It was all Billy Joel’s fault.

In 1995, the New York Islanders decided to freshen the team’s look by introducing a new logo, jersey and mascot. The decision eventually turned into one of the biggest sports marketing disasters of all time and a debacle that still rankles local hockey fans decades later.

“It was a last-gasp attempt to rejuvenate a small-market team on the brink of collapse, and it failed due to poor planning, penny-pinching, miscommunication and misfortune,” says Nicholas Hirshon, a journalism professor at William Paterson University and the author of the new book “We Want Fish Sticks: The Bizarre and Infamous Rebranding of the New York Islanders” (University of Nebraska Press, out Dec. 1).

The Islanders had once been a powerhouse team that had won four straight Stanley Cups in the early 1980s. But by the ’90s, it had lost steam. The underperforming club got swept by their hated rivals, the Rangers, in the 1994 playoffs, and attendance at the dilapidated Nassau Coliseum was flat-lining. Equally alarming was the team’s appalling merchandise sales: The Islanders ranked 24th out of 26 NHL teams in apparel dollars.

The team’s ownership group decided change was required.

“They needed to get new fans, but they couldn’t afford arena upgrades or to buy good players,” Hirshon says. “The easiest way to make a quick buck is to change the jersey around.”

In 1988, the Los Angeles Kings had trumpeted their acquisition of Wayne Gretzky by unveiling a new silver-and-black look. They rocketed from last to first in merchandise sales, leaving other sports franchises desperate to emulate that success.

And so the Islanders set out to ditch their logo — a map of Long Island with the letters NY emblazoned on top — which had been with the team since its founding in 1972.

They hired a Manhattan firm, Sean Michael Edwards Design, and attempted to answer the toughest question: What exactly constituted an “Islander”?

One exec joked it should be a woman carrying a Bloomingdale’s bag stepping out of a Lexus. No obvious candidates presented themselves for such a diverse community.

And this is where Billy Joel comes in. The Long Islander in 1990 had released the song “The Downeaster ‘Alexa,’ ” which detailed the plight of a local fisherman who was struggling with a dwindling catch and tough regulations.

The team’s ownership liked the idea of incorporating the island’s seafaring heritage into the team’s identity and saw the Joel song and its video, featuring weathered boatmen, as a direction to follow.

A designer eventually created an image of an older, bearded man in a rain slicker and oilskin hat holding a hockey stick.

The team rushed to unveil the new look to the public, but failed to do any focus-group research.

“If you would have thrown that image out to a group of kindergartners, they would have said this is the Gorton’s fisherman,” Hirshon says.

The new jerseys debuted in the 1995-96 season, and fans and detractors alike immediately noticed the resemblance to the frozen-food icon. One dismayed supporter hoisted a banner at the Coliseum reading, “Fish sticks are for dinner, not our logo.”

The Islanders also introduced a new mascot. Nyisles (pronounced “Niles”) was a 7-foot fisherman caricature with a 15-pound plastic head and a red flashing light atop his head. He fell as flat as a flounder.

Fans booed him at his debut, and one 10-year-old boy was quoted as saying, “I’d like to assassinate him. I think he’s stupid.”

Rob Di Fiore, the man inside the costume, who was paid $75 per game, was subjected to endless abuse. At one game, a young boy punched him and kicked him in the groin.

An angry Di Fiore changed into street clothes and later found the boy in the stands. He bent down and whispered in the child’s ear, “I know who you are.” The kid never bothered him again.

The disastrous marketing moves were not helped by the team’s performance. The Islanders finished in the division cellar.

Fan reaction to the logo change continued to be just as hideous. The team’s management caved to the pressure and was ready to change back by the end of the season. But the NHL, worried that retailers would be stuck with an unsellable product, made the team keep the fisherman around for a second season.

Although the reaction to the jersey change was overwhelmingly negative, the shift actually had helped sales.

The Islanders sold some 10,000 fisherman jerseys in the 1996-97 season and moved up to 17th in overall NHL apparel sales.

But the fisherman was soon drowned for good. The NHL gave the Islanders permission to wear their original jerseys for up to 15 home games in the 1996-97 season before abandoning the revamped look entirely the following year.

“It was clear that this logo brought out such strong feelings, that they wanted to move past it as quickly as they could,” Hirshon says.

“For years, it was whitewashed. There would be no merchandise available. You’d go around the arena and there wouldn’t be any photos of players wearing the jersey. There was nothing.”

One of the main lessons from the disaster was about timing.

“You really want to rebrand when you have a winning team,” Hirshon says. “It’s not a Band-Aid to cover up when you’re losing. Fans will see right through that.”

That and never turn to Billy Joel for marketing advice.