Microbial mat development and production varies from pond to pond due to the physio-chemical variation amongst the ponds. To study this variation a series of 13 ponds were selected that had originated from one greater pond which had drained due to a tide crack opening up. Cores of microbial mats were collected from all 13 ponds for particulate nutrient and pigment analyses, biomass determination ... and species composition. Surface water samples from 13 ponds were also collected for phytoplankton, chlorophyll a, particulate nutrients and dissolved nutrient analysis. Photosynthesis and nitrogen fixation experiments were conducted on microbial mats collected from 7 ponds. Conductivity and pH measurements, coupled with gross mat morphology were used to select the most contrasting ponds. Collected samples were experimented on and the photosynthesis and respiration rates were determined by measuring the rate of evolution or consumption of oxygen using oxygen electrodes. Samples for dissolved inorganic carbon uptake were taken and injected into vacuette tubes for analysis. Nitrogen fixation was determined and gas samples from the nitrogen fixation were then collected for analysis by gas chromatography.