scholarly journals Development and application of seasonal indices of coastal-zone eutrophication

2008 ◽  
Vol 65 (8) ◽  
pp. 1469-1474 ◽  
Author(s):  
Scott A. Ryan ◽  
John C. Roff ◽  
Philip A. Yeats
Keyword(s):  
Coastal Zone ◽  
Prince Edward Island ◽  
Atlantic Coast ◽  
Nutrient Ratios ◽  
Chl A ◽  
Nutrient Levels ◽  
The North ◽  
Total Phosphorous ◽  
Seasonal Indices ◽  
Nova Scotian

Abstract Ryan, S. A., Roff, J. C., and Yeats, P. A. 2008. Development and application of seasonal indices of coastal-zone eutrophication. – ICES Journal of Marine Science, 65: 1469–1474. Indices of coastal-zone eutrophication were developed based on combined values of nitrogen, phosphorus, and phytoplankton biomass (measured as Chl a). Measurements of nitrate, ammonia, phosphate, Chl a, and total phosphorous were taken at a series of inlets (bays and estuaries) along the Atlantic coast of Nova Scotia and the north shore of Prince Edward Island in summer 2006. Reference data from offshore sites and measured data are displayed on a N (nitrogen):P (phosphorus) nutrient–space diagram, which clearly indicates thresholds between impacted and unimpacted inlets. The problem of seasonal variability in nutrient levels and phytoplankton concentrations is accounted for by using an amalgamation of the Redfield nutrient ratios and the coastal carbon–Chl a ratio and allowing for sedimentary losses. This amalgamated ratio allows for the inverse seasonal relationship between labile nutrient levels and Chl a, permitting the collection, comparison, and interpretation of seasonally variable data. Measured concentrations of phosphate were adjusted from measured Chl a and were compared with measured levels of total phosphorous for the Nova Scotian sites to assess the accuracy of conversions. Given regional calibration, these indices should be applicable to all coastal waters.

scholarly journals Phylogeography in an “oyster” shell provides first insights into the genetic structure of an extinct Ostrea edulis population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Hayer ◽  
Dirk Brandis ◽  
Alexander Immel ◽  
Julian Susat ◽  
Montserrat Torres-Oliva ◽  
...  
Keyword(s):  
Large Scale ◽  
Wadden Sea ◽  
Atlantic Coast ◽  
Phylogenetic Reconstruction ◽  
Oyster Shell ◽  
Glacial Refugia ◽  
Late Nineteenth Century ◽  
Ostrea Edulis ◽  
Geographic Ranges ◽  
The North

AbstractThe historical phylogeography of Ostrea edulis was successfully depicted in its native range for the first time using ancient DNA methods on dry shells from museum collections. This research reconstructed the historical population structure of the European flat oyster across Europe in the 1870s—including the now extinct population in the Wadden Sea. In total, four haplogroups were identified with one haplogroup having a patchy distribution from the North Sea to the Atlantic coast of France. This irregular distribution could be the result of translocations. The other three haplogroups are restricted to narrow geographic ranges, which may indicate adaptation to local environmental conditions or geographical barriers to gene flow. The phylogenetic reconstruction of the four haplogroups suggests the signatures of glacial refugia and postglacial expansion. The comparison with present-day O. edulis populations revealed a temporally stable population genetic pattern over the past 150 years despite large-scale translocations. This historical phylogeographic reconstruction was able to discover an autochthonous population in the German and Danish Wadden Sea in the late nineteenth century, where O. edulis is extinct today. The genetic distinctiveness of a now-extinct population hints at a connection between the genetic background of O. edulis in the Wadden Sea and for its absence until today.

scholarly journals Effects of a 5-year trawling ban on the local benthic community in a wind farm in the Dutch coastal zone

2014 ◽  
Vol 72 (3) ◽  
pp. 962-972 ◽  
Author(s):  
Magda J. N. Bergman ◽  
Selma M. Ubels ◽  
Gerard C. A. Duineveld ◽  
Erik W. G. Meesters
Keyword(s):  
Coastal Zone ◽  
Benthic Community ◽  
Large Scale ◽  
Wind Farm ◽  
Diversity Index ◽  
Benthic Assemblages ◽  
The North ◽  
Wiener Diversity Index ◽  
Short Period ◽  
Reference Areas

