1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif 1212570_28446780.jpg logo_mu_cerne.gif trojlogo.gif Ecotoxicology Populations & Communities Ludek Blaha + ecotox colleagues 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif 1) From molecules to individuals http://www.epa.gov/ncer/rfa/2010/comptox_001.jpg MECHANISMS OF TOXICITY 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif 2) From molecules to individuals - AOPs ADVERSE OUTCOME PATHWAYS Models for ecotoxicology and risk assessment. Toxicokinetics are "what the organism does with the chemical" and toxicodynamics are "what the chemical does to the organism". 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif The ultimate objective of ECOTOXICOLOGY à to understand and protect populations, communities, ecosystems Populations Communities (interacting populations) Ecosystems (communities interacting with abiotic environment) 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif •Ecosystems are –not only more complex than we think – –but more complex than we can think * – * FRANK E. EGLER, THE NATURE OF VEGETATION: ITS MANAGEMENT ANDMISMANAGEMENT (1977). 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif •Population –… all the individuals that belong to the same taxonomic group or species, they can sexually reproduce, and they live within the same time and within the same geographical area •Toxicants have … §effects on structure (à we can measure structural parameters) §elderly vs. young, males vs. females §effects on functioning (à we can measure functional parameters) (~ maintenance & growth) §Natality, mortality, reproduction fitness § Effects at different levels https://encrypted-tbn1.google.com/images?q=tbn:ANd9GcRy8TZLY8w9X0x--nqSFW4CqPPTUX3RdYucJtb5pGmKOWt- n2r_ 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif STRUCTURAL PARAMETERS of populations („demographic parameters“) Primary parameters • size (performance) – number of individuals (animals), surface coverage (plants), amount of biomass (algae) • natality – increase of population size: numbers of organisms per unit of time • mortality – decrease of size: numbers of organisms per unit of time A close up of a map Description automatically generated Temporal variability in population of fish (due to overfishing) Capture of the Atlantic northwest cod stock in million tonnes, with Canadian capture in blue[8] [USEMAP] 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif E3 E3 Air contamination effects on populations (evolutionary adaptation, natural selection of genetic & phenotypic variants) 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif Air contamination effects on populations (evolutionary adaptation, natural selection of genetic & phenotypic variants) 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif E3 Effects of benzene and lead (Pb) on sex ratio in Drosophila Generic effect: HIGHER STRESS à more FEMALES (F are more „resistant“ also to assure survival of the population during the crisis) 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif Full-size image (30 K) Fig. 2. Log LC50 variability for all available test results and for the five most frequently used fish life stages (larvae (LV), juvenile (JV), fry (FY), fingerling (FI), alevin (AL), eyed egg (EY) and adult (AD) life stage) for CuSO4 - sulphuric acid, copper(2+) salt (1:1) (CAS 7758-98-7). Test results for all reported fish test species (A) and for Oncorhynchus mykiss (B) were compared. http://www.sciencedirect.com/science/article/pii/S0273230009000956 Aduit Fry Aduit Population = individuals at all life stages Higher sensitivity of juveniles à less adults à aging population Fry All fish species O. mykiss only A picture containing text, map Description automatically generated 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif E3 Caddisfly larvae Higher mortality at elderly at the same concentration E3 https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcRYChodUkrCAl2UNhsTl-3oms-MBwBoPHQe4sauLwnU9HH rmSrg9A Population = individuals at all life stages Higher sensitivity of elderly individuals Výsledek obrázku pro caddisfly 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif 1)Reproduction toxicity assays - D. magna – 21-day reproduction - Earthworms – several weeks: reproduction tests - Folsomia candida (springtails) – reproduction tests 2) Whole life cycle toxicity test - E.g. Chironomus (nonbiting midges) (OECD guideline 233) 3) Modelling (např. Distribution of energy –the „Enth“ example) 1) How to study effects on populations? 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif – –Toxicants (stressors) may have §… effects on structure of communities §Loss of species, loss of biodiversity §… effects on functioning § § § Communities … interacting populations http://www.combat-fishing.com/LowestReachesOZStreamSFW.JPG 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif E3 Natural variability in community (food web) Changes in populations (biomass / numbers of animals) during 12 years Image result for louka Image result for rabbits A bird standing on a dry grass field Description automatically generated A fox standing in the grass Description automatically generated 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif E3 Community STRUCTURE characterization -- example -- Floristic record Occurrence of species (+ < 1 < 2 < 3 < 4 < 5) in relationship to „stressor“ (conditions) MOIST vs DRY è B vs D are very different communities 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif E3 Ecotoxicology example Changes in community treated with three doses and control (L-low, M-medium, H-high, VH-vehicle/solvent) Same exposures but different responses in two different set-ups Microcosm << Mesocosm (highlighted) Image result for copepods A fish located in a grassy field Description automatically generated 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif How to simplify complexity of community characterization? Use index / indices Diversity indices Shannon-Wiener (H´ = - S Ni/N ln (Ni/N) ) –Higher H´ à Higher diversity –Shannon’s index of eveness (E = H´ / lnS) –Higher E à higher „eveness of community“ … and many others (Margalef’s e.g. D = (S-1) / lnN ) Ni – Number of individuals of one species N – Total number of individuals in community S – Number of species 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif Which of the following three communities has the highest EVENESS? Example of H´ calculation for locality A: H’ = - (6/9 . ln (6/9) turtles + 1/9 . ln (1/9) donkeys + 2/9 . ln (2/9) rabbits = …… E = …. ? A B C 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif How to compare communities? • •INDICES … for example … •Jaccard’s similarity index = [c / (A + B - c)] x 100% •Higher J-index – higher similarity c – number of shared (common) species A – number of species at locality A B – number of specieas at locality B C:\Users\ludek_blaha\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\ZIB9JPYT\MC900441407[1].wmf C:\Users\ludek_blaha\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\ZIB9JPYT\MC900441407[1].wmf C:\Users\ludek_blaha\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\ZIB9JPYT\MC900441407[1].wmf C:\Users\ludek_blaha\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\ZIB9JPYT\MC900441407[1].wmf C:\Users\ludek_blaha\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\ZIB9JPYT\MC900441407[1].wmf A B C Výsledek obrázku pro sýkora Výsledek obrázku pro sýkora C:\Users\ludek_blaha\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\ZIB9JPYT\MC900441407[1].wmf Which two are the most similar? AxB or AxC or BxC? (Ecotoxicology: A = control; B and C – different pesticides … which pesticide has „strongest“ effect?) 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif Key / Keystone species •Effects on keystone species à dramatic changes on all community •Usually predators (low numbers = high sensitivity to disruption) A picture containing text, map Description automatically generated 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif nature03962-f1 Knight et al., NATURE (2005) 437: 880 Fish as keystone species affecting also yields on nearby fields 1212569_21823227.jpg logo_mu_cerne.gif trojlogo.gif INDICATOR SPECIES (bioindicators) • •Species for which (not)presence indicate certain parameter of the environment •Sensitive or tolerant species •Ocurrence in community à INDICES A screenshot of a social media post Description automatically generated https://doi.org/10.1016/j.envpol.2013.07.045 A close up of a map Description automatically generated LICHENS – air quality Dry deposition of nitrogenous pollutants across the UK overlaid with dots showing the value of the lichen-based Weighted Pollution Index A picture containing food Description automatically generated