This is a very pernicious and problematic myth that I have seen crop up a number of times on quora (and there seem to be a lot of related questions on just this issue). Of course the Irish fished when they could instead of starving, but the industrial scale of fishing required to save more than 1 million people from starvation was beyond the means of the poor subsistence farmers. The idea that the Irish should have simply fished away the famine is not simply laughable, but it misunderstands the very nature of colonialism in Ireland and the structure of the Irish legal and economic history in the 1840s. Instead of understanding what went wrong or perhaps the inevitability of a major food shortage due to the economic structure of colonialism, the question blames the victims – poor Irish farmers with no means to exploit the highly productive fisheries just off their coast.
For context, it is useful to understand both the Irish diet and economic systems prior to colonialism by Britain in the 1600s. While England had at least nominal control of much of Ireland prior to the 1600s, it was not until roughly the 1600s that large scale plantations were set up across the country (although the Ulster plantations are by far the most famous). These plantations, as well as a series of laws from the 1600s to the 1800s deprived many of the local Irish inhabitants of their rights to own land and continuously undermined general property rights and ability to generate and pass on wealth.
Prior to the 1600s, native Irish rulers certainly had ships, sometimes whole fleets, of fishing and commercial vessels. This required not only the construction of these ships, but also the wealth to purchase them. For instance, one Irish clan – The O’Donnell family of today’s Donegal – was known in continental Europe as the Fisher-Kings for the export of fish from North West Ireland to Europe. This was an industrial affair and started at least as far back as the 1240s – fully 600 years before the Potato famine.
The better known case of Grace O’Malley, the Pirate Queen or Sea Queen of Connacht, shows how many ships a noble Irish family might have. She inherited the O’Malley clan’s fleet of ships, which were involved in international commerce, fishing, and piracy of other ships trading and fishing off the Ireland’s western coast. In 1591, Grainne O’Malley was said to have a fleet of 20 Irish Galleys. This is not to suggest that the average Irish person owned a ship previous to the English conquest of Ireland. There was widespread inequality between the Gaelic nobility and the average Irish person. But fishing, even industrial fishing, was a major occupation – especially so on the West Coast of Ireland which was to be so badly hit during the famine.
While the diet in Ireland did tend toward milk and meat products as shown in this video by Jazby below, this was obviously not the only source of calories. But it shows that milk and cattle were in high demand and were relatively plentiful. In Ireland, as elsewhere in Europe at the time, meat and especially cow meat, was a more prestigious diet – one that not every person in society could afford. Barley was heavily farmed, wild game was hunted – particularly deer, rabbit, and likely many smaller rodents. This is in addition to mushrooms, nuts, vegetables and… of course… both fresh and salt water foods. Ireland has a great deal of navigable rivers which have fish as well as crustaceans. These have not only formed a large part of the Irish diet, but also our history and myths. One of the most famous Irish myths is the Salmon of Knowledge – a salmon that is cooked and eaten.
As mentioned before, salt water fish was generally fished from boats often far out to sea, although there were several other species which were available from shore. Salt water foods also included Irish lobster, clams, mussels, crabs, oysters, etc. Not only were these foods exploited, but other more extreme foodstuffs were brought from the sea, including seaweed which was occasionally used in soups. To be clear, not every available food source was fully utilized during the famine, but that was as much likely due to internal migrants moving around in search of food and not being familiar with the new areas in which they found themselves. Let’s be clear – starving people in Ireland tried eating everything from tree bark to grass. They would be desperate for fish if they could find it.
The potato monoculture in Ireland developed for two main reasons. The first was the the potato was hardy and a good source of calories in relatively poor soils. This was important because the poor Irish farmers were increasingly pushed to ever more marginal lands that they were pushed to due to colonial era policies on land ownership. Therefore the majority of these farmers were subsistence farmers or sharecroppers. These farmers did not own their land – and often legally could not own their land. This meant that they were unable to improve the land, which was poor. The potato was in general terms the highest calorie plant that could grow in these areas. Additionally, since the main food part (the potato itself) was in the ground, there was some marginal protection from food theft or destruction by wildlife.
As the British colonial laws banned land ownership by many of those farmers, they were dependent on their landlords, who could (and did) kick them off the land unless the farmers paid often exorbitant rents. The farmers supplemented their food where they could, but they were unable to forage or hunt in the large estates held by the foreign nobility who were very often not even based in Ireland. This was also true for many of the rivers – and hunting or fishing on these estates carried severe penalties. The policies of taking the best land for food exports (often for British troops abroad) and high rents on extremely poor land were explicitly confiscatory in nature. But… that’s how colonialism worked.
The colonial system created a system where the previously varied Irish diet become increasingly and incredibly dependent on potatoes for the sheer hardiness and high calories of the plant. Once this was destroyed due to blight, the native farmers were too poor to buy food or buy materials to fish the sea or often even to make traps for lobster, etc. The idea that the Irish were just stupid feckers on an island who didn’t even fish is actually quite a bit racist. It wasn’t the fault of the farmers and it doesn’t have anything to do with these farmers being Irish, it was the fault of the colonial system. Irish farmers were pushed to the very brink already by an unfair colonial system. The blight was just the final straw that knocked the bottom out from under them. This is why you can see that the severity of the famine was highly correlated with areas of greatest poverty. (Both highly correlate to the land ownership system in the areas affected).
Finally, it should not be seen as the last or even the worst famine caused by British colonialism let alone European colonialism writ large. The colonial systems were set in place to make money or at the least to bring cheap imports into the mother country. Even in living memory, the Bengal famine of 1943 was more or less caused by the British. Again, this the result of colonial exploitation.
On a more personal note, I don’t necessarily blame the British for this madness. The average British person had little to do with the system and benefitted very little from it. Keeping the poor in debt and milking them for all they’re worth happened in England as well as Ireland – and it still happens in many places around the world today. It’s the system that was broken. And the system broke the Irish, with a million dying of starvation and another million fleeing the country.