OCNG 350

lecture 3

Scope for growth

developed to give a more general measure of the overall physiological health of the animals based on the energy budget.

measures the energy left for growth after the minimum biological functions

Scope for growth

(poduction) = energy absorbed -(respiration + excretion)

Energy absorbed (A)

energy taken from food minus what is lost as feces. measured by lookking at the filtration rate of the animal

Respiration (R)

represents the metabolic “cost of living”. measured via oxygen consumption

excretion (E)

energy lost through nitrogenous waste

Sessile Nature

because they are stationary, their energy budget reflects the exact pollution levels of a specific site. A fish might have just swam into a polluted area, but a mussel has lived there its entire life.

Filter feeders

they process masseive amounts of water. this makes them highly sensitive to both dissolved toxins and toxins attached t particles

measurable physiology

it is much easier to measure the filtration rate and oxygen consumption of a stationary mussel in a small chamber than it is for a mobile organisminte

integration of stress

SfG in bialves acts as an “early warning system”. Changes in their energy balance often appear long befroe the population starts to die off, giving scientists a way to qualntify those “difficult to measure” sub-lethal effects.

SfG Individual to Population

Shell erosion

reduced size and reduced reproductive performance

stressed animals often stop reproducting long before they stop growing

Univariate Analysis

the simplest form of analyzing data, data only has one variable, sucha as age, weight, population, density, etc. Gr

graphical methods

visually represent data and information

mulltivariate analysis

analyze data with more than two varibables

cluster analysis

nonmetric MDS

Principle component analysis

constrined techniques