Publications

Here you will find publications from DTU Aqua:

Recent publications

2019
 

Fish Ecology, Evolution, and Exploitation: A New Theoretical Synthesis

Year: 2019

Fish Ecology, Evolution, and Exploitation: A New Theoretical Synthesis

Andersen, K. H., 2019, New Jersey: Princeton University Press. 280 p. (Monographs in Population Biology, Vol. 62).

Research output: Book/ReportBook – Annual report year: 2019Researchpeer-review

Fish are one of the most important global food sources, supplying a significant share of the world’s protein consumption. From stocks of wild Alaskan salmon and North Sea cod to entire fish communities with myriad species, fisheries require careful management to ensure that stocks remain productive, and mathematical models are essential tools for doing so. Fish Ecology, Evolution, and Exploitation is an authoritative introduction to the modern size- and trait-based approach to fish populations and communities.

Ken Andersen covers the theoretical foundations, mathematical formulations, and real-world applications of this powerful new modeling method, which is grounded in the latest ecological theory and population biology. He begins with fundamental assumptions on the level of individuals and goes on to cover population demography and fisheries impact assessments. He shows how size- and trait-based models shed new light on familiar fisheries concepts such as maximum sustainable yield and fisheries selectivity—insights that classic age-based theory can’t provide—and develops novel evolutionary impacts of fishing. Andersen extends the theory to entire fish communities and uses it to support the ecosystem approach to fisheries management, and forges critical links between trait-based methods and evolutionary ecology.

Accessible to ecologists with a basic quantitative background, this incisive book unifies the thinking in ecology and fisheries science and is an indispensable reference for anyone seeking to apply size- and trait-based models to fish demography, fisheries impact assessments, and fish evolutionary ecology.
Original languageEnglish
Place of PublicationNew Jersey
PublisherPrinceton University Press
Number of pages280
ISBN (Print)9780691176550
ISBN (Electronic)9780691185491
Publication statusPublished - 2019
SeriesMonographs in Population Biology
Volume62
ISSN0077-0930

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Habitat Suitability for Juvenile Flatfish of the Inner Danish Waters: Section for Ecosystem Based Marine Management

Year: 2019

Habitat Suitability for Juvenile Flatfish of the Inner Danish Waters: Section for Ecosystem Based Marine Management

Brown, E. J., 2019, Kgl. Lyngby: Technical University of Denmark (DTU). 87 p.

Research output: Book/ReportPh.D. thesis – Annual report year: 2019Research

Coastal fish play important roles in ecosystem functioning in addition to their disproportionately large contribution to fisheries. By inhabiting coastal areas, fish are exposed to a wide range of human activities over and above their direct exploitation. This thesis illustrates the extent of these indirect anthropogenic impacts by reviewing evidence of human activities effects on exploited, coastal fish species from the northeast Atlantic, where ~92% of those species were impacted in at least one life-history stage. Furthermore, there is evidence of anthropogenic impacts acting on 78% of the juvenile life-history stages as they utilise coastal habitats.
With a clear need to understand the role that coastal habitats play in provisioning juveniles for replenishing exploited fish populations, this thesis continues by quantifying habitat suitability for juvenile flatfish of the inner Danish waters and establishing a method to trace their contributions to fished adult populations.
Two approaches are used to quantify habitat suitability, one obtains fish data and environmental data from a targeted survey of near-shore habitats, the other utilises existing surveys of juvenile fish and pairs it with modelled environmental data. Juvenile habitat suitability models are presented describing juvenile density and growth responses to changes in the physical environment. The results of both approaches are critically assessed and used to make interpolative maps of predicted habitat suitability across the inner Danish waters. The species-specific trends described in these models and predictions are discussed with reference to previous empirical findings from across their ranges. These two studies propose potential mechanisms creating the observed patterns of density and growth and discuss them in the context of current theories of density dependence and population connectivity.
The fourth work included in this thesis, documents the efficacy of otolith chemistry to differentiate between contiguous coastal juvenile habitats of the inner Danish waters, to enable future work on the connectivity between juvenile and adult habitats in this area as well as the neighbouring North and Baltic Seas.
Together, the four key studies that comprise the majority of this thesis provide both information for preliminary advice on the importance of juvenile habitats of the inner Danish waters, and a foundation for future work to further develop juvenile habitat models and describe the life-history connectivity of important fisheries species.
Original languageEnglish
Place of PublicationKgl. Lyngby
PublisherTechnical University of Denmark (DTU)
Number of pages87
Publication statusPublished - 2019

 

Bottom-up drivers of global patterns of demersal, forage, and pelagic fishes

Year: 2019

Bottom-up drivers of global patterns of demersal, forage, and pelagic fishes

Petrik, C. M., Stock, C. A., Andersen, K. H., van Denderen, P. D. & Watson, J., 2019, (Accepted/In press) In : Progress in Oceanography. 43 p.

