22 research outputs found
Organotin compounds in surface sediments of the Southern Baltic coastal zone: a study on the main factors for their accumulation and degradation
Abstract Sediment samples were collected in the Gulf of
GdaĆsk, and the Vistula and Szczecin Lagoonsâall located
in the coastal zone of the Southern Baltic Seaâjust after the
total ban on using harmful organotins in antifouling paints on
ships came into force, to assess their butyltin and phenyltin
contamination extent. Altogether, 26 sampling stations were
chosen to account for different potential exposure to organotin
pollution and environmental conditions: from shallow and
well-oxygenated waters, shipping routes and river mouths,
to deep and anoxic sites. Additionally, the organic carbon
content, pigment content, and grain size of all the sediment
samples were determined, and some parameters of the nearbottom
water (oxygen content, salinity, temperature) were
measured as well. Total concentrations of butyltin compounds
ranged between 2 and 182 ng Sn gâ1 d.w., whereas phenyltins
were below the detection limit. Sediments from the Gulf of
GdaĆsk and Vistula Lagoon were found moderately contaminated
with tributyltin, whereas those from the Szczecin
Lagoon were ranked as highly contaminated. Butyltin degradation
indices prove a recent tributyltin input into the sediments
adjacent to sites used for dumping for dredged harbor
materials and for anchorage in the Gulf of GdaĆsk (where two
big international ports are located), and into those collected in
the Szczecin Lagoon. Essential factors affecting the degradation
and distribution of organotins, based on significant correlations
between butyltins and environmental variables, were
found in the study area
Abundance of a chlorophyll a precursor and the oxidation product hydroxychlorophyll a during seasonal phytoplankton community progression in the Western English Channel
This study presents the first in-situ measurements of the chlorophyll a oxidation product, hydroxychlorophyll a as well as the chlorophyll a precursor, chlorophyll aP276 conducted over an annual cycle. Chlorophyll a oxidation products, such as hydroxychlorophyll a may be associated with the decline of algal populations and can act as an initial step in the degradation of chlorophyll a into products which can be found in the geochemical record, important for studying past climate change events. Here, hydroxychlorophyll a and chlorophyll aP276 were measured at the long-term monitoring station L4, Western Channel Observatory (UK, www.westernchannelobservatory.org) over an annual cycle (2012). Weekly measurements of phytoplankton species composition and abundance enabled detailed analysis of possible sources of hydroxychlorophyll a. Dinoflagellates, 2 diatom species, the prymnesiophyte Phaeocystis spp. and the coccolithophorid Emiliania huxleyi were all associated with hydroxychlorophyll a occurrence. However, during alternate peaks in abundance of the diatoms, no association with hydroxychlorophyll a occurred, indicating that the oxidation of chlorophyll a was dependant not only on species but also on additional factors such as the mode of mortality, growth limiting factor (i.e. nutrient concentration) or phenotypic plasticity. Surface sediment samples contained 10 times more hydroxychlorophyll a (relative to chlorophyll a) than pelagic particulate samples, indicating that more chlorophyll a oxidation occurred during sedimentation or at the sediment-water interface, than in the pelagic environment. In addition, chlorophyll aP276 correlated with chl-a concentration, thus supporting its assignment as a chl-a precursor
Occurrence of chlorophyll allomers during virus-induced mortality and population decline in the ubiquitous picoeukaryote Ostreococcus tauri
During viral infection and growth limitation of the picoeukaryote Ostreococcus tauri, we examined the relationship between membrane permeability, oxidative stress and chlorophyll allomers (oxidation products). Chlorophyll allomers were measured in batch-cultures of O. tauri in parallel with maximum quantum efficiency of photosystem II photochemistry (Fv/Fm), carotenoids, and reactive oxygen species and membrane permeability using fluorescent probes (CM-H2DCFDA and SYTOX-Green). Viral infection led to mass cell lysis of the O. tauri cells within 48 h. The concentration of the allomer hydroxychlorophyll a peaked with a 16-fold increase (relative to chlorophyll-a) just after the major lysis event. In contrast, cell death due to growth limitation resulted in a 2-fold increase in allomer production, relative to chl-a. Two allomers were detected solely in association with O. tauri debris after viral lysis, and unlike other allomers were not observed before viral lysis, or during cell death due to growth limitation. Conversely, the component chl-aP276 was found in the highest concentrations relative to chl-a, in exponentially growing O. tauri. The components described have potential as indicators of mode of phytoplankton mortality, and of population growth
Algal pigments in Hornsund (Svalbard) sediments as biomarkers of Arctic productivity and environmental conditions
Pigments (chloropigments-a and carotenoids) in sediments and macroalgae samples, collected in Hornsund, in July 2015 and July 2016, were analysed (HPLC) in this work. In spite of the aerobic conditions and the periodic intensive solar irradiation in the Arctic environment, neither of which favour pigment preservation in water column and surface sediments, our results indicate that these compounds can provide information about phytoplankton composition, primary production and environmental conditions in this region. The sum of chloropigments-a, a marker of primary production, in the Hornsund sediments varied from 0.40 to 14.97 nmol/g d.w., while the sum of carotenoids ranged from 0.58 to 8.08 nmol/g d.w. Pheophorbides-a and pyropheophorbides-a made up the highest percentage in the sum of chloropigments-a in these sediments, supplying evidence for intensive zooplankton and/or zoobenthos grazing. Among the carotenoids, fucoxanthin and its derivatives (19â-hexanoyloxyfucoxanthin and 19â-hexanoyloxy-4-ketofucoxanthin) contributed the highest percentage, which points to the occurrence mainly of diatoms and/or haptophytes in the water. The pigment markers show that the input of macroalgae to the total biomass could be considerable only in the intertidal zone
