With generous support from the Wolfgang Bosche Animal Wildlife Foundation and thanks to deep discounting from Bay Instruments, Mote Marine Laboratory (Mote) was able to purchase three Junior-PAMs for use in its Coral Health and Disease Research Program in 2022. With this new equipment, Mote has trained several young scientists in the use of Junior-PAM’s for coral physiology research, conducted a live experiment as part of an international coral restoration workshop, and integrated measures of coral photochemical efficiency into several on-going research projects. In each of these efforts, Mote’s goal is to quantify how corals respond to major threats facing coral reefs today – disease, climate change, ocean acidification, and poor water quality (i.e., sedimentation) – while training tomorrows scientists.
A PAM, or a ‘Pulse-amplitude modulated’ fluorometer, is an instrument that measures the photosynthetic efficiency of a coral’s algal symbionts. It provides a measure of the health of the symbiotic algae and its relationship with the coral host. Coral bleaching, a sign that a coral is stressed, occurs when the coral host expels its symbiotic algae and loses its color, usually due to higher than average ocean temperatures. Before a coral actually expels the algae and has any visible signs of bleaching, however, the symbionts stop photosynthesizing as efficiently as they would be under normal, non-stressful conditions. PAMs allow scientists to measure this stress before it is visible to the human eye. This approach to measuring coral health is a standard technique used by coral biologists around the world, and thus these instruments are invaluable to Mote’s Coral Health and Disease Program.
Mote has thus far used the funded equipment to:
Provide training on a universal method in coral physiology research using an advanced scientific instrument to undergraduate and graduate research interns.
Collect data on the health of coral genotypes used in restoration while also training visiting scientists in the use of the Junior-PAM at Mote’s International Center for Coral Reef Research and Restoration.
Determine the effect of natural antifouling compounds on the health (i.e. photophysiology) and growth of Acropora palmata, a threatened coral species that is a major focus for coral restoration efforts.
Integrating the PAM Fluorometer into ongoing Mote research has provided early career scientists the experience of learning a cutting edge tool used for measuring coral health. Thus far, two Mote research undergraduate interns, one Mote post-graduate intern, and one Mote graduate
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intern have been trained in the use and application of the Junior-PAM in the Coral Health and Disease Program at Mote’s Sarasota facility (Figure 1). Hands-on experience with the equipment enabled these young scientists to deepen their understanding of coral physiology by making measurements and observing chlorophyll fluorescence with the Junior-PAM.
In October 2022, Mote hosted a Coral Restoration Workshop at its International Center for Coral Reef Research and Restoration in Summerland Key, Florida. Twenty-five international participants gathered to learn from Mote research on coral reproduction and outplanting as well as coral health and disease. For the coral health and disease component, Mote postdoctoral researcher Dr. Courtney Klepac set up a short-term thermal heat stress experiment, using the Coral Bleaching Automated Stress System (CBASS; see Figure 2). This experiment exposed restoration corals to specific temperature profiles across multiple tanks over a 4-hour period to identify differences in heat tolerance among corals. For this experiment, coral bleaching was measured through chlorophyll fluorometry using the Junior- PAM. The coral health and disease team has also used this instrument with school groups, visiting scientists, and participants interested in learning about coral bleaching and how to measure bleaching responses.
This equipment was also used in a study on the use of essential oils with potential anti-fouling properties in coral aquaculture (Figure 3). One of the challenges facing coral restoration practitioners is fouling – by algae and other organisms – that interferes with optimal coral growth in land-based nurseries. The objectives of this research were to 1) test the anti-fouling capabilities of two essential oils (lavender and cinnamon) both in isolation and in combination when used on ceramic plugs that serve as substrate for land-based corals in the grow out phase, and 2) determine their effect of these oils on the growth rate and health of Acropora palmata, an important species of coral used in reef restoration. Research was led by a graduate research intern who also analyzed and presented the data. The research found that the different essential oil treatments did not affect the photosynthetic efficiency of the Acropora palmata (Figure 4 Top). In contrast, there were significant differences in photochemical efficiency among genotypes of Acropora palmata (Two way ANOVA: p-value of <.0001 and F-value: 6.961; Figure 4 Bottom).
The results suggest that the essential oils did not harm the coral’s symbiotic relationship or ability of the symbiotic algae to photosynthesize. Since corals can get up to 95% of their energy from their symbionts, this result supports the safety of essential oils for use on the ceramic plugs used to grow out corals for restoration, but perhaps not the efficacy of doing so; the essential oils did not prevent fouling activity when tested.
1. Order and receive PAMs – completed July 2022
2. Test PAMs to become familiar with the instrument – completed August 2022
3. Train undergraduate interns in the use of the PAM to assess coral health – completed summer 2022 (see Figure 1)
4. Conduct experiments using PAMs to measure coral holobiont stress –completed November 2022 (see Figure 3)
5. Present findings at University of Miami Rosenstiel School – completed May 2023
6. Prepare and submit final report – completed May 2023
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1. Integration of PAM into student-led projects – completed
2. Spreadsheet of PAM data for Acropora palmata grown on ceramic plugs with different natural antifouling components: – completed (link)
3. Final report – completed
Thus far, the generous support from the Wolfgang Bosche Animal Wildlife Foundation has allowed Mote to train future marine scientists and conservation leaders while conducting essential Coral Health and Disease research that supports Mote’s science-based coral reef restoration program. Mote has been able to leverage the use of the purchased equipment when applying for new grants and planning future research projects, which further improves Mote’s ability to secure research support. These instruments are essential tools to quantify how corals respond to major threats facing coral reefs to better understand and protect these valuable ecosystems.
The Coral Health and Disease team at Mote sincerely thanks the Wolfgang Bosche Animal Wildlife Foundation for its contribution to coral reef research and restoration.