Abstract As part of a large impact study in a wind farm (OWEZ) in the Dutch coastal zone, the effects of exclusion of bottom trawling on the benthic community were studied by comparison with nearby reference areas which were regularly fished. In addition to a standard boxcorer for common macrofauna, a Triple-D dredge was used to collect longer-lived, more sparsely distributed infauna and epifauna. Multivariate analysis did not reveal any difference between the assemblages in and outside OWEZ with respect to abundance, biomass, and production after a 5-year closure. The Shannon–Wiener diversity index pointed to a significantly higher diversity in OWEZ compared with some of the reference areas. A minority of the bivalve species assumed to be sensitive to trawling showed higher abundances (Spisula solida) or larger sizes (Tellina fabula, Ensis directus) in OWEZ than in some of the reference areas. In general, samples collected with the Triple-D showed more differences between areas than boxcore samples. No evidence was also found that the species composition in OWEZ relative to the reference areas had changed in the period between 1 (2007) and 5 (2011) years after closure. The change observed in all areas between 2007 and 2011 was mainly due to relatively small variations in species abundances. In conclusion, 5 years after the closure of OWEZ to fisheries, only subtle changes were measured in the local benthic community, i.e. a higher species diversity and an increased abundance and lengths of some bivalves. Depleted adult stocks, faunal patchiness, and a limited time for recovery (5 years) might explain that a significant recovery could not be found. The current study shows that designation of large-scale marine protected areas as planned for the North Sea will not automatically imply that restoration of benthic assemblages can be expected within a relatively short period of years.

scholarly journals An estimation of the effects of Ensis directus on the transport and burial of silt in the near-shore Dutch coastal zone of the North Sea

2017 ◽  
Vol 127 ◽  
pp. 95-104 ◽  
Author(s):  
Rob Witbaard ◽  
Magda J.N. Bergman ◽  
Evaline van Weerlee ◽  
Gerard C.A. Duineveld
Keyword(s):  
Coastal Zone ◽  
North Sea ◽  
The North ◽  
Near Shore ◽  
The North Sea

Coastal inundation in the north-eastern mediterranean coastal zone due to storm surge events

2010 ◽  
Vol 15 (3) ◽  
pp. 353-368 ◽  
Author(s):  
Yannis N. Krestenitis ◽  
Yannis S. Androulidakis ◽  
Yannis N. Kontos ◽  
George Georgakopoulos
Keyword(s):  
Storm Surge ◽  
Coastal Zone ◽  
Eastern Mediterranean ◽  
Coastal Inundation ◽  
The North ◽  
North Eastern

scholarly journals V.—Geology of the Channel Islands

1878 ◽  
Vol 5 (2) ◽  
pp. 79-86 ◽  
Author(s):  
J. A. Birds
Keyword(s):  
Atlantic Coast ◽  
Channel Islands ◽  
The North ◽  
The World ◽  
Almost All ◽  
Extended View ◽  
European Coast

In the most extended view, the Channel Islands may be regarded as fragments and relics of the Eastern or European coast of the Atlantic, reckoning from the North Cape to Cape St. Vincent, and including the Western shores of Scotland and Ireland, and the promontories of Pembrokeshire and Cornwall. They are excellent illustrations, says Professor Ansted, “of those spurs and tongues of porphyritic rock, of which almost all the promontories of the Atlantic coast of Europe consist.” Very small and insignificant specks indeed they seem in such a length of coast, stretching from lat. 37° to 72°, or upwards of 2000 miles; but there is a charm in such wide horizons, and it is a very allowable indulgence so to connect the little with the great, and to consider the position of such little specks in relation to the geography of Europe; one might almost as well say, of the world at large.

scholarly journals The impact of sedimentary alkalinity release on the water column CO<sub>2</sub> system in the North Sea

2016 ◽  
Vol 13 (3) ◽  
pp. 841-863 ◽  
Author(s):  
H. Brenner ◽  
U. Braeckman ◽  
M. Le Guitton ◽  
F. J. R. Meysman
Keyword(s):  
Coastal Zone ◽  
North Sea ◽  
Dissolved Inorganic Carbon ◽  
Co2 Uptake ◽  
Overlying Water ◽  
Southern North Sea ◽  
The North ◽  
Alkalinity Generation ◽  
The North Sea ◽  
The Impact

Abstract. It has been previously proposed that alkalinity release from sediments can play an important role in the carbonate dynamics on continental shelves, lowering the pCO2 of seawater and hence increasing the CO2 uptake from the atmosphere. To test this hypothesis, sedimentary alkalinity generation was quantified within cohesive and permeable sediments across the North Sea during two cruises in September 2011 (basin-wide) and June 2012 (Dutch coastal zone). Benthic fluxes of oxygen (O2), alkalinity (AT) and dissolved inorganic carbon (DIC) were determined using shipboard closed sediment incubations. Our results show that sediments can form an important source of alkalinity for the overlying water, particularly in the shallow southern North Sea, where high AT and DIC fluxes were recorded in near-shore sediments of the Belgian, Dutch and German coastal zone. In contrast, fluxes of AT and DIC are substantially lower in the deeper, seasonally stratified, northern part of the North Sea. Based on the data collected, we performed a model analysis to constrain the main pathways of alkalinity generation in the sediment, and to quantify how sedimentary alkalinity drives atmospheric CO2 uptake in the southern North Sea. Overall, our results show that sedimentary alkalinity generation should be regarded as a key component in the CO2 dynamics of shallow coastal systems.

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