Seabird-Derived Nutrients Supply Modulates the Trophic Strategies of Mixotrophic Corals

The ability of corals to modulate their nutrition strategy in response to variable nutrient supply remains poorly understood, limiting our understanding of energy flow in coral reef ecosystems and thus our comprehension of their resilience to global changes. We used a naturally occurring nutrient gradient along the reef flat of two seabird-inhabited islets in the SW Pacific to characterize spatiotemporal fluctuations in coastal nutrient availability, and how it modulates the trophic response of the mixotrophic coral Pocillopora damicornis. The clear gradients in dissolved [NOx] and δ15N values of macroalgae and both P. damicornis tissues and symbionts observed along the reef flat during the dry and the rainy season revealed that seabird-derived-N is supplied year-round to the reef flat. Yet, nitrogen isotope values of macroalgae show that the seabirds’ effect on coral reefs varies with sites and seasons. Metrics derived from the SIBER framework revealed that coral nutrition seasonally favored autotrophy when exposed to higher seabird guano concentrations and at inshore stations, while heterotrophy dominated in corals less exposed to seabird-derived nutrient supply. P. Damicornis is therefore able to cope with large changes in nitrogen supply induced by seabird island communities by switching between autotrophy and heterotrophy. These results shed light on the flexibility of resource sharing within the coral-algae symbiosis and highlight the importance of seabird populations to the functioning of coral reef ecosystems.

Kondisi Terkini Presentase Tutupan Terumbu Pada Masa Pandemi Covid-19 di Gili Air, Taman Wisata Perairan Gili Matra, Nusa Tenggara Barat

Gili Matra Aquatic Tourism Park has two conservation targets, namely biological targets and social, cultural and economic targets. Coral reef ecosystems, apart from being a conservation target, are also an attraction for tourists to visit. This research was conducted to determine the condition of the coral reef ecosystem to be used as the basis for the management of conservation areas. The research was conducted by collecting coral reef data either through surveys or secondary data from the results of previous studies. Coral reef survey using the standard Line Intercept Transect method. The survey results show that the condition of coral reefs in the utilization zone is better than the core zone. Live coral cover in the utilization zone reached 71% so it was categorized as good, while in the core zone it only reached 8% so it was categorized as bad. Coral reefs in the core zone are unable to recover even though the number of tourists has decreased during the Covid-19 pandemic. Therefore, the location of the core zone on Gili Air needs to be evaluated further so that the effectiveness of Gili Matra TWP management can be improved. Key words: coral reefs; Gili Matra; Conservation

Exploring the Lack of Funding for Coral Reef Research and it’s Effects on Coral Reef Management and Conservation

Climate change is greatly harming coral reefs (Gibbs and West, 2019). It is important to research how to help these coral reefs build resilience against climate change but research programs are severely underfunded (Johnston et al. 2020). This paper explored how lack of funding prevents scientists from saving coral reefs and how scientists themselves can be affected. The goal of this paper was to bring to light the struggles faced in the midst of underfunding to feasibly gain support from politicians and government officials to promote funding for these programs. Through three virtual interviews with two scientists and one college professor, I gathered personal experiences from these participants on how coral reefs are being affected today, why research is necessary, and how lack of funding prevents the restoration of these reefs. With the use of a thematic analysis, I was able to recognize common themes between the interviews in order to conclude how lack of program funding prevents scientists from managing and restoring these coral reef ecosystems. The initial assumption for this paper was that coral reef research is underfunded because coral reefs are considered less important, however, the analysis of the data for this paper concluded that all research programs are underfunded. In essence, marine biology, in general, is underfunded as opposed to mainly research on coral reefs. As a result, scientists can be very limited in their abilities to conduct research.

Restaurant decision-maker perceptions of barriers and opportunities for invasive lionfish consumption

Lionfish (Pterois volitans, Pterois miles), invasive coral reef fishes in the western Atlantic, cause extensive negative impacts to marine ecosystems. Following their introduction in Florida in the 1980’s, lionfish colonized numerous coral reef ecosystems and have been documented at depths ranging from 1-300m. In addition to depleting native reef fish biomass and threatening macroalgae induced phase shifts on shallow reefs, the invasion of lionfish has caused severe economic damage in the form of reduced native fish yields for local fisher people and high costs of management. While few examples exist of successful management of marine invasive species, studies have shown that lionfish removal can decrease their density and increase prey species biomass. A critical component and challenge for any effective lionfish removal effort is to maintain consistently high levels of lionfish harvesting so as to reduce lionfish abundance to levels that mitigate their negative ecological impacts. One popular market-based option that may achieve this is increasing the demand for the consumption of lionfish. This management solution offers potential benefits to both human livelihoods and marine ecosystems. Our study focuses on Florida’s consumptive lionfish market and fills a gap in understanding the lionfish supply chain for Florida’s restaurant industry. Although lionfish are commercially available in Florida, they are not currently widely consumed with consistency. We conducted interviews with twenty restaurant decision-makers in FL to understand their perceptions of barriers and opportunities for increasing their use of invasive lionfish. The most commonly identified barriers were: price and consistency of supply, while the most prominent opportunities were: improved awareness and culinary potential to increase the demand for lionfish. Conservation managers and policymakers should leverage these findings to facilitate opportunities, address barriers, and promote public education about invasive lionfish and their impacts.

