WFSC 403 6th Edition Lecture 25 Outline of Last Lecture I Evolutionary implications of population regulation statement page 273 a Behavior b Stress c Genetics d Dispersal II Chapter 15 basic concepts a First bullet point page 277 decreased natality b stock page 278 ho stable part III Logistic models Outline of Current Lecture I Chapter 17 Declining population paradigm a Lab 13 p 328 329 II Chapter 15 Harvesting III Basic concepts IV Logistic models a Equation 15 5 page 280 Current Lecture Lab quiz will be over chapter 15 Deterministic extinction o Overkill o Habitat destruction and fragmentation o Introduced species o Chains of extinction Food source could go extinct they will go extinct What is another concern with shrinking population aside from just going extinct o The population could become very homogenous and the gene pool shrinks Deterministic extinctions o Losses of species due to the removal of an essential resource Environmental stochasticity o Variation in population growth rates imposed by changes in weather and biotic factors as well as natural catastrophes like floods and hurricanes Genetic stochasticity These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Maximumsustained yield Stock First ruleof exploitation Two approachesto determineoptimumyield Logistic models Dynamic pool models o Any potential loss of genetic variation due to inbreeding or genetic drift the nonrandom assortment of genes during reproduction Small population paradigm o The focus of this approach is on rare species and on the population consequences of rareness and the abilities of small populations to deal with rarity I 2 MSY and Density Dependent Birth and Death Rates Pop size s K r selected K 2 K selected dN rN dt K N dN r K 2 dt K 2 N0 H Birth or Death Rate births or deaths per 1000 pop TIME K K K rK 4 rK MSY 4 Death rate Birth rate low Density Ne high 3 Logistic models assumptions o No time lags o Age structure has no effect o Constant catchability dN K N rN qXN dt K N is population size t is time r is per capita rate of population growth K is asymptotic density in absence of fishing q is catchability a constant X is amount of fishing effort so qX is fishing mortality rate o
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