2019 Coral Bleaching Event

   
As you may have already heard, we are currently experiencing widespread coral bleaching in Hawaiʻi that is predicted to get worse in the coming months. This is the 3rd bleaching event in the past five years, which is not normal. Widespread coral bleaching is primarily caused by warm water events resulting from the ocean absorbing high levels of greenhouse gas emissions.
 
The Gates Coral Lab at the Hawaiʻi Institute of Marine Biology (HIMB) is actively testing techniques from the assisted evolution toolkit we developed over the past 4 years alongside high-resolution monitoring to provide broader context and to enhance reef resilience. 
 

Projects and Activities

High Resolution Monitoring   


This year we formed a collaborative team (co-led by the Madin and Gates Coral Labs) to record coral bleaching and recovery over time at 31 sites in Kāneʻohe Bay using 3D photomosaics (covering ~120m2). We will use this data to answer questions about structure, fish communities and how small differences in historical temperatures at different reefs protect against or exaggerate bleaching through conditioning or local adaptation. We have historical temperature data from these sites in addition to tagged Montipora capitata colonies that have been monitored over time as part of our "living library". The Gates Coral Lab has collected coral samples, water samples and measured water chemistry while our collaborators monitor fish camera traps, conduct microbial sampling and use eDNA to assess cryptic diversity. Surveys will be completed bi-weekly until the end of 2019 or when corals have had time to recover from the bleaching event (for those colonies that have the ability to recover).
Monitoring reefs in Kāneʻohe Bay. Photos: Josh Madin Lab, HIMB
Acclimatization / Conditioning Experiments  
   
We initiated a large-scale conditioning study in May 2019, before coral bleaching was observed in the field. Corals (Montipora capitata) from 10 different genotypes were pre-conditioned under different thermal stress profiles and are now experiencing a realistic bleaching event. We are examining how this conditioning will influence bleaching and if it is a viable approach for future management efforts.

   
We are also investigating how pre-conditioning impacts the larvae of this same coral species. In July 2019 we reared and settled thousands of larvae under different temperature treatments. This bleaching event will test whether changes in larval development occurred by observing the bleaching response of the (now juvenile) corals.    
Selective Breeding  

We are monitoring 1-year-old selectively bred (from thermally tolerant parents) Montipora capitata juveniles and comparing them to 1-year-old wild type juveniles to examine the downstream consequences of selective breeding for thermal tolerance. This experiment will evaluate the longer-term impacts of selecting for thermal tolerance traits as well as explain some of the mechanisms that drive this response.
Coral Bleaching Mechanisms 

We are using techniques from human cancer research to identify the individual molecular mechanisms behind coral bleaching and testing inhibitors that may induce or prevent bleaching effects in the future.
    
Conducting acclimatization and conditioning experiments. Photos: Jenna Dilworth
   
We are currently monitoring corals at our future restoration sites across Oʻahu, Mauʻi and Hawaiʻi Island. At the height of the bleaching event (potentially late October based on  current projections ), we will tag and/or use 3D photomosaics to identify the colonies that did not bleach as a potential source of material for future restoration efforts. Active restoration will begin this Winter 2019/Fall 2020 when thermal stress is no longer a threat to corals in the field.
    
    
Monitoring selectively bred juvenile corals on the confocal microscope. Photo: Ariana Huffmyer

How can YOU get involved?  

Avoid adding more stress to corals!
   
  
Report coral bleaching in your area!
   
There are a few options based on the data you have available:

1) Do you have 2 minutes, latitude/longitude values, and a confirmed incidence of coral bleaching? Please report your observations to the
Hawai'i Coral Bleaching Tracker . Your report will help calibrate satellite observations and will complement satellite data collected throughout the event.

2) Are you able to provide more details (coral type or species, bleaching severity, depth patterns, images to share)? Please report your observations to Eyes of the Reef . Your more specific observations are extremely valuable for tracking bleaching susceptibility across coral types. Your submitted images also allow reef managers to verify bleaching occurrence in your area.

3) Are you using the Koʻa Card (color wheel) for estimating coral bleaching severity in your area? Report your findings to either Hawai'i Coral Bleaching Tracker OR Eyes of the Reef . Koʻa cards are available for pick-up for FREE at your local DAR office.
  
Using a Koʻa Card to quantify coral bleaching levels. Photo: Eva Majerova

Funding Agencies