What causes the difference between Maine and Canadian lobsters?

First of all, Ramsay was primarily concerned that they were advertising Maine Lobsters and selling Nova Scotia Lobsters. He actually didn't comment on the flavour.

I've searched about 20 web pages (nothing authoritative) and the consensus is that the colder the water, the better the lobster.

But, the waters off of Maine are fed by the Labrador current, which is the same water that flows past New Brunswick, PEI and Nova Scotia.

If there is a temperature difference, it is likely not very significant, and any effect it would have on flavour is minimal at best.

I have lobstered from Montauk New york all the way to just south of Greenland. I come from a family that has been deeply involved in the losbter fishing trade since the late 18th century. My grandfather, uncle and brother have all, in their repective times, been consultants to the national lobster fisheries advisory board of both Canada(my grandfather) and The United States(my uncle and brother). I have worked as a chef in restaurants in Maine, Nova Scotia, Prince Edward Island and Cape Cod since I was in my late twenties.

It is mine, and my family's, considered opinion that the esteemed, if somewhat self-aggrandizing, Chef Gordon Ramsay is DEAD WRONG in is opinion of the differences between Homarus Americanus caught in Canadian waters as opposed to those harvested in American waters. There is virtually no discernable difference whatsoever.

Ramsay's opinionated, albeit ill informed, attack on the New York restaurant owner doesn't surprise me at all. On the original British version of Kitchen Nightmares I once saw him introduce, as a new menu item in the episodes featured eatery, what he dubbed , and I quote " a classic ceasar salad". The salad was served with two crisp stripsw of fried BACON! My 70 year old Rome born father in law gasped and said, "CLASSIC!!... maybe in Yorkshire!... he scoffed.

Possibly two reasons: environmental concerns and a lack of standards.

For the environment, Ramsay has often advocated for restaurants to serve fresh, local seafood wherever available. He supports local industry and sustainable harvest. He has a recent scathing documentary about shark fin soup, openly protesting inflated prices for the rare, costly, and underwhelming dish that puts environmental strain on the fishing industry. I am unsure, but both lobsters are harvested from different countries with different fishing regulations. He may have critiques about Canadian or American fishing industry.

High quality seafood restaurants often advertise from where their seafood is obtained. I'm not in a region known for lobster, but a region known for oyster. We have many regions in the pacific northwest whence oysters are harvested. Oysters in regions mere miles apart can have wildly different flavors. In a blind taste test, it's quite easy to match oysters by region based on their characteristics. I think small regional differences can lead to large differences in flavor between shellfish, based on water characteristics. No particular region is bad or low quality here, but for a restaurant to not know whence their seafood comes shows a lack of class and standards.

As a lobster fisherman in Nova Scotia, I can say chef Ramsay is full of himself. He should never comment on anything that he has no idea of what he is talking about. If you are in a restaurant in Florida and you are served a Maine lobster, you have an 80% chance of getting a lobster from Nova Scotia, New Brunswick, or Prince Edward Island, though this is less common than the other two. There are no differences between them other than at times water temp, and time of year caught. This can lead to shells with very little meat, soft shells, or hard shells, that are very full of meat. A lobster here for instance caught in March, April, or May, is very full of meat and rich in taste compared to one caught in October or November. Not to say some caught in October or November are not but in general they are.

The idea behind the whole Maine lobster fuss is more of an American deal. Where as if you are a US citizen, you will be more likely to support your US fishermen. But, you must remember I may be in Nova Scotia, but when I leave my harbor I am in what they call The Gulf Of Maine. So could you not call my catch Maine Lobsters, and be correct? Now when you get further up in Bay Of Fundy, or get out on the Atlantic side of Nova Scotia in the Atlantic Ocean, this may not fly. But like one of the other answers above stated, if you see Maine lobster, you know right away what it is. This could possibly be the best reason for the Maine name.

I'm no expert in lobster but all sorts of things can affect the quality of produce even if it's the same variety.

Things like diet, water temperature and water quality could easily cause differences between two otherwise identical things.

There could also be differences in how they are fished/managed by the two nations.

I believe it is the same thing that sparkling wine from Champagne can be called champagne, but those made outside of it cannot be named that way. I watched that clip and it Gordon picked on false advertising, regardless if there are actual difference in taste.

I believe the restaurant owner called it Maine lobster is to differentiate it from other species we call lobster such as rock lobster. Maine lobster describes all (western) North Atlantic lobsters whether caught in Canada or the US. To further this answer refer to the definition of American Lobster on Wikipedia. It is also know as Maine Lobster and covers (comes from) the Canadian and U.S. NorthEast Coast from Newfoundland to New Jersey.

Within the same species/genus, the strain of lobster can account for a significant taste difference. Fishery quality and practices also matter, of course.

A Maine lobster is caught by someone who resides in Maine. A Nova Scotian lobster is one caught by someone who resides in Nova Scotia. It's the same Species, Atlantic lobster regardless of where it's caught.

Canada fishermen have different size standards, they are allowed to keep bigger lobsters which are not as good to eat, kind of like an old cow. When Canada lobsters are processed you get the good with the bad bringing down the overall quality.