lab 2: aquatic ecosystems

Describe the littoral zone.

It is shallow water where light reaches the bottom, stimulating the growth of rooted plants.

Describe the limnetic zone.

It is beyond the littoral zone and extends to the depth of light penetration. Microscopic phytoplankton (autotrophs) and zooplankton (heterotrophs), and nekton can be found here.

What are the zones of the limnetic zone?

Euphotic, profundal, and benthic zones.

What divides the euphotic and profundal zones of the limnetic zone?

The compensation level.

What is the euphotic zone?

The euphotic zone is the top layer of a body of water that receives enough sunlight for photosynthesis.

What is the compensation level?

The compensation level is the boundary between the euphotic zone and the profundal zone, where the rate of respiration equals the rate of photosynthesis.

What is the profundal zone?

The profundal zone is the area below the compensation level that relies on a rain of organic material from the limnetic zone for energy.

What is the benthic zone?

The benthic zone is common to both the littoral and limnetic zones and is the bottom region, which serves as the primary place of decomposition.

What is the scientific name for the smallmouth bass?

Micropterus dolomieu.

What is the scientific name for the brook trout?

Salvelinus fontinalis.

What are the characteristics of Micropterus dolomieu?

Carnivorous, apex predator, body is stout and compressed, found in slow lotic systems.

What are the characteristics of Salvelinus fontinalis?

Carnivorous, slender elongated body, found in colder waters, found in fast lotic systems.

What is the scientific name of the mayfly?

Hexagenia.

What order does Hexagenia belong to?

Ephemeroptera.

What are the characteristics of Hexagenia?

Part of the EPT group, feed on CPOM (detritus) as grazers/collectors, found in slow lotic systems or littoral zones of lentic systems, have 3 caudal filaments and abdominal gills.

What is the scientific name of the Perla?

Stonefly.

What order does Perla belong to?

Plecoptera.

What are the characteristics of Perla?

Part of the EPT group, found in slow or fast lotic systems or littoral zones of lentic systems, feed on CPOM as shredders, have 2 caudal filaments and thoracic gills.

What order does Net Spinning Caddisfly belong to?

Trichoptera.

What are the characteristics of Net Spinning Caddisfly?

Part of the EPT group, have dark shield-like scales on the thorax, produce silk netting to catch CPOM/FPOM and stay anchored, found in fast and slow lotic systems, collectors, do not have caudal filaments, have abdominal gills.

What order does Stone Case Caddisfly belong to?

Trichoptera.

What are the characteristics of Stone Case Caddisfly?

Build protective stone cases out of silk, found in fast and slow lotic systems, collectors, eat CPOM, do not have caudal filaments, have abdominal gills.

What is the scientific name of the water penny beetle?

Psephenus.

What order does Psephenus belong to?

Coleoptera.

What are the characteristics of Psephenus?

Found in fast lotic systems, grazers.

What order does Bloodworms belong to?

Diptera.

What family do Bloodworms belong to?

Chironomidae.

What are the characteristics of Bloodworms?

Have a long head, turn white when dead, red due to hemoglobin in hemolymph, collectors, have unjointed prolegs, no gills and have spiracles instead, indicator of poor water quality, deep lentic systems or at the bottom of slow lotic systems, eat decomposing plant matter.

What order does crane-fly belong to?

Diptera.

What family do Crane-flies belong to?

Tipulidae.

What are the characteristics of Crane-flies?

Grazer/gouger, do not have gills but have spiracles along the abdomen and need oxygen, indicators of poor water quality, found in deep lentic systems or at the bottom of slow lotic systems, eat decomposing plant matter.

What order do Hellgrammites belong to?

Megaloptera.

What are the characteristics of Hellgrammites?

Can tolerate pollution but are not indicators of water quality, found in fast or slow lotic systems, spiky protrusions on the abdomen are gills not legs (have 6 legs on the thorax), have hooked anal prolegs.

What is the ecological role of zooplankton?

Zooplankton provide a ton of energy either up the trophic food chain or directly to large organisms like whales.

What is the ecological role of phytoplankton?

Phytoplankton can release toxins into the water and are responsible for approximately 70% of the oxygen produced in the atmosphere.

What is an example of toxins released by phytoplankton?

Red tide, which is a bloom of microscopic algae that turns the ocean red and releases toxins.

What tool is used to examine organisms under a compound microscope?

A Sedgewick-Rafter counting cell.

What are the characteristics of a Sedgewick-Rafter counting cell?

It is a normal microscope slide with a metal frame glued to the top, holds 1 mL of fluid, and is capped with an elongated (and fragile) cover slip.

What is the capacity of the Van Dorn sampler?

2 liters.

What are the characteristics of the Van Dorn sampler?

It is a plastic tube with caps on each end attached by an elastic band, dropped by a rope, and a messenger causes the caps to slam shut when filled. It collects attached organisms (periphyton) and suspended organisms (plankton).

What happens to samples collected by the Van Dorn sampler?

Samples pass through a 63 μm mesh, allowing everything smaller than this to pass out.

Where is the Van Dorn sampler typically used?

Closer to vegetation and in shallow waters.

What is the capacity of the Schindler-Patalas plankton trap?

30 liters.

What are the characteristics of the Schindler-Patalas plankton trap?

It is a box with a hinged top and bottom, dropped into the water by a rope. When pulled upward, the top and bottom close, allowing it to collect organisms from any depth of water.

What happens to water in the Schindler-Patalas trap as it is pulled up?

Water drains out of a 63 μm mesh.

What are lentic environments?

Still or slow-moving water such as lakes and ponds.

What organisms are found in lentic environments?

Algae, zooplankton, amphibians, fish like bass and bluegill, and aquatic plants like water lilies.

What are lotic environments?

Flowing water systems such as rivers and streams.

What organisms are found in lotic environments?

Trout, mayflies, caddisflies, and periphyton (algae attached to rocks).

What adaptations do organisms in lotic environments have?

They are adapted to currents and require high dissolved oxygen levels.

What are some abiotic factors of lentic systems?

Lentic systems typically have lower dissolved oxygen, warmer temperatures, and slower nutrient cycling.

What organisms are supported by lentic systems?

Organisms that tolerate lower oxygen and warmer conditions.

What are some abiotic factors of lotic systems?

Lotic systems have higher dissolved oxygen due to turbulent flow, cooler temperatures, and continuous movement of nutrients.

What organisms are supported by lotic systems?

Organisms that need high oxygen levels and can handle water currents.

What is predation and competition like in lentic systems?

Predators like fish and birds influence the distribution of smaller organisms, such as plankton or small invertebrates.

What is predation and competition like in lotic systems?

Competition for food and shelter (e.g., rocks or debris) shapes the ecosystem. Aquatic insects may rely on biofilms or detritus for food.

What is the calculation for # of organisms per L?

(# of organisms/cell volume (mL)) x (bottle volume (mL)/sampler volume (L))