Successive Land-Based Seedstock Production of Chondracanthus chamissoi Using Reusable Secondary Attachment Discs: Effects of Harvest Strategy

The cultivation of Chondracanthus chamissoi has advanced in Chile and Peru, but seedstock production still depends on thalli collected from natural beds. This dependence may limit commercial scale-up and increase pressure on natural beds. This study evaluated a land-based system for successive seedstock production using secondary attachment discs (SADs) as reusable vegetative units. Donor thalli were attached to polycarbonate plates in outdoor tanks to induce SAD formation. After SAD establishment, two harvesting strategies were compared: partial harvesting, in which only newly formed thalli were removed while SADs were retained on the plates, and total scraping, in which all biomass, including SADs, was completely removed. Experiments were conducted in independent cultivation tanks (n = 3), and temporal responses were analyzed using repeated-measures analysis of variance (ANOVA). Across the study, the highest values recorded were 131 ± 22 SADs 100 cm−2, 15 thalli SAD−1, a growth rate of 9.93 ± 1.21% d−1, and 44 ± 6.2% plate coverage. The partial harvest strategy maintained production between cycles, yielding 58 ± 20 and 51 ± 23 g plate−1 in the first and second harvests, respectively. Under this strategy, thallus production reached 106 ± 12 and 152 ± 17 thalli g−1 in the first and second cycles. The harvested biomass consisted of numerous small vegetative units suitable for use as seedstock. Based on a conservative production scenario, a projected estimate indicates that this technology could yield approximately 1,200,000 thalli per harvest. Overall, these results support the use of SAD as a practical strategy for the successive production of C. chamissoi seedstock.