; (2) use designs consistent with accepted survey sampling practices; and (3) minimize the potential for bias and known sources of survey error. (c) Certification (1) In general The Secretary shall make a certification or a denial of certification for any marine recreational fisheries statistical survey submitted under subsection (a) not later than the end of the 6-month period beginning on the date that the survey and information needed to evaluate the survey under the standards established under subsection (b) are submitted. (2) Timing In the case of a certification request from a Gulf State, the Secretary shall begin evaluation of the request upon receipt of all information necessary to make a determination consistent with the standards set forth under subsection (b). (3) Deemed certified A marine recreational fisheries statistical survey shall be deemed to be certified effective upon the expiration of the 6-month period described in paragraph (1) if the Secretary has not made a certification or denial of certification. (d) Modification of surveys denied certification (1) In general If a marine recreational fisheries statistical survey of a Gulf State is denied certification under subsection (c), the Secretary shall, not later than 60 days after the date of the denial, provide the Gulf State a proposal for modifications to the survey. (2) Proposal A proposal provided to a Gulf State for a survey under paragraph (1)— (A) shall be specific to the survey submitted by such Gulf State and may not be construed to apply to any other Gulf State; (B) shall require revision to the fewest possible provisions of the survey