scholarly journals [Waders and seabirds (Charadriiformes) nesting along the north-eastern Adriatic coastline (Veneto and Friuli-Venezia Giulia) in 2008-2014: abundance, trends and major conservation issues]

2019 ◽  
Vol 88 (2) ◽  
pp. 33-41 ◽  
Author(s):  
Francesco Scarton ◽  
Emiliano Verza ◽  
Carlo Guzzon ◽  
Paolo Utmar ◽  
Giacomo Sgorlon ◽  
...  
Keyword(s):  
Abundant Species ◽  
Venice Lagoon ◽  
Water Levels ◽  
Common Tern ◽  
Fish Farms ◽  
The North ◽  
Ne Italy ◽  
The Common ◽  
Sandwich Tern ◽  
Friuli Venezia Giulia

[In 2008-2014 wader and seabird nesting pairs were censused along the 220-km long coastline of the NE Adriatic Sea, in the Veneto and Friuli-Venezia Giulia regions (NE Italy). Fourteen species were regularly breeding, with an annual mean of 20,610 pairs (±1553, 1 SD). The most abundant species was the Yellow-legged Gull (about 13,400 pairs on average, 65% of the whole population of the study area), followed by the Common Tern (1670 pairs, 8.1%) and Common Redshank (1525 pairs, 7.4%). The whole population of waders and seabirds increased with an annual rate, estimated with the TRIM software, of +0.8%, with a greater increase (+4.3%) if the Yellow-legged Gull was not included. Twelve species were stable or increasing; only the yellow-legged gull (-1%) and the common redshank (-2.4%) were decreasing. The populations of several species exceed 10% of those estimated for the whole of Italy; those of the Eurasian Oystercatcher, Common Redshank and Sandwich Tern are among the most important in the whole Mediterranean. On average, about 8860 pairs (43%) nest in the Venice lagoon, 6,400 pairs (31%) in the Po Delta, 5100 pairs (25%) in the Friuli-Venezia Giulia lagoons. Among nesting habitats, semi-natural (such as the fish farms) and man-made sites (dredge islands) make each year about 70% of the nesting pairs. Saltmarsh islets host large numbers of Common Redshank and Sandwich Tern, while along the beach zone the only abundant species are the Yellow-legged Gull and the Eurasian Oystercatcher. The major conservation threats observed in the study area were the erosion of littoral islands, the uncontrolled occurrence of sunbathers along the beaches, the vegetation overgrowth at dredge islands, the increasing frequency of saltmarsh submersion by high tides, the strong fluctuations of water levels inside the fish farms.] [Article in Italian]

scholarly journals Interactions between fish resources and Cormorants Phalacrocorax carbo in the Grado and Marano lagoon (NE Italy)

Acrocephalus ◽  
2009 ◽  
Vol 30 (140) ◽  
pp. 17-23 ◽  
Author(s):  
Mauro Cosolo ◽  
Paolo Utmar ◽  
Flavio Roppa ◽  
Stefano Sponza
Keyword(s):  
Fish Consumption ◽  
Adriatic Sea ◽  
High Variability ◽  
Fish Farms ◽  
Phalacrocorax Carbo ◽  
Fishing Activity ◽  
Fish Removal ◽  
Fish Resources ◽  
Ne Italy ◽  
Friuli Venezia Giulia

