In the ponds, the fish are gregarious and found in shoals, and they occupy the entire water column.
Its dilution effect stabilises the water column, increases the retention of nutrients washed off the islands and leads to periodic phytoplankton blooms.
This facies architecture suggests settling of size- and density-graded ash through the calm water column.
The high-diversity assemblages may preserve complex ecological associations of graptolites that existed in the water column during 'graptolite-friendly' environmental conditions.
The absence of fauna suggests a dearth of graptolites in the overlying water column caused by adverse environmental conditions.
The water column remained thermally stratified throughout the remaining record.
The copepodid is initially free living in the water column and finds and attaches to the host.
Although not age diagnostic, it demonstrates either stratification within the water column or dysoxia/anoxia within the top layer of sediments.
