<p> 101 samples of Thorold sandstone were collected from 12 geographically distinct regions along the Niagara Escarpment. The average number of vertical worm tubes in each region was determined as was clay content, organic matter, burrow diameter, interburrow distance, mean grain size, sorting, quartz proportion, distance from shore, porosity, and the sandstone/shale ratio. Stepwise linear regression and principal component analysis were used to investigate relationships between the variables. The number of worm tubes can be predicted by clay content, organic matter, distance from the shore, and porosity, a model which explains 62% of the observed variation. All 11 variables accounted for 99. 9% of the variation. Distance from shore can be predicted by organic matter, burrow diameter, mean grain size, and the sandstone/shale ratio, a model which explains 94% of the variation. All 11 variables accounted for 99.9% of the variation. Organisms living in the Thorold evidently reacted to environmental parameters in a similar fashion to modern tidal flat organisms.</p> / Thesis / Bachelor of Science (BSc)

Processes during the meroplanktonic phase regulate population dynamics for many marine benthic invertebrates. I examined changes in vertical distribution of different meroplanktonic larvae in a coastal embayment during a stable period, at high temporal frequencies and spatial resolutions. Plankton samples were collected at 6 depths (3, 6, 9, 12, 18, 24 m) using a pump, every 2-h over a 36- and a 25-h period, during a spring and neap tide, respectively, concurrently with measures of temperature, salinity, fluorescence and current velocity. For 10 gastropod taxa, larval vertical distribution was mostly related to the thermal structure of the water column. Each of 7 taxonomic groups was found either exclusively near the surface, associated with the fluorescence maximum, or showed diel changes in distribution. These larvae that occupy different depths in the water column exhibit different dispersal potentials. / Biogeographical data contained in this thesis will be submitted to the Oceanographic Biogeographic Information System (OBIS) and may be accessed on-line at http://www.iobis.org