Effects of Deer Island Outfall Tunnel

The new Deer Island Outfall Tunnel may have two major impacts on the marine life in the Boston area. When the new outfall tunnel is running, the nutrients will be deposited nine miles off the coast as opposed to the one that is being used currently that is depositing the nutrients one and a half miles off the coast. The location of the nutrients is going to have an effect on the quality of life for the marine animals.

Currently there is estimated to be 16,500,000 pounds of various fish brought in yearly within zero to three miles from the coast. Within the same range from the coast there is currently 20,400,000 pounds of shell fish brought in yearly. This range is where the current outfall tunnel is diffusing the nutrients (treated wastewater or effluent). For marine life that feed off the bottom these nutrients are a major attraction. When the new outfall tunnel is put into effect the number of shell fish may decrease due to the relocation of the nutrients.

Within three to two-hundred miles of the coast there is an estimated 200,000,000 pounds of fish brought in yearly. The amount of shellfish in this range is estimated to be 24,000,000 pounds caught in daily. When the new outfall tunnel is being used the marine life in this range will be effected. The nutrients that were once being distributed closer to shore will now be diffused directly into their environment. This could have an effect especiallly on the species that feed off the bottom where the sludge is being discharged.

There are many possible outcomes with the new outfall tunnel. The fish in the zero to three mile range may increase or decrease depending on their need for the nutrients provided by the sludge. The same could be true to the fish farther out. The fish farther out will now be receiving the nutrients which could increase or decrease the population. Until the new outfall tunnel is turned on it is not possible to provide specific statistics on the direct effects.

MWRA Update Information (August 2000):
Please also note that MWRA, in conjunction with many others, has been engaged in extensive monitoring and study since 1992 (3 million dollars a year have been spent) to help ensure that the ecosystem will be protected. The Program has built an unprecedented oceanographic database and has documented natural conditions and variability in the physical and biological oceanography of the Bay. MWRA also has an Ambient Monitoring Plan and a Contingency Plan in place that will protect against unexpected adverse effects from the outfall. An independent Outfall Monitoring Scientific Advisory Panel has also been created. So, considerable steps have been taken by MWRA, the regulators, and independent scientists to ensure water quality. (The Politics and Public Policy section which follows the Biology section does address the programs in some form, but it seems very separate from the biology section where one might expect to see it).

The existing write-up on your web page could be revised to reflect a higher level of understanding about nutrients. Earlier this month, an updated Harbor and the Bay Web site at was placed on line.

For exact detail on particular fish go to the National Marine Fisheries Service.

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