For The Restoration Of Coral Reefs

Coral reefs are found throughout the world and are widely known as being the most biologically diverse and richest of all marine ecosystems; because of that matter, they are often referred to as the “Rainforest of the Sea.” Healthy coral reefs serve as reservoirs of biological diversity supporting shelter and protection for large numbers of marine species. However, coral reefs are in great danger and many are on the verge of destruction. Due to many threats such as increased climate change, ships sailing across the oceans, tourism, and pollution, coral reefs are declining continuously. Florida’s reefs major human impact is caused by ships running into reefs and dredging for beach re-nourishment and channel maintenance (Jaap 2000).

According to Omori (2010), 19% of the worlds coral reefs have been destroyed and show no immediate prospects of recovery, and a further 15% are under imminent risk of collapse within 10-20 years. The study of restoring depleted reefs is important not only to the several species that are dependent on these creatures, but they play a huge role to mankind economically. Decreasing the quality and quantity of species’ reproduction process inevitably causes a breakdown in the ecosystem. The fertilization limitation of Diadema antrillarum on coral reefs in the Florida Keys was investigated by Feehan (2016) to determine whether the populations were limited by fertilization due to the dynamics of previous reoccurring disease outbreaks. Prior to these outbreaks, there was an abundance in spawning sea urchins. Since the disease outbreak in 1983 and 1991 scientists have seen populations of the herbivorous urchin D. antillarum dramatically reduced in the Florida Key’s.

Unfortunately, due to species in this region showing seldom recovery it has contributed to an increase of reduction of coral recovery. Therefore, it is critically important to maintain recovery for restocking reefs in the Florida Key’s. To examine fertilization success, scientists did a series of studies to assess the general hypothesis. Urchin reproductive health was addressed through the usage of a coupled advection-diffusion and fertilization kinetics model, testing their hypothesis and model predictions in spawning marine invertebrates’ fertilization success. Using the advection-diffusion equation they were able to determine the amount of sperm released at a given rate. This was calculated by using the formula Qs=SV/T and the fertilization kinetics model predicted the number of eggs fertilized. Together they combined both models of sperm-egg contact to examine variability in population parameters.

Once all data was obtained scientists discovered that following the first epidemic in 1983, D. antillarum male density has declined drastically from 1 or 10 to 0.1 males/m^2 and the fertilization success of female egg released decreased from 96% to 27%. This resulted in an additional decline following the second outbreak in 1991, dropping from 0.1 to 0.01males/m^2. Showing density to be positively correlated with reef complexity. These results indicated that in order to achieve a high fertilization success of the species D. antillarum the order of magnitude must increase in density.

After conducting a series of simulations to test the hypothesis of whether populations of D. antillarum were fertilization-limited, scientists concluded from their models that fertilization success in the Florida Key’s has declined significantly. Resulting in their hypothesis to be tested true. Using the models presented, they found fertilization success dropped to 3% following recurrent epidemics in eight years. Both of these recurrent disease outbreaks contributed to generational reproductive failures thereafter. To enhance fertilization success, scientists believe these species should be time controlled in a stocking density until fertilization can occur. It is not determined when population recovery should happen due to models being solely based on only sperm contribution. Ultimately, scientists believe that their results can aid in recovering reef habitats located in the Key’s by providing densities of D. antillarum needed to have fertilization success.

After doing on coral reef restoration I did not realize how much humans impacted and opposed threats to many coral reefs around the world. As an angler myself, I never took into account the impacts overfishing had and how it played a huge role in certain ecosystems. With that being said, fishing regulations should be more enforced and people should start giving more passion to change current situations. Although trophy fishing may be fun, fish play a vital role on the restoration of coral reefs and with certain fish captured in large numbers can contribute to inhibiting coral growth and recovery due to overgrowth of macro-algae. In the study I observed I believe the scientists helped aid in better understanding the factors that play a role in recovering reef habitats. Although, their models should have been based on sperm and egg contribution to predict when population would possibly recover. For this trend to decline we must get involved to help protect our beautiful reefs from diminishing as they not only serve a significance to marine life but to humans as well.