FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Cysewski Gerald R   2. Issuer Name and Ticker or Trading Symbol CYANOTECH CORP [CYAN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CSO (Last) (First) (Middle) 73-4460 QUEEN KAAHUMANU HWY #102 3. Date of Earliest Transaction (Month/Day/Year) 04/01/2019 (Street) KAILUA-KONA, HI 96740 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 04/01/2019   M(1)   8,333 A $ 0 133,803 D   Common Stock 04/01/2019   F(2)   3,130 D $ 3.24 130,673 D   Common Stock               250 I Held by spouse

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Restricted Stock Units

(3)

(4)

(4)

Common Stock

10,877

10,877

D

Stock Options

$ 3.58

(5)

06/30/2021

Common Stock

12,000

12,000

D

Stock Options

$ 3.82

(5)

08/27/2021

Common Stock

103,000

103,000

D

Stock Options

$ 5.84

(5)

07/18/2022

Common Stock

12,500

12,500

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Cysewski Gerald R 73-4460 QUEEN KAAHUMANU HWY #102 KAILUA-KONA, HI 96740	X		CSO

Signatures

/s/ Jesse Debban, by Power of Attorney		04/02/2019
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Represents the conversion upon vesting of restricted stock units into common stock.
(2)	No stock was sold. In connection with the vesting of 8,333 shares of stock, the Company withheld a total of 3,130 shares to satisfy a payroll tax liability incident to such vesting.
(3)	Each restricted stock unit represents the contingent right to receive one (1) share of Cyanotech Common Stock.
(4)	The restricted stock options vest as to 8,334 shares on March 31, 2020, 166 shares on April 5, 2019, 737 shares on July 13, 2019, 167 shares on April 5, 2020, 737 shares on July 13, 2020 and 736 shares on July 13, 2021, in each case subject to the reporting person's continued service with the Company on the vesting date.
(5)	Fully exercisable

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