Relative Population Growth Research Articles

Modeling Population Growth under Climate Stressors Using Age-Structured Matrix Models.

Climate resilience, a focus of many recent studies, has been examined from ecological, physiological, and evolutionary perspectives. However, sampling biases toward adults, males, and certain species have made establishing the link between environmental change and population-level change problematic. Here, we used data from four laboratory studies, in which we administered pre- and postnatal stressors, such as suboptimal incubation temperature, heat stress, and food restriction, to zebra finches. We then quantified hatching success, posthatch survival, and reproductive success, to parameterize age-structured population dynamics models with the goal of estimating the effect of the stressors on relative population growth rates. Using the same model structure, we tested the hypothesis that early life stages influence population growth rate more than later life stages. Our models suggested that stressful events during embryonic development, such as suboptimal incubation temperatures and reduced gas exchange for the embryos, have a greater total impact on population growth than posthatch stressors, such as heat stress and food restriction. However, among life history traits, differences in hatching success and sex ratio of offspring in response to stressors changed population growth rates more than differences in any other demographic rate estimates. These results suggest that when predicting population resilience against climate change, it is critical to account for effects of climate change on all life stages, including early stages of life, and to incorporate individuals' physiology and stress tolerance that likely influence future stress responses, reproduction, and survival.

An urban emergy footprint: Comparing supply- and use-extended input-output models for the case of Vienna, Austria

Urban activities currently consume 75% of global final energy demand, which is expected to increase given absolute and relative population growth in cities. Assessments of both producer (upstream) and consumer (downstream) ecological and socioeconomic impacts of urban inter-industry exchanges are needed to reduce energy consumption and resource use behind the industrial footprints of cities. Environmental extensions in the input-output analysis are designed from the user side perspective, focusing only on commercial energy supply and use. This study introduced emergy-evaluated supply-extended and use-extended carbon footprint models for Vienna and compared their empirical and conceptual implications. Emergy-evaluated footprints of Vienna's urban consumption were estimated by combining industrial and systems ecology approaches as per the research question, based on previous investigations of GHG emissions and energy supply- and use-extensions. Results showed that the ranking of footprints of final product categories is sensitive to the evaluation method, with products of extractive and manufacturing industries differing by more than 10% depending on whether emergy or carbon evaluation is chosen. The emergy-based comparison further reveals that for products of extractive industries, the difference between use and supply extension results can be more than 20% as opposed to carbon-based comparison with the difference between supply and use extension results for services not even amounting to 5%. Future studies could address the over-estimation of direct energy supply to the economy, under-estimation of product and service, inconsistency in standard use-extension design, and challenges in assembling emergy-evaluated supply and use extensions. Fundings are relevant for unified responsibility assessment of upstream and downstream sectors without prioritising structural features.

Life history strategies among soil bacteria—dichotomy for few, continuum for many

Study of life history strategies may help predict the performance of microorganisms in nature by organizing the complexity of microbial communities into groups of organisms with similar strategies. Here, we tested the extent that one common application of life history theory, the copiotroph-oligotroph framework, could predict the relative population growth rate of bacterial taxa in soils from four different ecosystems. We measured the change of in situ relative growth rate to added glucose and ammonium using both 18O–H2O and 13C quantitative stable isotope probing to test whether bacterial taxa sorted into copiotrophic and oligotrophic groups. We saw considerable overlap in nutrient responses across most bacteria regardless of phyla, with many taxa growing slowly and few taxa that grew quickly. To define plausible life history boundaries based on in situ relative growth rates, we applied Gaussian mixture models to organisms’ joint 18O–13C signatures and found that across experimental replicates, few taxa could consistently be assigned as copiotrophs, despite their potential for fast growth. When life history classifications were assigned based on average relative growth rate at varying taxonomic levels, finer resolutions (e.g., genus level) were significantly more effective in capturing changes in nutrient response than broad taxonomic resolution (e.g., phylum level). Our results demonstrate the difficulty in generalizing bacterial life history strategies to broad lineages, and even to single organisms across a range of soils and experimental conditions. We conclude that there is a continued need for the direct measurement of microbial communities in soil to advance ecologically realistic frameworks.

