The MR (medium range) tanker, the 30,263 gross ton-Green Sky is berthed at North Charleston, South Carolina.
Herbert Julian, who succeeded Koutoukakis as chief engineer, was also found guilty of conspiracy in the case that carries a five-year term.
The jury's verdict followed a three-week trial Charleston, South Carolina last week after an initial arraignment in July 2016.
Both men will be sentenced after the Federal Government prepares a pre-sentencing report, probably in the next two or three months, reported London's Tanker Operator.
According to court documents, Koutoukakis was CE on the Aegean managed chemical tanker at the time the pollution violations occurred.
Prosecutors claimed that he ordered crew members to bypass the ship's oily water separator and discharge oily waste overboard six times from May, 2015 through July, 2015.
He then failed to record the discharges as required by law in the ship's oil record book.
A US Coast Guard investigation started in August, 2015 when the Green Sky berthed at North Charleston. Court records showed that crew members told the USCG at the time that bilge waste was being discharged illegally.
They said they had been instructed to use a "magic pipe" - a hose that is used to bypass the ship's oily water separator.
The Green Sky's captain, Genaro Anciano, had previously pleaded guilty in Charleston to one felony charge of obstructing a USCG investigation. He has yet to be sentenced.
Green Sky is managed by Liberia-flagged Aegean Shipping Management SA and owned by Marshall Islands-flagged Aegeansun Gamma Inc.
Herbert Julian, who succeeded Koutoukakis as chief engineer, was also found guilty of conspiracy in the case that carries a five-year term.
The jury's verdict followed a three-week trial Charleston, South Carolina last week after an initial arraignment in July 2016.
Both men will be sentenced after the Federal Government prepares a pre-sentencing report, probably in the next two or three months, reported London's Tanker Operator.
According to court documents, Koutoukakis was CE on the Aegean managed chemical tanker at the time the pollution violations occurred.
Prosecutors claimed that he ordered crew members to bypass the ship's oily water separator and discharge oily waste overboard six times from May, 2015 through July, 2015.
He then failed to record the discharges as required by law in the ship's oil record book.
A US Coast Guard investigation started in August, 2015 when the Green Sky berthed at North Charleston. Court records showed that crew members told the USCG at the time that bilge waste was being discharged illegally.
They said they had been instructed to use a "magic pipe" - a hose that is used to bypass the ship's oily water separator.
The Green Sky's captain, Genaro Anciano, had previously pleaded guilty in Charleston to one felony charge of obstructing a USCG investigation. He has yet to be sentenced.
Green Sky is managed by Liberia-flagged Aegean Shipping Management SA and owned by Marshall Islands-flagged Aegeansun Gamma Inc.