Special teams cost Miami 21 points in a 41-14 loss Monday night. Two blocked kicks led to touchdowns, and the Patriots returned a kickoff 103 yards for another score.
The Dolphins (2-2) also had a punt blocked a week earlier in a loss to the New York Jets. The back-to-back divisional defeats have dropped Miami to third place in the AFC East.
Assistant special teams coach Darren Rizzi will replace Bonamego, coach Tony Sparano said. Bonamego was in his 12th NFL season and had been with the Dolphins since Sparano became head coach in 2008.
"It's a hard decision to make," Sparano said. "I know how hard this guy works. Nobody works harder than him at what he does."
Lapses by Bonamego's units turned a close game into a rout. The Patriots trailed 7-6 before Brandon Tate returned the second-half kickoff untouched for a score. Pat Chung blocked a punt to set up a touchdown, then blocked a field goal that Kyle Arrington returned 35 yards for a touchdown and a 34-14 lead early in the fourth quarter.
Sparano said Miami's breakdowns went beyond coaching.
"Our players also need to take responsibility," he said.
The Dolphins endured their most lopsided defeat since 2007, when they went 1-15. They lost even though they outgained the Patriots by 135 yards, limited them to 146 yards passing and held Randy Moss without a catch.
Rizzi took his first NFL job when Sparano hired him last year. He'll have extra time to sort out the situation because the Dolphins have a bye this week.