What Fishing Level Should I Start Catching Lobsters In RuneScape?

I’m level 37 fishing and i know that at level 40 you can start fishing for lobsters. However, people have told me not to start catching lobsters immediately at level 40 because they will go too slow.

So my question is, at what fishing level should i start catching lobsters so that they go pretty fast?

Also, what should i fish for to get to that level?

Thanks!

Enrico