Algae are used by human beings for food from ancient times, as they contain a wide range of elements. Using inexpensive, in-house bioassays for screening and monitoring of extracts where the aim of these bioassays is to provide a front-line screen that can be followed up by more specific and expensive bioassays. The phytochemical screening, assessment of toxicity and effects on growth parameters of Traticum sativum of ethanol and dichloromethane extracts of five macro-algal species (two green, two brown and one red) collected from Libyan coast were studied. The Brine shrimp lethality assay was conducted to determine the toxic effects of seaweed extracts on Artemia Salina nauplii larvae and this was to provide a front-line screen that can be backed up by specific and expensive bioassays once the active compounds have been isolated. The effect of seaweeds liquid fertilizer on growth parameters of Traticum sativum were examined using in vitro seed germination in petri dishes bioassay. Seed germination percentage, fresh and dry weight, shoots length and roots length were the parameters recorded in young seedlings post germination. Ethanolic and dichloromethane extracts of the five algae samples represented the presence of several chemical constituents. All extracts exhibited LC50 > 1000 μg per ml. In this study, all algal extracts are nontoxic according to Brine shrimp lethality assay so they may be considered as edible seaweeds. Different effects on growth parameters of Traticum sativum suggested the presence of micro-elements, macro-elements and different concentrations of plant growth hormones.