All known records indicate that Padina concrescens is endemic to the Galápagos Islands; so far reported from: Floreana: Black Beach (Taylor 1945: type locality) and Post Office Bay (2004 UC, K.A. Miller pers. comm.). Santa Fé: two localities (2004 UC, K.A. Miller pers. comm.). Isabela: Tagus Cove (Taylor 1945). Fernandina: Punta Espinosa (Wellington 1975). Española: Gardner Bay (Taylor 1945). Santa Cruz: Academy Bay (1973 CDS).
Type locality: Black Beach Anchorage, I. Santa Mara, Galpagos Islands, Ecuador
Habitat and Ecology
Habitat and Ecology
P. concrescens occurs in a wide range of depths but most commonly in shallow water. It is a warm water species, occurring above the thermocline. Its prostrate habit makes it easy to graze, therefore it may be adversely affected by sea urchin grazing.
IUCN Red List Assessment
Red List Category
Red List Criteria
Miller, K.A., Garske, L. & Edgar, G.
Stuart, S.N. & Carpenter, K.E. (Global Marine Species Assessment Coordinating Team)
Not common but widespread. However, difficult to distinguish from the more common species and therefore owing to insufficient information on population trends and distribution the species is assessed as Data Deficient.
P. concrescens is not a common species. Because it resembles other, more abundant Padina species, it is difficult to distinguish in the field; hence, its population has not been accurately assessed.
Presumably El Niño and climate change. Ecosystem interactions involving these two factors appear to have caused widespread decline in algal populations because of an increase in density of grazing sea urchins and other herbivores, following overexploitation of predators along with ENSO disturbances.
P. concrescens is present within the Galápagos Marine Reserve (IUCN category VI); Galápagos Archipelago Particularly Sensitive Sea Area (PSSA); Galápagos Island World Heritage Site (UNESCO N (i)(ii)(iii)(iv)), and Galápagos Island Man and Biosphere Reserve (UNESCO).