Date of Award

Fall 2024

Project Type

Thesis

Program or Major

Biological Sciences

Degree Name

Master of Science

First Advisor

Christopher Neefus

Second Advisor

Elizabeth Harvey

Third Advisor

Michael Chambers

Abstract

The aquaculture of macroalgae is multi-billion-dollar industry globally, but is primarily dominated by Asian production. The US macroalgae industry is relatively small but has grown over the last decade, heavily dominated by kelp aquaculture. The goal of this project is to facilitate the diversification of the US industry by developing nursery and grow-out techniques for the production of Wildemania amplissima, a native species of nori. Following the life history of Wildemania amplissima, a series of experiments were conducted to 1) compare culture initiation methods from wild-collected blades, 2) determine optimum culture conditions for vegetative growth of the conchocelis sporophyte stage, 3) determine the sequence of culture condition changes required to trigger the production and release of conchospores, which then grow into new blades, and 4) compare several methods of encouraging conchospore attachment to seed strings to be used for out planting to coastal farm sites. Culture initiation by maceration of fertile blades produced larger amounts of conchocelis biomass compared to the micropipette spore isolation technique, but was prone to higher levels of contamination. In the conchocelis growth experiment, it was found that light levels and photoperiod did not influence growth rates, but temperature does have a significant effect. It was found that 14 ͦ C had the highest specific growth rate, with 18 ͦ C having the lowest. Conchosporangial filament development, conchospore production, and conchospore release was found to occur after a decrease in temperature and photoperiod to 8 ͦ C short-day conditions in well plate cultures. Two methods for seeding string were found to be viable, one method using free-living conchocelis cultures, the other using conchocelis cultures established in sterile oyster shells; both processes took one to two months. At the end of the study, two attempts were made to deploy small lines of Wildemanis amplissima at a UNH coastal aquaculture site. Neither was successful as lines either had incorrect deployment time or went reproductive and degraded by the time they were collected. This project had success developing initial nursery conditions for Wildemania amplissima, but further work is needed with developing line deployment methods and upscaling for larger scale production.

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