A number of technologies exist that offer the potential to control Harmful Algal Blooms (HABs). Many of these technologies involved the discharge of solids, chemicals, biological agents, or other foreign materials into waters experiencing HABS. Other technologies are also available that could control HABS through the manipulation of environmental conditions such as water salinity, temperature, light intensity and stratification These potential control technologies would essentially accelerate or amplify the development of natural processes that terminate HABs. These technologies can be implemented over the entire range of conditions under which HABs occur and could limit the adverse environmental impacts to other organisms in the HAB impacted area. One of these potential technologies involve the application of the hypersaline concentrate waste water from desalination plants over an area impacted by a HAB. The near surface discharge of the desalination plant hypersaline waste water could an effective means of HAB control by inducing rapid changes in water salinity and stratification. The expected environmental impacts would be temporary, limited in both duration and areal extent. No foreign chemicals, materials, substances, organisms or biological agents would be introduced into the environment. Added benefits would include the beneficial reuse of the hypersaline waste water from desalination plants, reduction of waste water loading to the local area of the desalination plant, and the potential to generate revenue for the desalination plants by the sale of waste water.