Figure 1 illustrates the distribution of arrivals by type at the port of Mytilini in June 2019. Passenger ships constituted the largest percentage, representing 42.4% of the total arrivals. Following closely behind were Ro-Ro/Passenger vessels, accounting for 33.9% of the total arrivals. Ro-Ro Cargo ships, on the other hand, comprised approximately 3.5% of the total arrivals. These three types of ships, with regular schedules, constituted the majority of the arrivals, amounting to approximately 80% of the total. It is worth noting that there are other ships involved in essential supply services such as the delivery of heavy fuel oil and cement to the island. However, Fig. 1 does not include military shipping vessels or other non-scheduled shipping activities, which may contribute to a different total arrival count.
Short sea shipping routes play a significant role in maritime transportation, and understanding the emissions associated with these routes is crucial for environmental assessments. Several studies have examined the emissions from short sea shipping routes, providing valuable insights into their environmental impact. Research conducted by Jalkanen et al. (2018) investigated the emissions of greenhouse gases (GHGs) from short sea shipping in the Baltic Sea region. Their findings revealed that CO2 emissions accounted for the majority of GHG emissions, highlighting the importance of addressing carbon emissions in this sector. Additionally, a study by Psaraftis and Kontovas (2019) examined the emissions from short sea shipping in the European Union, emphasizing the need for efficient operational practices to reduce emissions and improve environmental performance. Furthermore, research conducted by Benveniste et al. (2020) focused on the air pollution impacts of short sea shipping in the Mediterranean region, highlighting the significance of reducing emissions of air pollutants such as sulfur oxides (SOx) and nitrogen oxides (NOx). These studies collectively contribute to our understanding of emissions from short sea shipping routes and provide insights into strategies for mitigating their environmental impact. Table 3 shows the mechanical characteristics and the shipping vessels that connect Mytilini-Ayvalik. After detailed research, it became clear that all routes are been carried out by the Turkish Ferry Company Turyol. The general information about the main engine power, the auxiliary engine power along with the number of total routes for each ship are provided below.
Table 3
Operational information - examined shipping vessels
| ME Power (KW) | AE Power (KW) | Total Routes | Calendar days of operation/ month |
Ship A | 1491 | 125 | 37 x 2 | 30 |
Ship B | 3123 | 148 | 15 x 2 | 14 |
Ship C | 3002 | 125 | 23 x 2 | 21 |
Ship D | 1233 | 411 | 26 x 2 | 26 |
Ship E | 822 | 160 | 27 x 2 | 25 |
Ship F | 1268 | 634 | 1 x 2 | 1 |
The information provided includes details about several ships operating on the Ayvalik-Mytilini route. The first ship, Lesvos (IMO: 9323924), is a Ro-Ro/Passenger Ship built in 2004, sailing under the flag of Turkey. It has a carrying capacity of 332 Gross Tonnage, a summer DWT of 180 t, and current draught of 2.3 meters. Another ship, Nazli Jale (IMO: 8506945), is also a Ro-Ro/Passenger Ship, built in 1986, with a carrying capacity of 288 Gross Tonnage, a summer DWT of 50 t, and current draught of 1.3 meters. Similarly, Esref Jale (IMO: 9053701) is a Ro-Ro/Passenger Ship built in 1992, with a carrying capacity of 269 Gross Tonnage, a summer DWT of 50 t, and current draught of 1.8 meters. Seda Jale (IMO: 8987591) is a Passenger Ship built in 2004, with a carrying capacity of 367 Gross Tonnage, a summer DWT of 167 t, and current draught of 2.3 meters. Lastly, Kaptan Ilyas Mert (IMO: 9697533) and Kaptan Sevket iyidere 1 (IMO: 9089176) are Passenger Ships with carrying capacities of 453 Gross Tonnage and 329 Gross Tonnage, respectively. These ships have varying fuel consumption rates depending on factors such as speed, with an average fuel consumption of 60 L/hour/100HP, which may increase by 20% at higher speeds. Hoteling times and maneuvering times are crucial for calculating in-port emissions. However, this study also aims to assess emissions during cruising. The specific values related to hoteling-idling times, maneuvering times, and cruising times are presented collectively in Table 4. Combined with the factors provided in Tables 1 and 2, these values are used to calculate both in-port and open-sea emissions.
