By estimating probabilistic reaction norms for age and size at maturation, we show that maturation schedules of Atlantic cod (Gadus morhua) off Labrador Newfoundland shifted toward earlier ages smaller sizes during the late 1980s early 1990s, when these populations underwent a severe collapse in biomass subsequently were closed directed commercial fishing. We also demonstrate this trend towards younger is halted even shows signs reversal closure fisheries. In addition, our analysis reveals...

A key question in many genetic studies on marine organisms is how to interpret a low but statistically significant level of differentiation. Do such observations reflect real phenomenon, or are they caused by confounding factors as unrepresentative sampling selective forces acting the marker loci? Further, levels differentiation biologically trivial, can represent meaningful and perhaps important finding? We explored these issues an empirical study coastal Atlantic cod, combining temporally...

In several species genetic differentiation across environmental gradients or between geographically separate populations has been reported to center at "genomic islands of divergence," resulting in heterogeneous patterns genomes. Here, genomic regions elevated divergence were observed on three chromosomes the highly mobile fish Atlantic cod (Gadus morhua) within fine-scaled coastal areas. The islands" extended least 5, 9.5, and 13 megabases linkage groups 2, 7, 12, respectively, coincided...

Marine protected areas (MPAs) are increasingly implemented as tools to conserve and manage fisheries target species. Because there opportunity costs conservation, is a need for science-based assessment of MPAs. Here, we present one the northernmost documentations MPA effects date, demonstrated by replicated before-after control-impact (BACI) approach. In 2006, MPAs were along Norwegian Skagerrak coast offering complete protection shellfish partial fish. By 2010, European lobster (Homarus...

Harvesting wild populations may contrast or reinforce natural agents of selection and potentially cause evolutionary changes in life-history traits such as growth maturation. Harvest also act on behavioral traits, although this field research has so far received less attention. We used acoustic tags a network receivers to monitor the behavior fate individual Atlantic cod (Gadus morhua, N = 60) their habitat Norwegian Skagerrak coast. Fish with strong diel vertical migration, alternating...

Abstract For marine fish, the choice of spawning location may be only means to fulfil dual needs surviving from egg juvenile stage and dispersing across different habitats while minimizing predation maximizing food intake. In this article, we review factors that affect fish propose a framework distinguish between ecological evolutionary constraints. We define former as boundaries for phenotypically plastic responses environmental change, in case ability specific genotypes change their...

Habitat selection is a complex process, which involves behavioural decisions guided by the multiple needs and constraints faced individuals. Climate-induced changes in environmental conditions may alter those trade-offs resulting habitat use patterns. In this study, we investigated effect of sea temperature on acoustically tagged Atlantic cod (Gadus morhua) at Norwegian Skagerrak coast. Significant relationships between ocean were found. Under favourable thresholds (<16 °C), selected...

The effects of oil spills on marine biological systems are great concern, especially in regions with high production harvested resources such as the Northeastern Atlantic. scientific studies impact fish stocks tend to ignore that spatial patterns natural mortality may influence magnitude over time. Here, we first illustrate how variation affect population by considering a thought experiment. Second, consider an empirically based example Northeast Arctic cod extend concept realistic setting....

Abstract Genetic divergence among populations arises through natural selection or drift and is counteracted by connectivity gene flow. In sympatric populations, isolating mechanisms are thus needed to limit the homogenizing effects of flow allow for adaptation speciation. Chromosomal inversions act as an important mechanism maintaining barriers, yet their role in with not entirely understood. Here, we revisit question whether play a connected marine fish Atlantic cod ( Gadus morhua ),...

In order to provide better fisheries management and conservation decisions, there is a need discern the underlying relationship between spawning stock recruitment of marine fishes, which influenced by environmental conditions. Here, we demonstrate how conditions (temperature food availability for fish larvae) influence stock-recruitment indeed what kind might see under different Using unique zooplankton data from Continuous Plankton Recorder, find that (i.e. zooplankton) in essence...

