Northern California Kelp Forest

Informing Invertebrate Recruitment Studies

Presenter: Annette Lee

Co-Presenter(s):
Tiffany Ko, Abigail Culpepper

Presenter Status: Undergraduate student

Academic Year: 22-23

Semester: Spring

Faculty Mentor: Brent Hughes

Department: Biology

Funding Source/Sponsor: Class Project

President's Strategic Plan Goal: Sustainability and Environmental Inquiry

Abstract:
Kelp forests are drastically diminishing along the coast of Northern California. Trophic cascades and climate change are the main causes of this phenomenon. The keystone species that control invertebrate populations are absent, leading to the grazing and over-consumption by herbivorous sea urchins of already fragile kelp forest ecosystems, expediting catastrophic habitat losses. This reduction of kelp forest viability leads to severe declines in ecosystem services and requires expanded exploration of population dynamics. To better understand the recruitment patterns of marine invertebrates, diving lines with artificial recruitment modules (e.g., brushes, tuffys, and PVC tiles) were positioned inside and outside the kelp forest. Due to their disproportionate impacts on kelp, a specific examination of sea urchin recruitment was executed to identify recurring conditions in assemblage patterns to direct future restoration measures. To sufficiently represent the entire population, additional investigation was conducted through a power analysis to quantify how many samples of each module, at minimum, are needed to reduce variability. Furthermore, this research emphasizes the importance of recognizing relationships between sample size and confidence in results and how future studies can better incorporate these factors in kelp forest restoration.