Irish Moss is a small perennial seaweed that grows best in water that is between the low tide mark and 30 feet of depth. The plants thrive in water ranging between 5 and 15 degrees Celsius. The life cycle of the plant begins in a seed form. These seeds are shed by the plant annually. The plant attaches to the ocean’s rocky bottom in a way that resembles being glued to the rocks. The small plant reaches maturity in three to five years, at which time the many branches that cover its top may range in colour from a light yellowish green to an almost purple colour.

Mature plants can reach heights up to seven inches and have the unique ability of growing from the bottom. Unlike plants that grow on land, Irish Moss must grow from the bottom due to the harsh environment in which it lives. Many times throughout its lifespan a storm will whip the water up around it and in turn break the top of the plant off. Growing from the bottom allows the plant to continue developing e Read More

Irish Moss is a small perennial seaweed that grows best in water that is between the low tide mark and 30 feet of depth. The plants thrive in water ranging between 5 and 15 degrees Celsius. The life cycle of the plant begins in a seed form. These seeds are shed by the plant annually. The plant attaches to the ocean’s rocky bottom in a way that resembles being glued to the rocks. The small plant reaches maturity in three to five years, at which time the many branches that cover its top may range in colour from a light yellowish green to an almost purple colour.

Mature plants can reach heights up to seven inches and have the unique ability of growing from the bottom. Unlike plants that grow on land, Irish Moss must grow from the bottom due to the harsh environment in which it lives. Many times throughout its lifespan a storm will whip the water up around it and in turn break the top of the plant off. Growing from the bottom allows the plant to continue developing even after the top has been broken off.


© Community Museum Association of Prince Edward Island, 2005. All rights reserved.

Irish Moss (Chondrus Crispus)

Barry King

© Barry King


Harvest Photos

Fishermen from picturesque harbours in western Prince Edward Island still use their boats to harvest Irish Moss from the ocean floor. The seaweed is then trucked to nearly plants for processing.

Community Museums Association of Prince Edward Island.

© Community Museum Association of Prince Edward Island, 2005. All rights reserved.


Video of the Irish Moss harvest

The harvesting of Irish Moss is still done the old-fashioned way in Miminegash, located in western PEI. Horse-drawn rakes pull the seaweed to shore where it’s transported by truck back to nearby farms.

Community Museums Association of Prince Edward Island.

© Community Museum Association of Prince Edward Island, 2005. All rights reserved.


Video of the Irish Moss harvest.

Before harvesters sell their Irish Moss it must first be carefully cleaned and then dried under the sun.

Community Museums Association of Prince Edward Island.

© Community Museum Association of Prince Edward Island, 2005. All rights reserved.


Video of the Irish Moss harvest.

In order for fishermen to get a high-quality moss, they must first separate it from other unwanted marine growth. The spacing between the rake teeth allows the fishermen to harvest the moss without destroying its ability to regenerate. The fishing boats rake moss close to shore in two to ten metres of water. Once the moss is ashore it can be sold one of two ways – wet or dry. Harvesters get more for dry moss because it takes a lot more work to get dried. The moss must first be spread under the hot sun. It has to be sifted and raked to get the moisture down and the price up.

Community Museums Association of Prince Edward Island.

© Community Museum Association of Prince Edward Island, 2005. All rights reserved.


Video about the Irish Moss harvest.

From early summer to late fall the Irish Moss harvesters are hard at work. And what the boats can’t get or miss, shore harvesters try their hand at it. Hauling a smaller rake behind them, the shore harvesters walk the beach towing for the moss. Moss is also harvested by animal. This one-horse power model is towing a medium-sized rake. Irish Moss harvesting, because it involves young and old, male and female, is considered a family tradition on Prince Edward Island.

Community Museums Association of Prince Edward Island.

© Community Museum Association of Prince Edward Island, 2005. All rights reserved.


There are two ways to harvest Irish Moss. The first, and most common, requires a license and is done from a fishing boat in the shallow water just off the shore. This fishery utilizes the same type of boat that is used in countless other Island fisheries including lobster, tuna and groundfish. The moss fishing season runs from early summer to late autumn. The method of harvesting from a boat is really a simple procedure. A small fishing vessel hauling upwards of six drags of varying sizes moves slowly and continually around the shallow water where the moss grows. Any moss that may be loose or disengaged from the rocks is picked up by rakes. When the rakes are full, they are raised to the boat using a hauler and a series of pulleys and booms where it is emptied onto the floor of the boat.

