Physical connectivity simulations reveal dynamic linkages between coral reefs in the southern Red Sea and the Indian Ocean

Abstract

The southern Red Sea is genetically distinct from the rest of the basin; yet the reasons responsible for this genetic separation remain unclear. Connectivity is a vital process for the exchange of individuals and genes among geographically separated populations, and is necessary for maintaining biodiversity and resilience in coral reef ecosystems. Here, using long-term, high-resolution, 3-D backward particle tracking simulations, we investigate the physical connectivity of coral reefs in the southern Red Sea with neighbouring regions. Overall, the simulation results reveal that the southern Red Sea coral reefs are more physically connected with regions in the Indian Ocean (e.g., the Gulf of Aden) than with the northern part of the basin. The identified connectivity exhibits a distinct monsoon-related seasonality. Though beyond the country boundaries, relatively remote regions of the Indian Ocean may have a substantial impact on the southern Red Sea coral reef regions, and this should be taken into consideration when establishing conservation strategies for these vulnerable biodiversity hot-spots.

Towards an End-to-End Analysis and Prediction System for Weather, Climate, and Marine Applications in the Red Sea

“…Panels (Raitsos et al, 2013). The panel suggests basin-wide connectivity with the central Red Sea driven by mesoscale activity, except for the southern Red Sea which connects more with the Gulf of Aden (Raitsos et al, 2017;Wang et al, 2019).…”

“…Zhan et al 2015), biological connectivity among different coral reef complexes at coastal(Nanninga et al 2015), basin(Raitsos et al 2017), and cross-basin scales(Wang et al 2019). Oil spill transport and weathering processes are simulated with the well-established MEDSLIK oil spill, trajectory and pollutant transport prediction model (De Dominicis et al 2013a,b; http://www.oceanography.ucy.ac.cy/medslik/) as Lagrangian particles transported by ocean currents, wind, and waves, and a stochastic displacement that parameterizes turbulent diffusion(Zodiatis et al 2019).…”

“…Despite a limited supply of nutrients, their subsurface intrusion from the Gulf of Aden and the winter deepconvection drive elevated values of primary productivity in the south during summerDreano et al 2016) and in the north during winter(Gittings et al 2018). Moreover, marine larvae/planulae disperse nearly passively with the circulation, forming a homogenous genetic connectivity across geographically separated reef sites within most of the basin (Fig.9;Raitsos et al 2017), except for the southern Red Sea which was suggested to be physically connected with the Indian Ocean(Wang et al 2019). Mesoscale circulation: The upper-layer Red Sea circulation is characterized by complex and highly varying mesoscale activity, consisting of energetic semi-permanent and transient eddies, with stronger activity during winter(Zhan et al 2014).…”

Developing an Atlas of Harmful Algal Blooms in the Red Sea: Linkages to Local Aquaculture

“…Our atlas reveals that the highest number of HAB events occurred in the SRS, followed by the SCRS and subsequently the NCRS, over the period of 2003-2017. The SRS and the substantial parts of SCRS are subject to a biannual influx of nutrient-rich waters from the Indian Ocean through the Gulf of Aden, driven by the seasonally reversing Indian monsoon winds [25,[31][32][33][34][35][36][37][38][39]. During the winter monsoon (October-April), prevailing south-easterly winds promote the northward advection of nutrient-rich surface waters into the Red Sea from the Gulf of Aden [32,[40][41][42].…”

“…We also propose the SRS to be a prime candidate, as it exhibits the highest number of HABs as well as the most persistent and large-scale events in the entire Red Sea. In addition, it is also a region where the seasonal inflow of surface water from the Gulf of Aden appears to play an important role in the maintenance of pelagic organisms and their distribution within the Red Sea [12][13][14]30,39,62,63]. Previous studies have also identified the region as the most highly HAB-affected part of the Red Sea and is often associated with severe fish mortalities and numerous ecological impacts [9,[12][13][14]17].…”