Miss Ella Lis1, Mr Beau Masters1, Mr Hochang Yoo1, Mr David Aguirre1
1Massey University – Auckland, Auckland, New Zealand
The productivity and physical structure provided by kelp is the foundation for rocky reef communities in temperate regions globally. However, declines in kelp populations are accelerating globally, contributing to a reduction in three-dimensional structure and change in environmental conditions and ocean chemistry, ultimately impacting biodiversity. With expansion of coastal development, fisheries that continue extracting top predators resulting in booming urchin populations, warming oceans that challenge physiological tolerances of kelp and invite herbivores into forests, passive restoration of kelp forests appears unlikely in preventing large-scale decline. Active restoration of kelp forests using techniques such as green gravel, the transplantation of gravel seeded with laboratory cultured kelp sporophytes or gametophytes, is a simple technique offering great promise in restoring large areas of declining kelp forests. In Aotearoa, New Zealand, and in particular north-eastern Aotearoa, many rocky reef ecosystems have experienced catastrophic phase-shifts from kelp dominated states to barren dominated states and there is a clear need for active restoration of the dominant ecosystem-engineering kelp Ecklonia radiata. Here, we examined the effects of gravel type on sporophyte cover in the laboratory, as well as the effects of depth, kelp canopy cover and attachment on sporophyte growth and survival in the field for a 9-month period. Although early in the project, the data indicates that gravel type had negligible effects on sporophytes in the lab and that environmental effects (depth and canopy cover) on seeded Ecklonia radiata growth and survival may be less influential than procedural effects (manual attachment or not) in the field.
Presentation Slides – Ella Lis
