Abstract: A zebra mussel control device uses a combination of electrical current and air bubbles to kill or disable mussels entering water intakes. The current is fed between electrodes that extend radially at equiangular positions around a cylindrical inlet of the water intake. Bubbles are created by an annular air chamber of the water intake below the cylindrical inlet. The bubbles rise, and pass through the gaps separating adjacent electrodes. Mussels entering the gaps are moved upwardly in the gaps by the action of the bubbles, thus increasing the normal transit time of the mussels through the gaps. In the result, the mussels are subjected to electrical current for a longer time than would be the case without the bubbles, and are disabled for a time sufficient to ensure that they pass through the water intake without attaching. The bubbles also drag any drifting mussels away from the water intake. This arrangement has been shown to be a very effective way to control zebra mussel blockage of water intakes.

Abstract: A modular breakwater device for placement on the floor in a body of water to alleviate erosion effects. There is a seaward face surface and a landward face surface. A plurality of passages extend between those surfaces permitting water to pass through them. The body has a continuous, uninterrupted lower surface. A number of legs extend from the lower surface and raise it off the floor and define a second passage beneath the lower surface and enables stable footing of the device on the beach floor. Details of the legs, the undersurface and the shaping of the seaward and landward surfaces appear.