The Hawaiian Koʻa Card: coral health and bleaching assessment color reference card for Hawaiian corals

Abstract

Coral reefs are the foundation to our social, cultural, and economic life; however, reefs around the world are currently being threatened by many local and global impacts. Ongoing increases in seawater temperature pose significant threats to the integrity of these valuable ecosystems through extensive coral bleaching events. Therefore, we developed a coral health reference card, the Hawaiian Koʻa (coral) Card, to assess and quantify coral bleaching and to educate the community about its impacts in Hawai‘i. To accurately quantify the change in coral color during bleaching, controlled laboratory studies followed by field validations and surveys were conducted. Colors presented on the Hawaiian Koʻa Card have been linked to physiological state and health (e.g., symbiont density, chlorophyll levels, photosynthetic performance) of common coral species in Hawaiʻi due to bleaching. The Hawaiian Koʻa Card provides a technical solution to inform and improve management of our nearshore resources through collaborative monitoring efforts by community members, educators, researchers, and managers on a state-wide scale, which will assist in determining management efficacy, identifying regions and species of resilience, establishing baselines and focus areas, and developing and executing rapid response plans.

Metrics of Coral Microfragment Viability

“…For subsequent bleaching treatments, the combination of menthol and light was used. Before the bleaching treatment, microfragments were imaged, assigned a health score (Table 2), and given a color rank assessed by Ko a Card (Bahr et al 2020) in order to determine any change in health during the bleaching process. During the day, microfragments were placed in aerated, 2 L aquaria with 0.58 mM menthol (99%, Sigma Aldrich, St. Louis, MO) in ethanol (190 proof, Decon Labs, Inc., King of Prussia, PA) in filtered seawater with aeration for approximately 6-7 h, 26 °C, ~5 PAR.…”

High-frequency imagery to capture coral tissue (Montipora capricornis) response to environmental stress, a pilot study

“…Compared with existing methods based on long-term recordings and color reference cards to extract color information [10,11,[15][16][17][18][19][20], we focus more on the dynamics of the coral system and deliberately set the frequency of recording according to the tissue motion of Montipora capricornis [21]. Without the adequate frequency of recording, the trends for dominant color and correlation coefficient variations would be similar but the high-frequency information would be lost, resulting in the incorrect characterization of the dynamics of coral tissue response.…”

“…To date, qualitative and quantitative methods have been developed to monitor coral tissue response, where color is an important information. Therein, qualitative methods mostly rely on visual assessment of coral color change and visual comparison between coral color and color cards, which are convenient and easy to operate [10][11][12]. They can provide general information about coral color and health.…”

Examining the UV-Absorbing Properties of Scaevola taccada (Goodeniaceae) and Its Potential Use as a Sunscreen

“…This process allowed us to accurately compare fragments before and after treatment and assess the damage from the treatments. The photos were taken using an Olympus Tough TG-4 camera (Olympus, Tokyo, Japan) and the Hawaiian Ko'a Card for color reference (Bahr et al 2020). Computerassisted photo analysis (NIH ImageJ) was used to measure changes in color in the treatment areas.…”