**Exhibit 31.3**

 

**Certification PursuantTo 18 U. S. C. Section 1350,As Adopted Pursuant ToSection 302 of the Sarbanes-Oxley Act of 2002**

 

I,William R. Maris, Chief Financial Officer certify that:

 

1.      I have reviewed this annual report on Form 10-K/A of CyanotechCorporation;

 

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

 

3.      Based on my knowledge, the financial statements, and other financialinformation included in this report, fairly present in all material respectsthe financial condition, results of operations and cash flows of the registrantas of, and for, the periods presented in this report;

 

4.      The registrant’s other certifying officer and I are responsible forestablishing and maintaining disclosure controls and procedures (as defined inExchange Act Rules 13a-15 (e) and 15d-15 (e)) and internal controlover financial reporting (as defined in Exchange Act Rules 13a-15(f) and15d-15(f)) for the registrant and we have:

 

a)     Designed such disclosure controls and procedures, or caused suchdisclosure controls and procedures to be designed under our supervision, toensure that material information relating to the registrant, including itsconsolidated subsidiaries, is made known to us by others within those entities,particularly during the period in which this report is being prepared;

 

b)     Designed such internal control over financial reporting, or caused suchinternal control over financial reporting to be designed under our supervision,to provide reasonable assurance regarding the reliability of financialreporting and the preparation of financial statements for external purposes inaccordance with generally accepted accounting principles.

 

c)     Evaluated the effectiveness of the registrant’s disclosure controls andprocedures and presented in this report our conclusions about the effectivenessof the disclosure controls and procedures, as of the end of the period coveredby this report based on such evaluation; and

 

d)     Disclosed in this report any change in the registrant’s internalcontrol over financial reporting that occurred during the registrant’s mostrecent fiscal quarter (the registrant’s fourth quarter in the case of an annualreport) that has materially affected, or is reasonably likely to materiallyaffect, the registrant’s internal control over financial reporting; and

 

5.      The registrant’s other certifying officer and I have disclosed, basedon our most recent evaluation of internal control over financial reporting, tothe registrant’s auditors and the audit committee of registrant’s board of directors(or persons performing the equivalent function):

 

a)     All significant deficiencies and material weaknesses in the design oroperation of internal controls over financial reporting which are reasonablylikely to adversely affect the registrant’s ability to record, process,summarize and report financial information; and

 

b)     Any fraud, whether or not material, that involves management or otheremployees who have a significant role in the registrant’s internal controlsover financial reporting.

 
| Date:   September 30, 2008 |     | /s/ William R. Maris      |
|--------------------------------------|----------|---------------------------|
|                                 |     | William R. Maris          |
|                                 | * * | *Chief Financial Officer* |

 

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