Carbon dioxide (CO2) and methane (CH4) are major greenhouse gases (GHG) and have been under constant monitoring for decades. Both gases have signiﬁcantly increased in recent years due to anthropogenic activities, with fossil fuel CO2 emissions peaking over 10GtCyr−1fortheﬁrsttimeinhistoryin2018. This has huge detrimental repercussions within natural systems including the warming of the planet. Although these GHG are extremelysigniﬁcant,therearealsovastareasofstudywithlittletonodatainregardsto emissions and budgets. These gaps are mainly within the aquatic regions (or the Land Ocean Aquatic Continuum (LOAC)).As a consequence, there can be large discrepancies between budget numbers and in turn, scaling and future predictions. One of the main reasons for discrepancies is due to diﬀering regimes between the land and ocean where the two systems use diﬀerent practices to optimise the instruments and measuring standards. Oceanographers, for example, focus more on accuracy and precision due to far smaller concentrations and variability. In order to combine oceanographic and limnological methods this thesis presents a novel sensor package and show its application in multiple campaigns across the entire LOAC. The sensor set-up contained the sensors HydroC CO2 FT (pCO2), HydroC CH4 FT (CH4), HydroFlash O2 (O2) and a thermosalinograph for temperature and conductivity measuring all simultaneously. We extensively mapped inland regions and assessed the ways in which such high-resolution and accuracy measurements could potentially assist in ﬁlling some of these data gaps: First, the sensors’ capabilities were tested in a range of salinities (saline to fresh) and across a range of seasons (spring, summer and autumn). We found the sensors performed well in all regions, however, to fully appreciate the data, extensive corrections had to be applied, vital within inland regions. Following on from this we applied a simple model to calculate a continuous dataset for total alkalinity (TA) for the inland delta system. With this dataset, and our continuous pCO2 data, we were able to calculate the full carbonate system. We found the whole delta system to be supersaturated in regards to CO2, with each system (lakes, rivers or channels) showing very diﬀerent dynamics. Both lakes and channels typically ﬂuctuated between under and supersaturation (depending on season and region of the delta), while rivers were consistently supersaturated. Dissolved inorganic carbon (DIC) and O2 ratios were extracted for each region (∆DIC: ∆O2), showing lakes tending to be heavily inﬂuenced by regions adjacent to them, such as wetlands that typically had the highest ranges of DIC. On top of this spatial-variability extraction, by extensive mapping techniques we were able to assess the presence of diel cycles. We found that lakes tended to have a strong diel cycle, with pCO2 increasing during the night but typically returning to previous concentrations over the day. However, during these diel cycles, even though we observed a strong hysteresis, pCO2 rarely rose above saturation (∼ > 400 µatm). This led us on to the ﬁnal section where we extracted full diel cycles. Due to CH4 being highly prominent in inland waters, the focus was mainly on the ﬂuxes and concentrations. We found extreme diel cycles for CH4, even more so than with pCO2. In the lakes there was a clear hysteresis linking with sunrise and sunset. With the almost linear CH4 increase and O2 decrease during the night (molar CH4:O2 ratio 1:50) this led to the explanation of strong stratiﬁcation during the day, followed by nocturnal convection during the night. This would release the build-up of CH4 in the bottom waters, mixing with the high O2 surface waters. This was further conﬁrmed by the concentrations reducing to initial conditions, such as with pCO2, following sunrise as stratiﬁcation occurred. In channels, however, this was slightly diﬀerent yet still showed the potential of stratiﬁcationwithinthewaterbody,leadingtoCH4 build-up in the bottom waters before release following the mixing during the night. Channel concentrations varied roughly a magnitude larger than lakes, however all regions of the delta were supersaturated with CH4 in comparison with the atmosphere. We found channel CH4 concentrations and ﬂuxes potentially being underestimated by up to +25% and +20% respectively when not including a full diel cycle. In lakes however, we found the opposite, with an overestimation in concentration and ﬂuxes (+3.3% and +4.2%) when not considering the diel cycle, although this greatly depends on time of the sampling. Overall, this work presents a set-up that is capable to transverse across salinity boundaries, while gathering much needed, high-resolution, spatiotemporal data. We showed the possibilities that such a set-up can do, and the signiﬁcance of sampling times in highly dynamic systems. These results conﬁrm the existence of a diel cycle that, although have been noted before, are still not considered within the global budgets or within climate and environmental models.