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Relationship: 2013
Title
Increased Mortality leads to Decrease, Population growth rate
Upstream event
Downstream event
Key Event Relationship Overview
AOPs Referencing Relationship
AOP Name | Adjacency | Weight of Evidence | Quantitative Understanding | Point of Contact | Author Status | OECD Status |
---|---|---|---|---|---|---|
Acetylcholinesterase Inhibition leading to Acute Mortality via Impaired Coordination & Movement | adjacent | Allie Always (send email) | Under development: Not open for comment. Do not cite | |||
Acetylcholinesterase inhibition leading to acute mortality | adjacent | Moderate | Moderate | Cataia Ives (send email) | Under Development: Contributions and Comments Welcome | Under Development |
Deiodinase 2 inhibition leading to increased mortality via reduced posterior swim bladder inflation | adjacent | Moderate | Moderate | Brendan Ferreri-Hanberry (send email) | Under Development: Contributions and Comments Welcome | WPHA/WNT Endorsed |
Deiodinase 2 inhibition leading to increased mortality via reduced anterior swim bladder inflation | adjacent | Moderate | Moderate | Arthur Author (send email) | Under Development: Contributions and Comments Welcome | WPHA/WNT Endorsed |
Deiodinase 1 inhibition leading to increased mortality via reduced posterior swim bladder inflation | adjacent | Moderate | Moderate | Agnes Aggy (send email) | Under Development: Contributions and Comments Welcome | WPHA/WNT Endorsed |
Deiodinase 1 inhibition leading to increased mortality via reduced anterior swim bladder inflation | adjacent | Moderate | Moderate | Allie Always (send email) | Under Development: Contributions and Comments Welcome | WPHA/WNT Endorsed |
Thyroperoxidase inhibition leading to increased mortality via reduced anterior swim bladder inflation | adjacent | Moderate | Moderate | Evgeniia Kazymova (send email) | Under Development: Contributions and Comments Welcome | WPHA/WNT Endorsed |
Thyroperoxidase inhibition leading to altered visual function via altered retinal layer structure | adjacent | Moderate | Moderate | Allie Always (send email) | Open for citation & comment | Under Review |
Thyroperoxidase inhibition leading to altered visual function via decreased eye size | adjacent | Evgeniia Kazymova (send email) | Under development: Not open for comment. Do not cite | Under Development | ||
Thyroperoxidase inhibition leading to altered visual function via altered photoreceptor patterning | adjacent | Cataia Ives (send email) | Under development: Not open for comment. Do not cite | Under Development | ||
Inhibition of Fyna leading to increased mortality via decreased eye size (Microphthalmos) | adjacent | High | High | Brendan Ferreri-Hanberry (send email) | Open for citation & comment | |
GSK3beta inactivation leading to increased mortality via defects in developing inner ear | adjacent | High | High | Cataia Ives (send email) | Open for citation & comment |
Taxonomic Applicability
Sex Applicability
Sex | Evidence |
---|---|
Unspecific | Moderate |
Life Stage Applicability
Term | Evidence |
---|---|
All life stages | High |
Key Event Relationship Description
Increased mortality in the reproductive population may lead to a declining population. This depends on the excess mortality due to the applied stressor and the environmental parameters such as food availability and predation rate. Most fish species are r-strategist, meaning they produce a lot of offspring instead of investing in parental care. This results in natural high larval mortality causing only a small percentage of the larvae to survive to maturity. If the excess larval mortality due to a stressor is small, the population dynamics might result in constant population size. Should the larval excess be more significant, or last on the long-term, this will affect the population. To calculate the long-term persistence of the population, population dynamic models should be used.
Evidence Collection Strategy
Evidence Supporting this KER
Survival rate is an obvious determinant of population size and is therefore included in population modeling (e.g., Miller et al., 2020).
Biological Plausibility
- Survival to reproductive maturity is a parameter of demographic significance. Assuming resource availability (i.e., food, habitat, etc.) is not limiting to the extant population, sufficient mortality in the reproductive population may ultimately lead to declining population trajectories.
- Under some conditions, reduced larval survival may be compensated by reduced predation and increased food availability, and therefore not result in population decline (Stige et al., 2019).
Empirical Evidence
- According to empirical data, combined with population dynamic models, feeding larvae are the crucial life stage in zebrafish (and other r-strategists) for the regulation of the population. (Schäfers et al., 1993)
- In fathead minnow, natural survival of early life stages has been found to be highly variable and influential on population growth (Miller and Ankley, 2004)
- Rearick et al. (2018) used data from behavioural assays linked to survival trials and applied a modelling approach to quantify changes in antipredator escape performance of larval fathead minnows in order to predict changes in population abundance. This work was done in the context of exposure to an environmental oestrogen. Exposed fish had delayed response times and slower escape speeds, and were more susceptible to predation. Population modelling showed that this can result in population decline.
- In the context of fishing and fisheries, ample evidence of a link between increased mortality and a decrease of population size has been given. Important insights can result from the investigation of optimum modes of fishing that allow for maintaining a population (Alekseeva and Rudenko, 2018). Jacobsen and Essington (2018) showed the impact of varying predation mortality on forage fish populations.
- Boreman (1997) reviewed methods for comparing the population-level effects of mortality in fish populations induced by pollution or fishing.
