Apparatus and method for harvesting plankton and/or other biomass from a dead zone in a body of water includes structure and/or function whereby at least one support float is provided to float on a surface of the body of water. At least one support structure is coupled to the at least one support float, and is configured to support a substantially rigid frame within a dead (e.g., hypoxic) zone below the surface in the body of water. A main funnel is coupled to the at least one support structure within the dead zone, and is configured to collect descending biomass and funnel it toward a lower funnel that is coupled to the bottom of the main funnel. A collection canister is preferably disposed within the lower funnel, and is configured to store the descending biomass. A guide float is configured to float on the surface of the body of water, and hauling structure is preferably coupled to the guide float, and is configured to haul the collection canister from the lower funnel to the surface to harvest the biomass.
