Trends of Nitrogen and Phosphorus in Surface Sediments of the Lagoons of the Northern Adriatic Sea as a Study Case

The analysis of nutrient concentrations in surface sediments is a reliable tool for assessing the trophic status of a water body. Nitrogen and phosphorus concentrations are strongly related to the sediment characteristics but are mainly driven by anthropogenic impacts. The results of the determination of total nitrogen and total inorganic and organic phosphorus in surface sediments of the lagoons and ponds of the northwestern Adriatic Sea (Marano-Grado, Venice, Po Delta, Comacchio Valleys, Pialassa della Baiona) show the merit of this approach. Indeed, when previous data are available, the ratio between the actual and background values can provide useful information on the trophic changes that have occurred in the most recent times, and the results can also explain the conditions present in less studied environments. In this context, numerous studies performed in the Venice lagoon since the second half of the 20th century during different environmental scenarios provide mean concentration ranges and propose the main causes of changes. The results of single datasets available for the other lagoons fall into scenarios that occurred in the Venice lagoon. At present, the most eutrophic basins are Pialassa della Baiona, the Po Delta lagoons and ponds and the Comacchio valleys due to industrial effluents, fish farming and clam harvesting, respectively, whereas the Venice lagoon is now experiencing environmental recovery.

Download Full-text

Mechanisms of production and fate of organic phosphorus in the northern Adriatic Sea

Marine Biology ◽

10.1007/bf00392904 ◽

1987 ◽

Vol 94 (1) ◽

pp. 117-125 ◽

Cited By ~ 13

Author(s):

I. Ivančić ◽

D. Degobbis

Keyword(s):

Adriatic Sea ◽

Organic Phosphorus ◽

Northern Adriatic Sea ◽

Northern Adriatic

Download Full-text

On the causes of (high water) in the Northern Adriatic Sea, with special reference to the Venice Lagoon

Annals of Geophysics ◽

10.4401/ag-5013 ◽

2011 ◽

Vol 26 (2-3) ◽

Author(s):

P. CALOI

Keyword(s):

Special Reference ◽

Adriatic Sea ◽

High Water ◽

Venice Lagoon ◽

Northern Adriatic Sea ◽

Northern Adriatic

Download Full-text

Reconstructing the baseline population structure of the exploited bivalve Arca noae in the Northern Adriatic Sea

10.5194/egusphere-egu21-7694 ◽

2021 ◽

Author(s):

Saskia Macharia ◽

Rafał Nawrot ◽

Michaela Berensmeier ◽

Ivo Gallmetzer ◽

Alexandra Haselmair ◽

...

Keyword(s):

Adriatic Sea ◽

Size Structure ◽

Anthropogenic Impacts ◽

Natural State ◽

Published Data ◽

Northern Adriatic Sea ◽

Important Species ◽

Northern Adriatic ◽

Shell Bed ◽

The Impact

The Northern Adriatic Sea is one of the most impacted ecosystems worldwide with a long history of anthropogenic impacts, ranging from overfishing and bottom trawling to eutrophication, deoxygenation and pollution. The impact of these multiple pressures on populations of economically important species is often difficult to evaluate due to paucity of long-term monitoring data. The edible bivalve Noah&#8217;s Ark shell (Arca noae L.) was intensively harvested in the eastern Adriatic Sea until 1949-1950 when it suffered a catastrophic population collapse due to unknown agents. The assessment of its subsequent recovery is hindered by the lack of data on the population size structure prior to that event. To reconstruct the natural baseline state of populations of A. noae before the onset of extensive harvesting, we studied fossil assemblages from two 1.5-m-long sediment cores collected in the southern Gulf of Trieste (off Piran, Slovenia), both recording the last ~9,500 years.The abundance and shell length of A. noae remained low in the lower part of the cores but increased strongly within the oyster-Arca shell bed corresponding to maximum flooding and early highstand sea-level phases (6,500-1,000 years ago). In contrasts, the top 8 cm of the core (the late highstand phase), marked by high concentration of pollutants and organic enrichment, contained only few and small (< 10 mm) A. noae shells. Moreover, no living individuals were found in grab samples taken from the two stations suggesting that the dense populations of A. noae, persisting there for several thousand years, were locally extirpated in the 20th century. To evaluate population recovery in other parts of the NE Adriatic, we compared the size distribution of fossil A. noae from the shell bed interval to the previously published data on living populations of this species sampled along Istrian peninsula between 1966 and 1978. Both fossil and extant populations were characterized by similar median size, modal size class and proportion of specimens > 50 mm (minimal legal landing size). These results suggest that within few decades after the 1949-1950 mass mortality event the size structure of populations of A. noae have largely returned to their earlier, natural state. The recovery was spatially variable, however, as attested by the decline of A. noae populations due to loss of suitable shell-bed habitats in the two studied stations off Piran.