Predation risk affects the ecotoxicity evaluation of antibiotics: Population growth and antioxidase activity in the ciliate Paramecium jenningsi

Although predation risk exists under natural conditions, its role is usually ignored when evaluating the ecotoxicity of environmental contaminants, and the interaction between predation risk and antibiotic ecotoxicity is not yet clear. To investigate the nonconsumptive effects (NCEs) of predation on the ecotoxicity evaluation of antibiotics, the median lethal concentration (LC50), relative population growth rate (RGR), and activities of three antioxidases were measured in the ciliate Paramecium jenningsi exposed to graded concentrations of the antibiotics nitrofurazone (NFZ) or erythromycin (ERY) in the presence or absence of a predator, i.e., the ciliate Didinium nasutum. The results showed that (1) NCEs significantly reduced the LC50 of NFZ but had no effect on that of ERY; (2) predation pressure alone had no significant effect on the inhibitory rate of the P. jenningsi population, but the interaction with NFZ was synergistic, while that with CRY was additive; (3) the concentrationresponse (i.e., mortality) model for each antibiotic exposure with and without predation pressure differed significantly in the parameter slope; (4) RGRs were significantly reduced by antibiotic exposure or NCEs; only in NFZ-exposed groups did the RGRs decrease linearly with increasing exposure concentration; and (5) the activities of all three antioxidases significantly increased due to NCEs or following exposure to antibiotics. In brief, NCEs were detected in P. jenningsi, and these had additive or synergistic effects on antibiotic ecotoxicity, but their magnitude depended on the properties and exposure concentrations of the antibiotics. Our findings suggest that it is necessary to consider the roles of NCEs in the ecotoxicity evaluation of environmental contaminants.

Breeding ground temperature rises, more than habitat change, are associated with spatially variable population trends in two species of migratory bird

Habitat loss and climate change are key drivers of global biodiversity declines but their relative importance has rarely been examined. We attempted to attribute spatially divergent population trends of two Afro‐Palaearctic migrant warbler species, Willow Warbler Phylloscopus trochilus and Common Chiffchaff Phylloscopus collybita, to changes in breeding grounds climate or habitat. We used bird counts from over 4000 sites across the UK between 1994 and 2017, monitored as part of the BTO/JNCC/RSPB Breeding Bird Survey. We modelled Willow Warbler and Common Chiffchaff population size and growth in relation to habitat, climate and weather. We then used the abundance model coefficients and observed environmental changes to determine the extent to which spatially varying population trends in England and Scotland were consistent with attribution to climate and habitat changes. Both species' population size and growth correlated with habitat, climate and weather on their breeding grounds. Changes in habitat, in particular woodland expansion, could be linked to small population increases for both species in England and Scotland. Both species' populations correlated more strongly with climate than weather, and both had an optimum breeding season temperature: 11°C for Willow Warbler and around 13.5°C for Common Chiffchaff (with marginally different predictions from population size and growth models). Breeding ground temperature increases, therefore, had the potential to have caused some of the observed Willow Warbler declines in England (where the mean breeding season temperature was 12.7°C) and increases in Scotland (mean breeding season temperature was 10.2°C), and some of the differential rates of increase for Common Chiffchaff. However, much of the variation in species' population abundance and trends were not well predicted by our models and could be due to other factors, such as species interactions, habitat and climate change in their wintering grounds and on migration. This study provides evidence that the effect of climate change on a species may vary spatially and may switch from being beneficial to being detrimental if a temperature threshold is exceeded.

Human Paleodemography and Paleoecology of the North Pacific Rim from the Mid to Late Holocene.

Using 14 proxy human population time series from around the North Pacific (Alaska, Hokkaido and the Kuril Islands), we evaluate the possibility that the North Pacific climate and marine ecosystem includes a millennial-scale regime shift cycle affecting subsistence and migration. We develop both visual and statistical methods for addressing questions about relative population growth and movement in the past. We introduce and explore the use of a Time Iterative Moran I (TIMI) spatial autocorrelation method to compare time series trends quantitatively - a method that could prove useful in other paleoecological analyses. Results reveal considerable population dynamism around the North Pacific in the last 5000 years and strengthen a previously reported inverse correlation between Northeast and Northwest Pacific proxy population indices. Visual and TIMI analyses suggest multiple, overlapping explanations for the variability, including the potential that oscillating ecological regime shifts affect the North Pacific basin. These results provide an opening for coordinated research to unpack the interrelated social, cultural and environmental dynamics around the subarctic and arctic North Pacific at different spatial and temporal scales by international teams of archaeologists, historians, paleoecologists, paleoceanographers, paleoclimatologists, modelers and data management specialists.

