In the first part of my talk, I will introduce the notion of a modular operad following the paper by Getzler and Kapranov. I will give a few examples and recall Kontsevich´s graph complex.

In the second part of my talk, I will give an example of a modular operad coming from a holomorphic symplectic manifold. Then I will explain how it is related to the Rozansky-Witten invariants.