Fishery Science Improvement Act of 2011 - Amends the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006 to postpone from fishing year 2011 to 2014 the effective date upon which a mechanism for specifying annual catch limits and accountability measures for fisheries other than those determined by the Secretary of Commerce to be subject to overfishing must be established in fishery management plans prepared by any Regional Fishery Management Council or the Secretary, implementing regulations, or annual specifications.
Makes the catch limit mechanism, for all fisheries, inapplicable to a fishery for any stock of fish: (1) for which a peer reviewed stock survey and stock assessment have not been performed during the five-year period before enactment of this Act and for which the Secretary determines overfishing is not occurring, and (2) that is an ecosystem stock.
Defines "ecosystem stock" as a stock of fish determined by the Secretary to be a nontarget stock that is not overfished or likely to become overfished.
Requires the Secretary, within 270 days after determining that a fishery is overfished, to perform a stock survey and stock assessment of each of the overfished stocks in the fishery and transmit the assessment to the appropriate Council.