The Destiny of Living Animals Imported into Chinese Zoos

Ex situ conservation is one of the major ways to strengthen biodiversity conservation. In China, ex situ conservation institutions mainly include zoos, aquariums, and breeding centers. In 1996, China began to import living animals duty-free for conservation purposes. Here, we built a dataset of nearly 300 vertebrate species (mammals, birds, fish and reptiles) imported into China over this past 20 years by interviewing all 123 institutions importing animals duty-free during 1996–2015. We then analyzed the annual variation of the species composition and individual numbers of these imported species, and quantified the relative population growth rate of each imported species for the first time. We found that the number of living animals imported into China decreased significantly year by year. The number of imported bird species and reptile individuals decreased the most, but the population growth rate was increasing for about half of the imported threatened species. We recommend that conservation institutions should enhance communication and promote cooperative breeding among them. Scientific research and sustainability assessments of threatened species should also be enhanced, which will allocate trade licenses and quotas more effectively. We hope that the data presented in this paper will contribute to the development of conservation policies, leading to stronger management of these imported species in China.

REVIEW ESSAY

This essay reviews ecological economist, Giorgos Kallis’ recent book, ‘Why Malthus Was Wrong and Why Environmentalists Should Care’ (2019) to review the debate around population and sustainability. In the name of sustainability and resource scarcity, debates on population tend to blame the poor without adequately problematizing structural inequalities that sustain racial capitalism and stimulate scarcity. This narrative is a remnant of the Malthusian thesis that problematized population growth in relation to food scarcity without problematizing utilitarian human wants. In this essay, I review this book because the author expands on the politics of scarcity and urges us to nurture ethics and the politics of limits. My contribution in this extended review comes in offering a perspective from post‐colonial countries like India, and in the global South more broadly, that align with ‘other’ notions of limits, the good life, and sustainability.

Economic Impacts of Violent Conflicts in Nasarawa State, Nigeria

The study analysed the impacts of violent conflicts on the economies of rural communities in Nasarawa State, Nigeria. Primary data were collected from the respondents using a structured interview schedule, while focus group discussions (FGD) sessions were employed to assess effects of conflicts on communities. Data were analysed using simple descriptive statistics, alternative resource cost estimation (ARCE) and content analysis while the Likert scale was used to measure the perception of respondents towards the causes of conflicts. There were six (6) major categories of conflicts identified in the area. These categories were communal conflicts, ethnic conflicts, resource conflicts (most often land conflicts), politically motivated conflicts, conflicts due to traditional chieftaincy, and the conflicts between state forces and militia groups. Expansion of agro-pastoralism (4.6) and Extensive sedentism (4.5) were very serious factors that were perceived to lead to conflicts. A total of ₦2,289,859,549 worth 30.28% of the State’s 2018 IGR (Internal Generated Revenue) were lost in these conflicts. It was recommended that laws regarding people with diverse backgrounds and socioeconomic needs and population growth in relation to limited resources should be developed with great care and attention paid to all the parties involved in the process. Participatory approaches to problem identification, conflict management and resolutions need to be established in the communities with regular interactions between and among locals periodically and frequently.

Comparative Population Growth of the Khapra Beetle (Coleoptera: Dermestidae) and the Warehouse Beetle (Coleoptera: Dermestidae) on Wheat and Rice.

We evaluated the relative population growth of two stored-product insect species in the genus Trogoderma, the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), and the warehouse beetle, Trogoderma variabile Ballion (Coleoptera: Dermestidae). Ten adults of each species were placed in vials containing wheat or paddy rice. These tests were performed at 27 and 32°C and the number of adults in the vials were counted after 35 and 70 days. For all the time intervals and temperatures of both species on wheat, the resulting larval abundances were similar, with the exception of 27°C at 70 days where more T. variabile larvae developed. At the higher temperature, both species had similar population growth on rice. However, the success was mixed at 27°C with T. granarium having a greater abundance after 35 days, while T. variabile dominated after 70 days. Frass production in both commodities was usually similar for the two species, but greater frass production occurred by T. variabile on wheat after 70 days at 27°C, while T. granarium produced more frass on rice after 35 days at 32°C. Both species nearly always caused equivalent commodity damage. Our research suggests that under ideal conditions these two closely, but very differently treated species in commerce from the genus Trogoderma have comparable population growth, and cause similar damage on wheat and rice.

