9/4/2023 0 Comments Tidal range suez canal![]() ![]() Here, for the first time, we reconstruct a continuous record of the volumetric flow rate (hereafter simply indicated by transport) through the SC for the period 1923–2016. Previous works used simplified models to study the dynamics of the SC 14 and/or its contribution to asymmetric migration 7 however, these studies focused on short periods and lacked any climatic interpretations of their findings. Notably, in what follows we only consider species that traverse the Suez Canal by drifting or swimming, while alien species that crossed the Suez Canal by other modes of introduction, such as shipping, were probably negligibly affected by the SC dynamics and its physical conditions (currents, salinity, temperature, turbidity, etc). In the current study, we combined 3D hydrodynamic models and sea-level (SL) observations to study the long-term dynamic variations in the SC and their potential impacts on species migration between the MS and the RS. 1b), which could result in a new wave of species invasion to the MS 13. Over 150 years after its establishment 12, the ecological effects of the SC are still increasing, resulting in challenges and concerns for the scientific community: for example, in 2015, a new 35-km bypass enabling two-way traffic (also knowns as “new Suez Canal”) was excavated in parallel to part of the original 165-km canal (Fig. Moreover, the accelerated rate of species invasion from the RS to the MS since the early 1980s has been related to either climate change (warming of the eastern Mediterranean) or a reduced physical barrier caused by the expansion of the SC over the years 11. The asymmetric migration has been attributed to a dominant northward current through the SC from the RS to the MS, or to other factors such as environmental conditions and species adaptation 7. ![]() 1a) on species migration between the two seas have not been studied rigorously. However, the effects of SC dynamics and their response to its deepening and expansion over the years (Fig. The high salinity and the seasonal flow of the SC were assumed to pose an effective physical obstacle influencing the type of migrating species and their migration rates and direction (RS to MS or vice versa) 1, 4, 5, 7, 8, 9, 10. Of the alien species that traverse the SC do so by drifting or swimming, where other pathways of introduction, such as transport via ballast water of ships, have less contribution 2, 3, 4, 5, 6. However, only a few records exist of species successfully migrating in the opposite direction, from the MS to the RS. The recorded migration is highly asymmetric, with \(\sim \) 500 species known to have entered the MS through the SC (also known as non-indigenous species), resulting in the continuous loss of important native populations in the MS, including habitat-forming ecosystem engineers 1. It is also a well-known conduit for marine species invasions between the RS and the MS. The SC is a dynamically complex body of water, connecting several lakes with widely diverse salinities to two marginal seas with very different thermohaline properties and sea level conditions. Since its opening, the canal was expanded and deepened a number of times to overcome the increasing volume of commercial shipping and the increasing size and draughts of modern ships (Fig. The Suez Canal (SC) spans over 165 km of sandy desert between Port Said on the Mediterranean Sea (MS) and Port Suez on the Gulf of Suez, northern Red Sea (RS) (Fig. It was then gradually reduced by accelerated sea-level rise in the northern Indian Ocean. The southward flow was primarily enhanced by Indian Ocean cooling and the Eastern Mediterranean Transition in deep water formation during the period 1980–2000. Our record not only supports previous observations of the unidirectional invasion until the 1980s and the accelerated species migration rates to the Mediterranean ever since, but also suggest that southward migration could have become possible since the early 1980s. According to this reconstruction, the flow intensity and direction through the canal are strongly influenced by seasonal and long-term sea-level changes, which could also play a role in the characteristics of species migration through it. We present the first reconstructed flow transport record through the canal during the period 1923–2016. Species invasion through the Suez Canal from the Red Sea vastly influences the ecology of the Mediterranean, but the level of reverse migration is assumed to be negligible. The Mediterranean and Red Sea, which were connected via the Suez Canal during the 19th century after eons of separation, host two distinctive ecosystems. ![]()
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