Description 

The different species of genus Lessonia are often confused with each other, due mainly to the fact that the characteristics that are most often used to distinguish species (blade/stipe length, shape of blade base, formation of mucilage canals, etc) have been found to be fairly dependent on environmental conditions and plant age. Lessonia trabeculata is one of these species of kelp found around the southern coasts of South America. Like the other species of Lessonia (such as Lessonia flavicans and Lessonia nigrescens), Lessonia trabeculata shows the distinctive dichotomously branched stipes leading to flattened blades. However, Lessonia trabeculata can be distinguished from the other species by the massive, asymmetrical, irregularly shaped holdfast that differs markedly from that of other species, which are typically semi-spherical to conical. The holdfast is actually derived from fused haptera and further sculpted by the effects of animals which feed on and take up residence within the tissue of the holdfast.  Like Lessonia nigrescens, Lessonia trabeculata also has several to many (up to 47!) erect, rounded stipes arising from a single holdfast. These then branch repeatedly in a dichotomous fashion, finally giving rise to golden brown colored linear to lanceolate blades with variable splitting patterns.

Overall this kelp is able to reach heights of 2.5 meters with a 13 to 20 centimeter high holdfast.  Lessonia trabeculata is found only subtidally, up to 20 meters deep, on rocky substrate. This species forms extensive, though scattered kelp beds and is able to stand up to heavy wave exposure that limits the distribution of other species. The density of Lessonia trabeculata stands is fairly dependent on growing conditions, including depth.

 

Names 

huiro palo, huiro varilla

 

Phylum Classification 

Ochrophyta

 

Geographic Distribution 

Distribution is limited to the Southern Hemisphere; Lessonia trabeculata is most common from southern Peru to central Chile.

 

Uses 

Lessonia trabeculata is one of the major kelp species that is harvested for the commercial production of alginate, a gelling agent with many applications in medical, textile, and food industries, often used as a thickening agent in drinks, ice cream, and cosmetics. Lessonia trabeculata is now also being cultivated in integrated aquaculture studies with abalone farms in Chile.

 

Harvesting 

Lessonia trabeculata is primarily collected off of the coasts of northern and central Chile.

 

Harvesting Techniques 

Lessonia trabeculata is harvested by hand at low tide either by trimming off the blades and the top of the stipes or by removing whole plants, leaving one third of the standing population.  Each technique has its own set of flaws, but both offer the benefit of allowing the population of Lessonia trabeculata to re-grow and are generally regarded as responsible, sustainable management practices.  Often harvest of entire plants that are torn off in rough weather and cast ashore is possible, however this is not preferred because the alginate produced by beach-cast Lessonia trabeculata is generally of a lower quality.

 

Ecosystem 

Lessonia species (such as Lessonia trabeculata, Lessonia nigrescens, and Lessonia flavicans) are important components of their ecosystems, forming the basis of a complex food web.  Many species use kelp species such as Lessonia trabeculata for food and shelter.  The canopy formed by these species also form a protected area for less tolerant algal species to thrive, increasing the complexity and biodiversity of the ecosystem.  Lessonia trabeculata is also able to support a wide variety of life within its massive holdfast.  Invertebrate species such as crustaceans, snails, and worms create complex networks of holes and tunnels within these holdfasts which are then able to serve as valuable refuge space for juveniles of many species.  Lessonia trabeculata has been threatened by over-harvesting and by natural disasters such as El Niñ–o events, which have been known to destroy almost the entire population of Lessonia species. Good management of kelp communities including sustainable harvest is critical to the health of these ecosystems.