Assessing the performance of statistical classifiers to discriminate fish stocks using Fourier analysis of otolith shape

The assignment of individual fish to its stock of origin is important for reliable stock assessment and fisheries management. Otolith shape is commonly used as the marker of distinct stocks in discrimination studies. Our literature review showed that the application and comparison of alternative statistical classifiers to discriminate fish stocks based on otolith shape is limited. Therefore, we compared the performance of two traditional and four machine learning classifiers based on Fourier analysis of otolith shape using selected stocks of Atlantic cod (Gadus morhua) in the southern Baltic Sea and Atlantic herring (Clupea harengus) in the western Norwegian Sea, Skagerrak, and the southern Baltic Sea. Our results showed that the stocks can be successfully discriminated based on their otolith shapes. We observed significant differences in the accuracy obtained by the tested classifiers. For both species, support vector machines (SVM) resulted in the highest classification accuracy. These findings suggest that modern machine learning algorithms, like SVM, can help to improve the accuracy of fish stock discrimination systems based on the otolith shape.

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Content of metals in flounder, Platichthys flesus L., and Baltic herring, Clupea harengus membras L., from the southern Baltic Sea

Archives of Polish Fisheries ◽

10.2478/v10086-012-0006-2 ◽

2012 ◽

Vol 20 (1) ◽

Cited By ~ 1

Author(s):

Kamila Pokorska ◽

Mikołaj Protasowicki ◽

Kinga Bernat ◽

Monika Kucharczyk

Keyword(s):

Baltic Sea ◽

Clupea Harengus ◽

Southern Baltic Sea ◽

Platichthys Flesus ◽

Baltic Herring ◽

Southern Baltic

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Diet composition of herring (Clupea harengus L.) and cod (Gadus morhua L.) in the southern Baltic Sea in 2007 and 2008

Oceanological and Hydrobiological Studies ◽

10.2478/s13545-011-0046-z ◽

2011 ◽

Vol 40 (4) ◽

Cited By ~ 6

Author(s):

Diana Dziaduch

Keyword(s):

Baltic Sea ◽

Diet Composition ◽

Gadus Morhua ◽

Clupea Harengus ◽

The Baltic Sea ◽

Commercial Fish ◽

Southern Baltic Sea ◽

Starting Point ◽

Southern Baltic ◽

The Baltic

AbstractDiet composition of two commercial fish species, herring and cod, were studied in some regions (mainly Gda’nsk and Bornholm Basins, and the Polish coast) of the southern Baltic Sea in 2007 and 2008. Herring is the dominant zooplanktivorous species in the ecosystem of the Baltic Sea, but apart from mesoplanktonic organisms it also eats macroplanktonic and benthic species in considerable amount. The diet of cod consists of fish and crustaceans from pelagic, hyperbenthic and benthic habitats. The feeding preferences of fish indirectly reflect changes in the whole food chain in the Baltic Sea. This research focuses specifically on these invertebrate species, which are eliminated from the environment by most of the ichthyofauna of this region. The aim of this research is to examine the role of invertebrate organisms belonging to Crustacea in the diet of herring and adult cod to supply updated results about feeding of these fish as little data have been collected since the 1990s. The present study is a preliminary survey and results can not be considered conclusive. The restricted numbers of analyzed stomachs of fish and selected seasons of the year addressed in this paper are a starting point for further studies with a larger scope. In this study, 20 to 90% of herring had empty stomachs. Mesozooplankton dominated the diets of small and large herring. Mysidacea, which were historically important prey for herring, are now scarce and have been replaced by planktonic Amphipoda. In the case of cod, consumption of Mysidacea has never been as low as in this study. As for other invertebrate prey, the benthic isopod Saduria and Crangon shrimp achieved the highest amount by number and weight. These results show distinct changes in diet when compared to previous investigations and require verification at a larger spatial scale.

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Reference organisms for assessing the impact of ionizing radiation on the environment of the southern Baltic Sea

Oceanological and Hydrobiological Studies ◽

10.2478/s13545-012-0033-z ◽

2012 ◽

Vol 41 (4) ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Tamara Zalewska ◽

Maria Suplińska

Keyword(s):

Ionizing Radiation ◽

Baltic Sea ◽

Benthic Fauna ◽

Clupea Harengus ◽

Assessment System ◽

Ecological Niches ◽

Hediste Diversicolor ◽

Southern Baltic Sea ◽

Southern Baltic ◽

The Impact

AbstractAssessing the impact of ionizing radiation on the marine environment requires a well-defined methodology, which includes, among other elements, the analysis of exposure and effects. One of the most important components of the assessment system is the choice of reference organisms specific for the assessed area that fulfill requirements such as radioecological sensitivity, widespread distribution, and amenability to research and monitoring. The following species specific to the southern Baltic Sea that represent diversified ecological niches were proposed as reference organisms. Polysiphonia fucoides was proposed as a representative of macroalgae. Pelagic and benthic fauna were represented by Crangon crangon (crustacean), Saduria entomon (crustacean), Hediste diversicolor (polychaete), and Mytilus trossulus (mollusc). Fish were represented by Clupea harengus (pelagic planctotrophic fish), Gadus morhua (pelagic carnivorous fish), and Platichthys flesus (benthic fish). Activity concentrations of 137Cs were determined in reference biota as well as in seawater, as required for the total dose-rate evaluation, and relevant concentration factors were calculated.

