Do these shelves need extra support?

[Afro Boy]

My first bookshelf is coming together. I'm wondering if the shelves in the first pic below need extra support such as dowels? There's a 5mm rabbit and the shelf is 19mm thick Vic Ash.

The other side of the shelf will be supported by a single bean perpendicular to the shelf (second photo). That side I'm not worried about as the fit is nice and tight and there is plenty of support available.

Secondly, there's a bit of a crack forming in the Oregon. Would epoxy be the right thing to use to fill it to keep it from continuing through?

Thanks,
Af.

[artme]

Afro - are the shelves Glued? If they are they may hold up in the short term. I suggest you glue them and pin with hidden nails,
The nails may be hidden by using a very narrow chisel to partialy pare away (curl back ) the area where you drive the nails. After punching the nails you then place glue in the area, lay back the pared grain, clamp flat firmly until dry and then sand.

Give the Oregan a couple more days to see how much it splits before filling.

[Afro Boy]

Yep, they'll be glued.