Regime shifts on tropical coral reef ecosystems: future trajectories to animal-dominated states in response to anthropogenic stressors

Despite the global focus on the occurrence of regime shifts on shallow-water tropical coral reefs over the last two decades, most of this research continues to focus on changes to algal-dominated states. Here, we review recent reports (in approximately the last decade) of regime shifts to states dominated by animal groups other than zooxanthellate Scleractinian corals. We found that while there have been new reports of regime shifts to reefs dominated by Ascidacea, Porifera, Octocorallia, Zoantharia, Actiniaria and azooxanthellate Scleractinian corals, some of these changes occurred many decades ago, but have only just been reported in the literature. In most cases, these reports are over small to medium spatial scales (<4 × 104 m2 and 4 × 104 to 2 × 106 m2, respectively). Importantly, from the few studies where we were able to collect information on the persistence of the regime shifts, we determined that these non-scleractinian states are generally unstable, with further changes since the original regime shift. However, these changes were not generally back to coral dominance. While there has been some research to understand how sponge- and octocoral-dominated systems may function, there is still limited information on what ecosystem services have been disrupted or lost as a result of these shifts. Given that many coral reefs across the world are on the edge of tipping points due to increasing anthropogenic stress, we urgently need to understand the consequences of non-algal coral reef regime shifts.

Will coral reefs survive by adaptive bleaching?

Some reef-building corals form symbioses with multiple algal partners that differ in ecologically important traits like heat tolerance. Coral bleaching and recovery can drive symbiont community turnover toward more heat-tolerant partners, and this ‘adaptive bleaching’ response can increase future bleaching thresholds by 1–2°C, aiding survival in warming oceans. However, this mechanism of rapid acclimatization only occurs in corals that are compatible with multiple symbionts, and only when the disturbance regime and competitive dynamics among symbionts are sufficient to bring about community turnover. The full scope of coral taxa and ecological scenarios in which symbiont shuffling occurs remains poorly understood, though its prevalence is likely to increase as warming oceans boost the competitive advantage of heat-tolerant symbionts, increase the frequency of bleaching events, and strengthen metacommunity feedbacks. Still, the constraints, limitations, and potential tradeoffs of symbiont shuffling suggest it will not save coral reef ecosystems; however, it may significantly improve the survival trajectories of some, or perhaps many, coral species. Interventions to manipulate coral symbionts and symbiont communities may expand the scope of their adaptive potential, which may boost coral survival until climate change is addressed.

Detecting 2020 Coral Bleaching Event in the Northwest Hainan Island Using CoralTemp SST and Sentinel-2B MSI Imagery

In recent years, coral reef ecosystems have been affected by global climate change and human factors, resulting in frequent coral bleaching events. A severe coral bleaching event occurred in the northwest of Hainan Island, South China Sea, in 2020. In this study, we used the CoralTemp sea surface temperature (SST) and Sentinel-2B imagery to detect the coral bleaching event. From 31 May to 3 October, the average SST of the study area was 31.01 °C, which is higher than the local bleaching warning threshold value of 30.33 °C. In the difference images of 26 July and 4 September, a wide range of coral bleaching was found. According to the temporal variation in single band reflectance, the development process of bleaching is consistent with the changes in coral bleaching thermal alerts. The results show that the thermal stress level is an effective parameter for early warning of large-scale coral bleaching. High-resolution difference images can be used to detect the extent of coral bleaching. The combination of the two methods can provide better support for coral protection and research.

Coral diseases of mushroom coral (Fungiidae) in Pari Island, Kepulauan Seribu, Jakarta

Coral disease is one of the causes of the decline in the condition of coral reef ecosystems. This study aims to measure coral health based on the abundance and prevalence of coral health categories. The research was conducted in the Pari Island Cluster, Seribu Islands at four stations. The Belt Transect method with 2 × 100 meters was used to calculate coral health and a 30 m Line Intercept Transect (LIT) with three replications to determine substrate cover. The condition of coral reefs can be categorized as moderate to good based on this percentage value. The study results found five genera from the Fungiidae, namely Fungia, Ctenactis, Herpolitha, Heliofungia, and Sandalolitha. The most commonly found genus is the genus Fungia. The health condition of Fungiidae corals in Pari Island is divided into two categories, namely 35% healthy and 65% unhealthy, consisting of changes in tissue color - white (coral bleaching), changes in tissue color - not white (yellow band disease), and compromised health (damage by sedimentation). Yellow band disease is only found in the genus ˆ and is not found in other genera.

Photobleaching and Recovery of Symbiodiniaceae Effrenium voratum SCS01 Reveals Life Form Transformation Under Thermal Stress

Dinoflagellates in the family Symbiodiniaceae contain a number of species and play an important role in the establishment of coral reef ecosystems in oligotrophic marine waters. Effrenium voratum is likely an exclusively free-living and heterotrophic species of Symbiodiniaceae. How this species responds and acclimates to warming is largely unknown. The present study experimentally established the phenotypic landscapes related to the photobleaching and recovery processes of Effrenium voratum SCS01 following thermal stress. We found that thermal stress bleached the plastids of E. voratum SCS01 and caused the cells to become lighter in color. Thereafter, the bleached cells recovered rapidly when they returned to the optimal temperature. The dominant life form of E. voratum SCS01 shifted from mastigote cells to coccoid cells then returned to mastigote cells. Transcriptome analysis revealed that the photobleaching of E. voratum SCS01 was due to increased degradation and decreased biosynthesis of photosynthetic pigments. The thermally induced life form changes were related to the downregulation of genes for cell motility. Our results revealed the mechanism of photobleaching in E. voratum SCS01 and indicated life form transformation as a newly identified survival strategy of Effrenium voratum SCS01 under thermal stress.