Understanding how populations respond to changes in climate requires long-term, high-quality datasets, which are rare for marine systems. We estimated the effects of warming on cod lengths and length variability using a unique 91-y time series more than 100,000 individual juvenile from surveys that began 1919 along Norwegian Skagerrak coast. Using linear mixed-effects models, we accounted spatial population structure nested survey data reveal opposite spring summer lengths. Warm temperatures...

Although growing evidence supports the idea that animal personality can explain plasticity in response to changes social environment, it remains be tested whether spatial responses of individuals face natural environmental fluctuations. This is a major challenge ecology and evolution as dynamics link individual- population-level processes. In this study, we investigated potential individual personalities predict differences fish behaviour wild. Specifically, our goal was answer if space use...

Coexistence in the same habitat of closely related yet genetically different populations is a phenomenon that challenges our understanding local population structure and adaptation. Identifying underlying mechanisms for such coexistence can yield new insight into adaptive evolution, diversification potential organisms to adapt persist response changing environment. Recent studies have documented cryptic, sympatric Atlantic cod (Gadus morhua) coastal areas. We analysed genetic origin 6,483...

Abstract Acoustic telemetry has become a popular means of obtaining individual behavioural data from wide array species in marine and freshwater systems. Fate information is crucial to understand important aspects population dynamics such as mortality, predation or dispersal rates. Here we present method infer fate acoustic arrays receivers with overlapping detection ranges. Our depends exclusively on animal movements the characteristics configuration equipment. By answering limited number...

Understanding the responses of aquatic animals to temperature variability is essential predict impacts future climate change and inform conservation management. Most ectotherms such as fish are expected adjust their behaviour avoid extreme temperatures minimize acute changes in body temperature. In coastal Skagerrak, Norway, sea surface (SST) ranges seasonally from 0 over 20°C, representing a challenge community which includes cold-, cool- warm-water affinity species. By acoustically...

In the last decade, ocean has absorbed a quarter of Earth's greenhouse gas emissions through carbon (C) cycle, naturally occurring process. Aspects C cycle are now being incorporated into climate change mitigation and adaptation plans. Currently, too little is known about marine vertebrate functions for their inclusion in policies. Fortunately, biology, behavior, ecology lens nutrient cycling flux an emerging area research that rich existing data. This review uses literature trusted data...

Life on Earth has been characterized by recurring cycles of ecological stasis and disruption, relating biological eras to geological climatic transitions through the history our planet. Due increasing degree abruption caused human influences many advocate that we now have entered era Anthropocene, or "the age man." Considering ongoing mass extinction ecosystem reshuffling observed worldwide, a better understanding drivers will be requisite for identifying routes intervention mitigation....

Injection of visible implant elastomer (VIE) was evaluated as a way to provide age-0 brown trout Salmo trutta with externally internal marks. We first tested this fluorescent material in laboratory experiment using single color and body position batch-mark the fish (28.9–44.1 mm fork length). The lasted for 77 d, no mortality or tag loss significant (P = 0.44) effect on growth. Similar marks were then used individually (26–70 mm) small streams wild four different colors several positions....

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 333:249-255 (2007) - doi:10.3354/meps333249 Egg distribution, bottom topography and small-scale cod population structure in a coastal marine system Halvor Knutsen1,2,*, Esben Moland Olsen1,2, Lorenzo Ciannelli2,4, Sigurd Heiberg Espeland2, Jan Atle Knutsen1, Henrik Simonsen1, Stig Skreslet3, Nils Chr....

Reproductive success and its determinants are difficult to infer for wild populations of species with no parental care where behavioural observations or impossible. In this study, we characterized the breeding system provide estimates individual reproductive under natural conditions an exhaustively sampled stream-resident brown trout (Salmo trutta) population. We inferred parentage using a full probability Bayesian model that combines genetic (microsatellite) phenotypic data. By augmenting...

Harvesting of marine resources raises concerns about how to identify and preserve biocomplexity, including the diversity life histories found within among wild populations a species. In order fully accomplish this, there is need elucidate underlying causes phenotypic variation, this variation responds environmental changes. general, both evolutionary (genetic) nonevolutionary (plastic) responses may occur. Plastic change are expected shift phenotype along reaction norm, while an response...