Where necessary for the purposes of the collection of the data under the national programmes, Member States shall design and implement at-sea monitoring of commercial and recreational fisheries.

The tasks of the at-sea monitoring shall be determined by the Member States.

The masters of Community fishing vessels shall accept on board samplers operating under the at-sea monitoring scheme and designated by the body in charge of the implementation of the national programme and cooperate with them in order to allow them to discharge their duties while on board Community fishing vessels.

The masters of Community fishing vessels may refuse to accept on board the samplers operating under the at-sea monitoring scheme only on the basis of an obvious lack of space on the vessel or for safety reasons in accordance with national legislation. In such cases, data shall be collected through a self-sampling programme, carried out by the crew of the Community fishing vessel, and designed and controlled by the body in charge of the implementation of the national programme.