Noise has long been neglected as an environmental pollutant and impairment health factor in maritime transport. Recently, acoustic pollution indicates the highest growth in transport external cost unit values. In 2020, questionnaires were submitted to seafarers to examine their noise exposure and perception on board and attitudes towards noise abatement measures. Responses of 189 participants were processed using descriptive statistics and Likert scale valuation, while their consistency was tested with indirect indicators using linear regression and correlation test. Results show that more than 40% of respondents do not consider noise as a significant environmental problem. The negative perception among respondents with ≥10 years of work experience was much lower (23.53%). Most are aware of the onboard noise harmful effects that can influence their health. Despite that, they use personal protection equipment only sometimes. A higher positive perception was recorded in groups of respondents with a university degree (90%), work experience longer than ten years (82.35%), and monthly income higher than 4000 € (70%). Respondents are not strongly motivated to participate in funding noise mitigation measures, and such a viewpoint is not related to their monthly incomes. The low awareness and motivation regarding acoustic pollution generally shown by the surveyed seafarers should be watched as a threat by the company managers. Better education and awareness are likely to be crucial to change the current state of affairs.

Autonomous ships are in experimental stage nowadays with Maritime Autonomous Surface Ships (MASS) already defi ned by IMO. Since MASS rely heavily on communications, security of communication systems and data security is critical. Secure communication is required to avoid bad actors to interfere with the communications or seizing control of a autonomous ship. In this paper, implementation of blockchain technology to improve autonomous vessels control security is investigated. This technology is already used in maritime bill of lading, acts on ship's technical inspection and for more accurate container tracking etc. The paper is organized as follows: fi rst section describes current status on autonomous ships, basic defi nitions and terms, second section describes what is blockchain technology and how does it work, third section deals with blockchain technology applications with the proposed usage of the technology in autonomous vessels control scheme.

Croatia has a fishing fleet of 7559 vessels. Of these, small-scale coastal fishing boats, less than 12 meters in length, makes up 95,7% of the fleet. However, the largest percentage of catches, more than 94%, is made by purse-seiners that are representing only 3% of total fishing vessels. These vessels target small pelagic fish, predominately sardine and anchovy. This paper describes all the technical characteristics of the Croatian purse seiner fleet, based on 113 purse seine vessels registe-red in 6 Croatian ports and targeting anchovy in order to allow a precise determination of that fleet fishing capacity and subsequent management of the fleet in a responsible and sustainable manner. Comparison of different technical characteristics showed that the length of a vessel corresponds to the amount of the catch as well as to size of the fish. Hence, results confirm superiority of sonar, as a fish-finding device, over sounder in detecting fish shoals, which is prerequisite for purse seine fishing.

Sport and recreational marine fishery can significantly contribute to the national budget through its economic and social effects. The main aim of this research is to define the economic and social significance of sport and recreational fishing in Croatia through the assessment of the lower limit of its economic value. This is done by analyzing the segments of sport and recreational fishing together with the economic and other activities which are closely related to it. When expressed by the number of stakeholders involved in sport and recreational fisheries and the share in the gross domestic product, it can be concluded that the economic effects of these activities are only slightly lower than in commercial fisheries. This research provides the groundwork for pointing out the basic guidelines of the social significance of sport and recreational marine fishery in Croatia. Hence, it can be noted that sport and recreational fishing in local coastal communities support the overall development of rural areas and the local communities in particular.

In this paper, all factors that have an impact on marine pollution by sanitary wastewater from cruise ships were explored and analysed. A case study was done in which the movement of cruise ships in the Adriatic Sea was followed. Based on the results of that case study, a model of cruise ship traffic in the Adriatic Sea was developed, which, based on cruise ships itineraries in a certain period of time, gives retention times of ships in fourteen defined geographical areas of the Adriatic Sea. This model provides basic input parameters for the original evaluation model of marine pollution by wastewater from cruise ships, which is presented in this paper. By changing operation modes of the ship in different scenarios, evaluation model enables simulation of various scenarios in order to obtain the desired or expected load values of wastewater from cruise ships in fourteen defined geographical areas of the Adriatic Sea.