Concise review of the genus Alaria Greville, 1830

Abstract

The brown seaweeds of the genus Alaria are economically important species in respect of food, health supplements and cosmetics. They are used as a sea vegetable in many Asian countries and are becoming increasingly popular in western cuisine. This has led to the development of cultivation of this genus in Europe. As the species in the genus are adapted to temperate-to-cold waters in the northern hemisphere, its distribution is restricted to specific zones, e.g. Alaria esculenta, to the 16 °C isotherm explaining its absence in the southern North Sea and beyond the English Channel to the south. It has been observed that the genus Alaria has a high level of morphological plasticity and over 40 different species have been ascribed to the genus in the last century. Most species have been described from the North Pacific in cold temperate waters of the northern hemisphere and only a few from the North Atlantic. Recent advances in taxonomy and phylogeny have reduced several species to the Alaria marginata complex and the polymorphic Alaria esculenta species complex and moved one species to a new genus reducing the number to eight species and one sister species. Alaria mostly occupies wave-exposed subtidal rocky shores and is of interest for its food value and cultivation potential. Aquaculture of Alaria is highly attractive due to easy practices, fast growth and economic benefits (job creation, processing etc) and environmental benefits (bioremidiation, IMTA, carbon sink). Alaria is traditionally consumed in Japan, Russia, Europe and North America; and its popularity is on the increase due to changing nutritional habits in the global population. Many interesting bioactive molecules, minerals and vitamins and a mild flavour profile make Alaria of interest for the food, functional food and health and well-being sectors.