American Lobster - Oceana Canada

Cephalopods, Crustaceans, & Other Shellfish

American Lobster

Homarus americanus


Atlantic lobster, true lobster, lobster


Temperate waters of northwest Atlantic, from Labrador to North Carolina


Rocky reefs


Foraging predator


Order Decapoda (crayfish, crabs, lobsters, shrimp); Family Nephropidae (clawed lobsters)


American lobster, unlike most invertebrates, have teeth. However, these teeth aren’t located in their mouths – they are in their stomach. Their stomach chews food using what looks like molars, called a “gastric mill.” Lobster has not always been a sought-after seafood, in fact, in the seventeenth and eighteenth centuries, it was so cheap that Americans used it as lawn fertilizer and fed it to prisoners and indentured servants. In Massachusetts, some servants fought against this by having it added to their contracts that they would not be fed lobster more than three times a week.  


American lobsters are the largest crustacean in the world by weight, growing to lengths of around 80 centimetres and weighing more than 18 kilograms. Like all other crustaceans, they have a hard exoskeleton, or outer shell. The exoskeleton of American lobsters is a dark, rusty brown to olive green and is flecked with red, orange and black. However, there are rare cases of bright blue lobsters, bright green, or others that are perfectly divided down the middle with different colours on each side of their body. 

They will molt this exoskeleton many times during their lifetime, growing a new one underneath the old one until it becomes so large that it splits the existing exoskeleton and sheds it off. They are a decapod, meaning they have 10 legs, including their large front claws, called chelipeds, two pairs of antennae, and five pairs of feathery-like structures under their abdomen and tail, called pleopods, which help with movement of water and are used for reproduction and carrying of eggs. They have poor eyesight but a well-developed sense of taste and small.



Unlike many other aquatic species, American lobsters reproduce via internal fertilization. A pair will mate in a rocky shelter during the summer, where the female seduces the male through behaviours such as peeing in his face. Lobster urine contains various chemicals such as hormones that is used to communicate during fighting or mating. During reproduction the male will turn the female over on her back and transfer his sperm into the female using his pleopods. He will then flip her back over and stay with her for a few days, before heading off again. 

The female will store the sperm for several months, with some females keeping the sperm for over a year. After this time, the female will excrete her eggs, which stick to her pleopods, where she will then fertilize them with the stored male’s sperm.  She will keep her tail tucked up her, carrying and protecting the eggs for almost a year, after which she will lift her abdomen and flick her tail to release the microscopic lobster larvae. 

The larvae are typically released between May and September, and will float around in the water column with other phytoplankton and zooplankton, molting several times before reaching the juvenile stage between three and 12 weeks after hatching, depending on water temperature. At this point in time they will chose a spot to settle on the ocean floor, and will find a suitable shelter to live until they reach maturity. 



Shellfish, such as lobster, clams, scallops and crab, bring in 77 per cent of the value of the Canada’s seafood landings. More than 10,000 licensed harvesters target lobster in 45 different lobster fishing areas.  All of the fisheries harvest lobster by trap, with the Gulf of Maine, Bay of Fundy, the Southern Gulf of St. Lawrence and coastal Nova Scotia supporting the most active fisheries. Lobster are typically caught in shallower, rocky regions, less than 40 metres deep; however the offshore fishery and those operating in the Bay of Fundy and Gulf of Maine will harvest lobster much further from shore at depths of around 200 metres. The lobster fishery is highly regulated in Canada, with size limits (minimum and maximum limits), zero retention of egg-bearing females and strict fishing seasons, all with the goal of conserving the fishery and ensuring it will remain viable for years to come.

American lobster in Atlantic Canada is considered a sustainable option by some certifications, but there are concerns that the current high demand for this species could lead to overfishing and population decline.  More research is needed to ensure fisheries are sustainable and protecting the future of lobster populations as well as the health of the larger ecosystem.



The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) has not yet assessed American lobster in Canadian waters. However, under the Precautionary Approach Framework by the Department of Fisheries and Oceans (DFO), the different populations or management units have been assessed as either Healthy or Unknown. These assessments are almost solely based on catch data from the lobster fishery, with most units appearing healthy, and those assessed as Unknown simply lacking a sufficient amount of information to be accurately assessed according to current methods.

Oceana Canada is working to protect Canada’s oceans for species like the lobster. Find out more about our campaigns and join us in helping to bring abundance back to the ocean.