Research output: Contribution to journalJournal article – Annual report year: 2019Researchpeer-review

Large-scale spatial heterogeneity in fisheries production is predominantly controlled by the availability of zooplankton and benthic organisms, which have a complex relationship with primary production. To investigate how cross-ecosystem differences in these drivers determine fish assemblages and productivity, we constructed a spatially explicit mechanistic model of three fish functional types: forage, large pelagic, and demersal fishes. The model is based on allometric scaling principles, includes basic life cycle transitions, and has trophic interactions between the fishes and with their pelagic and benthic food resources. The model was applied to the global ocean, with plankton food web estimates and ocean conditions from a high-resolution earth system model. Further, a simple representation of fishing was included, and led to moderate matches with total, large pelagic, and demersal catches, including re-creation of observed variations in fish catch spanning two orders of magnitude. Our results highlight several ecologically meaningful model sensitivities. First, the latitudinal distribution of the total catch is modulated by the temperature dependence of metabolic rates, with increased sensitivity pushing fish toward the poles. Second, coexistence between forage and large pelagic fish in productive regions occurred when forage fish survival is promoted via both favorable metabolic allometry and enhanced predator avoidance in adult forage fish. Third, the prominence of demersal fish is highly sensitive to the efficiency of energy transfer to benthic invertebrates. Fourth, forage fish biomass is suppressed by strong top-down controls on temperate and subpolar shelves, where mixed assemblages of large pelagic and large demersals exerted high predation rates. Last, spatial differences in the dominance of large pelagics vs. demersals is strongly related to the ratio of pelagic zooplankton production to benthic production. We discuss the potential linkages between model misfits and unresolved processes including movement, spawning phenology, seabird and marine mammal predators, and socioeconomically driven fishing pressure. Ultimately, our model provides a new tool for understanding, quantifying, and predicting global fish biomass and yield, now and in a future dominated by climate change and improved fishing technology.
Original languageEnglish
JournalProgress in Oceanography
Number of pages43
ISSN0079-6611
DOIs
Publication statusAccepted/In press - 2019

Bibliographical note

In press, Progress in Oceanography, doi 10.1016/j.pocean.2019.102124.

 

Consistent individual competitive ability in rainbow trout as a proxy for coping style and its lack of correlation with cortisol responsiveness upon acute stress

Year: 2019

Consistent individual competitive ability in rainbow trout as a proxy for coping style and its lack of correlation with cortisol responsiveness upon acute stress

Gesto, M., 2019, (Accepted/In press) In : Physiology & Behavior. 33 p.

Research output: Contribution to journalJournal article – Annual report year: 2019Researchpeer-review

For a given fish species, individuals are different in their ability to cope with stressors; each individual has its own set of physiological and behavioral responses to stress (stress-coping style). This individual diversity is of importance when considering the welfare of fish reared in aquaculture facilities. In this study with rainbow trout (Oncorhynchus mykiss) we investigated the link between the ability to compete for food of each individual (used as a proxy of dominance behavior/proactive stress-coping style) and its ability to cope with stress; we hypothesized that fish that are better competitors would be more robust against common aquaculture stressors. We screened 680 rainbow trout individuals for competition ability. This was done by submitting groups of 20 individuals to a 1-week competition trial where they were kept at low stocking density and were provided a restricted amount of food. A 15% of the screened fish were selected as “winners” and another 15% were selected as “losers”, based on growth rates during the competition trials. Fish were re-tested in a second competition trial after several weeks, to assess for consistency of competitive ability. Winner and loser fish were individually exposed to confinement and their neuroendocrine stress response was evaluated (serotonergic activity in telencephalon and brain stem, plasma levels of cortisol, glucose and lactate). Furthermore, behavioral responses to confinement and net restraining tests were also investigated. The results showed good temporal consistency of competitive ability in the lapse of time of the experiments. Besides, competitive ability showed a positive association to fish activity during the net restraining tests. However, plasma stress marker data showed a lack of relevant differences between the acute stress responses of winner and loser fish, adding up to the body of evidence suggesting that stress responsiveness might not be consistently linked to SCS in vertebrates. This, together with the inability of winner fish to outperform loser fish in usual stocking density conditions, suggests that there is no clear welfare or performance benefits in selecting fish of a specific coping style for fish farming, at least in the domesticated trout population used in the current study.
Original languageEnglish
JournalPhysiology & Behavior
Number of pages33
ISSN0031-9384
DOIs
Publication statusAccepted/In press - 2019


https://www.aqua.dtu.dk/english/about/publications
19 JUNE 2019