tobacco, and wood) in the region is identified to increase the concentration of toxic environmental organic compounds in the lakes.

In Winter, there is often increase in the water levels of Lake Ichkeul due to increased freshwater inflows from six main wadis, namely, the Doumiss, Sejnane, Melah, Ghezala, Joumine, and the Tine. The increased water inflows into the Ichkeul often leads to water flowing from the lake (about three times its volume during winter and spring) into the Bizerte Lagoon. During summer, water levels fall in the Ichkeul which results in Wadi Tinja transporting salting water from the Bizerte Lagoon into the Ichkeul Lake.

Maps of satellite-derived monthly averages of the Total Suspended Matter (TSM) and Chlorophyll of Lakes Ichkeul and Bizerte show spatio-temporal variations in concentrations for both lakes with much higher concentrations in Lake Ichkeul. The highest monthly TSM concentration for Ichkeul is in June and might be influenced by water level changes. Lake Bizerte shows clear water until April and increasing concentrations from May onwards. The spatial pattern of TSM in Ichkeul may be related to where the main rivers enter the Lake and volume of surface runoff during peak rainfall.