Apparatus and method for harvesting biomass from a dead zone in a body of water includes structure and/or function whereby, preferably, at least one guide float is configured to float below the water surface. At least one support structure is configured to be coupled to the bottom beneath water, and is configured to support a substantially rigid frame within the dead zone. A main funnel is coupled to (i) the at least one guide float and (ii) the substantially rigid frame 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 disposed adjacent the lower funnel and is configured to store the descending biomass. Hauling structure is coupled to the guide float and is configured to haul the collection canister from the lower funnel to the surface.