Relationship between psychological capital and quality of life among seniors working after retirement: The mediating role of hope of success.

IntroductionAs a result of the increasing average human life expectancy and the related population growth in many countries, research on factors increasing seniors’ quality of life is becoming particularly important. An event critical for seniors’ functioning is retirement. A concept reflecting the dynamics of seniors’ personality associated with the changes taking place in their life situation is psychological capital. This concept was identified as a factor that is constituted by four personality variables changing because of experiences: self-efficacy, optimism, psychological resilience, and hope of success. An interesting issue is the relationship between psychological capital and quality of life in seniors working after retirement.AimThe aim of this paper was to analyze the relationship between psychological capital (self-efficacy, dispositional optimism, psychological resilience) and quality of life in seniors working after retirement, as well as the mediating role of hope of success in this relationship.MethodsA total of 304 seniors—103 women and 201 men—participated in the study. The mean age was 65.24. The Quality-of-Life Scale (CASP-19), the Polish adaptation of Life Orientation Test (LOT-R), the Generalized Self-Efficacy Scale (GSES), the Hope of Success Questionnaire (KNS), and polish adaptation of the Resilience Assessment Scale (SPP-25) were employed in the research. A mediation model was applied to explore the pathway from psychological capital via hope of success to quality of life.ResultsThe tested components of psychological capital correlate positively with working senior citizens’ quality of life. The mediating role of hope of success between psychological capital and quality of life was confirmed. The study presented three mechanisms in which hope of success strengthens the relationships between the components of psychological capital and working senior citizens’ quality of life.ConclusionsThe mediating role of hope of success between the remaining components of psychological capital and quality of life confirms pattern posited in the COR theory, namely, that increasing one resource leads to the activation of others, which results in a spiral of personal resources being generated. One the one hand, people who have greater resources have a greater capacity for generating spirals of gains. One the other hand, individuals who lack personal resources are both more exposed to losing them and less capable of starting a spiral of gains in resources.

The role of genetic diversity and arbuscular mycorrhizal fungal diversity in population recovery of the semi-natural grassland plant species Succisa pratensis

BackgroundEcosystem restoration is as a critical tool to counteract the decline of biodiversity and recover vital ecosystem services. Restoration efforts, however, often fall short of meeting their goals. Although functionally important levels of biodiversity can significantly contribute to the outcome of ecosystem restoration, they are often overlooked. One such important facet of biodiversity is within-species genetic diversity, which is fundamental to population fitness and adaptation to environmental change. Also the diversity of arbuscular mycorrhizal fungi (AMF), obligate root symbionts that regulate nutrient and carbon cycles, potentially plays a vital role in mediating ecosystem restoration outcome. In this study, we investigated the relative contribution of intraspecific population genetic diversity, AMF diversity, and their interaction, to population recovery of Succisa pratensis, a key species of nutrient poor semi natural grasslands. We genotyped 180 individuals from 12 populations of S. pratensis and characterized AMF composition in their roots, using microsatellite markers and next generation amplicon sequencing, respectively. We also investigated whether the genetic makeup of the host plant species can structure the composition of root-inhabiting AMF communities.ResultsOur analysis revealed that population allelic richness was strongly positively correlated to relative population growth, whereas AMF richness and its interaction with population genetic diversity did not significantly contribute. The variation partitioning analysis showed that, after accounting for soil and spatial variables, the plant genetic makeup explained a small but significant part of the unique variation in AMF communities.ConclusionsOur results confirm that population genetic diversity can contribute to population recovery, highlighting the importance of within-species genetic diversity for the success of restoration. We could not find evidence, however, that population recovery benefits from the presence of more diverse AMF communities. Our analysis also showed that the genetic makeup of the host plant structured root-inhabiting AMF communities, suggesting that the plant genetic makeup may be linked to genes that control symbiosis development.

Determinants of Unemployment in East African Community Countries

The purpose of this research study is assessing the relationship between unemployment and its determinants for five east Africa community countries i.e., Kenya, Uganda, Tanzania, Rwanda & Burundi. Particularly, discussed are some economic variables and their significant effects especially in the long run. The study variables include; inflation, GDP growth, population growth and foreign direct investments in relation to unemployment. In order to achieve the research objectives, a methodology framework of panel autoregressive distributed-lag (PARDL) is undertaken. The study finds that a long-run relationship exists among all the variables. Moreover, GDP, POPL, and FDI are found significant to interpret the unemployment in the long-run whereas INF is found insignificant to interpret unemployment in the long-run. The findings also reveal that the tradeoff between inflation and unemployment in EACCs is in the short run and not in the long run. This study concludes that foreign direct investment and gross domestic product have negative and significant relationship with unemployment. Population growth has positive and significant relationship with unemployment and it contributes to unemployment while inflation rate has a positive and insignificant relationship with unemployment. According to the findings of this study population growth is the key determinant of unemployment in EACCs.