Interactions between fish resources and CormorantsPhalacrocorax carboin the Grado and Marano lagoon (NE Italy)The aim of this study was to determine the importance of different environments for CormorantPhalacrocorax carbobiology in the Grado and Marano lagoon (Friuli Venezia Giulia, NE Italy, Upper Adriatic Sea), and to estimate the levels of fish removal within such areas. Data were collected on Cormorant abundance and the amount of fish consumed in two fishing valli (Valle Noghera and Valle Artalina) and in three tidal areas (Goppion, Cavanata sea, Grado and Marano lagoon). The number of Cormorants per 100 ha was relatively low in all the study areas. The highest density of feeding cormorants in November (24 birds/100 ha) was in Valle Noghera. The latter is ascribed to an isolated event of 50 birds in social fishing activity. During the rest of the November survey time (72% of the total), lower densities were noted (2.5 birds/100 ha). Fish consumption was also relatively low. In Valle Artalina the maximum was 6.8 kg/100 ha in December. The highest fish consumption was estimated in Valle Noghera in November (41.9 kg/100 ha) and in the Grado and Marano lagoon in January (7.6 kg/100 ha). In fish farms, the highest fish consumption is recorded in November and December, exclusively within wintering basins and canals. So these areas should be covered with wire nets. Furthermore, considering the high variability and irregularity of fish removal, the use of active deterring methods (e.g. gas cannons) can give good results, especially if applied during social fishing events.

scholarly journals Long term trends and breeding parameters of Gull-billed Tern Gelochelidon nilotica in three Italian coastal sites

2020 ◽  
Vol 89 (2) ◽  
Author(s):  
Marcello Grussu ◽  
Francesco Scarton ◽  
Emiliano Verza ◽  
Roberto G. Valle
Keyword(s):  
Venice Lagoon ◽  
Water Levels ◽  
Strong Increase ◽  
Sudden Increase ◽  
Fish Ponds ◽  
Lagoon Of Venice ◽  
Fish Farms ◽  
Breeding Parameters ◽  
Salt Pans ◽  
Po Delta

Between 2001 and 2018 colonies of Gull-billed Tern were monitored in large wetland complexes of Veneto (lagoon of Venice and the Northern Po Delta) and Sardinia (western and southern) regions. Most of the colonies settled in man-made structures such as islets, levees, dams, located inside fish farms, fish ponds and salt pans. Laying took place around half May until early June (Veneto), with eggs occurring in the nests until half July (Sardinia). Colonies had 3-230 pairs, with several instances of isolated pairs; colonies were mono- or plurispecific, with other Charadriiformes. The number of eggs per clutch was 2.6±0.6 (N=111, 1 SD) in the Venice lagoon, 2.6±0.6 (N=182) in the Po delta, 2.3±0.70 (N=1007) in Sardinia; hatched eggs were 2.2±0.6 (N=111), 2.0±0.7 (N=182) and 1.7±0.67 (N=40) per nest, respectively. The most important cause of breeding failure was due to flooding of nesting sites, due to the rapid increase of water levels inside fish farms and salt pans. During the 2001-2018 years, the Gull-billed Tern nested regularly in Sardinia, whereas in the Po Delta the first nesting occurred in 2001 and in the lagoon of Venice in 2008. The whole population ranged between 34 and 417 pairs until 2017 (223.6±113.4, N=17), with a sudden increase up to almost 1,000 pairs in 2018; the overall trend is of strong increase (p<0.01), with an annual rate of 10.5%.

scholarly journals The Influence of Spring Flood Water Levels on the Distribution and Numbers of Terns (On the Example of the Lower Desna River)

2015 ◽  
Vol 49 (5) ◽  
pp. 439-446 ◽  
Author(s):  
N. S. Atamas’ ◽  
O. V. Tomchenko
Keyword(s):  
Water Levels ◽  
Common Tern ◽  
Landsat 8 ◽  
River Bed ◽  
Breeding Habitats ◽  
Water Conditions ◽  
Floodplain Inundation ◽  
The Common ◽  
Black Tern ◽  
Chlidonias Niger

