ISP Research Proposal v1

The island of Mo’orea is the heart of French Polynesia’s pineapple production. Ever since farmers advocated for the opening of the Rotui Juice Factory in 1981, production has increased to support growing demand for the factory’s tropical fruit juices. Today, pineapple (Ananas comosus) persists as the primary cash crop, accounting for 140 hectares of the island’s agricultural land (PROTEGE, 2021). Pineapple cultivation on Mo’orea is concentrated in the slopes of ‘Opunohu Valley where pineapple producers generally follow conventional agricultural production methods, such as monocropping, application of toxic synthetic fertilizers and pesticides, and tilling. In fact, pineapple plantations score lowest for soil health among crop production systems surveyed throughout French Polynesia (Surchat et al., 2021). Conventional methods notoriously cause soil compaction, decreased water infiltration, decreased soil microbiomes, decreased soil organic matter, decreased biodiversity, and leave large areas of land without living cover for extensive periods, leading the topsoil to become critically vulnerable to erosion. On pineapple farms, one study identified the bare access corridors and roads between fields as the most at-risk sites for erosion (Binnet & Gonnot, 2005). In addition, researchers estimated soil loss in recently cleared fields to be 400 T/ha/year (Gonnot et Binet, 2004). Notably, the island experiences periods of heavy precipitation that exacerbate on-farm soil erosion. Sediment runoff from the fields contributes to the estimated 388.5 /sediment/day that feed into the ‘Opunohu Bay from the ‘Opunohu River (Taiarui et al., 2017). Erosion control is crucial for ‘Opunohu Bay because sedimentation becomes another stressor for Mo’orea’s reefs. Multiple studies demonstrate that increased sedimentation and turbidity negatively impact coral health and lead to decreased biodiversity in the fringing reef (Morancy, 1994). Sediment smothers corals and decreases light availability for symbiotic algae, thus reducing photosynthetic efficiency (Fabricius, 2005; Tuttle & Donahue, 2022). Corals also experience decreased gamete fertilization, reduced larval settlement, decreased growth rate, and mortality.The impacts of agricultural erosion on marine life should be a concern for local authorities and could be mitigated by decreasing the amount of exposed soils (Boutillier & Duane 2006). If conventional production methods also degrade marine ecosystems then: How can incorporating agroecology-based farming principles into the Opunohu Valley’s pineapple producing-sites benefit coral reef management and conservation in Mo’orea, French Polynesia?