Download Full-text

Temporal variability of particulate organic carbon, nitrogen and phosphorus in the Northern Adriatic Sea

The Interactions between Sediments and Water ◽

10.1007/978-94-017-3366-3_44 ◽

2003 ◽

pp. 319-325

Author(s):

Michele Giani ◽

Fabio Savelli ◽

Alfredo Boldrin

Keyword(s):

Organic Carbon ◽

Particulate Organic Carbon ◽

Temporal Variability ◽

Adriatic Sea ◽

Nitrogen And Phosphorus ◽

Northern Adriatic Sea ◽

Northern Adriatic

Download Full-text

Seasonal and Interannual Trends of Oceanographic Parameters over 40 Years in the Northern Adriatic Sea in Relation to Nutrient Loadings Using the EMODnet Chemistry Data Portal

Water ◽

10.3390/w12082280 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2280 ◽

Cited By ~ 1

Author(s):

Federica Grilli ◽

Stefano Accoroni ◽

Francesco Acri ◽

Fabrizio Bernardi Aubry ◽

Caterina Bergami ◽

...

Keyword(s):

Climate Changes ◽

Management Practices ◽

Adriatic Sea ◽

Nutrient Concentrations ◽

Data Series ◽

Mean Flow ◽

Northern Adriatic Sea ◽

Po River ◽

Northern Adriatic

Long-term data series (1971–2015) of physical and biogeochemical parameters were analyzed in order to assess trends and variability of oceanographic conditions in the northern Adriatic Sea (NAS), a mid-latitude shallow continental shelf strongly impacted by river discharges, human activities and climate changes. Interpolation maps and statistical models were applied to investigate seasonal and spatial variability, as well as decadal trends of temperature, salinity, chlorophyll-a and nutrients. This analysis shows that sea surface temperature increased by +0.36% year−1 over four decades. Annual mean flow of the Po River markedly changed due to the occurrence of periods of persistent drought, whereas the frequency of flow rates higher than 3000 m3 s−1 decreased between 2006 and 2015. Moreover, we observed a long-term decrease in surface phosphate concentrations in Po River water (−1.34% year−1) and in seawater (in summer −2.56% year−1) coupled, however, to a significant increase in nitrate concentration in seawater (+3.80% year−1) in almost all seasons. These changes indicate that the nutrient concentrations in the NAS have been largely modulated, in the last forty years, by the evolution of environmental management practices and of the runoff. This implies that further alteration of the marine environment must be expected as a consequence of the climate changes.

Download Full-text

Sediment Carbon Variations in the Venice Lagoon and Other Transitional Water Systems of the Northern Adriatic Sea

Water ◽

10.3390/w12123430 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3430

Author(s):

Adriano Sfriso ◽

Alessandro Buosi ◽

Yari Tomio ◽

Abdul-Salam Juhmani ◽

Stefania Chiesa ◽

...

Keyword(s):

Inorganic Carbon ◽

Anthropogenic Impacts ◽

Venice Lagoon ◽

Total Carbon ◽

Central Basin ◽

Northern Adriatic Sea ◽

Biological Origin ◽

Northern Adriatic ◽

High Concentrations ◽

Shell Fragments

The concentrations of inorganic, organic and total carbon, and some sedimentary parameters (sediment density, fines, pH, and shell fragments), have been analyzed in surface sediments of the Venice Lagoon since 1987. Environmental scenarios, characterized by different anthropogenic impacts, have been considered, especially in the central basin where more information is available. Data collected in 2009 in the lagoons and ponds of Po Delta, in Comacchio Valleys and Pialassa della Baiona have been also considered and analyzed together with those recorded in the whole Venice Lagoon in 2011. The results show a strong correlation of the inorganic carbon (Cinorg) with the carbonatic or siliceous origins of the sediments and changes of both Cinorg and organic carbon (Corg) according to different anthropogenic impacts, especially eutrophication and clam-fishing activities. Higher sediment density, grain-size, and pH were associated to good-high ecological conditions and the higher presence of inorganic carbon of biological origin (shell fragments and calcified macroalgal fragments). Conversely, Corg, which is associated to eutrophic conditions, was strongly affected by the sediment disturbance and the presence of high concentrations of bivalves which enhance its consumption.

Download Full-text