Chott el Djerid is a salt lake located in present day Tunisia. It's altitude varies between 10 meter above sea level to 25 meter below sea level.
https://en.wikipedia.org/wiki/Chott_el_Djerid
(Below a map of Tunisia)

Chott el Djerid is the large blue colored salt lake in the middle of the country.
What if one of the societies there had greated a canal connecting Chott el Djerid to the mediterranean? It could be a Berber state, the Carthaginians, the Romans, the Vandal kingdom, the Byzantine empire, a caliphate, the Ottomans, the French or anyone that could possible be i a position that might allow for this canal to be built. Which of these would be most likely to embark on such a project, and how would their level of technology impact the project?
How could this project impact the surronding area of Chott el Djerid? Would it strengthen the societies north of the salt lake? Would it strenghten the societies on North Africas mediterranean coast? Would it make it easier for the ruling power in the region to control the North East Maghreb?
Would the sand surronding the new Chott el Djerid panhandle part of the mediterranean eventually plug it? Or would the new part of the mediterranean last?
Would the flooded Chott el Djerid be a bay? Or would it be a gulf?
How would the flooding of the Chott el Djerid saltlake affect he local human populations? Would the areas be more economically open to trade? What kind of traditions might perish, change or begin due to the flooding?
Would the flooding of Chott el Djerid make cross Saharan trade easier or more prominent?
The crocodiles of Chott el Djerid would they have time to adapt to the changing nature of their surrondings or would they perish?
https://en.wikipedia.org/wiki/Chott_el_Djerid#Fauna
https://en.wikipedia.org/wiki/West_African_crocodile
The Pink Flamingo has been using Chott el Djerid as a nesting site. Being a in a salt lake it is relativly safe there. How would the Pink Flamingo fare if Chott el Djerid was flooded?
https://en.wikipedia.org/wiki/Chott_el_Djerid#Fauna
Would the new Chott el Djerid part of the mediterranen start to get sealife? If so, in what quantities?
Perhaps the great project of connecting the salt lake(Chott el Djerid) to the mediterranen could be expanded to other salt lakes in the area?