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EXHIBIT 31.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO RULE 13a-14a/ 15d-14a

I, Henry Linsert, Jr., certify that:

1.     I have reviewed this annual report on Form 10-K of Martek Biosciences
Corporation;

2.     Based on my knowledge, this annual report does not contain any untrue
statement of a material fact or omit to state a material fact necessary to make
the statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this annual
report;

3.     Based on my knowledge, the financial statements, and other financial
information included in this annual report, fairly present in all material
respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this annual report;

4.     The registrants other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:



| | a) |  | designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under our supervision,
to ensure that material information relating to the registrant,
including its consolidated subsidiaries, is made known to us by others
within those entities, particularly during the period in which this
annual report is being prepared;        
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| | b) |  | evaluated the effectiveness of the registrants disclosure controls
and procedures and presented in this report our conclusions about the
effectiveness of the disclosure controls and procedures, as of the end
of the period covered by this report based on such evaluations; and                                                                                                         
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| | c) |  | disclosed in this annual report any change in the registrants
internal control over financial reporting that occurred during the
registrants most recent fiscal quarter (the registrants fourth fiscal
quarter in the case of an annual report) that has materially affected,
or is reasonably likely to materially affect, the registrants internal
control over financial reporting; and

5.     The registrants other certifying officer and I have disclosed, based on
our most recent evaluation of internal controls over financial reporting, to
the registrants auditors and the audit committee of the registrants board of
directors (or persons performing the equivalent functions):



| | a) |  | all significant deficiencies and material weaknesses in the design or
operation of internal control over financial reporting which are
reasonably likely to adversely affect the registrants ability to
record, process, summarize and report financial information; and
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| | b) |  | any fraud, whether or not material, that involves management or other
employees who have a significant role in the registrants internal
control over financial reporting.                                                                                               

Date: January 29, 2004

/s/ Henry Linsert, Jr.Henry Linsert, Jr.
Chief Executive Officer