Current trends in ship movement via the suez canal in relation to future legislation and mitigation of marine species introductions

The opening of the Suez Canal in 1869 created a tremendous impact both on the shipping industry, by shortening navigational routes, and on ecological communities in the Mediterranean Sea, by facilitating numerous introductions of non-indigenous species (NIS). These impacts are deeply intertwined as the majority of Mediterranean Sea introductions are ship-facilitated. Here we analyzed shipping data for the Canal between 2011–2018, and characterized the shipping trends of the Canal in relation to global shipping trends and to the introduction of NIS. We differentiated the data analysis between ballast-weighted ships and cargo laden ships according to nine ship categories: Tankers, LNG (Liquid Natural Gas) Ships, Bulk Carriers, General Cargo, Container Ships, Ro/Ro (Roll on/ off) ships, Car-Carriers, Passenger Ships, and Others. We used statistical tests to determine whether the August 2015 expansion influenced shipping trends and discuss our findings with respect to patterns in species introductions. Our findings show that although there has been an increase in tonnage being shipped through the Canal, this is a consequence of an increase in ship dimensions, while the actual number of ships for some categories has decreased. This pattern was particularly evident in the container ship category, which had the highest global growth compared to other ship categories. A few categories, such as bulk carriers and tankers, had more traffic in particular directions of passage. Only passenger ships and bulk carriers revealed significant seasonal transit trends, with higher transfers during spring and autumn for passenger ships and summer/autumn for bulk carriers. An increase in average ship size was evident for almost all categories. Larger ships imply a longer turnover time spent in ports and a larger available wetted surface area that is susceptible to fouling, thus potentially providing a larger fouling community with more time to propagate and settle in a novel habitat. Our findings emphasize the importance of identifying current shipping trends that may pose a threat to the Mediterranean Sea biodiversity in order to construct a follow-on policy to mitigate the transfer and delivery of NIS via the Suez Canal. Specifically, enforcement of antifouling regulations is highlighted as a significant contribution to the European Union Marine Strategy Framework Directive goals to achieve a good environmental status.