Uncertainties and Inconsistencies
- The extent to which larval mortality affects population size could depend on the fraction of surplus mortality compared to a natural situation.
- There are scenarios in which individual mortality may not lead to declining population size. These include instances where populations are limited by the availability of habitat and food resources, which can be replenished through immigration. Effects of mortality in the larvae can be compensated by reduced competition for resources (Stige et al., 2019).
- The direct impact of pesticides on migration behavior can be difficult to track in the field, and documentation of mortality during migration is likely underestimated (Eng 2017).
Known modulating factors
Quantitative Understanding of the Linkage
- Assuming other relevant demographic parameters are available, the effect of increased mortality rates on population status can be quantitatively predicted using standard population modeling approaches.
- Stage population matrix models (Caswell, 2000) simulate population growth rates based on age-specific parameters and can be adapted to a range of species (Pinceel et al., 2016). For zebrafish, individually based models (IBM) have been developed to link responses at the individual level to the population level (Beaudouin et al., 2015). However, authors agree that survival is one of the most uncertain parameters in the model and more research on the topic is needed.
Response-response Relationship
Time-scale
Known Feedforward/Feedback loops influencing this KER
Domain of Applicability
Taxonomic: All organisms must survive to reproductive age in order to reproduce and sustain populations. The additional considerations related to survival made above are applicable to other fish species in addition to zebrafish and fathead minnows with the same reproductive strategy (r-strategist as described in the theory of MaxArthur and Wilson (1967). The impact of reduced survival on population size is even greater for k-strategists that invest more energy in a lower number of offspring.
Life stage: Density dependent effects start to play a role in the larval stage of fish when free-feeding starts (Hazlerigg et al., 2014).
Sex: This linkage is independent of sex.
References
Alekseeva SM, Rudenko AI. 2018. Modeling of optimum fishing population. Marine Intellectual Technologies. 3(4):142-146.
Beaudouin, R., Goussen, B., Piccini, B., Augustine, S., Devillers, J., Brion, F., Pery, A.R., 2015. An individual-based model of zebrafish population dynamics accounting for energy dynamics. PloS one 10, e0125841.
Boreman J. 1997. Methods for comparing the impacts of pollution and fishing on fish populations. Transactions of the American Fisheries Society. 126(3):506-513.
Caswell, H., 2000. Matrix population models. Sinauer Sunderland, MA, USA.
Eng, M.L., Stutchbury, B.J.M. & Morrissey, C.A. Imidacloprid and chlorpyrifos insecticides impair migratory ability in a seed-eating songbird. Sci Rep 7, 15176 (2017)
Hazlerigg, C.R., Lorenzen, K., Thorbek, P., Wheeler, J.R., Tyler, C.R., 2012. Density-dependent processes in the life history of fishes: evidence from laboratory populations of zebrafish Danio rerio. PLoS One 7, e37550.
Jacobsen NS, Essington TE. 2018. Natural mortality augments population fluctuations of forage fish. Fish and Fisheries. 19(5):791-797.
MacArthur, R., Wilson, E., 1967. The Theory of Island Biogeography. Princeton: Princeton Univ. Press. 203 p.
Miller, D.H., Ankley, G.T., 2004. Modeling impacts on populations: fathead minnow (Pimephales promelas) exposure to the endocrine disruptor 17β-trenbolone as a case study. Ecotoxicology and Environmental Safety 59, 1-9.
Miller, D.H., Clark, B.W., Nacci, D.E. 2020. A multidimensional density dependent matrix population model for assessing risk of stressors to fish populations. Ecotoxicology and environmental safety 201, 110786
Pinceel, T., Vanschoenwinkel, B., Brendonck, L., Buschke, F., 2016. Modelling the sensitivity of life history traits to climate change in a temporary pool crustacean. Scientific reports 6, 29451.
Rearick, D.C., Ward, J., Venturelli, P., Schoenfuss, H., 2018. Environmental oestrogens cause predation-induced population decline in a freshwater fish. Royal Society open science 5, 181065.
Schäfers, C., Oertel, D., Nagel, R., 1993. Effects of 3, 4-dichloroaniline on fish populations with differing strategies of reproduction. In: Braunbeck, T. , Hanke, W and Segner, H. (eds) Ecotoxicology and Ecophysiology, VCH, Weinheim, 133-146.
Stige, L.C., Rogers, L.A., Neuheimer, A.B., Hunsicker, M.E., Yaragina, N.A., Ottersen, G., Ciannelli, L., Langangen, Ø., Durant, J.M., 2019. Density‐and size‐dependent mortality in fish early life stages. Fish and Fisheries 20, 962-976.Hazlerigg, C.R.E., Tyler, C.R., Lorenzen, K., Wheeler, J.R., Thorbek, P., 2014. Population relevance of toxicant mediated changes in sex ratio in fish: An assessment using an individual-based zebrafish (Danio rerio) model. Ecological Modelling 280, 76-88.
Stige, L.C., Rogers, L.A., Neuheimer, A.B., Hunsicker, M.E., Yaragina, N.A., Ottersen, G., Ciannelli, L., Langangen, O., Durant, J.M., 2019. Density- and size-dependent mortality in fish early life stages. Fish and Fisheries 20, 962-976.