Monitoring van paraffine-achtige stoffen op Nederlandse stranden en in magen van Noordse Stormvogels

Within the KB-Program System Earth Management 2018 (KB-24-002-036) a pilot study was conducted into options to monitor of paraffin- or palmfat-like substances on Dutch beaches and in stomachs of corpses of beached Northern Fulmars. Such substances are, in part legally, discharged by tanker ships cleaning their tanks at sea.Paraffin was chemically identified by the presence of alkanes in the samples. It remains to be investigated in detail which other mineral oil derivatives may show similar alkane patterns. In the absence of alkanes further analyses were conducted to assess the type of material involved.Samples taken from beaches showed to be paraffin in 30 of 32 analyses (94%). One sample contained palmoil related substances, one sample remained unclear but contained phthalates (eg used as plastic softeners). The materials from bird stomachs proved to be different. Paraffin was only found in 31% of 32 samples. In 41% of the stomachs vegetable fatty substances were demonstrated, usually palm oil related. The remainder of samples had an uncertain mix of vegetable and animal fats. The difference between beaches and bird stomachs may have several backgrounds, including attraction for wildlife, melting points, and biodegradability.Over 20% of fulmars found in the Netherlands has chemical suspect materials in the stomach. Not much is known about potential health impacts. Over the years no clear changes can be detected. Quantities of material ingested are highly variable. Frequency of occurrence may slightly reduce over the more recent years, but there is no statistically significant trend. It would make sense to add records on chemical suspect materials in fulmar stomachs to the existing monitoring of plastics in the framework of OSPAR and the EU Marine Strategy Framework Directive. Clearly chemical analyses of substances encountered on beaches and in birds is additionally recommended

Adding insult to injury : effects of chronic oxybenzone exposure and elevated temperature on two reef -building corals

Coral bleaching due to global warming currently is the largest threat to coral reefs, which may be exacerbated by altered water quality. Elevated levels of the UV filter oxybenzone in coastal waters as a result of sunscreen use have recently been demonstrated. We studied the effect of chronic oxybenzone exposure and elevated water temperature on coral health. Microcolonies of Stylophora pistillata and Acropora tenuis were cultured in 20 flow-through aquaria, of which 10 were exposed to oxybenzone at a field-relevant concentration of ~0.06 μg L−1 at 26 °C. After two weeks, half of the corals experienced a heat wave culminating at 33 °C. All S. pistillata colonies survived the heat wave, although heat reduced growth and zooxanthellae density, irrespective of oxybenzone. Acropora tenuis survival decreased to 0% at 32 °C, and oxybenzone accelerated mortality. Oxybenzone and heat significantly impacted photosynthetic yield in both species, causing a 5% and 22–33% decrease, respectively. In addition, combined oxybenzone and temperature stress altered the abundance of five bacterial families in the microbiome of S. pistillata. Our results suggest that oxybenzone adds insult to injury by further weakening corals in the face of global warming

Improving the knowledge basis for advice on North Sea horse mackerel : developing new methods to get insight on stock boundaries and abundance

The North Sea horse mackerel stock is currently classified by ICES as a data poor stock, for which the catch advice is based on the trend in an abundance index. The development of an analytical stock assessment, necessary to give more accurate advice, is hampered by a number of limitations on the input data, among which the most important are the poor quality of catch-at-age data and the absence of a targeted survey for North Sea horse mackerel. The aim of this project was to study possibilities to improve the data quality used for an analytical stock assessment model

Occurrence of halogenated flame retardants in commercial seafood species available in European markets

PBDEs (congeners 28, 47, 99, 100, 153, 154, 183, 209), HBCD (α, β, γ), emerging brominated flame retardants (PBEB, HBB and DBDPE), dechloranes (Dec 602, 603, 604, syn- and anti-DP), TBBPA, 2,4,6-TBP and MeO-PBDEs (8 congeners) were analysed in commercial seafood samples from European countries. Levels were similar to literature and above the environmental quality standards (EQS) limit of the Directive 2013/39/EU for PBDEs. Contaminants were found in 90.5% of the seafood samples at n. d.-356 ng/g lw (n. d.-41.1 ng/g ww). DBDPE was not detected and 2,4,6-TBP was detected only in mussels, but at levels comparable to those of PBDEs. Mussel and seabream were the most contaminated species and the Mediterranean Sea (FAO Fishing Area 37) was the most contaminated location. The risk assessment revealed that there was no health risk related to the exposure to brominated flame retardants via seafood consumption. However, a refined risk assessment for BDE-99 is of interest in the future. Moreover, the cooking process concentrated PBDEs and HB

Experimental validation of geosmin uptake in rainbow trout, Oncorhynchus mykiss (Waldbaum) suggests biotransformation

The bioconcentration of waterborne geosmin in rainbow trout, Oncorhynchus mykiss (Waldbaum) was assessed. Fifty rainbow trout with a mean (SD) weight of 226.6 (29.0) g and lipid content of 6.2 (0.6) % (w/w) were exposed to geosmin in static water for 0, 2, 4, 6, 8, 12, 24, 36, 48 and 120 hr, with one tank containing five fish for eac h exposure period. Geosmin concentrations were measured in fish tissue and water samples collected over time. With time the geosmin concentration in the fish increased and decreased in the water. However, the total absolute amount of geosmin in the system declined over time which could be explained by induction of biotransformation. This is in accordance with the decreasing lipid normalized geosmin levels in the liver compared with the liver-free carcass. Geosmin distribution within rainbow trout clearly is not exclusively governed by the lipid content of tissues. In vivo geosmin bioconcentration in rainbow trout is slower and the body burden reached is lower than the generally accepted theoretical model predicts

Monitoring van paraffine-achtige stoffen op Nederlandse stranden en in magen van Noordse Stormvogels

Within the KB-Program System Earth Management 2018 (KB-24-002-036) a pilot study was conducted into options to monitor of paraffin- or palmfat-like substances on Dutch beaches and in stomachs of corpses of beached Northern Fulmars. Such substances are, in part legally, discharged by tanker ships cleaning their tanks at sea.Paraffin was chemically identified by the presence of alkanes in the samples. It remains to be investigated in detail which other mineral oil derivatives may show similar alkane patterns. In the absence of alkanes further analyses were conducted to assess the type of material involved.Samples taken from beaches showed to be paraffin in 30 of 32 analyses (94%). One sample contained palmoil related substances, one sample remained unclear but contained phthalates (eg used as plastic softeners). The materials from bird stomachs proved to be different. Paraffin was only found in 31% of 32 samples. In 41% of the stomachs vegetable fatty substances were demonstrated, usually palm oil related. The remainder of samples had an uncertain mix of vegetable and animal fats. The difference between beaches and bird stomachs may have several backgrounds, including attraction for wildlife, melting points, and biodegradability.Over 20% of fulmars found in the Netherlands has chemical suspect materials in the stomach. Not much is known about potential health impacts. Over the years no clear changes can be detected. Quantities of material ingested are highly variable. Frequency of occurrence may slightly reduce over the more recent years, but there is no statistically significant trend. It would make sense to add records on chemical suspect materials in fulmar stomachs to the existing monitoring of plastics in the framework of OSPAR and the EU Marine Strategy Framework Directive. Clearly chemical analyses of substances encountered on beaches and in birds is additionally recommended