This study investigated the physicochemical properties and nutrient dynamics on the Romanian shelf of the northwestern Black Sea in July 2024, collecting data across 36 stations (13–1116 m depth) heavily influenced by Danube discharges. Vertical CTD profiling revealed a pronounced seasonal thermocline and a deep-lying permanent halocline. The Cold Intermediate Layer (CIL) boundary, defined by the 8 °C isotherm, was absent, indicating warmer subsurface waters. Surface nutrient concentrations, particularly for nitrate (NO₃) and phosphate (PO₄), were considerably lower than peak eutrophication periods, approaching pre-1970s values, suggesting a positive trend due to reduced anthropogenic loading. They are also comparable to or lower than other coastal regions in the Black Sea. Vertical nutrient profiles confirmed the typical anoxic Black Sea structure, but with regional specifics: the PO₄ maximum was slightly deeper, and the NO₃ maximum position and concentration mirrored the pre-eutrophication period, further supporting reduced anthropogenic nitrogen input. Silicate (SiO₄) concentrations were consistently low throughout the water column, suggesting the northwest shelf functions as a SiO₄ sink compared to the southeastern Black Sea. Overall results indicate a shift towards a less eutrophic state on the Romanian shelf while highlighting the continued dominance of Danube-driven hydrodynamics. In addition to those investigations, this study assessed nutrient preservation techniques, finding that pasteurization was significantly superior to freezing for maintaining the stability of PO₄ and NOx (losses up to 20% and 47% for frozen samples, respectively) over six months. Though SiO₄ was stable under both methods, the freezing produced lower concentrations, possibly from incomplete depolymerization during thawing. These findings stress that pasteurization could be taken into consideration as a reliable preservation technique for long-term storage of nutrient samples.

Secondary explosives such as 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and 2,4,6-trinitrotoluene (TNT) were commonly used in the production of many types of munitions during World War II and still continue to be used, for example, 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) and pentaerythritol tetranitrate (PETN). After the war, numerous remaining munitions were disposed of by dumping them into the Baltic Sea. The same was true for the Black Sea, but due to a lack of documentation about these dumpsites, the awareness of hazards and knowledge about the scale of the problem have significantly increased in the last 30 years. After decades spent in salty water, the shells of said projectiles corroded, and currently, they pose a risk of environmental contamination and explosion. Because of this, new underwater detection methods that are reliable, quick, remote and, at the same time, insensitive to the external interference of sea water are needed. The detection of explosives used in projectiles can be performed using field Raman spectrometers. Raman spectroscopy is an analytical method that is non-invasive: it allows one to perform analysis without taking samples out of the projectile. Field detectors are water-resistant due to the frequent need for decontamination. Therefore, in this study, a ThermoScientific Gemini analyzer (Waltham, MA, USA) was used. The purpose of the study was to determine how the Raman spectra of pressed explosives are influenced by two main factors: the distance between the Raman probe and the sample and the type of medium that stands between the Raman probe and the sample. For the purpose of this study, four explosives: TNT, RDX, PETN, and HMX were tested through various layers of distilled water, tap water, silica dispersion, Black Sea water and, finally, Baltic Sea water.