In this paper, we investigate the relationship between the discreteness of the spectrum of a non-compact, extrinsically bounded submanifold ϕ : M m → N n and the Hausdorff dimension of its limit set lim ϕ. In particular, we prove that if ϕ :, where H Ψ is the generalized Hausdorff measure of order Ψ(t) = t 2 | log t|. Our theorem applies to a number of examples recently constructed by various authors in the light of N. Nadirashvili's discovery of complete, bounded minimal disks in R 3 , as well as to solutions of Plateau's problems, giving a fairly complete answer to a question posed by S.T. Yau in his Millenium Lectures. Suitable counter-examples show the sharpness of our results: in particular, we develop a simple criterion for the existence of essential spectrum which is suited for the techniques developed after Jorge-Xavier and Nadirashvili's examples.