Water Quality and the Observation of Aquatic Macroinvertebrate

Diversity

Aquatic Macroinvertebrates

Aquatic Macroinvertebrates

• Insects, worms, snails, crayfish, other arthropods

• Live in all types of water habitats• Most have gills for absorbing oxygen• Cannot escape pollution events• Certain species are more or less tolerant of

pollution

Biomonitoring

• Stream biomonitoring is the study of the biological organisms present in a stream. 

• Based on what organisms are present, you can get an idea of what the water quality is like.– Species dependent – depends on number of

species of different sensitivities to pollution

Watershed

• land area draining into one water body

Our Watershed

• The next time you get some water from the tap, trace where it has been before reaching your glass.

• Where does it go when you pour it down the drain?

• In what ways do our lives change when we expand the boundaries of our home to include our watershed?

Bath Nature Preserve

Bath Creek

Lots of sunlightAbundant plant growthWarmer water Mud bottomSlow water flow

North Fork of Yellow Creek

ShadedCooler waterFew aquatic plantsFast flowing waterRocky bottom

Did you know???• Photosynthesis – happens during the day,

and only in plants• Cellular Respiration – happens all the time,

in ALL living things (including green plants!)• In streams with lots of plants, the amount of

oxygen increases during the day, but may drop very low at night. This means some organisms may not be able to survive in the river

Photosynthesis

6CO2 + 6H2O + sunlight → C6H12O6 + 6O2Carbon dioxide + water + sun → organic matter + oxygen

Cellular Respiration C6H12O6 + 6O2 → 6CO2 + 6H2O + energyGlucose + oxygen → carbon dioxide + water + energy

Which stream would have more dissolved oxygen?

Bath Creek Yellow Creek

Which is Bath Creek?

Quantifying the hemolymph glucose concentration response in crayfish

In plain English…

• Studying how blood sugar changes in a response to the environment

• Think about how organisms would change over generations, in response to the environment

Comparative BiologyWhy is it so important?

Comparing features (physiology, behavior, etc.) across different species experiencing similar situations,

helps us to hypothesize trends in how organisms respond to their environment!

Physiology comparisonsMost invertebrates Most vertebrates

Circulatory system: similar (blood transports nutrients)

but different (open vs. closed)

Crayfish produce Crustacean Hyperglycemic Hormone (CHH) from the sinus glands behind their eyes!

CHH

This hormone is similar to glucagon in humans – it tells the crayfish’s body to release more glucose into the hemolymph!

Temperature affects blood-glucose levels

Endotherms (mammals, birds) and Ectotherms (reptiles, fish, arthropods, crustaceans) both need to maintain proper blood-glucose levels at different temperatures (remember homeostasis?)

Salinity affects blood-glucose levelsSubstances absorbed/ingested from the environment (food, air, water) can affect your body’s release of hormones such as cortisol (stress hormone), which can in turn stimulate other hormones, including insulin and glucagon, which can affect your blood-glucose level! (homeostasis again!)

Stress affects blood-glucose levels

• Stress (searching for mates, fighting for territory, avoiding predators, etc.) can elevate blood-glucose levels

• Fight-or-flight response:

Your body releases many hormones, including glucagon, which provides your cells with more glucose, so you have more energy to deal with a tough situation!