Table 4
Routing times of examined shipping vessels.
| Cruise (hours) | Manoeuvring (h) | Hotelling (h) |
Ship A | 1.37 | 0.15 | 0.3 |
Ship B | 0.75 | 0.15 | 0.3 |
Ship C | 0.75 | 0.15 | 0.3 |
Ship D | 1.43 | 0.15 | 0.3 |
Ship E | 1.47 | 0.15 | 0.3 |
Ship F | 1.50 | 0.15 | 0.3 |
Figure 2 presents the energy consumption of each examined shipping vessel by type of action, i.e, cruising, hoteling and maneuvering. The energy consumption of ships in short sea shipping routes has been a subject of extensive research, aiming to improve efficiency and reduce environmental impacts. Studies have explored various aspects of energy consumption in this context. For instance, a study by Hildebrandt et al. (2017) examined the energy consumption patterns and optimization potential of short sea vessels, emphasizing the importance of energy-saving measures. Saarela et al. (2018) analyzed the energy efficiency of short sea shipping in the Baltic Sea region, considering factors such as vessel size, speed, and cargo volume. Andersson et al. (2019) investigated energy consumption in short sea shipping, focusing on vessel design and operational factors.
Figure 3 presents the total energy consumption from all the shipping vessel combined for a whole calendar month. An interesting result -and one of the most significant results if this study - is that while cruising is consuming the most energy for all the examined ships, hoteling also has a significant impact and should be co-assessed as a significant contributor of emissions and of energy use. Goulielmos et al. (2020) assessed the energy efficiency of short sea container shipping, highlighting the role of ship design and operational practices. Wergeland et al. (2021) evaluated the energy consumption of short sea vessels in the Norwegian transport system, identifying opportunities for energy savings. These studies collectively contribute to a better understanding of energy consumption in short sea shipping and provide insights for achieving more sustainable maritime transportation practices. A point to be made is that the optimal design of short sea shipping routes in accordance to the specific shipping vessel can potentially reduce significantly the energy consumption and the emissions of the sector.
Figure 4 presents the total emissions from the examined ships that did the route Mytilini - Ayvalık during July 2019. Nitrogen oxides (NOx) emissions are the emissions with the highest amount of production followed by sulphur oxides. Nitrogen oxides (NOx) emissions in short sea shipping have been a significant concern due to their environmental impact. Lutzhoft et al. (2019) examined the impact of ship speed and engine load on NOx emissions in short sea shipping routes. The authors found that higher speeds and increased engine loads contribute to higher NOx emissions. Another study by Baldauf et al. (2020) focused on the characterization of NOx emissions from short sea shipping vessels, analyzing the effects of different operational and technical parameters. They emphasized the importance of adopting emission control measures and technologies to reduce NOx emissions. Additionally, a study by Xu et al. (2021) evaluated the effectiveness of using exhaust gas recirculation (EGR) systems to mitigate NOx emissions in short sea shipping. The authors found that EGR systems can significantly reduce NOx emissions under various operating conditions. These studies contribute to understanding the factors influencing NOx emissions in short sea shipping and provide insights for developing strategies to minimize their environmental impact.
Sulfur emissions in short sea shipping have been a significant environmental concern due to their impact on air quality and human health. Several studies have examined sulfur emissions in this sector and proposed strategies for mitigation. Apostolopoulou et al. (2020) investigated sulfur emissions from short sea shipping vessels in the Mediterranean Sea. The authors analyzed the effect of different fuel sulfur content and emission control technologies on sulfur emissions. They highlighted the importance of adopting low-sulfur fuels and implementing exhaust gas cleaning systems to reduce sulfur emissions. Stournaras et al. (2019) focused on assessing the impact of the sulfur emission control area (SECA) regulations on short sea shipping in the Baltic Sea. The authors found that SECA implementation significantly reduced sulfur emissions and improved air quality in the region. Additionally, a study by Psaraftis et al. (2018) evaluated the environmental and economic implications of different sulfur emission reduction strategies for short sea shipping. The authors assessed the feasibility and cost-effectiveness of using low-sulfur fuels, exhaust gas cleaning systems, and alternative energy sources.