The floodplain reservoirs of the lower Desna River are known to represent suitable breeding habitats for the Black Tern (Chlidonias niger) and the White-winged Tern (Chlidonias leucoptera), while the Common Tern (Sterna hirundo) and the Little Tern (Sterna albifrons) nest on sandy islands and river spits at the river bed. We combined analysis of Landsat 8 satellite images and the breeding abundance of the lower Desna River resident terns to investigate if the levels of the floodplain inundation affect the terns’ distribution and numbers. Under the high flood conditions of 2013, we observed a significant decrease in the numbers of colonies and nesting pairs of the Common and Little Terns, which was probably caused by the delayed exposure of their breeding habitats at the river bed. In contrast, in the low water conditions of 2014, areas of sandy islands and river spits increase in the form of temporary sandbanks. Under low-water conditions, we observed a marked increase of the number of colonies and nesting pairs of the Little Tern, while the White-winged Tern disappeared from nesting sites and the Black Tern decreased in numbers.

scholarly journals Linear Transect Surveys of Abundance and Density of Cetaceans in The Area Near the Dzharylgach Island in the North-Western Black Sea

2017 ◽  
Vol 51 (4) ◽  
pp. 335-342
Author(s):  
E. V. Gladilina ◽  
K. A. Vishnyakova ◽  
O. O. Neprokin ◽  
Yu. F. Ivanchikova ◽  
T. A. Derkacheva ◽  
...  
Keyword(s):  
Black Sea ◽  
Coastal Area ◽  
Bottlenose Dolphins ◽  
Habitat Preferences ◽  
Abundant Species ◽  
Cetacean Species ◽  
The North ◽  
The Common ◽  
Common Dolphins ◽  
North Western

Abstract The first assessment of cetacean density and abundance by linear transect survey was conducted in 2016 and 2017 in the shallowest coastal area of the Ukrainian sector of the north-western Black Sea, in the Dzharylgach Gulf and the northern Karkinit Gulf, total area up to 259 km2. Three cetacean species were found present in the area in summer, and the harbour porpoise was the most abundant species with the abundance of at least a few hundred animals (estimated as 175 individuals in the Dzharylgach Gulf), whereas the common dolphins (59) and bottlenose dolphins (31) were present in lesser numbers. Common and bottlenose dolphins showed the clearest patterns of habitat preferences, being restricted respectively to the Dzharylgach and the northern Karkinit Gulf; an unusual trait is the preference of the shallowest habitat by common dolphins. Recorded density of harbour porpoises in the Dzharylgach Gulf is among the highest in the whole Black Sea. Thus, the studied area may be an important summer habitat for cetaceans.

Environmental impact of nutrients from nordic fish farming

1995 ◽  
Vol 31 (10) ◽  
pp. 61-71 ◽  
Author(s):  
M. Enell
Keyword(s):  
Major Part ◽  
Fish Farming ◽  
Fish Farms ◽  
Feed Composition ◽  
The North ◽  
Comprehensive Development ◽  
The Baltic ◽  
Inland Water Bodies ◽  
The Impact ◽  
Feed Coefficient

During the last 20 years there has been an interesting development of the Nordic fish farming, with regard to the feeding and farming technology and to the increase in production quantities. During the period 1974-1994 the production increased from 15,800 to about 250,000 tonnes/year. In 1974 the major part of the production was in Denmark, and in 1994 the major part was in Norway. The nutrient impact of fish farming on surrounding sea areas is mainly a function of the feed coefficient, the feed composition and metabolic processes in the fish. The comprehensive development of the feed composition and the feeding technology has resulted in reduced load of unmetabolized nutrients from fish farms, calculated per tonne fish produced. In 1974 the mean Nordic feed coefficient was 2.08 and in 1994 the coefficient was 1.25. Feed coefficients of 1.0-1.1 are now reported for Danish and Norwegian freshwater and marine fish farms. The nitrogen (N) and phosphorus (P) content of the feed has decreased, in addition the quality of the nutrient substances in the feed has changed, especially for N. The N content has decreased from 7.8 to 6.8% during the period 1974-1994 and the content of P has decreased from 1.7 to 0.7% during the same period. This development of the feed coefficient and the feed composition has resulted in a present load from a typical Nordic fish farm of 55 kg N and 4.8 kg P/t fish produced. The figures for 1974 were 132 kg N and 31 kg P/t fish produced. The Nordic fish farming production in 1994 resulted in a load of about 13,750 t N and about 1,200 t P on the actual recipients. The load from the Swedish, Finnish and Danish fish farming operations, with the Baltic Sea and the Skagerrak as the recipients, is negligible in comparison with other pollution sources. The quantities of N and P from the fish farming are equal to 0.5% of the atmospheric deposition on the sea surface and 3% of the atmospheric P load. Norwegian, Icelandic and the Faroe Islands fish farming operations are using the North Sea and the Norwegian Sea as the recipients. However, the nutrient load from single fish farms in certain coastal and inland water bodies can be significant and must be considered in the impact assessment together with other sources.

