## 5 Conclusions  
It is of paramount importance for future studies to continue investigating the consequences of climate change and human impacts on the marine food chain, particularly in the Western Northern Adriatic coastal strip which serves as the main nursery area for many species of fish (e.g., _Solea solea, Mullus barbatus, Pagellus erythrinus, Squilla mantis, Engraulis encrasicolus_, and _Eledone moschata_[105; 106; 107; 108]).  
The recent basin evolution with a significant positive trend in nitrate concentrations in offshore seawater in almost all seasons during the decade 2006-2015 occurred despite a decreasing trend in N concentration in the Po River water. The rise in N/P ratios in river water and the excess of N in the marine environment, which cannot be utilized by phytoplankton due to P limitation, can explain this phenomenon. The change in the hydrodynamic regime was one of the main factors that altered phytoplankton abundance, community composition, and seasonal cycles.  
The changes in nutrient dynamics indicate that the productivity of the Northern Adriatic Sea has been largely affected in the last 40 years by the combination of river water discharges and human activities. Further changes can be expected in the future, particularly in the case of a further reductions in anthropogenic phosphorus loads. Furthermore, another UE directive (91/676/EEC) aims to regulate the use of N in agriculture, but specific measures have not yet been adopted by many EU countries, including Italy.  
Studies in this direction will be indispensable in the management of fisheries and the development of aquaculture, which are important policy concerns, such as in the EU, where the development of aquaculture is currently supported at the expense of industrial sea fishing. Additionally, the findings from these studies can inform policy decisions and help in designing targeted measures to mitigate the impacts of eutrophication and other environmental stressors. Implementing effective nutrient management strategies, reducing anthropogenic inputs, and promoting sustainable fishing practices are key steps towards safeguarding the Adriatic Sea's ecological integrity and ensuring the continued availability of its marine resources for future generations.  
\begin{table}
\begin{tabular}{c c c} \hline
**Dataset** & **Time Period (Years)** & **References** \\ \hline River load & 1970–2022 &
\begin{tabular}{c} [[https://simc.arpae.it/dext3r/](https://simc.arpae.it/dext3r/)]([https://simc.arpae.it/dext3r/](https://simc.arpae.it/dext3r/)) (accessed on 1 July 2023) \\ (accessed on 1 July 2023) \\ \end{tabular} \\ Nitrogen and phosphorus in the sea & 1972–2019 & [2; 4; 23; 70] \\ Meteorological data & 1850–2003 & [36; 38; 39] \\ Plankton & 1978–2020 & [13; 15; 83; 84; 85] \\ Oceanographic data & 1911–2019 & [14; 23; 28; 46; 73; 79; 87; 94] \\ \end{tabular}
\end{table}
Table 1: Datasets in the Northern Adriatic Sea.  
**Author Contributions:** Conceptualization, M.M. and F.G.; writing--original draft preparation, M.M. and F.G.; writing--review and editing, M.M. and F.G. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.