Aquatics

Stream Order A first-order stream has no tributaries and flows directly from its source—a spring, lake or melting snow. When two first-order streams join, they make a second-order stream. Two second-order streams join to make a third-order stream, and so on. Stream order increases only when two streams of the same order join.

Stream Order

Stream Order Characteristics First Order Very small Cold, clear, clean Can jump across them Start from springs, groundwater Forested, rocky, steep Brook trout (PA State fish), only native inland trout, prefer cold, very skittish Shredder and collector insects (stonefly, caddisfly, cranefly) Energy comes from outside stream Second Order Wider- maybe jump, can throw More water Warmer water More fish diversity Larger fish size Brown trout tolerate temps (prefer low light) Sculpins, shiners, daces, fallfish Can stock rainbows

PA Annual Precip. Pennsylvania receives an average of ______ inches of precipitation each year. Where does that water go? The total must equal _____. Evaporation & transpiration ____ inches Run off ____ inches Percolation ____ inches Total _____ inches 41 inches

As you move downstream: – Stream gradients decline – Currents slow, sediments increase allowing for bottom dwelling collectors – Temperatures increase, dissolved oxygen decreases – Channel widens and deepens – Only edge is shaded – More riffles and pools with cobble/gravel – Mayflies collect and graze – More predatory insects – Rocks have more algae, more vegetation – Energy is found within the river; waste nutrients act as fertilizer, allowing for plants and plankton

Water Pollution Basics Impaired or degraded- Waters that are unable to support the fish and other aquatic life that they once did or should Tolerance- the range of conditions in which an organism can survive

pH measure of H+ (acidity) in a solution – Influences the amount of heavy metals dissolved in water (increased acidity=increased dissolved metals) Combine synergistically- effects worse than sum – Influenced by water source, rocks, and soil – Calcium shelled organisms do poorly in pH <7 – Affects body function, eggs, larvae

Temperature Fish are exotherms Changes influence O 2, metabolism, reproduction, and growth Ideal range is better than tolerance- less stress Rapid changes are deadly Slow change (think seasonally) is no trouble

Dissolved Oxygen (DO) O 2 Not the same as O bound to hydrogen (H 2 O) Influence by temp, velocity, wind, depth, plants Warmer water, less DO

Agricultural Runoff occurs when runoff from rain or melting snow carries soil, pesticides and fertilizers from fields into nearby waters. Soil runoff suspends in water, collects as silt clogging gills, smothers eggs Cloudy water absorbs more light, increasing temperature Largest source of nitrogen and phosphorus which increase plant and algae growth Decomposing plants decrease DO levels

Agricultural Runoff Livestock erode stream banks, increasing silt Manure increases plants, depleting DO Pesticides also kill aquatic life

Abandoned Mine Drainage (AMD) Water reacts with iron pyrite in coal and forms acid which runs off into waterways Decreases pH Gill damage, decreases blood sodium Wipes out all young, lessening age diversity Al, Fe, Mn enter water, coating bottom, smothering eggs and shelter areas

Acid Rain Forms when moisture mixes with sulfur or nitrogen produced by burning fossil fuels Precipitation with a pH less than 5.6 Average PA rainfall is 4.3 Often worst in spring as snowmelt hits streams, stream stocking adjusted based on snowmelt Similar effects to AMD

How the Fish & Boat Commission Addresses Pollution Permits and Regulations – regulates industry, stream bank activities, discharge must meet certain standards’ Monitoring, law enforcement- issue citations and fines to violators

Individual Steps Limit fertilizer and pesticide use Purchase fishing licenses Volunteer Report problems

Macroinvertebrate Feeding Predators- mobile animals that kill and eat prey – Searchers- move along looking for less mobile prey – Ambushers- lie in wait for unsuspecting prey Parasites- take advantage of other animals Grazers- feed on algae, fungi, bacteria attached to rocks; – specialized stomachs to digest plant material Shredders- eat large organic materials from streamside vegetation – Rugged mouthparts Collectors- gather or filter small food from water – Benefit from the waste of shredders Symbionts- benefit from a mutualistic relationship

