The impact of climate change on both terrestrial and aquatic ecosystems tends to become more progressively pronounced and devastating over the years. The sector of aquaculture is severely affected by natural abiotic factors, on account of climate change, that lead to various undesirable phenomena, including aquatic species mortalities and decreased productivity owing to oxidative and thermal stress of the reared organisms. Novel innovative technologies, such as aquaponics that are based on the co-cultivation of freshwater fish with plants in a sustainable manner under the context of controlled abiotic factors, represent a promising tool for mitigating the effect of climate change on reared fish. The rainbow trout (Oncorhynchus mykiss) constitutes one of the major freshwater-reared fish species, contributing to the national economies of numerous countries, and more specifically, to regional development, supporting mountainous areas of low productivity. However, it is highly vulnerable to climate change effects, mainly due to the concrete raceways, in which it is reared, that are constructed on the flow-through of rivers and are, therefore, dependent on water’s physical properties. The current review study evaluates the suitability, progress, and challenges of developing innovative and sustainable aquaponic systems to rear rainbow trout in combination with the cultivation of plants. Although not commercially developed to a great extent yet, research has shown that the rainbow trout is a valuable experimental model for aquaponics that may be also commercially exploited in the future. In particular, abiotic factors required in rainbow trout farming along, with the high protein proportion required in the ratios due to the strict carnivorous feeding behavior, result in high nitrate production that can be utilized by plants as a source of nitrogen in an aquaponic system. Intensive farming of rainbow trout in aquaponic systems can be controlled using digital monitoring of the system parameters, mitigating the obstacles originating from extreme temperature fluctuations.

As the greenhouse cultivation industry considers new ways to reduce energy demand and increase sustainable production, the global energy crisis constitutes a major issue. In this paper, two different energy sources for heating and cooling the root zone area of baby leafy vegetables grown in hydroponic tanks by resistors and chillers, respectively, were compared in order to fully cover power demand. The energy needs in the first case were met by the public electricity grid, while in the second case, the energy needs were covered by a photovoltaic system. The greenhouse was equipped with photovoltaic panels, an inverter, a charge controller and a storage system. The target-value of the root zone temperature was 22 °C. Data on solar radiation, root zone temperature, air temperature and humidity from the indoor and outdoor space of the greenhouse were recorded, and the energy production and carbon footprint for different seasons of the year were evaluated along with the crop yield. The results showed that the energy provided by solar panels was able to cover 58.0%, 83.3% and 9.6% of the energy for heating or cooling the root zone area during the spring, summer and winter periods, respectively. Regarding the carbon footprint of the energy used between the two systems, the system with the PV had a substantially lower value, which was calculated at 1.6 kg CO2-eq kg−1, compared to 49.9 kg CO2-eq kg−1 for the system with PPG for the whole year.