Despite the existence of morphologically diverse algae in a wide variety of terres­trial and aquatic habitats, work with algae has been restricted to a relatively few representatives. This seems partly the result of difficulties encountered in both
the isolation and the subsequent purification of the algae. It has been suggested that the techniques normally used to isolate algae may severely limit the number of algal species that can be readily cultured (Castenholz, 1988). The goals of algae isolation and screening efforts are to identify and maintain promising algal specimens for cul­tivation and strain development. Because it is premature to decide on the system of mass cultivation, new strains should be isolated from a wide variety of environments to provide the largest range of metabolic versatility possible. Algae can be isolated from a variety of natural aquatic habitats, ranging from freshwater to brackish water, to marine and hyper-saline environments, to soil (Round, 1984; Mutanda et al., 2011). Furthermore, large-scale sampling efforts should be coordinated to ensure the broadest coverage of environments and to avoid duplication of efforts. The selec­tion of specific locations can be determined by sophisticated site selection crite­ria through the combined use of dynamic maps, geographic information systems (GIS) data, and analysis tools. Ecosystems to be sampled could include aquatic (i. e., oceans, lakes, rivers, streams, ponds, and geothermal springs, which includes fresh, brackish, hypersaline, and acidic and alkaline environments) and terrestrial environments in a variety of geographical locations to maximize genetic diversity. Collection sites can include public lands as well as various sites within national and state park systems. In all cases, questions of ownership of isolated strains should be considered. Additionally, within an aqueous habitat, algae are typically found in planktonic (free floating) and benthic (attached) environments. Planktonic algae may be used in suspended mass cultures, whereas benthic algae may find application in biofilm-based production facilities. Sampling strategies should not only account for spatial distribution, but also for the temporal succession brought about by seasonal variations of algae in their habitats (Mutanda et al., 2011).