Plastic ingestion by pelagic and demersal fish from the North Sea and Baltic Sea

2016 ◽  
Vol 102 (1) ◽  
pp. 134-141 ◽  
Author(s):  
Christoph D. Rummel ◽  
Martin G.J. Löder ◽  
Nicolai F. Fricke ◽  
Thomas Lang ◽  
Eva-Maria Griebeler ◽  
...  
2012 ◽  
Vol 69 (1) ◽  
pp. 8-22 ◽  
Author(s):  
Simon P. R. Greenstreet ◽  
Helen M. Fraser ◽  
Stuart I. Rogers ◽  
Verena M. Trenkel ◽  
Stephen D. Simpson ◽  
...  

Abstract Greenstreet, S. P. R., Fraser, H. M., Rogers, S. I., Trenkel, V. M., Simpson, S. D., and Pinnegar, J. K. 2012. Redundancy in metrics describing the composition, structure, and functioning of the North Sea demersal fish community. – ICES Journal of Marine Science, 69: 8–22. Broader ecosystem management objectives for North Sea demersal fish currently focus on restoring community size structure. However, most policy drivers explicitly concentrate on restoring and conserving biodiversity, and it has not yet been established that simply restoring demersal fish size composition will be sufficient to reverse declines in biodiversity and ensure a generally healthy community. If different aspects of community composition, structure, and function vary independently, then to monitor all aspects of community general health will require application of a suite of metrics. This assumes low redundancy among the metrics used in any such suite and implies that addressing biodiversity issues specifically will require explicit management objectives for particular biodiversity metrics. This issue of metric redundancy is addressed, and 15 metrics covering five main attributes of community composition, structure, and function are applied to groundfish survey data. Factor analysis suggested a new interpretation of the metric information and indicated that a minimum suite of seven metrics was necessary to ensure that all changes in the general health of the North Sea demersal fish community were monitored properly. Covariance among size-based and species-diversity metrics was low, implying that restoration of community size structure would not necessarily reverse declines in species diversity.


2014 ◽  
Vol 14 (15) ◽  
pp. 21943-21974 ◽  
Author(s):  
J. E. Jonson ◽  
J. P. Jalkanen ◽  
L. Johansson ◽  
M. Gauss ◽  
H. A. C. Denier van der Gon

Abstract. Land-based emissions of air pollutants in Europe have steadily decreased over the past two decades, and this decrease is expected to continue. Within the same time span emissions from shipping have increased, although recently sulphur emissions, and subsequently particle emissions, have decreased in EU ports and in the Baltic Sea and the North Sea, defined as SECAs (Sulphur Emission Control Areas). The maximum allowed sulphur content in marine fuels in EU ports is now 0.1%, as required by the European Union sulphur directive. In the SECAs the maximum fuel content of sulphur is currently 1% (the global average is about 2.4%). This will be reduced to 0.1% from 2015, following the new IMO rules (International Maritime Organisation). In order to assess the effects of ship emissions in and around the Baltic Sea and the North Sea, regional model calculations with the EMEP air pollution model have been made on a 1/4° longitude × 1/8° latitude resolution, using ship emissions in the Baltic Sea and the North Sea that are based on accurate ship positioning data. The effects on depositions and air pollution and the resulting number of years of life lost (YOLL) have been calculated by comparing model calculations with and without ship emissions in the two sea areas. The calculations have been made with emissions representative of 2009 and 2011, i.e. before and after the implementation of stricter controls on sulphur emissions from mid 2010. The calculations with present emissions show that per person, an additional 0.1–0.2 years of life lost is estimated in areas close to the major ship tracks with present emission levels. Comparisons of model calculations with emissions before and after the implementation of stricter emission control on sulphur show a general decrease in calculated particle concentration. At the same time, however, an increase in ship activity has resulted in higher emissions and subsequently air concentrations, in particular of NOx, especially in and around several major ports. Additional model calculations have been made with land based and ship emissions representative of year 2030. Following a decrease in emissions, air quality is expected to improve, and depositions to be reduced. Particles from shipping are expected to decrease as a result of emission controls in the SECAs. Further controls of NOx emissions from shipping are not decided, and calculations are presented with and without such controls.


