Concise review of the red macroalga dulse, Palmaria palmata (L.) Weber & Mohr

Palmaria palmata, commonly referred to as dulse, is a well-known and highly valued red macroalga distributed along the North Atlantic shores within a latitude range of approximately 40 to 80 °N. It is a species of commercial importance with historical records of use as food dating back several centuries to the current harvesting of dulse by hand-picking on the foreshore in Western Europe as well as Canada (New Brunswick and Nova Scotia) and USA (Maine). Because the demand for P. palmata increases and future sustainable commercial developments cannot rely solely on wild-harvested biomass, significant efforts have been made by research and industrial actors to cultivate the species. The low rates of spore release and germination, high mortality and epibiont contaminations remain major bottlenecks and point towards the need for optimized hatchery methods to enable upscaling the biomass production. The present review summarizes the available knowledge related to the biology, including the unique life history of the species among the Rhodophyta, the ecology as well as the nutrient composition and quality of P. palmata as food. Recent advances in taxonomy and cultivation techniques are reported along with a status of regulations for the commercial harvest of wild populations. An outlook on future industrial perspectives using biomass of P. palmata is also given.