Comment on Shashar et al. Artificial Reef Deployment Reduces Diving Pressure from Natural Reefs—The Case of Introductory Dives in Eilat, Red Sea. Oceans 2024, 5, 71–80

1. Introduction

The recent publication “Artificial Reef Deployment Reduces Diving Pressure from Natural Reefs—The Case of Introductory Dives in Eilat, Red Sea” by Shashar, N. et al. (2024) [1] caught our interest. The study provides insights into the potential of Artificial Reefs (ARs) to mitigate diving pressure on natural reefs. Based on analyzing dive routes in Eilat, on the Red Sea, the authors claim that the deployment of a single AR (“Tamar Reef”) shifted introductory dive routes away from the natural fringing reef within a marine protected area (MPA). They suggest that this behavioral shift, which persisted for over a decade, highlights the potential of ARs as a conservation tool

2. Comments

While the study offers unequivocal conclusions based on interviews with dive guides, we believe that the evidence is largely circumstantial and inconclusive. Specifically, the two periods examined in the paper, <2006 and >2018, leave a lot of time in between when many other things occurred.

We suggest that the observed shift in dive routes can be attributed to factors beyond the AR’s deployment. Since 2011, the Israel Nature and Parks Authority (INPA) has implemented regular briefings in which a marine ranger meets with instructors from diving clubs in Eilat and presents principles for responsible diving. Among other things, the ranger presents a map showing diving areas suitable for different types of diving (Figure 1). Note that the figure explicitly requires that introductory dives be conducted in two defined areas, one of which is outside the MPA in the area where the AR is located (marked by a yellow star) and the other of which is an area inside the MPA where there is a robust sandy area, following the recommendations of Zakai and Chadwick-Furman (2002) [2]. These briefings request that dive instructors avoid conducting introductory and trainee dives within the MPA. Therefore, the observed shift in dive routes is likely a result of these educational efforts, rather than solely the presence of the AR. It is important to note that the division into diving areas is not strictly mandatory, but most dive guides openly sympathize with the desire to protect the coral reefs in Eilat and therefore comply.

In addition, evidence for the link between diving routes and diving pressures is inconclusive. ARs can attract more divers to the area overall, which may not necessarily reduce the number of divers on natural reefs [3,4]. Indeed, this is a point made in the paper, where the authors note the potential economic benefits of ARs. The authors state in their discussion that this AR did not increase the overall number of dives in the area because (1) it is too small to become a focal point of diving by itself, and (2) locations to be visited during introductory dives are commonly determined by the dive guides. These assumptions need to be supported by data. Regarding the first one, a quantitative examination of the number of divers in the area before and after the deployment of the AR is necessary, especially because the AR—Tamar Reef—is well marketed as a diving site and there is even a children’s book written about this AR (“Tamar’s Reef”) with impressive photographs and illustrations [5]. Regarding the second assumption, the diving guides indeed determine the route once their services are engaged, but the diver’s decision on the diving location probably depends, among other things, on the advertised diving attractions there.

As for the strength of any general conclusions, the authors have based their study on only a single AR (i.e., n = 1). Repetitions are necessary in order to generalize the results to ARs in general. Moreover, there is a very large gap in the data presented during the years 2006–2018; many things may have happened that could have influenced a change in dive routes. Apart from INPA’s efforts to educate diving instructors (see above), there has been an overall increase in awareness of environmental issues that has probably led to more responsible diver behavior. Additionally, damage to the fringing reef due to floods, extreme low tides (e.g., Figure 2) and storms could have caused changes in the diving habits of dive instructors, because it is likely that they prefer to lead the divers to the more beautiful and less damaged areas of the reef.

3. Conclusions

While ARs can be a tool for reef conservation, we believe that to effectively reduce diving pressure on natural reefs, the deployment of ARs is not sufficient; such initiatives need to be part of a comprehensive dive management strategy. Goals for deploying ARs should be clearly defined, and effective, well-designed monitoring has to assess relevant success indicators not only after, but also before deployment. These have to include some objective natural measures of the benefits to the reef, in addition to changes in diving habits. It will then be possible to confidently determine whether ARs achieved their declared goals. As it is, we are not convinced that the Tamar Reef has indeed reduced diving pressure on the natural reef.