Figure 5 presents the CO2 emissions from the examined route. CO2 emissions are in the center of conversation due to their contribution to climate change. A study by Cullinane et al. (2020) examined the factors influencing CO2 emissions in short sea shipping and identified operational and technological measures for CO2 reduction. The authors emphasized the importance of optimizing ship speed, route planning, and adopting energy-efficient technologies. Another study by Tsitsifli et al. (2019) assessed the CO2 emissions from short sea shipping routes in the Mediterranean Sea and proposed a methodology for calculating emissions based on ship characteristics and operational data. They highlighted the need for accurate emissions measurement and monitoring to support effective mitigation strategies. Additionally, a study by Wijnolst et al. (2018) investigated the potential of alternative fuels and propulsion systems to reduce CO2 emissions in short sea shipping. The authors assessed the environmental and economic feasibility of LNG, biofuels, and battery-powered vessels as viable alternatives. These studies contribute to understanding CO2 emissions in short sea shipping and provide valuable insights for developing sustainable and low-carbon shipping practices.
Atmospheric contamination is the greatest challenge for commercial shipping today as it threatens to undo the gains enjoyed by longer travel distances after China and India joined the WTO as a result of anti-pollution travel expenses. If environmental protection-based levies tend to be important, it would have the same effect as import levies that would hit items coming from longer distances. A large proportion of the Short Sea fleet currently operating intra-EU trade is over 25 years old, the oldest ships apparently carrying Russian, Norwegian, Greek and Turkish flags. Ship age affects the cost of shipping mostly through the effect of the maintenance and repair bill, but also through the effect of the maintenance and repair bill (Corres & Psaraftis, 2005). It is a costly endeavor to replace old ships with new, replacing whole pieces of a huge fleet
such as the short sea fleet is a mammoth process that will take at least 25–30 years to complete. Therefore, in order to be able to get environmentally friendly ships serving in EU trade, the EU's attitude about shipbuilding and, of course, the scrapping of the shipbuilding directives will need to be modified, with the exception of funds. At this point it is important to note that on a study conducted by Becker et al.,0000 (2008), comparing the costs of manufacturing and upgrading short and deep sea ships with regards to emissions, it was found that it is more expensive to care for based on the fact that most shipping companies give their full attention to their deep sea vessels and this is a wide phenomenon, nor restricted in the EU (Becker et al, 2008). Most of the short sea flee as mentioned previously is quite old, and companies in the maritime industry do not wish to upgrade these vessels since there is no such support from EU (Corres, 2013).
The outcomes of this study can be used as a blueprint for assessing the environmental impact of other international short sea shipping routes / cases. In accordance with Mannarini et al. (2021) on the matter of emissions of short flee routes in Adriatic, they found that the Adriatic area is a significantly busy area for international short sea routes since it is on a close proximity with Italy, Montenegro, Croatia and Albania. Even though the ships used to carry out these routes account for the 3% of the total, they do have significantly high emissions, nearly 10%. That shows us that there is a need for action. Alongside the International transportations by cargos etc., IMO should also include the International short sea routes as well since the emission of these ships is quite high (Mannarini et al., 2021). Additionally, Luttenberger, Ancic and Sestan (2014) on a study conducted for the purpose of calibrating the emissions produced by Croatia’s short sea flee, they found that the substructure for minor emissions on these ships is quite low and undersized, even though Croatia is quite popular and significant when it comes to International short sea routes (Luttenberger, Ancic, Sestan, 2014). Lastly, Christodoulou & Woxenius (2019) underline the issue on absence of accountancy on the matter of sustainability of short sea international routes in the Mediterranean area by shipping companies and organizations of the maritime industry (Christodoulou, Woxenius, 2019).
Future studies ought to consider how much non-renewable energy sources are consumed and the CO2 outflows created in the development of comparable power and the hydrogen expected to keep up with shores. The pattern of advances lies in power capacity innovation, the fruitful revelation of new materials for battery makes and the acknowledgment that the focal point of worldwide industry improvement is on more effective types of sustainable power. The development of electric ships and hydrogen fuel, which creates power to charge batteries on electric ships, is conceivable through the utilization of existing advances (Rutherford et al, 2020). Contrasted with marine diesel vessels, electric ships lead to a decrease of CO2 outflows by up to 90%, including altogether lower NOx, SOx, and PM discharges, and working expenses by up to 80%. The utilization of hydrogen as a fuel can make a huge commitment to decreasing ozone depleting substance discharges, as well as further developing air quality and lessening commotion. Along these lines, with the backing of the European Commission, hydrogen is progressively tracking down its direction into all methods of transport and entering the European Union market.