San Diego announced a controlled release of red dye into Mission Bay to study water circulation connected with future restoration projects.

Tracer dye gives researchers a visible and measurable way to follow currents, mixing and residence time. Those observations can improve models used to assess habitat designs and water-quality effects.

The vivid color was temporary, but the information was intended for long-term planning. Restoring wetlands or changing shorelines can alter how water moves, making circulation data essential before designs are finalized.