Tracking trends in eutrophication based on pigments in recent coastal sediments
Eutrophication in two different coastal areas â the Gulf of GdaĆsk (southern Baltic) and the Oslofjord/Drammensfjord (Norway) â both subject to human pressure and with restricted water exchange with adjacent seas, was investigated and compared. Sediment cores (up to 20 cm long) were collected at 12 stations using a core sampler, 6 in each of the two areas, and divided into sub-samples. The physicochemical parameters characterizing the adjacent water column and near-bottom water, i.e. salinity, oxygen concentration and temperature, were measured during sample collection. Chlorophylls-a, -b and -c, their derivatives and selected carotenoids were determined for all the samples, as were additional parameters characterizing the sediments, i.e. Corg, Ntot, ÎŽ13C and ÎŽ15N, grain size. 210Pb activity was also determined and on that basis sediment mixing and accumulation rates were estimated. The distribution of pigments in sediments was related to environmental conditions, the sampling site location and sediment characteristics. The results are in agreement with other observations that eutrophication in the Gulf of GdaĆsk has increased, especially since the 1970s, whereas in the Oslofjord it decreased during the same period. The pigments are better preserved in inner Oslofjord sediments than in those from the Gulf of GdaĆsk. The results demonstrate that the sum of chloropigments-a in sediments calculated per dry weight of sediments is a valuable measure of eutrophication, providing that the monitoring site is selected properly, i.e. sediments are hypoxic/anoxic and non-mixed. Besides, the results confirm previous observations that the percentages of particular chlorophyll-a derivatives in the sum of chloropigments-a are universal markers of environmental conditions in a basin. The ratios of chloropigments-b and chlorophylls-c to the sum of chloropigments-a (ÎŁChlns-b/ÎŁChlns-a; Chls-c/ÎŁChlns-a) may by applied as complementary markers of freshwater and marine organic matter input, respectively
Canthaxanthin in recent sediments as an indicator of heterocystous cyanobacteria in coastal waters
Summary: The mean share of heterocystous cyanobacteria in total chlorophyll-a production in coastal waters, based on cyanobacterial marker carotenoid and chloropigments preserved in recent sediments (0â5 cm, ca 30 years), has been studied in the Gulf of GdaĆsk (southern Baltic) and for comparison in the Oslofjord/Drammensfjord (southern Norway). First of all, Baltic cyanobacteria, both from laboratory cultures and field samples, were analysed to select marker heterocysteous cyanobacteria carotenoids for sediments. The pigment relation to diatom percentages of different salinity preferences has been tested, to confirm origin of cyanobacteria. The results indicate that canthaxanthin is the best marker of heterocystous cyanobacteria in the southern Baltic Sea. These filamentous cyanobacteria inflow to the Gulf of GdaĆsk from the open sea and their abundance has increased in the last thirty years, in comparison with previous time. In that period they made up ca 4.6% of the total chlorophyll-a production in the Gulf of GdaĆsk. The estimate for Oslofjord, at the same assumptions, suggests that heterocystous cyanobacteria occurred there also (up to 5.8% of the total chlorophyll-a production), were of marine origin, but their abundance has decreased during the last thirty years. Such an estimate may be used in environmental modelling and can be applied to other coastal areas, once the marker pigments of the main cyanobacteria species have been identified, and the percentage of total chlorophyll-a produced in a basin, preserved in sediments, has been determined for such area. Keywords: Cyanobacteria, Carotenoids, Canthaxanthin, Gulf of GdaĆsk (southern Baltic), Oslofjor
Factors affecting the occurrence of algae on the Sopot beach (Baltic Sea)
This study was financed by the EU CosCo project ("Regional cycle development through coastal co-operation - sea grass and algae focus" - INTERREG IIIC 2N00251) and the statutory IO PAS programme.AbstractThe occurrence of algae on the Sopot beach was investigated from 2004 to 2006 from the beach management point of view. Various methods were applied in an attempt to understand the mechanisms underlying the accumulation of algae on the shoreline. They included daily observations of the occurrence of macrophyta on the beach, absorption measurements of acetone extracts of the particulate matter in the seawater, the collection of macrophyta and phytoplankton samples for biomass and taxonomic identification, and determination of the degree of decomposition on the basis of chloropigment analyses. The results were related to the environmental conditions: meteorological data and the physico-chemical parameters of the seawater. The biomass recorded on the beach consisted mainly of macroalgae and a small proportion of sea grass (Zostera marina). The phytoplankton biomass consisted mainly of dinoflagellates, diatoms, cyanobacteria, euglenoids and cryptophytes. The conclusions to be drawn from this work are that the occurrence of huge amounts of macrophyta amassing on the Sopot beach depends on the combined effect of high solar radiation in spring and summer, high-strength (velocity Ă frequency) south-westerly winds in May-September, followed by northerly winds, bringing the macrophyta from Puck Bay on to the Sopot beach. At the same time, their abundance along the beach varies according to the shape and height of the shore, the wind strength and the local wind-driven seawater currents. According to estimates, from 2.2-4.4 Ă 102 tons (dry weight) of macrophyta can be moved on to the Sopot beach in one hour. In October, strong south-easterly winds can also transport huge amounts of decomposing biomass onshore. The phytoplankton content in the total biomass is negligible, even though at low concentrations its biological activity may be considerable. The intensive phytoplankton blooms observed on the Sopot beach in summer are not always caused by cyanobacteria