Impacts of population growth in relation to changes in aquaculture and fisheries prices

The paper reviewed the impacts of population growth and the ways it affects aquaculture and fisheries prices. As the world population continues to grow arithmetically, great pressure is placed on arable lands, water, energy, and biological resources to provide an adequate supply of food while maintaining the integrity of the ecosystem. In 2010, FAO projected the world population to double from 6.2 billion in October, 1999 to 12.5 billion in the year 2050. This had created serious negative impacts on the aquaculture and fisheries prices. At present fertile crop lands had been lost at an alarming rates while some abandoned during the past 50 years because erosions made it unproductive. Other vices such as food crisis, political unrest and war (Mexico, Uzbekistan, Turkistan, Yemen, Iraq, Afghanistan, Syria, Morocco and Sudan), civil strife and multiple years of draught (Niger, Mauritania and Senegal), impacts of HIV/AIDS Ebola, Lassa fever and Coronavirus the world over, clashes between cattle rearers and farmers and boko haram issues (Nigeria) as well as kidnapping and corruptions have severely affected aquaculture and fisheries production and accompanied prices. Thus, this review was conducted to raise a cry for farmers and citizens to engage and participate in intensive culture and fisheries practices in order to fill the demand - supply gap so as to make fish food products available for the teeming masses.

Consistency of aquatic enclosed experiments: The importance of scale and ecological complexity

AbstractAimMarine and freshwater ecosystems are increasingly threatened by human activities. For over a century, scientists have been testing many biological, chemical and physical questions to understand various ecosystems and their resilience to different stressors. While the majority of experiments were conducted at small‐scale laboratory settings, lately large mesocosm experiments have become more and more common. Yet, it still remains unclear how the scale (i.e. space) and ecological complexity (i.e. community versus limited number of species) of experiments affect the results and to what extent different experimental types are comparable.InnovationHere, we conducted two types of experiments, run at different scale and ecological‐complexity levels (i.e. outdoor large‐scale community‐level mesocosm versus indoor small‐scale two‐species laboratory experiment), to assess the effects of marine heatwaves on two gammarid species.Main ConclusionsOur approach detected differences in abundance and relative population growth between the two experimental types for one out of the two tested species, but no difference in heatwave impacts on any of the species, independently of which experimental type was used. The larger space in the mesocosm, accompanied with inclusion of the community, benefited this species, demonstrating stronger performance in the mesocosm than in the laboratory experiment. Though, our study design cannot directly distinguish if scale or ecological complexity of the experiments, or both, caused the observed discrepancy in our findings. Furthermore, inconsistency in results among laboratory experiments complicates the extrapolations and generalization of the laboratory results. Yet, our findings indicate the importance of space, density‐dependent effects, biotic interactions and complexity of natural environments in buffering, or boosting, the direct effects of environmental stress on organisms. Therefore, we urge the use of large‐scale community‐level mesocosm experiments instead of small‐scale single‐species laboratory ones whenever possible, and emphasize a necessity of great caution when interpreting the results of laboratory experiments.

Effects of human land use and temperature on community dynamics in European forests

Climate change and human land use are thought to play a dominant role in the dynamics of European central-latitude forests in the Holocene. A wide range of mathematical and statistical models have been used to study the effects of these variables on forest dynamics, including physiologically-based simulations and phenomenological community models. However, for statistical analysis of pollen count data, compositional data analysis is particularly well suited, because pollen counts give only relative information. We studied the effects of changes in human land use and temperature on European central-latitude forest dynamics at 7 sites over most of the last 10ka, using a stochastic model for compositional dynamics of pollen count data. Our approach has a natural ecological interpretation in terms of relative proportional population growth rates, and does not require information on pollen production, dispersal, or deposition. We showed that the relative proportional population growth rates of Fagus and Picea were positively affected by intensified human land use, and that those of Tilia and Ulmus were negatively affected. Also, the relative proportional population growth rate of Fagus was negatively affected by increases in temperature above about 18∘C. Overall, the effects of temperature on the rate of change of forest composition were more important than those of human land use. Although there were aspects of dynamics, such as short-term oscillations, that our model did not capture, our approach is broadly applicable and founded on ecological principles, and gave results consistent with current thinking.

