The forgotten feeding ground: patterns in seasonal and depth‐specific food intake of adult cod <scp><i>Gadus morhua</i></scp> in the western Baltic Sea

Funk, Steffen; Frelat, Romain; Möllmann, Christian; Temming, Axel; Krumme, Uwe

doi:10.1111/jfb.14615

Cited by 24 publications

(37 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The predominantly shallowwater occurrence of round goby, as evidenced in our study, may result in predation release of juveniles of commercial fish species from fish-eating birds (Johnson et al 2005). The main top predatory fish in the Baltic, cod (Gadus morhua) traditionally preys mainly on clupeids, but may shift to include substantial shares of round goby where these are abundant in coastal areas (Almqvist et al 2010;Funk et al 2020). In addition, from 2007 onwards, round goby has occurred in cod stomachs (Huwer et al 2014), suggesting that they act as prey also for cod foraging on deeper waters.…”

Section: The Ecological Implications Of Biomass Movement: Round Goby As a Competitormentioning

confidence: 68%

Seasonal depth distribution and thermal experience of the non-indigenous round goby Neogobius melanostomus in the Baltic Sea: implications to key trophic relations

et al. 2021

View full text Add to dashboard Cite

Native to the Ponto-Caspian region, the benthic round goby (Neogobius melanostomus) has invaded several European inland waterbodies as well as the North American Great Lakes and the Baltic Sea. The species is capable of reaching very high densities in the invaded ecosystems, with not only evidence for significant food-web effects on the native biota and habitats, but also negative implications to coastal fishers. Although generally considered a coastal species, it has been shown that round goby migrate to deeper areas of the Great Lakes and other inland lakes during the cold season. Such seasonal movements may create new spatio-temporal ecosystem consequences in invaded systems. To seek evidence for seasonal depth distribution in coastal marine habitats, we compiled all available catch data for round goby in the Baltic Sea since its invasion and until 2017. We furthermore related the depths at capture for each season with the ambient thermal environment. The round goby spend autumn and winter at significantly deeper and offshore areas compared to spring and summer months; few fish were captured at depths < 25 m in these colder months. Similarly, in spring and summer, round goby were not captured at depths > 25 m. The thermal conditions at which round goby were caught varied significantly between seasons, being on average 18.3 °C during summer, and dropping to a low 3.8 °C during winter months. Overall, the fish sought the depths within each season with the highest possible temperatures. The spatial distribution of the round goby substantially overlaps with that of its main and preferred prey (mussels) and with that of its competitor for food (flatfish), but only moderately with the coastal predatory fish (perch), indicating thereby very complex trophic interactions associated with this invasion. Further investigations should aim at quantifying the food web consequences and coupling effects between different habitats related to seasonal migrations of the round goby, both in terms of the species as a competitor, predator and prey.

show abstract

Section: The Ecological Implications Of Biomass Movement: Round Goby As a Competitormentioning

confidence: 68%

Seasonal depth distribution and thermal experience of the non-indigenous round goby Neogobius melanostomus in the Baltic Sea: implications to key trophic relations

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Therefore, despite a documented preference for hard substrates of high structural complexity in older juveniles and adults, cod individuals exhibit active movement patterns within the larger seascape and still make use of soft‐bottom areas to some degree (Cote et al, 2004). For example, cod may use soft‐bottom areas to forage on shore crab ( Carcinus maenas ), which is one of the main prey items for adult cod in the SW Baltic Sea (Funk et al, 2021). Still, the use of MaxN as a relative abundance metric derived from BRUVS data enabled us to discern a strong reef association for cod, while eDNA sampling did not detect any habitat association.…”

Section: Discussionmentioning

confidence: 99%

Environmental DNA reveals fine‐scale habitat associations for sedentary and resident marine species across a coastal mosaic of soft‐ and hard‐bottom habitats

et al. 2022

View full text Add to dashboard Cite

Accurate knowledge on spatiotemporal distributions of marine species and their association with surrounding habitats is crucial to inform adaptive management actions responding to coastal degradation across the globe. Here, we investigate the potential use of environmental DNA (eDNA) to detect species–habitat associations in a patchy coastal area of the Baltic Sea. We directly compare species‐specific qPCR analysis of eDNA with baited remote underwater video systems (BRUVS), two non‐invasive methods widely used to monitor marine habitats. Four focal species (cod Gadus morhua, flounder Platichthys flesus, plaice Pleuronectes platessa, and goldsinny wrasse Ctenolabrus rupestris) were selected based on contrasting habitat associations (reef‐ vs. sand‐associated species), as well as differential levels of mobility and residency, to investigate whether these factors affected the detection of species–habitat associations from eDNA. To this end, a species‐specific qPCR assay for goldsinny wrasse is developed and made available herein. In addition, potential correlations between eDNA signals and abundance counts (MaxN) from videos were assessed. Results from Bayesian multilevel models revealed strong evidence for a sand association for sedentary flounder (98% posterior probability) and a reef association for highly resident wrasse (99% posterior probability) using eDNA, in agreement with BRUVS. However, contrary to BRUVS, eDNA sampling did not detect habitat associations for cod or plaice. We found a positive correlation between eDNA detection and MaxN for wrasse (posterior probability 95%), but not for the remaining species and explanatory power of all relationships was generally limited. Our results indicate that eDNA sampling can detect species–habitat associations on a fine spatial scale, yet this ability likely depends on the mobility and residency of the target organism, with associations for sedentary or resident species most likely to be detected. Combined sampling with conventional non‐invasive methods is advised to improve detection of habitat associations for mobile and transient species, or for species with low eDNA concentrations.

show abstract

“…• Cod and whiting stomach samples were taken to supplement the Western Baltic cod stomach data base of the University of Hamburg dating back to 2016 (see Funk et al, 2021b). • Cod fin clips were taken for potential cod stock discrimination analyses using genetics.…”

Section: Fishery Datamentioning

confidence: 99%

The forgotten feeding ground: patterns in seasonal and depth‐specific food intake of adult cod Gadus morhua in the western Baltic Sea

Cited by 24 publications

References 62 publications

Seasonal depth distribution and thermal experience of the non-indigenous round goby Neogobius melanostomus in the Baltic Sea: implications to key trophic relations

Seasonal depth distribution and thermal experience of the non-indigenous round goby Neogobius melanostomus in the Baltic Sea: implications to key trophic relations

Environmental DNA reveals fine‐scale habitat associations for sedentary and resident marine species across a coastal mosaic of soft‐ and hard‐bottom habitats

Monitoring winter spawning activity of Western Baltic cod (Gadus morhua) (2021-25) Cruise No. AL568b

Contact Info

Product

Resources

About