Abstract: Rapidly settling algal strains are selectively developed through a method that is based on manipulating the velocity of a host liquid. In one embodiment, the method includes the steps of providing a uniform flow velocity to the liquid, thereby promoting development of one or more algal strains; stopping or at least reducing the uniform flow velocity; removing the upper portion of the water, including any suspended algal strains; providing a second uniform flow velocity to the liquid, which may be the same as the flow velocity that was applied during the first step; stopping or at least reducing the second uniform flow velocity; and removing the upper portion of the remaining liquid, leaving a residual liquid amount that includes one or more rapidly settling algal strains in the form of a rapidly settling algal floc or of a precursor thereof.

Abstract: A scalable fish rearing raceway system is provided, incorporating a fish containment structure having two semi-circular end sections, and two or more parallel fish raceways, surrounding a central zone for housing water treatment systems and a secondary fish crop. Heavy particulates are eliminated from the main fish rearing channels by use of conical areas located at either end of the parallel elongated raceways. Continuous removal of dead or dying fish from the raceway is accomplished by means of a floating mortality catcher consisting of a screened ramp at the surface of the cones which continuously collect moribund and dead fish. Grading bars separate and move fish underwater to an adjacent raceway through a common fish transfer channel. This larger scalable fish production system substantially reduces the direct labor and capital costs associated with the production of fish as compared with conventional circular fish rearing tanks.