LAKE HURON 



The present emphasis of research in Lake Huron is on 

 whitefish, and the principal concern is the wide variation in 

 the year class success which causes fluctuations of abund- 

 ance from year to year. There are several discreet popula- 

 tions in different parts of the lake which further complicate 

 the problem. Information is being collected on age, size etc., 

 of whitefish caught by various types of gear. One of the 

 most important results will be the hoped-for ability to fore- 

 cast catches in subsequent years. 



In 1%6, commercial fishermen at Providence Bay reported 

 taking 16 lake trout x brook trout (splake) which were identi- 

 fied as being from the 1963 Providence Bay planting. This 

 catch, added to the 1964 catch of 2,500 fish and the 1965 

 catch of 839, gives a total of 3,355 of the 1963 planting of 

 3,500 fish. In June 1966, 50,000 splake yearlings were planted 

 in Burnt Island Bay, Lake Huron. In South Bay in 1966, 4,000 

 splake were planted. 



The greatly increased planting program of splake in Lake 

 Huron has followed the gradual improvements in successive 

 generations of hybrids derived from the research program. 

 Additional numbers of year classes are in culture and will 

 come through the selection procedures in subsequent years. 

 In co-operation with U.S. agencies for the rehabilitation of 

 the Lake Huron fishery (splake replacement of lake trout), 

 the final stages are being reached in the testing program. 

 Real success is largely dependent on the ability of the 

 hybrids to reproduce naturally. 



Game Fish Program 



The Harkness Laboratory was operated again in 1966 in 

 accordance with the terms of the agreement between the 

 Department of Lands and Forests and the University of 

 Toronto. The facilities were used by staff and graduates of 

 the University of Toronto and the Ontario Research 

 Foundation. 



In addition to the continued analysis of long-accumulated 

 creel census data, projects included experimental plantings, 

 population dynamics, lake trout biology, and plankton- 

 feeding versus fish-feeding lake trout. Also, a scientist made 

 a trip to a number of European countries to investigate the 

 potential of certain of their fish for introduction to Ontario 

 waters, particularly the Great Lakes, where conditions due 

 to water enrichment have changed markedly. Four species 

 would appear to have real potential. 

 Studies of natural populations of brook trout were pursued 

 in 1966 as part of a background against which experimental 

 results are to be compared. Projects in Algonquin Park lakes 

 included stocking rate studies using hatchery-reared trout; 

 plankton and bottom fauna studies; population fluctuations 

 throughout the year; fish toxicants to remove undesirable 

 competing species; spawning facilities and planting 

 techniques. 



The smallmouth bass project was activated- in 1966 in Lake- 

 of-the-Mountain. This is a study of factors, especially sum- 

 mer water temperatures, which influence the production of 

 eggs, fry and fingerlings up to the dispersal stage. These 

 include studies of tagging, first year growth, creel census 

 data, evaluation of hatchery plantings and sub-lethal effects 

 of pollutants. Essential laboratory work was conducted at 

 the nearby Glenora station. 



Ecological studies of walleyes in 1966 were pursued at 

 Baptiste Lake. Emphasis was placed on the factor of light 

 intensity, which seems to play a major part in determining 

 the location and activity of walleyes. They were generally 

 found to be shielded from direct sunlight. 



Other Research Programs 



The limnology unit continued to co-ordinate meteorological 

 and hydrographic data collected from the several fisheries 

 research units with special relation to standardization, and 

 with particular reference to the Great Lakes — such as of 

 the thermal regime and zooplankton of South Bay — and 

 hydrography and phytoplankton of the Bay of Quinte. 

 The selective breeding program on splake (referred to 

 previously under Lake Huron) continued to make advances 

 in 1966, using both laboratory and field studies of more 

 advanced hybrid generations. 



During 1966, the inventory unit continued to assess the 

 productivity of Ontario lakes, concentrating on factors of 

 total dissolved solids, alkalinity and turbidity. 

 A scientist continued to examine parasites collected by field 

 staff, with the object of eventually determining their effect 

 on abundance of important fish species. 



FORESTRY SECTION 



The following is a brief summary of forestry research con- 

 ducted from Maple headquarters and five permanent 

 research establishments throughout the Province. In addi- 

 tion to this, the Research Branch is working co-operatively 

 with the Faculty of Forestry, University of Toronto; the 

 Ontario Research Foundation; Canada Department of 

 Forestry; and the wood-using industries of the Province. 



Regional Silvicultural Research 



It is to be understood that while the following summary is 

 dealt with under the headings of the several regions of the 

 Province, in actuality the researchers expand their programs 

 beyond the boundaries of the regions. 

 NORTHWESTERN ONTARIO 



In 1966, the field program was dominated by re-examination 

 work on a large number of long-term regeneration and stand 

 development plots according to their five-year re-measure- 

 ment schedule. Another important development was the 

 establishment of a program of research for black spruce — 

 a species which had not received sufficient research atten- 

 tion in the past. 



One of the re-examination programs continued in 1966 was 

 concerned with white spruce - balsam fir stands. This study 

 relates to the long-term effects of diameter limit selective 

 cutting, mechanical scarification, and conventional versus 

 mechanical clearcutting. Of especial note is that abundant 

 white spruce regeneration follows scarification in mixed- 

 wood stands, but it was found necessary in 1966 to release 

 this desired crop from re-invading dense underbrush by use 

 of selected toxicants. 



Another study continued to determine the effects of 

 mechanical clearcutting of all species in jack pine cover 

 types embracing jack pine, trembling aspen and black 

 spruce to favour jack pine. 



A poplar project was continued to determine the relation- 

 ship between aspen reproduction of high quality and its 

 age, site type and density following mechanical cutting 

 operations. 

 CENTRAL ONTARIO 



Since the start of work in this region in 1959, concentration 

 has been on laboratory and field studies of problems of tree 

 nutrition, particularly in spruce species, and studies of the 

 productivity, ecology and racial variation of red spruce. 

 The special attention being given to red spruce is because 

 this species has characteristics which make it very useful 

 in improving the productivity of derelict tolerant hardwood 

 and mixedwood stands. The study is designed to measure 

 growth and productivity of red spruce in poor and mixed 

 stands on all physiographic sites across its range in 

 Ontario. 



