With approximately eight million tonnes traded annually, there are very few seafoods that can match the global appeal or economic importance of shrimp. Providing a nutritious, low-calorie alternative to meat, shrimp are a good source of vitamins B12 and D, iodine, iron, selenium and zinc.
The popularity of shrimp is further underpinned by their flexibility; they are well suited and celebrated in most cuisines and there are countless product formats and ways of preparing them.
There are more than 2,000 different varieties of these much-coveted crustaceans, appearing everywhere – from the tropics to the coldest waters on Earth, although just a small fraction of these account for the majority of commercial sales. Consequently, and perhaps more than any other aquatic product, the names of shrimp species interchange according to geography and markets. For example, there are a number of different species that are called “pink shrimp”, “rock shrimp” or “tiger shrimp”. Therefore, to help buyers make the correct sourcing decisions, the seafood supply chain often uses the Latin names alongside local names.
Unfortunately, more confusion is caused by the word “prawn”, which is widely used in Europe and Australia and has nothing to do with size. North America commonly favours “shrimp”, although the market always refers to the “spot prawn” species rather than a shrimp. Incidentally, this particular species can reach sizes of up to 30cm.
While the names “shrimp” and “prawn” are both used to refer to “decapod crustaceans”, which are animals that are found in saltwater and freshwater – usually near the ocean floor in search of food – and have 10 legs and an exoskeleton, there are some key differences.
As well as belonging to different species sub-groups, the two differ with regards to gill and leg structures, pincers and reproduction. Prawns have branching gills while shrimp have lamellar (plate-like) gills. Shrimp have shorter legs and claws only on two pairs of legs, while prawns have longer legs and have claws on three pairs of their legs. The front pincers are usually the largest on shrimp, whilst the second pincers are larger with prawns. With regards to reproduction, shrimp carry their eggs and are present throughout the breeding season, while prawns lay their eggs and leave them to develop on their own.
According to the Food and Agriculture Organization of the United Nations (FAO), the world’s wild-capture shrimp fisheries provide around 3.5 million tonnes of products, with China responsible for some 35% of the total harvest. India, Vietnam, Indonesia, Canada and the United States follow but with comparatively much lower production levels.
Wild shrimp refers to either cold water or warm water varieties that are harvested from coastal ocean waters with traditional vessels. Coldwater shrimp are the smaller varieties, harvested in ocean waters such as the northwest and northeast regions of the United States and Canada, but also close to Greenland, Iceland and Norway. A popular species is the pink-coloured northern cold water prawn (Pandalus borealis), which is commonly used in sandwiches, salads and chowders.
Warm water shrimp, meanwhile, are harvested in tropical and sub-tropical regions. Among the most iconic varieties are the brown, white and pink shrimp – collectively known as “Gulf shrimp” – which are commercially important to both the United States and Mexico. All Gulf shrimp are harvested with trawl nets.
With most wild-capture shrimp fisheries at maximum sustainable yield, global shrimp production has grown to a level that now exceeds 4.5 million tonnes, with China again responsible for more than one-third of the harvest. However, India and Ecuador have been the main drivers of the increased supply in recent years.
Essentially, the shrimp species that have proved the most suited to aquaculture are located mainly in tropical and semi-tropical regions, most notably the whiteleg (Penaeus vannamei) and black tiger (Penaeus monodon) varieties. Generally, it takes approximately three to six months for farmers to raise market-sized shrimp, with many producers growing two to three crops per year.
Growing environmental and social awareness among consumer groups has been driving improvements in fisheries and farming systems alike. Thanks to these enhanced management practices, there is no shortage of sources of responsibly caught or farmed shrimp available to end markets, including many with eco-labels, such as the Marine Stewardship Council, the Aquaculture Stewardship Council, Friend of the Sea, Naturland and Best Aquaculture Practices (BAP) certification.
From a global perspective, shrimp consumption has risen steadily over the past two decades and this is expected to continue at the same or higher rates. At the same time, trade patterns have been increasingly shifting.
While Asian markets have traditionally dominated both wild-caught and farmed shrimp exports, the main importing nations have long been led by the United States, followed by Japan and then key European markets. However, the domestic demand within Asian markets is now growing at the most prolific rates.
China, in particular, is widely expected to continue to ramp up its shrimp consumption to a level of around two million tonnes within the next two years, and this trend is anticipated to have a considerable impact on future supplies and prices worldwide.