How clean is Zanzibar coast line?

How clean is Zanzibar line? I have seen some vacation brochures and this island seems like a perfect place to go. Still, I have heard from some friends that parts of the coast are polluted and I don’t know what to do. Are there parts of the island that are not recommendable because of polluted shores? Has anyone been there?

I know that this place is a famous vacation destination. I haven’t been there, but from the photos I have seen I could conclude that beaches are pretty clean. But as usually there are some beaches which are not suitable for sunbathing activities, but you will see where all tourists go. Anyway, first you should visit Zanzibar City which is the capital of this country and there are clean beaches. It has recently been listed as UNESCO heritage site. The best beaches are considered to be those on the eastern part of the island and they are definitely clean, so if you are not sure what to do, I suggest you to stay at this part of island.