Coral spawn.</p>

Coral spawn.

	REU Intern taking measurements in the coral lab.</p>

REU Intern taking measurements in the coral lab.

In the last few decades, threats to coral reefs have increased through human impacts and climate change. Unfortunately, sub-lethal stress caused by changes in the ambient environmental conditions (e.g., increased water temperature, sedimentation) has been shown to cause significant changes in the reproductive activities of many corals as resources are diverted to maintaining other life functions. Successful coral reproduction is essential for the addition of new colonies to a reef, the colonization of new areas, and the regeneration of areas damaged by natural or human disturbances.  Therefore, an understanding of coral reproductive cycles and recruitment is an important component of our knowledge base on the ecological processes of coral reefs and, as such, is necessary for their management and preservation.

The corals of Bermuda are of particular interest to reproductive and recruitment studies since the isolation and low winter seawater temperature mean that many species are at their distribution extreme and experience a wide variation in environmental parameters compared to reefs in the lower Caribbean.  Bermuda’s high latitude reefs will also be some of the first to experience the changes associated with ocean acidification (OA), and so are the ‘canary in the coal mine’ for OA studies.  The reefs also serve as an excellent natural laboratory for OA studies as there are spatial and temporal changes in seawater chemistry across the various reef zones. In addition, Bermuda is a geographically isolated reef system and is therefore likely to experience only sporadic larval contribution from distant reef systems, meaning that recovery is dependent on the existing corals in the immediate locality. Understanding and documenting coral reproductive cycles and recruitment is vital when considering reef recovery, development and resistance.

Research by The Coral Reproduction and Recruitment Lab at BIOS includes:

  • The effects of environmental parameters (e.g., seawater temperature, lunar cycle, diel cycle) on coral reproductive cycles
  • An investigation on the effects of ocean acidification, temperature, light, and nutrients on coral settlement and early calcification by new recruits
  • Coral recruitment and population dynamics