Port wardens shall be allowed fees to be paid by the person requesting their services, as follows: For survey of hatches, $2; for each survey of cargo on shipboard, $1; for certificate of stowage of cargo, $2; for each subsequent certificate, $1; for each survey to ascertain extent of damage, $2; for each certificate thereof, $2; for each survey required by section 43, $4; for each certificate thereof, $2; on each survey as required by section 44 for each person, $2; for each certificate thereof, $2.