GAZA, Aug.7 (Xinhua) -- Palestinian farmer Wael Musalam uses a net to check Azolla aquatic ferns grown in a greenhouse at his farm in the northern Gaza Strip town of Beit Lahia, on Aug. 6, 2019. Due to high price of animal feed in the Gaza Strip caused by Israeli restrictions on imports and lack of income, Palestinian farmers are cultivating Azolla ferns to feed their livestock.