AUD 2b Lect #2 (pond biology & ecology)

Why do food chains not represent actual lakes/ponds?

doesn’t account for omnivory (an organism eating several trophic levels), mixotrophy (an organism being both a producer and heterotrophic), or ontogeny (an organism’s diet shifting during development)

Why is it important to understand all parts of a ponds food web

treatments will change linkages in the web

What happens if cyanobacteria are unpalatable to grazers such as daphnia

can have a competitive advantage over desirable algae species (such as fragilaria)

What is the nutrient positive feedback loop

decomposing biomass (algae/plants) refuels nuisance growth

*important to leave some plant growth

What is inter-intraspecific competition

• plants/algae constantly fighting for nutrients

• if one wins, either have a clear/plant dominate system or turbid/algae dominate system

What 2 nutrients cause growth in waterbodies

• phosphorus

• nitrogen

What activities (human and natural) cause increases in eutrophication

• overfertilizing soils

• erosion of soils

• adding impervious surfaces

• animal waste

• removing vegetation in a watershed

What are activities that slow eutrophication (BMPs)

• sediment barrier

• rain garden

• permeable surfaces

What are aqua doc services that mitigate nutrient issues

• alum / lanthanum

• dredging

• aeration (sometimes)

List similarities between plants and algae

• photosynthetic

• made of eukaryotic cells

• cell walls made of cellulose

• base of food web

How are aquatic plants different from algae

• more complex biochemically

• multicellular

• roots, stems, leaf

• obtain nutrients from roots

• use flowering structures

How is algae different from aquatic plants

• less complex biochemically

• can be single celled

• free floating

• obtain nutrients through absorption in water column

• reproduce asexually

What is the littoral zone

area in a pond where sunlight can penetrate to the bottom and allow for rooted plant growth

Why are aquatic plants important

• photosynthesize oxygen

• provide habitat/reproduction structures

• absorb nutrients

• compete with algae

List common submergent aquatic plants (& know what they look like!)

• milfoil

• pondweeds

• naiads

• waterweeds

• coontail

• macroalgae

List common floating aquatic plants (& know what they look like!)

• water lily

• water shield

• duckweed

• watermeal

List common emergent aquatic plants (& know what they look like!)

• cattails

• phragmites

• arrowhead

What are the 3 types of algae we see

• planktonic

• filamentous

• macrophytic

Why is it important to correctly ID cyanobacteria (HABs)

• neurotoxins (nervous system)

• hepatoxins (liver)

• dermatoxins (skin)

Describe spirogyra

• filamentous

• early season

• cool water

• bright green

• slimy

• easy to control

Describe pithophora

• filamentous

• coarse

• dark green to yellow green

• high nitrogen/phosphorous

• difficult to manage

Describe hydrodictyon

• filamentous

• net-like structure

• yellow-green

• difficult to manage

Describe oscillitoria

• filamentous cyanobacteria

• grey-green

• mats

• high nutrient loads w/no competition

• difficult to manage

Describe chara

• charophyte green algae

• multicellular

• attached to substrate

• hard water, will calcify

• easy to control

Describe planktonic algae

• green algae

• cyanobacteria

• diatoms

• difficult to control

• can cause fish kill