Keanu Mir-Scaer , Zen Mir-Scaer

This paper examines the scattered nearshore kelp beds in Laguna Beach subtidal shallow rock reef substrate between Brooks Street and Thalia Street, referred to as town. The nearshore kelp is approximately 200 meters from the shore. This area has been protected since 2012 when it was considered a California Marine Protected Area (MPA) and classified as Laguna Beach State Marine Reserve (LBSMR).  We observed a lack of historic nearshore kelp in town during the last decade, from 2015 to 2023. Our observations were confirmed by reviewing images from KelpWatch.org, where data is processed from NASA’s Landsat satellite program, the largest map of kelp forest canopy from 1984 to 2021 (1). 

We observed an increase in marine life in town from 2022 to 2024, and in spring 2024 we observed a resurgence of native giant kelp (Macrocystis pyrifera). Most of the giant kelp blades quickly succumbed to bryozoan (Membranipora membranacea) encrustation in less than two months, and by month three the kelp beds had been reduced by approximately 70%. Giant kelp fronds naturally senescence when they reach between three to twelve months (2). Although kelp has a natural growth cycle and warmer sea temperatures may expedite senescence, bryozoan encrustation possibly delayed senescence by providing physical structure to the disintegrating blades. Nearshore kelp is once again growing in Laguna Beach, likely due to the biodiversity afforded by MPA protection, however, additional action is required to protect kelp in warming waters due to climate crisis and we see a need for additional research into the relationship between kelp and bryozoan.