PART VIII — AQUATIC ECOSYSTEMS 



Release of heated waste water into 

 the Great Lakes should not be per- 

 mitted until studies have shown that 

 the previously abundant native spe- 

 cies will not be adversely affected. 

 The only fish that can thrive in lakes 

 the size of the Great Lakes are cold- 

 water species, and all spend portions 

 of their life cycle either near the 

 shore or the surface of the lakes. 

 Fish in the larval and juvenile life 

 stages are the ones that usually live 

 near shore or the surface and would 

 be most sensitive to the influence 

 of heat wastes in these regions. Their 

 presence in these regions would be 

 mostly during late winter to early 

 summer, when thermal gradients 

 would be the sharpest and possibil- 

 ities of detrimental effects the great- 

 est. 



Restoration of Fish Stocks — Cur- 

 rent with restoration of more fa- 

 vorable environmental conditions, 

 steps must be taken to restore more 

 favorable stocks. Sea-lamprey control 

 now being conducted in Lakes Supe- 

 rior, Michigan, and Huron must be 

 intensified and extended to Lakes 

 Ontario and Erie. Measures to reduce 

 alewives should be intensified by 

 introduction of large predators such 

 as lake trout and salmon and by 

 exploitation where necessary. The 

 most critical requirement, while re- 

 ducing alewife populations, is a con- 

 current restoration of the small native 

 forage species. This transition will 

 require several decades and will re- 

 quire careful measurement and close 

 regulation of the kinds and amounts 

 of fish introduced or removed from 

 the lakes. 



Successful restoration of fish in 

 Lakes Erie and Ontario will require 

 sufficient improvement of water qual- 

 ity to permit establishment of pre- 

 viously abundant species. Control 

 of sea lampreys and reduction of 

 alewives in Lake Ontario should re- 

 verse deterioration of fish stocks as 

 water quality is improved. Restora- 

 tion of Lake Erie will require the 

 development of some method to re- 

 duce the extreme abundance of 



sheepshead in the open lake and carp 

 in the shallow areas to create condi- 

 tions favorable for return of more 

 desirable species. 



Present Urgency 



The need for immediate action to 

 restore the environmental quality, 

 biological stability, and fisheries of 

 the Great Lakes cannot be stressed 

 too strongly. At present, Erie and 

 Ontario are the only lakes that have 

 been measurably affected by water- 

 quality deterioration throughout the 

 entire lakes. One of the largest rivers 

 in the world — the St. Clair-Detroit 

 River system — flows through these 

 lakes, and the water entering this 

 river system from Lake Huron is still 

 of high quality. Erie and Ontario are 

 the smallest of the Great Lakes and 

 have flushing rates (ratio of lake 

 volume to volume of annual inflow) 

 of approximately 3 and 8 years, re- 

 spectively. Thus, if all wastes are 

 prevented from entering Lakes Erie 

 and Ontario, there should be initial 

 improvement of water quality within 

 5 to 10 years and significant improve- 

 ment of water quality and aquatic life 

 within 20 years. 



The most urgent need, however, is 

 to stop the environmental deteriora- 

 tion of Lake Michigan. Degradation 

 of Lake Michigan has approached the 

 point that biological processes are 

 being adversely affected. Once dis- 

 rupted, it may not be possible to re- 

 store the fishery productivity of Lake 

 Michigan. Even with complete re- 

 moval of all wastes from effluents 

 entering the lake, or diversion of all 

 effluents from the basin, the water 

 from natural runoff into Lake Mich- 

 igan would be richer than water 

 within the lake. Consequently, Lake 

 Michigan could not be flushed or 

 "cleaned." (The only possibility for 

 flushing Lake Michigan would be 

 to divert a large quantity of water 

 from Lake Superior and introduce it 

 at the southern end of Lake Mich- 

 igan.) The deterioration of Lake 

 Michigan would hasten the deteriora- 



tion of Lake Huron. If this should 

 occur, the present source of "clean 

 water" essential for the restoration 

 (flushing) of Lakes Erie and Ontario 

 would be eliminated. 



Policy Requirements 



The techniques and instrumenta- 

 tion are available and there is a cadre 

 of scientific personnel knowledgeable 

 about the broad biological problems 

 and requirements for their solution 

 on the Great Lakes. There is, how- 

 ever, no U.S. organization with the 

 specific mission or clear responsibility 

 to conduct the studies or establish 

 the guidelines that are necessary to 

 assure the biological stability or 

 maintenance of the over-all fishery 

 productivity of the Great Lakes, 

 other fresh water, or estuarine wa- 

 ters of the United States. Also, the 

 facilities are lacking for necessary 

 further study. There is also no pro- 

 vision in the scattered existing moni- 

 toring systems for the comprehensive 

 coverage of all physical and chemical 

 parameters that would be required 

 for biological studies, and biological 

 and fishery monitoring are minimal in 

 some areas and lacking in most areas. 



The Great Lakes are a national and 

 international resource and must be 

 managed as a complete system. 

 There is no federal agency or com- 

 bination thereof that can assume full 

 U.S. responsibility, nor are there in- 

 ternational agreements that can guar- 

 antee full and effective joint interna- 

 tional action. Of the several agencies 

 and commissions with responsibilities 

 concerning the Great Lakes, the 

 Great Lakes Fishery Laboratory (U.S. 

 Department of the Interior) and the 

 Great Lakes Fishery Commission 

 (U.S. -Canada compact) have the 

 broadest experience and delegations 

 of responsibility for studies and the 

 greatest capacity to make recom- 

 mendations concerning environmental 

 quality — particularly concerning 

 problems related to biological degra- 

 dation and fishery resources. 



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