X0609 4 2026-03-31 0000880242 BIOLARGO, INC. BLGO 0001361115 Marshall Dennis E false 14921 CHESTNUT ST. WESTMINSTER CA 92683 1 0 Option to Purchase Common Stock 0.162 2026-03-31 4 A 0 138889 A 2026-03-31 2036-03-31 Common Stock 138889 5317088 D Option to Purchase Common Stock 0.162 2026-03-31 4 A 0 115741 A 2026-03-31 2036-03-31 Common Stock 115741 5432829 D This Option was granted to Reporting Person to replace an option to purchase 68,182 shares that had been issued to compensate Reporting Person for $22,500 in services to the Issuer and had expired unexercised due to a discrepancy between the original exercise price and Issuer's current stock price, pursuant to plan adopted by the Issuer's Compensation Committee. Total reflects the expiration of options to purchase 68,182 shares that expired March 31, 2026. This Option was issued to Reporting Person as payment for $18,750 in fees due to Reporting Person by Issuer in exchange for services on its board of directors for the most recently completed quarterly period, pursuant to the Issuer's 2024 Equity Incentive Plan. The number of shares in the Option is equal to the amount of fees due divided by the exercise price of the Option. /s/ John R. Browning, attorney-in-fact 2026-04-01