Crustaceans

Let’s face it. Crustaceans are pretty weird. Weird, and delicious. They belong to the arthropod family, which includes crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, barnacles, copepods, amphipods, mantis shrimp and sea lice. Crustaceans occupy a vital link in the foob web, often referred to as the cleaners of the sea - an important ecosystem service for other bottom-dwelling organisms.

Their shells are a rich source of chitin, from which chitosan can be extracted. Chitosan is a polysaccharide with a number of commercial and possible biomedical uses. It can be used in agriculture as a biostimulant and biopesticide, helping plants to fight off fungal infections. In winemaking, it can be used as a fining agent, also helping to prevent spoilage. In industry, it can be used in a self-healing polyurethane paint coating, or in anti-microbial biopackaging. In medicine, it is useful in bandages to reduce bleeding and as an antibacterial agent; or to help deliver drugs through the skin.

Of course, those with a shellfish allergy should perhaps give these ones a miss (along with everything else on this website!)

Brown Crab (Cancer pagurus)

Brown crab, also known as edible crab, is a benthic species that lives on a wide range of seafloors: sand, gravel, and rock, at depths of 6 to 100 metres. It is found in the Eastern Atlantic, from northern Morocco, extending along the Atlantic coast of Europe, to the British Isles and northern Norway. With their characteristic pie crust shell, big claws and squat stance, they are easily recognised. The “Cromer” Crab on the UK’s East Coast is famed for its sweet flavour. It tastes delicious either fresh with some lemon and salad, in a burger or a crab-butty.

Brown crabs are omnivores, scavengers, and active predators. Their main diets are bivalves, smaller crustaceans, barnacles, and snails. Their omnivore diet contributes to keeping the seafloor free from
organic debris.

In 2019, the FAO reported a total global catch of 50.480 tonnes of brown crab. The majority of this (60% or 31.004 tonnes) was caught by the UK. At the time of writing, there are currently no quota restrictions on brown crab, which could change. There is also potential for passive crab & lobster fisheries in combination with offshore wind farms.

European Lobster (Homarus gammarus)

Another ironic example of a once “poor man’s food”, now more highly prized than salmon. Lobster has a curious history, once being used exclusively to feed prisoners and indentured servants in the American colonies, as they were once so abundant that they piled up several foot high on the shoreline. At some point in the 1800s, lobster was re-packaged as a canned food for upmarket railway passengers, and it caught on.

This, followed by overfishing made the lobster what it is today: an expensive but unbeatable delicacy for the rich - or anyone with half a brain and a lobster pot.

Common Prawns & shrimps

What’s the difference between a prawn and a shrimp? It turns out not much. The prawn (Palaemon sp.) is transparent with long legs and is found amongst the weed in rock pools on the shore and belongs to the Palaemon family. The shrimp is the sandy coloured crustacean that lives in the sandy shallows. It has short legs and buries itself in the sand. It is called by the scientific name of Crangon and is found all around the British coast.

Prawn & shrimp fisheries are among the most environmentally damaging, as the small net sizes result in a lot of bycatch, including juveniles of various other species (a bit like fishing for plankton). Bottom-trawling is another common method of shrimp fishing which destroys benthic species and habitats. In other words, not sustainable. More like shooting yourself in the foot. Not to mention the huge plastic nets which get snagged on rocks and have to be cut loose.

Shrimps and prawns can be quite easily foraged, especially if you have a shrimp or ‘push’ net. Potted shrimp is a classic recipe from the middle ages which creates a seal using butter for longer preservation.

Langoustine / Dublin bay prawn / norwegian lobster (Nephrops norvegicus)

Half way between a prawn and a lobster, the langoustine has several names. The breadcrumbed tails are commonly referred to with the Italian name scampi, which can often be found on pub menus across the UK. “Langoustine” in French is a diminutive of '“langouste” which roughly translates as “lobsterette” or “mini-lobster”.

The name Dublin Bay prawn came about, because it was in Dublin that they were first regularly landed. They were regarded as an incentive for the crew when caught as unsolicited bycatch by trawlers fishing the northern edge of the Irish Sea. The crew would sell the bite-sized lobsters to street vendors to make extra cash. Since the Dublin Bay prawn wasn’t strictly ‘above board’, they were off-loaded at sea, in Dublin Bay to be precise, before the ship landed its official catch in the harbour.

These species are also fished by bottom-trawling, which churns over the sea floor to scare them out of their holes. However, there have been recent attempts to breed langoustines, much in the same way as lobster (see National Lobster Hatchery). Due to a pronounced penchant for cannibalism, the juveniles have to be kept separated in splendid isolation, which I’m sure a few kids can understand sometimes!