Higher energy efficiency and lower environmental impact have become very important aspects in the evaluation of the design and operation of technical systems. The same goes for the fish farming sector, which continuously aims to reduce its environmental footprint as well as its operating costs. This paper reviews the energy needs of the fish farming sector and their impact on the environment, and discusses the possibilities of improving the environmental friendliness of this sector by employing a higher share of renewable energy sources. The fish farming process is divided into its constitutive phases: fish breeding with associated activities, transportation, and handling of grown fish, together with relevant processes; and final processing and distribution to the customers. For these phases, the energy consumption and associated emissions, depending on the energy source, have been assessed. The parts of the process with the highest potential for the integration of alternative powering options and consequent environmental improvements are identified. The case study deals with the fish farming process in Croatia, for which a set of alternative powering options has been proposed, considering the existing energy supply, i.e., import of fossil fuels and current Croatian electricity mix, as well as renewable energy potential, which is reviewed in the paper.

Colorado potato beetle (CPB) is an economic pest of potato that has developed resistance to all classes of chemical insecticides, thus requiring alternative control measures. As a potential solution, entomopathogenic nematodes (EPNs) have proven effective in suppressing this pest, but their efficacy against overwintering generations of CPB in Croatia has not been sufficiently researched. The aim of this two-year (2018–2019) field study was to determine the efficacy of Steinernema feltiae and Steinernema carpocapsae applied to overwintering CPB adults. EPNs were applied at three doses (7.5 mil./10 m2, 5.0 mil./10 m2 (the recommended dose) and 2.5 mil./10 m2) by watering the soil where the adults were overwintering. The first-year results were satisfactory for both EPNs: the efficacy of S. feltiae ranged from 79.03% to 100.00%, while the efficacy of S. carpocapsae ranged from 77.32% to 96.22%. In the second year, the highest efficacy (69.57%) was obtained using the recommended dose of S. feltiae. Although the results are not consistent across the two years of our study and suggest further research, they indicate that EPNs have great potential in controlling overwintering CPB generations to reduce first generation abundance and damage, and also to prevent the spread of new generations to surrounding potato growing areas.

The growth in population and the higher need for aquatic products make the aquaculture industry the world’s fastest-growing food industry. With its rapid development, production is facing various challenges to achieve sustainability and cost-effectiveness. Some obstacles in production are related to the design of mariculture cages, automatization, location of the farm, biofouling, feeding, waste management, and others. This paper deals with the extended bibliometric analysis of technical problems in mariculture based on keywords, citations, journals, and other factors by means of scientometric software, CiteSpace, and VOSviewer. Important keywords related to aquaculture and mariculture were obtained from the Web of Science platform and further analyzed by means of the mentioned scientometric software offering knowledge domain visualization and construction of knowledge maps. Apart from the identification of research topics of the highest importance, research hotspots are characterized as follows: technical, biological, digital, and environmental. The most cited articles are related to the environmental problems and solutions in marine aquaculture and the study of biofouling and how to control it. Other important documents with high citation rates are related to the cages, offshore mariculture, location conditions, and sustainability. This study recognizes trends by combining aquaculture production with floating structures for energy extraction of sea resources; thus, making aquaculture more interdisciplinary than before.

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