When the boat is full, it returns to the harbour where a buyer (often a moss plant owner) waits with a half-ton truck with high sideboards. A special hoist on the wharf is used to empty the boat. Read More

There are two ways to harvest Irish Moss. The first, and most common, requires a license and is done from a fishing boat in the shallow water just off the shore. This fishery utilizes the same type of boat that is used in countless other Island fisheries including lobster, tuna and groundfish. The moss fishing season runs from early summer to late autumn. The method of harvesting from a boat is really a simple procedure. A small fishing vessel hauling upwards of six drags of varying sizes moves slowly and continually around the shallow water where the moss grows. Any moss that may be loose or disengaged from the rocks is picked up by rakes. When the rakes are full, they are raised to the boat using a hauler and a series of pulleys and booms where it is emptied onto the floor of the boat.

When the boat is full, it returns to the harbour where a buyer (often a moss plant owner) waits with a half-ton truck with high sideboards. A special hoist on the wharf is used to empty the boat. The fishermen shovel the moss into a container that is raised using the hoist and dumped into the truck. This is repeated until the boat is unloaded the moss is then spread on the ground and sun dried. Fishermen get a much better price for dry moss than they would for wet. In 2004, the rate was 17 cents per pound for wet moss and 42 cents per pound for dry plants.

The other method of taking the moss from the water is as unique as the people who do it. After a storm with high winds washing moss into the more shallow areas, the gathering of moss begins. Moss that is washed up into the very shallow areas is gathered by hand using small hand held nets or long hand rakes. The slightly deeper areas of the shore require horses to collect the moss.


© Community Museum Association of Prince Edward Island, 2005. All rights reserved.

Gathering moss with a horse in West Prince, PEI.

Barry King

© Barry King


Harvesting Irish Moss from a boat.

Barry King

© Barry King


It is a charming sight to see a dozen horses, sometimes up to their neck in water, walking back and forth in the shallows gathering the rich moss in the rakes or drags they pull behind them. The operation works in much the same way as plowing a field, except in the case of moss, the person guides the horse from the animals back. The horse is harnessed to the basket that they will drag and will pass back and forth through the water until it is full. The moss is dragged up onto the beach and forked into a truck with high sideboards to hold large loads. The moss is then taken from the shore and spread out on fishermen’s lawns and driveways to dry so they can get the best price possible. As it dries, the moss is cleaned and sorted, removing any other sea plants or stones from the product.

It is a charming sight to see a dozen horses, sometimes up to their neck in water, walking back and forth in the shallows gathering the rich moss in the rakes or drags they pull behind them. The operation works in much the same way as plowing a field, except in the case of moss, the person guides the horse from the animals back. The horse is harnessed to the basket that they will drag and will pass back and forth through the water until it is full. The moss is dragged up onto the beach and forked into a truck with high sideboards to hold large loads. The moss is then taken from the shore and spread out on fishermen’s lawns and driveways to dry so they can get the best price possible. As it dries, the moss is cleaned and sorted, removing any other sea plants or stones from the product.


© Community Museum Association of Prince Edward Island, 2005. All rights reserved.

Moss horses must be very big and extremely powerful

Barry King

© Barry King


Once the moss is dry, it is trucked one of the three local plants to be prepared and sold to an off island buyer who extracts the carrageenan. When the moss is first trucked to the plants, it is dumped into what is known as a shaker, which does just as its name would suggest. As the moss passes over a belt, it is vibrated in order to shake out any remaining sand. It then lands on the floor and is gathered into huge piles using a loader or tractor with a bucket on the front. The high piles can be easily moved into the baler, which compresses the moss and forms it into large square bales, each bale weighing about 175 pounds. The bales are then stacked until they are shipped to the purchaser that will extract and sell the valuable carrageenan.
Once the moss is dry, it is trucked one of the three local plants to be prepared and sold to an off island buyer who extracts the carrageenan. When the moss is first trucked to the plants, it is dumped into what is known as a shaker, which does just as its name would suggest. As the moss passes over a belt, it is vibrated in order to shake out any remaining sand. It then lands on the floor and is gathered into huge piles using a loader or tractor with a bucket on the front. The high piles can be easily moved into the baler, which compresses the moss and forms it into large square bales, each bale weighing about 175 pounds. The bales are then stacked until they are shipped to the purchaser that will extract and sell the valuable carrageenan.

© Community Museum Association of Prince Edward Island, 2005. All rights reserved.

Irish Moss being piled in preparation for baling.

Irish Moss Interpretive Centre

© Irish Moss Interpretive Centre


Learning Objectives

The learner will:
  • describe how Irish Moss is harvested on Prince Edward Island;
  • summarize the steps that fishermen follow in order to process Irish Moss.

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