Fiona Pfäffli

The United Nations named their goal number 14 “life under water”. However, research shows that there is not much life left in underwater coral reefs and the little there is, is directly threatened by human action. In the following essay I will lay focus on the situation of the coral reefs on Reunion Island. I will examine the condition of the island’s coral reefs and the reasons for their critical state. To do so, I will first of all examine the issue of protected areas. In a second step the subject around shark control measures will be discussed to finally adress internal and external factors that menace these reefs.

Figure 1: Coral reef on Reunion Island (Réserve Naturelle Marine de la Réunion, 2022).

Global state of coral reefs and the role of France

One of the most vulnerable under water habitats are coral reefs. They are threatened by a combination of factors related to climate change, overfishing and direct physical destruction. To name a few, there are the dangers of ocean warming, acidification, eutrophication and the expansion of dead zones (Altieri et al., 2017; Harmelin-Vivien, 1994; Szmant, 2002; United Nations, 2021). These threats are so severe, the destruction already so advanced that the United Nations (2021) predict the extinction of coral reefs in tropical and subtropical areas by 2050 if the emissions of greenhouse gases are not substantially reduced. However, it is not only a question of global warming to protect these areas, the concerned states in which coral reefs are found play a crucial role in protecting them. One might think primarily of tropical paradises like the Maldives, Fidji or Australia when talking about coral reefs. Nevertheless, also European Nations and mainly France has a considerable area of coral reefs within its territories. The French coral reefs make up 10% of the worldwide distribution of the latter (Lemahieu et al., 2013).  Amongst others on Reunion Island, where the state of the latter is rather critical. Whereas most of France’s coral reefs in the Pacific and Atlantic Ocean (Guadeloupe, Martinique, Saint Barthelemy) are protected, the situation in the Indian Ocean is different. Although Mayotte’s reefs profit from the big Marine Nature Park, similarly the areas around Europa Island and Reunion Island have no coherent protected reserve around. The reefs are not protected in a coherent area, with some areas not benefitting from protection at all (cf. Arizona State University, 2021; protected planet, 2022).

Issues of Reunionese coral reefs 

First of all, there is the issue of a protected marine area. Even though Reunion Island does have such a protected marine park it does not cover a coherent area (protected planet, 2022). Research clearly shows that a fragmentation of protected areas is not favourable to the protection of the latter. If the patches protected are too small, the effects on its borders overweigh their benefit (Buser Moser, 2020). Consequently, the reef on Reunion Island is not sufficiently protected, even though a marine park covers almost 80% of it (Réserve Naturelle Marine de la Réunion, 2022) .

Additionally, there is the issue of an apparent shark crisis on Reunion Island. The territory has, for over a decade, been going through a period of repeated fatal shark attacks. To tackle the issue several drastic measures were put in place, amongst others, the targeted hunt of certain big shark species, such as the bulldog shark. This intervention might have dramatic consequences on the health of other ecosystems, especially the coral reefs. Since young sharks getting into the reef and especially reef sharks are responsible for regulating population within the reef, the community composition of the reef might be disturbed by external hunting. Research on this point is still weak and the causality of the two phenomena is still disputed within the scientific community (Lemahieu et al., 2017).

Finally, the overall condition of the reef is quite poor with 65% of it threatened. Its bleaching degree is moderate to severe (Arizona State University, 2021). One might say that this goes with an overall trend, since globally their condition did not improve since 2010, however, Reunion’s coral reefs seems to be particularly impacted (United Nations, 2021). Although not all the specific threats that threaten Reunion’s reefs are France’s fault, there are some that could be blamed quite directly to the nation. There is the significant point of physical destruction by tourists. As one can observe, the badly informed tourists and locals walk over the delicate area with protective shoes and destroy a considerable amount of the coral. One might call this an internal factor, together with overfishing and poor waste management. However, there are also external factors that specifically threaten Reunion’s reef where France has very little influence. This includes rising water temperatures and, mainly, destructive cyclones (Harmelin-Vivien, 1994; United Nations, 2021).

Tackling the knowledge gap

The UN addresses reasons why there could be knowledge gaps concerning coral reef protection. They suspect that too little research means that the effects of human activities cannot yet be correctly assessed. Thus, the affected countries and their delegates may not have recognized the seriousness of the situation. The UN also thinks that the value and service of the coral reef ecosystem is not correctly accounted for. Thus, the cost-benefit calculations for development projects that protect coral reefs are not always accurate (cf. United Nations, 2021).

Take home message

One can conclude that Reunion’s coral reefs are in a poor condition which is partly due to a non-coherent protected area, a disputable management of a shark problem, a lack of knowledge amongst the population and intense cyclones (Harmelin-Vivien, 1994; Lemahieu et al., 2017; United Nations, 2021). It is quite astonishing that one of the richest nations in the world protects its reefs more poorly than less developed countries such as the Seychelles (United Nations, 2021; Arizona State University, 2021; protected planet, 2022). It is therefore crucial to tackle the United Nations goal number 14 not only by addressing developing countries and supporting them but also by reminding wealthier countries of the duties and responsibilities they have.

For a further paper it would be interesting to analyze the condition of Mayotte’s coral reefs to compare them with, for example, the Comoros. The two territories are geographically very similar but politically fairly different. A comparison between these two might bring answers to the questions raised in this essay.

References

Altieri, A. H., Harrison, S. B., Seemann, J., Collin, R., Diaz, R. J., & Knowlton, N. (2017). Tropical dead zones and mass mortalities on coral reefs. Proceedings of the National Academy of Sciences of the United States of America, 114(14), 3660–3665. https://doi.org/10.1073/pnas.1621517114

Arizona State University. (2021). Allen Coral Atlas. https://allencoralatlas.org/atlas/#2.96/-50.0628/-49.7440

Buser Moser, C. (2020, December 7).  Lecture in ecology “Praktischer Naturschutz”. ETH Zürich.

Harmelin-Vivien, M. L. (1994). The effects of storms and cyclones on coral Reefs: A Review. Journal of Coastal Research, 12, 211–231. http://www.jstor.org/stable/25735600

Lemahieu, A., Blaison, A., Crochelet, E., Bertrand, G., Pennober, G., & Soria, M. (2017). Human-shark interactions: The case study of Reunion island in the south-west Indian Ocean. Ocean and Coastal Management, 136(October 2021), 73–82. https://doi.org/10.1016/j.ocecoaman.2016.11.020

Lemahieu, A., Pennober, G., David, G., Lavigne, F., Pothin, K., & Gérard, L. (2013). Élaboration d’un protocole de suivi de la fréquentation au sein de la Réserve naturelle marine de la Réunion, France, Océan Indien. Http://Journals.Openedition.Org/Vertigo, Volume 13 Numéro 1. https://doi.org/10.4000/VERTIGO.13379

protected planet. (2022). Protected Areas West Asia. https://www.protectedplanet.net/region/WA

Réserve Naturelle Marine de la Réunion. (2022). La Réserve Naturelle Nationale Marine de la Réunion. https://archive.wikiwix.com/cache/index2.php?url=http%3A%2F%2Fwww.reservemarinereunion.fr%2FIMG%2Fpdf%2Fexposition_rnmr.pdf%2Findex.html#federation=archive.wikiwix.com

Szmant, A. M. (2002). Nutrient Enrichment on Coral Reefs : Is It a Major Cause of Coral Reef Decline? Estuaries, 25(4), 743–766.

United Nations. (2021). The Second World Ocean Assessment. I, 570. https://doi.org/10.4324/9781315626932