Caddisflies Tricoptera Complete metamorphosis (ELPA) Larvae build protective cases, some carry the cases, others attach them to rocks Most eat plants, one species (colored green) is a predator Pupa forms nearly a year after hatching Emerge from pupa at or near the surface Adults look like small moths, mate soon after emerging, may live several months

Clams and Mussels Mollusks- PA has gastropods and bivalves Bivalves are filter feeders- Siphon water in, filter out food, expel wastes Eggs develop inside parent’s shell, larva are expelled and find a fish to attach to, Fish forms a cyst over the larvae, which they must break out of to live as adults Killed by silt and sediment, dredging, loss of host fish

Crayfish Decopods 5 pairs of jointed legs, can move in all directions Swimmerets help with swimming and balance Can regrow lost appendages Shed exoskeletons Eyes are movable, have antennae, emit chemicals to communicate Omnivorous scavenging predators, Facing competition from non-native crayfish

Dobsonfly Megaloptera Larvae is called a hellgrammite 2-5 year life cycle, ELPA, nocturnal adults Larvae- good water, high DO, swim, strong mandibles, can even eat small fish, can live in and out of the water Burrow in soil, under debris, to transform Adulthood lasts only days, weak fliers, males, longer mandibles Eggs laid on structures that overhang water

Dragons & Damsels Odonata Incomplete metamorphosis (ENA) Mostly predatory nymphs Nymphs leave water before adults emerge Mates fly in tandem during mating Eggs on vegetation above and below surface

Mayflies Ephemeroptera Incomplete (ENA) Hairy eggs stick to bottom Nymphs may burrow or swim, scavenge or predate Live as nymphs about 1 year, shed skin 45 times Adult has 2 stages: duns are non-reproductive, spinners are reproductive Mate in big clouds, eggs dropped into water

Phytoplankton First link in aquatic food chains Phytoplankton- single celled plants, producers, algae, float about, amount is controlled by nutrients – Nostoc, Spirogyra, Volvox, Diatoms Zooplankton- single celled animals

Snails Mollusk members called Gastropods “stomach foot” Scrape food with radula Mostly hermaphroditic Burrow in mud to hibernate of ponds freeze solid, or to avoid summer dryness

Stoneflies Plecoptera Prefer fast moving, clear streams Incomplete (ENA) metamorphosis Nymphs- 2 tails, gills near middle body by legs Hatch on dry land, unlike most insects Adults- wings lay back flat on body, rarely eat as adults, attract mates by drumming, female deposits eggs in water

Water Walkers Neuston- organisms that live on water surfaces Surface tension- adhesive attraction of water to itself due to H-bonding creating an elastic- like film – Traps and holds many animals long enough for predators to eat them

Water Walkers Bugs (Hemiptera) – Water strider- skate on water surface; long rear legs, short front; rear legs steer, middle legs propel, front grab prey; feet covered with hair and wax; can sense vibrations and light movements – Water boatman- swim right-side up; short forelegs dig in mud, other legs covered in hair to increase surface area and make the paddle-like; middle legs act as rudder, long hind legs act as oars; also strong fliers – Backswimmers- look like boatman but swim upside down; oar-like hind legs, swim in looping path, must rise up between strokes; can dive, but don’t have gills so they take an air bubble down with them allowing them to stay down for 6 hours

Water Walkers Beetles (Coleoptera) – Whirligig beetles- congregate in groups, interact lie bumper cars; 4 eyes, two above to watch for predators, 2 below to look for prey; – Stenus- land beetle, secretes fluid to lower surface tension which propels it across the water

Water Walkers Flies (Diptera) – Mosquito larvae- still water; get oxygen from air allowing them to survive in poor water quality; larvae breathe through a snorkel Spiders (Arachnida) – Fishing Spider- covered in thousands of water- repellent hairs; hairs increase surface area and distribute weight;

Zooplankton Consumers that feed on phytoplankton; microscopic – Protozoa- Paramecium, covered in cilia, more protozoa in a waterway than any other kind of animal – Rotifers- have tufts of hair that rotate food toward mouth – Arthropods- largest zooplankton; shrimp, fleas, isopods, scuds, and side swimmers Copepods- large antennas used to paddle Isopods- largest zooplankton