The use of diatom assemblages to determine paleotrophic changes in lakes

The purpose of this study was to develop a classifi cation scheme for l ake trophic status based on the relative abundance of l ake sediment diatom trophic indicator species. A total of 600 diatom frustules were counted from the surface sediments of e a ch of 30 lakes selected to repr e seni~ a continuum from u.lt ra-oligotrophic t,o fairly eutrophic but not hype r-' eutrophic conditions. Published autecological information was used to determine the trophic indicator status of each of the s pecies. A quotieht was derived by dividing the s um of all the e utrophic indicator species by the sum of all oligotrophic indicai.-:.or species. Oligo'- mesotrophic. mesotrophic and meso-eutrophic species were added to both the numerator and denomina tor. Five categories of diatom i.nferred trophic status were recognized : ultra-oligotrophic - 0'-0.2:3, oligotrophic::: 0.24-0 . 70, mesotrophic :: 0.'71 -0.99, meso-elxtrophic :: 1. 00-1. '78 and eutrophic:: 1.. 79-2. 43. But only three of these (oligotrophic:: 0-0.69, mesotrophic ::: 0 . 70'-1.69 j and eutrophic:: 1.70-2.50) proved usef ul. The present study of the relationship between diatom inferred trophic status and the literature-derived trophic status of SO lake s (which were purposely chosen to represent a broad spectrum of lakes in Canada) indicated that: 1) Based on diatom species (assemblages ) it is possible to segregate the lakes from which. th",)se diatoms were taken into three basic categories : o ligotrophic, mesotrophic and eutrophic lake types. ~~) It was not possible t,o separate meso-eutrophic and o l igo-mesotrophic lakes f rom mesotrophic l akes as the the degree of overlap betwee n the diat,om species in these lake types was extremely high. 3) Ha d mo r e ul tra-oligotroph,ic lakes been sampled it might have been possible to more a ccurately s eparate them f rom oligotrophic Jakes. 4 ) Had. more humic lakes been sampled in this s tudy I f eel it would have been possible to identify a unique diatom a ssemblage which would h a ve chara cterized t his lake type . Re gression analyses were performed using the aforementioned diatom inferred trophic index as a f unction of 1) log Sec chi transparency (r = - 0.70) 2) total phosphorus (r = 0. 77 ) and 3) chlorophyll-a (r = 0.74). Once e ach of these rel ationships had been established , it was possible to infer paleotrophic (downcore) changes in an oligotrophic lake (Barbara Lake) and in a eutrophic lake (Chemung Lake) . Barbara Llake was dominated by oligotrophic s pecies and remained oligotrophic throughout the 200-·year history r epresented by i t s 32 em long sediment core. Chemung Lake is currently dominated. by eutrophic species but went through a mesotrophic st,age which was associated with a rise in the water level of the lake followi n g dam construction in its watershed in the early 1.900 J ::;. This was followed by its reversion to it,s present day eutrophic stage (dominated by eutrophic species) possibly as a r esult of shallowing process which can be attributed to " silting' up" of the reservoir and the invasion of the l ake by Myriophyllum spjcatum (Eurasian milfoil) i n the 1970's . In addition, nutrient .:r':l.ch run"'offwhich resulted from increased human a.ctivities associated with cottage development along its shores has contribut ed to its eutrophication. There is some evidence that the rat,e o :f its prog ressive eutrophication has declined during the last decade. This was correlated with legislation enacted in the 60's and 70's in Ontario which was aimed at reducing nutrient loading from cottages.

Bowslaugh Family fonds, 1860-1861, 1868, 1876-1877, 1880-1882, 1886-1890, 1892-1893, 1895, 1898-1899, n.d.

Edward W. Bowslaugh (1843-1923) was the son of Jacob and Anna (Beamer) Bowslaugh. Edward Bowslaugh married Mary Southward, and the couple had six children, Edgar Morley, Edward Freeman, twins Alfred Malcolm and Alice Mary, Annie Olivia, John Jacob and Mabel Florence. Edward W. Bowslaugh was a farmer, contractor and owner of the Grimsby Planing Mills in Grimsby, Ont. and Bowslaugh’s Planing Mill in Kingsville, Ont. The mills manufactured door and sash trim and other wood related products. Some customers contracted the firm to provide wood products for cottages being built at Grimsby Park, the Methodist camp ground. Some time before 1885 Edward Bowslaugh and his family moved to Kingsville, Ont. to open up a new planing mill and door and sash manufactory. He later sold the Grimsby Planing Mills to Daniel Marsh. The diaries and account books include many names of workers as well as friends and family members residing in the Grimsby and Kingsville areas. James M. Bowslaugh (1841-1882) was the son of Jacob and Anna (Beamer) Bowslaugh. James married first Anna Catharine Merritt and after her death in 1875 he married Mary Gee in 1877. James and Anna had three children, Eliza, James Herbert, George Hiram, all died very young. James and Mary Gee had one son, Charles Leopold Kenneth Frederich Bowslaugh, b. 1881. James Bowslaugh was a farmer and lumberman, much like his younger brother Edward. James’ early diaries often note the activities of himself and his brother Edward. Both Edward and James were heavily involved in the Methodist church, teaching or leading Sunday school and attending prayer meetings. Alfred M. Bowslaugh b. 1873 was the son of Edward W. Bowslaugh and his wife Mary Southward. The school notebook is from his days as a student in Kingsville, Ont.

A Notorial Transumpt, 1497

Govan was an ancient settlement, former burgh and now a district in Glasgow, Scotland. It is situated 2.5 miles west of Glasgow City Centre, on the south bank of the River Clyde, opposite the mouth of the River Kelvin and the district of Patrick. Archaeological evidence shows that there was a church and burial ground here as early as 600-800 AD. Numerous carved tombstones dating from 900- 1100 have been found. Govan was a village comprised of thatched cottages until well into the 19th century. It became a shipbuilding town in the early 19th century.