Coral Management And Conservation

Coral reefs around the world have suffered immensely from the human-induced stressors described earlier. However, studies suggest that coral reef conservation and restoration practices can help prevent further coral reef degradation (Spalding et al.2001). Conservation efforts such as the creation of marine protected areas and no-take zones on degraded coral reefs and the establishment of laws that mitigate human-induced impacts such as pollution and sedimentation, can prevent further coral reef degradation (Spalding et al. 2001).

A study conducted by Selig and Bruno (2010) found that coral reefs in marine protected areas (MPAs) and no-take zones had higher coral cover than those in unprotected areas. This study also found that coral cover on marine protected sites remained static over time but decreased on coral reefs in unprotected areas (Selig and Bruno 2010). Other regulatory practices that help prevent further coral reef degradation include those that reduce rates of sedimentation from coastal development, that regulate boating and recreational activities that physically damage corals and that prevent human and agricultural pollution from reaching coral reefs (Spalding et al. 2001).

Active restoration

Within the past 40 years, the structural complexity of Caribbean coral reefs has declined dramatically. This decline has been attributed to the loss of architecturally complex branching corals, Acropora cervicornis and Acropora palmata in the 70’8 and 80’s, and massive reef-building corals such as Orbicella annularis, Orbicella faveolata and Orbicella franksi in the 2000s, due to disease, climate-driven bleaching, and other factors (Alvarez-Filip et al. 2008). In contrast to the decline seen in species of Caribbean reef-building corals, small, weedy coral species have increased in abundance on reefs throughout the Caribbean region (Green et al. 2008, Alvarez-Filip et al. 2008; Edmunds 2010).

Because of their short life-histories and small size, weedy corals do not provide the same ecological services that Acroporid or Orbicellid corals provide such as habitat complexity, shoreline protection and contributions to reef growth (Alvarez-Filip at al. 2009; Newman et al. 2015; Hesley et al. 2017; Status of Puerto Rico’s Coral Reefs in the Aftermath of Hurricanes Irma and Maria).

Within the past two decades, scientists have turned to active coral restoration techniques specifically coral gardening (the process of growing coral fragments in in-situ or ex-situ nurseries), as a means to re-establish certain populations of coral species on heavily degraded reefs (Edwards 2010; Lirman and Schopmeyer 2016; Hesley et al. 2017). The majority of coral propagation programs have focused on growing and transplanting branching coral species specifically those in the Acropora genus (Hesley et al. 2017; Lirman and Schopmeyer 2016; Levy et al. 2018). This is due to the fact that these corals are easy to fragment (fragmentation is an important component of their reproductive life-history strategy) and have rapid growth rates (Lirman and Schopmeyer 2016). In addition, Acroporid corals play a fundamental role in coral reef formation and structure (Acropora Biological Review Team 2005).

Over the past 20 years, scientists have investigated the best possible restoration methods needed to successfully fragment, rear and transplant Acroporid corals onto degraded Caribbean reefs (Lirman and Schopmeyer 2016; Levy et al. 2018). Although transplant survivorship is highly dependent upon local coral reef conditions and genotypic variability, results from various studies suggest that active restoration using Acropora species can be a successful re-population strategy (Schopmeyer et al. 2017; Hesley et al. 2017; Levy et al. 2018).

Despite their ecological significance and substantial contribution to coral reef structural complexity, active restoration techniques using massive reef-building coral species have been less explored (Lirman and Schopmeyer 2016; Levy et a. 2018). This is due to fact that species of massive corals are harder to fragment and have slower fragment growth rates than Acroporid corals (Lirman and Schopmeyer 2016; Levy et a. 2018).

However, within the past few years, scientists have discovered that by cutting fragments into 1cm² pieces, a process termed “micro fragmentation”, fragment growth rates can been accelerated in massive coral species (Forsman et al. 2015; Lirman and Schopmeyer 2016). The process of “micro fragmentation” was accidentally developed by Dr. Vaughan who found that coral fragments approximately 1 cm² is size grew four times faster than larger fragments from the same species (Page 2015). This technique has been so effective that in 2012, Dr. Vaughan and his team successfully produced 700 coral fragments in just a few weeks using micro fragmentation (Page 2015).

Although a new method, a study conducted by Forsman et al. (2015) found that tissue growth in massive corals can be accelerated through the micro fragmentation method. In addition to accelerated growth rates, micro-fragments from the same colony have the ability to fuse with one another through self-self recognition. By fusing many micro-fragment together, larger fragments can be produced and transplanted to degraded reefs in a short period of time (Forsman et al. 2015; Page 2015).

Over the past couple of decades abundances and coral cover of massive reef-building corals, specifically species in the Orbicella genus, have declined dramatically on reefs throughout the US Virgin Islands (Edmunds 2013; Edmunds and Elahi 2007). These corals were severely impacted by Hurricanes Irma and Maria in September of 2017. Out of the 1,548 colonies of Orbicella annularis surveyed, 43% showed signs of storm damage (Assessment Report Submitted by NOAA to the FEMA Natural and CulturalResources Recovery Support Function).

It has been suggested that within the next 50 years, these corals may become locally extinct on many reefs in the region (Edmunds 2013; Edmunds and Elahi 2007). If these species are locally extirpated from the region, the ecological and socio-economical impacts will be substantial (Alvarez-Filip et al. 2009; Edmunds 2013; Newman et al. 2015). Therefore, it is imperative that active restoration techniques such as micro fragmentation, are used to help restore these ecologically important species on coral reefs in the US Virgin Islands.