Lake and inland dunes as interconnected Systems: The story of Lake Tresssee and an adjacent dune field (Schleswig-Holstein, North Germany)

The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling
Keyword(s):  
Water Level ◽  
Bronze Age ◽  
Environmental Changes ◽  
High Water ◽  
Alluvial Fan ◽  
Water Levels ◽  
Lake Area ◽  
Dune Field ◽  
The North ◽  
Sand Drift

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.

scholarly journals Deep-Water Cartilaginous Fishes in the Central Mediterranean Sea: Comparison between Geographic Areas with Two Low Impact Tools for Sampling

2021 ◽  
Vol 9 (7) ◽  
pp. 686
Author(s):  
Angela Carluccio ◽  
Francesca Capezzuto ◽  
Porzia Maiorano ◽  
Letizia Sion ◽  
Gianfranco D’Onghia
Keyword(s):  
Adriatic Sea ◽  
Fish Habitat ◽  
Conservation Status ◽  
Abundant Species ◽  
Cartilaginous Fish ◽  
Fish Diversity ◽  
Ionian Sea ◽  
Central Mediterranean ◽  
The North ◽  
North Western

Baited lander represents a low impact technique, an alternative to the traditional trawl sampling for collecting data on fish diversity and abundance, especially for threatened species such as Chondrichthyes living in sensitive habitats. In this study, distribution and abundance of cartilaginous fish were compared between two geographic areas, the southern Adriatic Sea and the north-western Ionian Sea, with two low impact sampling gears, an experimental bottom longline and a baited lander. Species diversity was evaluated by applying ecological indices and difference in mean abundances were tested using multivariate analysis. A total of 13 species of cartilaginous fish were collected. Significant differences in the assemblage recorded in the same area using different sampling tools were detected and no significant differences were detected among different areas explored with the same method. Using longline, the most abundant species collected in both areas was Galeus melastomus, while using lander, the most observed species were Dalatias licha in the southern Adriatic Sea and Hexanchus griseus in the north-western Ionian Sea. According to IUCN classification, of the 13 species collected, 2 are near threatened and 5 are threatened. A better governance of sensitive habitats coinciding with the essential fish habitat for these species would ensure them a better conservation status.

Further Investigation upon the Water Movements in the English Channel. Drift-Bottle Experiments in the Summers of 1927, 1928 and 1929, with Critical Notes on Drift-Bottle Experiments in General.

1930 ◽  
Vol 17 (1) ◽  
pp. 241-275 ◽  
Author(s):  
J. N. Carruthers
Keyword(s):  
Wind Speed ◽  
North Sea ◽  
English Channel ◽  
The North ◽  
Different Types ◽  
The North Sea ◽  
The Common ◽  
Relationship Of ◽  
Great Simplicity ◽  
Simple Surface

In July–August of three different years common surface-floating bottles were set adrift at International Station E2 (49° 27' N.—4° 42' W.). With them, various types of drag-fitted bottles were also put out. The journeys accomplished are discussed, and the striking differences as between year and year in the case of the common surface floaters, and as between the different types in the same year, are commented upon in the light of the prevailing winds. An inter-relationship of great simplicity is deduced between wind speed and the rate of travel of simple surface floating bottles up-Channel and across the North Sea from the results of experiments carried out in four different summers.

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