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Implementing ecosystem-based fisheries management: from single-species to integrated ecosystem assessment and advice for Baltic Sea fish stocks

ICES Journal of Marine Science ◽

10.1093/icesjms/fst123 ◽

2013 ◽

Vol 71 (5) ◽

pp. 1187-1197 ◽

Cited By ~ 63

Author(s):

Christian Möllmann ◽

Martin Lindegren ◽

Thorsten Blenckner ◽

Lena Bergström ◽

Michele Casini ◽

...

Keyword(s):

Baltic Sea ◽

Fisheries Management ◽

Gadus Morhua ◽

Single Species ◽

Clupea Harengus ◽

Fish Stock ◽

Fish Stocks ◽

The Baltic ◽

Ecosystem Based Fisheries Management ◽

Sea Fish

Abstract Theory behind ecosystem-based management (EBM) and ecosystem-based fisheries management (EBFM) is now well developed. However, the implementation of EBFM exemplified by fisheries management in Europe is still largely based on single-species assessments and ignores the wider ecosystem context and impact. The reason for the lack or slow implementation of EBM and specifically EBFM is a lack of a coherent strategy. Such a strategy is offered by recently developed integrated ecosystem assessments (IEAs), a formal synthesis tool to quantitatively analyse information on relevant natural and socio-economic factors, in relation to specified management objectives. Here, we focus on implementing the IEA approach for Baltic Sea fish stocks. We combine both tactical and strategic management aspects into a single strategy that supports the present Baltic Sea fish stock advice, conducted by the International Council for the Exploration of the Sea (ICES). We first review the state of the art in the development of IEA within the current management framework. We then outline and discuss an approach that integrates fish stock advice and IEAs for the Baltic Sea. We intentionally focus on the central Baltic Sea and its three major fish stocks cod (Gadus morhua), herring (Clupea harengus), and sprat (Sprattus sprattus), but emphasize that our approach may be applied to other parts and stocks of the Baltic, as well as other ocean areas.

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Environmental genotoxicity and cytotoxicity in flounder (Platichthys flesus), herring (Clupea harengus) and Atlantic cod (Gadus morhua) from chemical munitions dumping zones in the southern Baltic Sea

Marine Environmental Research ◽

10.1016/j.marenvres.2013.08.012 ◽

2014 ◽

Vol 96 ◽

pp. 56-67 ◽

Cited By ~ 25

Author(s):

Janina Baršienė ◽

Laura Butrimavičienė ◽

Wlodzimierz Grygiel ◽

Thomas Lang ◽

Aleksandras Michailovas ◽

...

Keyword(s):

Baltic Sea ◽

Gadus Morhua ◽

Atlantic Cod ◽

Clupea Harengus ◽

Southern Baltic Sea ◽

Platichthys Flesus ◽

Southern Baltic ◽

Environmental Genotoxicity

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Feeding preferences of herring (Clupea harengus) and sprat (Sprattus sprattus) in the southern Baltic Sea

ICES Journal of Marine Science ◽

10.1016/j.icesjms.2003.12.011 ◽

2004 ◽

Vol 61 (8) ◽

pp. 1267-1277 ◽

Cited By ~ 94

Author(s):

Michele Casini ◽

Massimiliano Cardinale ◽

Fredrik Arrhenius

Keyword(s):

Baltic Sea ◽

Entire Range ◽

Field Studies ◽

Clupea Harengus ◽

Feeding Preferences ◽

Southern Baltic Sea ◽

Mysis Mixta ◽

Temora Longicornis ◽

Southern Baltic ◽

Autumn And Winter

Abstract No field studies have been performed on the selectivity of herring and sprat in the southern Baltic Sea in relation to their entire range of prey. Accordingly, we tested in the field the following hypotheses: (i) sprat and herring are selective feeders and (ii) sprat and herring selectivity is size- and season-dependent. The results show that (i) smaller herring and all size classes of sprat are strictly zooplanktivorous, selecting principally Temora longicornis and Bosmina maritima during the autumn and Pseudocalanus elongatus in winter; (ii) larger herring are essentially nektobenthos feeders, predating on Mysis mixta during the autumn and amphipods and polychaetes during the winter; and (iii) herring and sprat seem to avoid Acartia spp. in both autumn and winter. During the autumn, herring are zooplanktivorous up to 18–20 cm, whereas in winter herring feed on nektobenthos starting from 14–15 cm. Selectivity was not an absolute process but it was related to prey relative abundance in the sea and, possibly, to prey profitability (e.g. size, conspicuousness, and reaction time).

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Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)

Oceanological and Hydrobiological Studies ◽

10.2478/v10009-008-0017-x ◽

2008 ◽

Vol 37 (4) ◽

Cited By ~ 6

Author(s):

Małgorzata Leśniewska ◽

Małgorzata Witak

Keyword(s):

Baltic Sea ◽

The South ◽

Gulf Of Gdańsk ◽

The Baltic Sea ◽

Southern Baltic Sea ◽

Gulf Of Gdansk ◽

Southern Baltic ◽

The Baltic ◽

Palaeoenvironmental Changes

Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)The palaeoenvironmental changes of the south-western part of the Gulf of Gdańsk during the last 8,000 years, with reference to the stages of the Baltic Sea, were reconstructed. Diatom analyses of two cores taken from the shallower and deeper parts of the basin enabled the conclusion to be drawn that the microflora studied developed in the three Baltic phases: Mastogloia, Littorina and Post-Littorina. Moreover, the so-called anthropogenic assemblage was observed in subbottom sediments of the study area.

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