Designed to assist the teacher who wishes to use marine organisms for biological laboratory investigations, this manual includes general information on maintaining marine aquaria and collecting marine organisms as well as five tested laboratory exercises. The exercises deal with the measurement of oxygen consumption (giving techniques for measuring relative rates of respiration in fish and a manometric technique for direct measurement of oxygen consumption), population density, fertilization in the sea urchin, salinity tolerance, and food webs of shore organisms. Following each exercise are suggestions for further research, and a list of related references for the teacher. A general bibliography is included. This work was prepared under an ESEA Title III contract. (EB)