WFSC 403 6th Edition Lecture 26 Outline of Last 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 Outline of Current Lecture I Basic Concepts a R G M F II Logistic models a MSY rk 4 at k 2 III Dynamic Pool models a Nt Re F M t equation 15 6 page 281 b Y FN Wt equation 15 7 page 282 t t tc IV Stock and recruitment a Beverton Holt b Ricker WFSC CH 15 Harvesting c 403 613 Match mismatch Populations Current Lecture Can interpret 15 1 if you flip the curve so k is on the bottom can make it easier to read Sigmoid curve theory to describe the growth of a population that could be exploited o Figure 15 1 4 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 II Logistic models WFSC 403 613 CH 15 Harvesting Populations Populations Responseof a population to exploitation according the logistic type model according Responseof to a po pulation to exploitation to thelogistic typemodel 7 Figure 15 2 7 Figure 15 2 o Question is arrows between c and d is this a sustainable yield population Yes it recovers between populations Relation between total fishingeffort and total catch of the Peruvian anchovy Relation between total fishing effort and total catch of the Peruvian anchovy Figure 15 3 8 o Fish more you catch more fish more catch more o Until a certain point when there is an over exploitation o Note axis Assumptions for equations III oDynamic poolrate mode ls Mortality is constant density independent III Dynam ic pool mode ls estimrates atesof are growth mortality and o Include Growth age specific re Include timatesof growth mortality and cruitmes nt o Fishing mortality is additive recruitm ent As sumptions o 1 AsRecruitment is constant Natural mortality rate is constant density sumptions Figure 15 3 8 pende nt 1 inde Natural mortality rateis constant density2 Growth rate sareage specific independe nt 32 Growth Fishingmortality ise additive ratesareag specific Ge tricm growth population biomass 3 om Fise hing ortality in is additive Geometric growth in population biomass 9 9 11 Relationship between stock and recruitment in an exploited fish population Figure 15 6 12 o Plateaus out o El Nino could effect Not taken into account in classic models o If peaking at the same time that is good a match If peak abundance of resources is way before or way after when the resources are needed that is a mismatched and they won t be used and lots of death
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