2009 ◽  
Vol 75 (1-2) ◽  
pp. 138-149 ◽  
Author(s):  
Jørgen Bendtsen ◽  
Karin E. Gustafsson ◽  
Johan Söderkvist ◽  
Jørgen L.S. Hansen

2016 ◽  
Vol 52 (4) ◽  
pp. 523-531 ◽  
Author(s):  
Mette Møller Nielsen ◽  
Cristina Paulino ◽  
João Neiva ◽  
Dorte Krause-Jensen ◽  
Annette Bruhn ◽  
...  

2019 ◽  
Vol 6 (9) ◽  
pp. 190886 ◽  
Author(s):  
Aurora García-Berro ◽  
Johanna Yliportimo ◽  
Kai Lindström ◽  
Charlotta Kvarnemo

The operational sex ratio (OSR, ready-to-mate males to females) is a key factor determining mating competition. A shortage of a resource essential for reproduction of one sex can affect OSR and lead to competition within the opposite sex for resource-holding mates. In the sand goby ( Pomatoschistus minutus ), a fish with paternal care, male readiness to mate depends on acquiring a nest-site, whereas food abundance primarily impacts female egg production. Comparing body condition and gonadal investment of fish from two populations with different availability in resources (Baltic Sea: few nest-sites, more food; North Sea: many nest-sites, less food), we predicted females carrying more mature eggs in the Baltic Sea than in the North Sea. As predicted, ovaries were larger in Baltic Sea females, and so was the liver (storage of energy reserves and vitellogenic compounds) for both sexes, but particularly for females. More females were judged (based on roundness scores) to be ready to spawn in the Baltic Sea. Together with a nest colonization experiment confirming a previously documented difference between the two areas in nest-site availability, these results indicate a more female-biased OSR in the Baltic Sea population, compared to the North Sea, and generates a prediction that female–female competition for mating opportunities is stronger in the Baltic population. To our knowledge, this is the first time that female reproductive investment is discussed in relation to OSR using field data.


2020 ◽  
Vol 77 (5) ◽  
pp. 1772-1786 ◽  
Author(s):  
A D Rijnsdorp ◽  
J G Hiddink ◽  
P D van Denderen ◽  
N T Hintzen ◽  
O R Eigaard ◽  
...  

Abstract Fisheries using bottom trawls are the most widespread source of anthropogenic physical disturbance to seafloor habitats. To mitigate such disturbances, the development of fisheries-, conservation-, and ecosystem-based management strategies requires the assessment of the impact of bottom trawling on the state of benthic biota. We explore a quantitative and mechanistic framework to assess trawling impact. Pressure and impact indicators that provide a continuous pressure–response curve are estimated at a spatial resolution of 1 × 1 min latitude and longitude (∼2 km2) using three methods: L1 estimates the proportion of the community with a life span exceeding the time interval between trawling events; L2 estimates the decrease in median longevity in response to trawling; and population dynamic (PD) estimates the decrease in biomass in response to trawling and the recovery time. Although impact scores are correlated, PD has the best performance over a broad range of trawling intensities. Using the framework in a trawling impact assessment of ten métiers in the North Sea shows that muddy habitats are impacted the most and coarse habitats are impacted the least. Otter trawling for crustaceans has the highest impact, followed by otter trawling for demersal fish and beam trawling for flatfish and flyshooting. Beam trawling for brown shrimps, otter trawling for industrial fish, and dredging for molluscs have the lowest impact. Trawling is highly aggregated in core fishing grounds where the status of the seafloor is low but the catch per unit of effort (CPUE) per unit of impact is high, in contrast to peripheral grounds, where CPUE per unit of impact is low.


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