Deforestation and world population sustainability: a quantitative analysis

In this paper we afford a quantitative analysis of the sustainability of current world population growth in relation to the parallel deforestation process adopting a statistical point of view. We consider a simplified model based on a stochastic growth process driven by a continuous time random walk, which depicts the technological evolution of human kind, in conjunction with a deterministic generalised logistic model for humans-forest interaction and we evaluate the probability of avoiding the self-destruction of our civilisation. Based on the current resource consumption rates and best estimate of technological rate growth our study shows that we have very low probability, less than 10% in most optimistic estimate, to survive without facing a catastrophic collapse.

Monitoring the land consumption rate of urban growth from the Urban Footprint of Mexico, an online national cartographic platform

The spatial monitoring of the urban expansion and related population growth is useful for urban planning assessment of cities and megacities in the global South. Although market driven public programs for peri-urban low-income housing have retained much attention over the past twenty-five years in Mexico, a spatially explicit database of the consequent urban footprint together with the population census information has not been available online to the public. In this research, we build a geoscientific data collection consisting of: 
 
 A built-up layer in 2000 and 2010 for the 10 major metropolitan areas of the Mexico Central Altiplano Region;
 A built-up layer in 2000 for the remaining 14 most prominent cities of the Mexican Urban System. 
 A land consumption index at county (“Municipio”) level in the Mexico Central Altiplano Region. 
 
 The Urban Footprint of Mexico is the first online national cartography incorporating built-up and demographic expansion.

Investigating uneven recovery of repatriated bobcats (Lynx rufus) in a mined landscape: space use, habitat use and condition in coal country

Abstract ContextBobcats (Lynx rufus) were extirpated from Ohio, USA, during the mid-1800s. Genetic evidence indicates that they recolonised from neighbouring states. Initial re-establishment occurred almost simultaneously in two spatially distinct areas of a coal-mined landscape in the 1980s. Relative population growth was apparently higher in the eastern than in the southern area. AimsUnderstanding the reasons for the disparity in population dynamics and sustainability is essential for proper bobcat management. It also addresses substantial knowledge gaps in vertebrate carnivore ecology on mined land. We hypothesised that the characteristics of mined land in the eastern Ohio area provided bobcats with greater resources, enabling a more rapid recovery. MethodsWe trapped bobcats and took body measurements and weights to determine condition indices. We attached GPS radio-collars and used locations to determine annual home-range and core-area sizes, home-range and core-area overlap, and habitat selection using remotely sensed land cover data and mine permit records. We compared factors between the two bobcat population areas. Key resultsBody condition indices were higher, and home ranges and core areas of males and females were smaller, for eastern Ohio bobcats. Home-range overlap did not differ for any dyad type. Selection of mined land by habitat type differed at the home-range level, with eastern bobcats selecting more mined habitats and southern bobcats showing an opposite tendency. ConclusionsAn interaction may exist between landscape features of former surface mines and bobcat recovery. Results suggest more favourable habitat conditions in the eastern area, which featured more mined land and more older, less regulated mines, than in the southern area. These conditions may support a higher bobcat reproductive success. ImplicationsThe first bobcat harvest season in Ohio is under development by authorities. We recommend the regulation of eastern and southern Ohio as separate bobcat management units; the southern population should remain protected, and the eastern population should be managed conservatively as a source population to further colonise southern Ohio. Our data suggest that surface-mined land can be conducive to the restoration and conservation of species.

The growth and decline of fisheries communities: Explaining relative population growth at municipality level

In several countries, maintaining the population of fisheries dependent communities are of major importance in the fisheries governance system. However, most studies investigating the relationship between fisheries and communities have a qualitative focus on the impact of fisheries policies on the communities. We have access to data on population and key employment indicators of every Norwegian municipality in addition to fisheries catch, landings and employment. These data allow us to study the effect of fisheries on population growth in fisheries dependent municipalities relative to all other municipalities. The data are analyzed using a multi-level approach integrating micro- and macrodata. The results indicate that general trends have a stronger influence on population growth than fisheries activities, implying that measures for increased fisheries landings are poor tools to support population growth.