Initial Progress in Addressing Human-Induced Alterations
To address the state of the Great Lakes, an unprecedented response was
mustered. In the 1960s, led by government agencies who largely lacked a clear
statutory mandate, a coordinated resource and waste management strategy was
launched. It was a “top-down, bottom-up” strategy driven by a scientific
understanding of how the lakes operated as a system. The “top” and “bottom”
in the strategy have not-so-much to do with people – they do not describe
federal officials and local citizens – they describe the top and bottom of the food
chain in the open lakes.
The “top-down” strategy was a two-part effort to restore top predators to
the lakes. The lake trout population had been virtually wiped out by the sea
lamprey. To restore its functional role in the system, it was decided to introduce
pacific salmon. These fish could be raised in hatcheries and, once released into
the lakes, could restore grazing pressure on the alewife. The second part of the
strategy was to control sea lamprey populations. Spawning streams were
chemically treated to kill lampreys. New physical barriers, called lamprey weirs,
were installed in streams that had spawning habitat.
The “top-down” strategy had immediate pay-off. Government could and
did act directly. Hatcheries began to produce salmon fry and release them to the
lakes. This was a war of production, and the government had the means.
The “bottom-up” strategy was a bit more difficult to implement. The essence
of the bottom-up approach was to tackle the base of the food chain by reducing the
input of nutrient chemicals. Finding sources to control was no problem. Virtually
no municipalities provided biological sewage treatment. Similarly, most industries
provided virtually no treatment of their wastes. But there was little agreement on
exactly which nutrients were the problem, which sources should install controls,
what performance levels were required, and who was to pay for the treatment
equipment. Further, there was no legal requirement to do anything.
Initial Progress in Addressing Human-Induced AlterationsTo address the state of the Great Lakes, an unprecedented response wasmustered. In the 1960s, led by government agencies who largely lacked a clearstatutory mandate, a coordinated resource and waste management strategy waslaunched. It was a “top-down, bottom-up” strategy driven by a scientificunderstanding of how the lakes operated as a system. The “top” and “bottom”in the strategy have not-so-much to do with people – they do not describefederal officials and local citizens – they describe the top and bottom of the foodchain in the open lakes.The “top-down” strategy was a two-part effort to restore top predators tothe lakes. The lake trout population had been virtually wiped out by the sealamprey. To restore its functional role in the system, it was decided to introducepacific salmon. These fish could be raised in hatcheries and, once released intothe lakes, could restore grazing pressure on the alewife. The second part of thestrategy was to control sea lamprey populations. Spawning streams werechemically treated to kill lampreys. New physical barriers, called lamprey weirs,were installed in streams that had spawning habitat.The “top-down” strategy had immediate pay-off. Government could anddid act directly. Hatcheries began to produce salmon fry and release them to thelakes. This was a war of production, and the government had the means.The “bottom-up” strategy was a bit more difficult to implement. The essenceof the bottom-up approach was to tackle the base of the food chain by reducing theinput of nutrient chemicals. Finding sources to control was no problem. Virtuallyno municipalities provided biological sewage treatment. Similarly, most industriesprovided virtually no treatment of their wastes. But there was little agreement onexactly which nutrients were the problem, which sources should install controls,what performance levels were required, and who was to pay for the treatmentequipment. Further, there was no legal requirement to do anything.
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