Thank you for your advices Gonen !
Seems Aegean levrek have same manners as our Black sea levrek

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Sinarite is different and unknown for me. More 10 meters is difficult for me. I mean I can go to 10 meters, but my apnea there is only 30 seconds. I suppose I need minimum 2 min apnea if sinarite is there.
What about the grass? I visited Lesvos and there everywhere is grass only. There have not rocks. Strange island. Can I find sinarite in the grass?