New Saltwater Systems Help Scientists Understand What Makes Corals Resilient

FLORIDA—In a Dec. 3 news release, The National Oceanic and Atmospheric Administration (NOAA) announced scientists at NOAA’s Southeast Fisheries Science Center partnered with the University of Miami to build a coral cultivation and research facility. The facility will help advance NOAA’s ability to restore corals on Florida’s reefs. Controlled variables such as temperature, light, and salinity will enable scientists to understand better what ingredients contribute to more resilient corals.

 

Corals in the wild are threatened by everchanging and uncertain ocean conditions and stressors associated with coastal population growth, such as nutrient pollution and sedimentation. Scientists know that specific changes, such as warming ocean temperatures, threaten coral more than others. However, determining how and why some corals can survive these stressors is more challenging.

 

The Coral Research and Assessment Lab (CoRAL) team at NOAA built a series of three indoor seawater systems at the University of Miami Experimental Hatchery in Key Biscayne. The workspace serves as a strong improvement in NOAA’s ability to address numerous gaps in knowledge and advance methods to restore resilient coral populations. In addition, having these systems allows for new and longer-term research that was previously impossible.

 

The first step in NOAA’s system is a space that was created to facilitate larval settlement and breed young corals, or “recruits.” Next, NOAA will need a space for the corals to grow. NOAA has a set of large tanks with flow-through seawater that can support hundreds to thousands of corals at multiple life stages whether its recruits, juveniles, or adults; these systems are temperature-controlled and fed by filtered and UV-sterilized seawater. This system decreases the likelihood of accidental disease or the introduction of unwanted organisms.

 

The CoRAL team is building an experimental collection of 30 20-gallon aquariums to accommodate these coral propagation systems. NOAA will use these aquariums to conduct experiments using corals and reef-associated organisms, such as fish, crabs, and urchins. NOAA will manipulate temperature, light, and water flow in these tanks.

 

According to NOAA, access to corals and aquariums that can house corals is often the limiting factor for researching coral species. For example, in the past, NOAA would rent space for 1–2 months during peak spawning time and collect gametes (a mature haloid male or female germ cell); then, NOAA would conduct short-term (days to weeks long) experiments in temporary systems and share the majority of larvae with partners and could only keep coral recruits for 1–2 months.

 

The ability to breed corals produced from NOAA’s coral spawning operations allows NOAA to identify resilient individuals and restore genotypically diverse populations. This is a primary goal of recent coral restoration efforts. The experimental tank system also increases the quality and quantity of NOAA’s research. It also allows their team to better address urgent questions about threatened coral species and coral reef restoration.

 

NOAA is already rearing thousands of recruits from seven different coral species within six months. These species include several Endangered Species Act-listed coral species such as elkhorn, staghorn, and mountainous star coral.

 

Caption 1:  The first step is to collect coral spawn. Two ESA listed species that NOAA regularly monitors and collect from, Acropora palmata and Orbicella faveolata.  Collection nets are placed over the coral, and once “bundles” are released from the coral they float towards the surface and collect in the collector cup positioned at the top of the net.  Collector cups are brought up to the boat where gametes are mixed, and the fertilization process begins.