Healthy Reefs Make More Baby Corals

Published 2017-10-24

Photo: Kristen Marhaver

A new study found that healthy reef coral populations are an important source of the next generation of corals. The study, published in Conservation Letters reports that healthy coral populations produced more offspring per square meter than nearby degraded reef sites.

The authors of this study measured live coral cover as a metric of the health on 6 reef sites on the island of Curacao in the Caribbean. Three of the sites were located in an undeveloped area of the island while the other three were in an urban area with higher human impact. The researchers then measured fecundity of parental coral colonies by counting the number of larvae released from three different species of corals at each site. They found that coral parents from healthier reef communities produced about four times more larvae per square centimeter area of tissue than parents from the degraded sites. This translates to more than 200 times more larvae per square meter of healthy reef area. Interestingly, these parents also released higher quality larvae with more lipid energy reserves.

This study highlights that reproduction is not necessarily proportional to the coral cover on a reef, but rather than healthy populations play a very large role in producing coral offspring. Therefore, the ecological value of these remaining healthy reef communities may have been underestimated in the past.

Journal Reference:

Aaron C. Hartmann, Kristen L. Marhaver, Mark J. A. Vermeij. Corals in Healthy Populations Produce More Larvae Per Unit Cover. Conservation Letters, 2017; DOI: 10.1111/conl.12410