The contribution of free-floating bacteria versus bacteria attached to particulate material to the microbiology of the Fraser River Estuary was assessed. Approximately 60 % of bacterial biomass and heterotrophic activity was associated with suspended particulates in the turbid Fraser River (0 Y&o S). The influence of attached bacteria decreased down the estuary as salinity increased dropping to 15-39 % of total bacterial numbers and 4 % of heterotrophic activity in the Strait of Georgia (26 Ym S). Bacteria, both attached and free-floating, were the predominant part of the microbial population in the river in terms of biomass and productivity. In the Strait of Georgia, however, bacteria constituted only 4 % of the microbial biomass and 25 % of microbial productivity. Heterotrophic activity and productivity were stimulated in the plume (15 % S) to levels higher than those found in either the strait or the river. The percentage glucose respired was always found to be lowest in the river. INTRODUCTIONnoted the importance of detritus with its attached microflora to the dynamics of several estuaries. The relative abundance of free-floating bacteria and Accordingly, we report herein upon biomasses, those attached to suspended matter in aquatic environheterotrophic activities and productivities of free-floatments is controversial. In the open ocean most invesing and attached bacteria within the estuary of the tigators have found that the majority of the planktonic Fraser River through its plume into the saline waters of bacteria are unattached and free-floating (Wiebe and the Strait of Georgia. Pomeroy, 1972;Sieburth et al., 1974;Ferguson and Rublee, 1976; Azam and Hodson, 1977).However, data from various freshwater environments vary. Rieman (1978) observed 50-93 % of glu-MATERIALS AND METHODS cose uptake activity passed through a 1.0 pm Nuclepore filter; however, these percentage values varied Samples were collected from the Fraser River Estuwith the seasons. Burnison (1975) found 82 % of the ary on 6 cruises over a period of 13 months (Table 1). bacterial biomass passed through a 1.0 pm Nuclepore Three stations only were examined during the first 5 filter in samples from the Bay of Quinte. Berman and cruises. The 'river' station was situated approximately Stiller (1977) noted 90 % of carbon uptake in the fil-40 km upstream from the river mouth and the salinity trate from a 3.0 km Nuclepore filtration of Lake Kinwas always 0 % S (Station 10, Fig. 1). Surface water neret water.(1 m) at 15 Om S was chosen as the 'plume' station. This Within estuaries the situation may be even more location varied between Stations 1 and 4 (Fig. l ) complex because of the changing physicochemical and depending on the tide and discharge volume of the biological reactions which occur as the fresh river river. The 'strait' station constituted the third and last water meets the sea water. Unfortunately literature on location lying in the Strait of Georgia midway between bacterial attachment to solid surfaces in estuaries is Vancouv...

THE folIowing is a brief description of a ship-canal across East Bay Neck-a peninsula on the east coast of Tasmania-the construction of which has been recently completed, providing a waterway between Frederick Henry Bay, near Hobart, and Blackman Bay, near Maria Island, and thus saving a long and often very stormy passage round by the open sea.The canal is 7 furlongs in length between the low-water marks on either side of the peninsula, and long approaches have been dredged to deep water at either end of the canal. The greatest depth of cutting is about 33 feet, the material excavated being clay, with layers of sand. Dams were constructed at the ends of the canal, and the excavation was performed in the dry, springand rain-water being removed by continuous pumping.The cutting is 18 feet in width at the bottom, the side-slopes being 2 to 1 ; and the approaches are 33 feet in width. A siding is provided to permit of vessels passing one another. The depth of water in the canal is 10 feet at, low-water, the tidal range being 5 feet.A swing-bridge of 30 feet span has been erected to take the main road over the canal. The roadway is carried on iron girders supported on a concrete pier, and sufficient space has been provided to permit of widening and deepening the canal, if required, in the future.From observations made previously it was calculated that a current would flow in the canal from north to south ; it is now found that a current of 2 to 3 miles an hour flows in winter from south to north, and in summer from north to south, with irregular intervals during gales.The canal is intended for the use of coasting-steamers and fishing-craft, and was constructed from plans and specifications prepared by the Author. Downloaded by [ UNIVERSITY OF MINNESOTA] on [12/09/16].