Defense Date

12-7-2022

Document Type

Thesis

Degree Type

Master of Science

Degree Name

Marine Science

First Advisor

Dr. D. Abigail Renegar

Second Advisor

Dr. David Gilliam

Third Advisor

Dr. Bernhard Riegl

Keywords

Outplanting, attachment, epoxy, coral, toxicity, exposure, fragmentation

Abstract

As coral cover decreases around the world due to disease, bleaching events, and anthropogenic effects, coral restoration projects become increasingly important. A crucial part of many coral restoration projects is the attachment of corals to substrates in nurseries or reef substrates during outplanting. The effective anchoring of transplants is a critical phase in coral restoration and the adhesive used for attachment is crucial. Commonly used adhesives have several drawbacks: there are long mixing times, low substrate adhesion, and lengthy hardening times. To address these issues and provide an effective alternative for coral restoration activities, a new two-part Mixed Adhesive was developed by TRI Austin. This new adhesive can be dispensed underwater using a caulk-type applicator gun and static mixing tips and has a hardening time of approximately 10 seconds. However, it was necessary to determine potential aquatic toxicity of the adhesive prior to utilization in coral restoration activities. A preliminary exposure to determine experimental design and four static dose-response assays were used to examine the potential toxicity of Part A, Part B, the Mixed Adhesive in contact with coral tissue, along with a second Mixed Adhesive experiment of no contact with coral tissue vs. direct contact. Part A of the Mixed Adhesive had no significant effects on corals, while Part B was found to be highly toxic and causes 100% mortality within five hours. The fully mixed adhesive had no significant effects on corals and was easily dispensed underwater. The new Mixed Adhesive shows potential as a new tool in coral restoration in comparison to current adhesives.

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