5.0 Aquatic & Mosquito Questions and Answers Already Passed

5.0 Aquatic & Mosquito Questions and Answers Already Passed List the roles plants play in a healthy aquatic ecosystem. -producing oxygen -preventing shoreline erosion -lessening excess nutrients during growing season -stabilizing lake bottom -providing food and habitat for fish, waterfowl, and other aquatic animals List ways that excessive plant growth can adversely affect the ecology and uses of a water body. -harm ecology of aquatic ecosystem -curtail or prevent recreational water uses (e.g. fishing, boating, swimming) -impart tastes or odors to drinking water -hamper water treatment operations -adversely affect aesthetics, resort trade, and waterfront property values -produce toxins that harm animals drinking the water Describe the general growth habits of, means of dispersal and potential problems caused by: Emergent aquatic plants -*growth habits*: rooted in shallow water, most growth above water -*means of dispersal*: underground root systems -*potential problems*: very dense and may exclude recreational pursuits like boating, fishing, and swimming. Purple loosestrife is an example of a problem species. Describe the general growth habits of, means of dispersal and potential problems caused by: Submergent aquatic plants (both pondweeds and plants with whorled leaves) -*growth habits*: grow mostly under water surface, pondweeds sometimes have floating leaves in addition to their submerged leaves; whorled-leaf plants grow underwater with whorled leaf attachments -*means of dispersal*: pondweeds have extensive root systems, runners, and can also reproduce from seeds; plants with whorled leaves can disperse when uprooted by breaking free and getting moved by the wind -*potential problems*: most pondweeds not nuisance except for curlyleaf pondweed and sometimes sago pondweed; whorled leaf plants can uproot and break free easily and drift with wind to clutter shoreline; Eurasian watermilfoil is an aggressive non-native that can affect habitat and restrict recreation. Raking is required to remove these clutters. Describe the general growth habits of, means of dispersal and potential problems caused by: Free- floating and rooted floating-leaved aquatic plants -*growth habits*: occur on water surface and can be free-floating or rooted with large floating leaves -*means of dispersal*: free floating plants are easily windblown. rooted ones not so much -*potential problems*: free-floating plants accumulate on shorelines and are difficult to control in large waterbodies; rooted plants are rarely a nuisance. Describe the general growth habits of, means of dispersal and potential problems caused by: Free- floating, filamentous, and "rooted" algae -*growth habits*: found free-floating (planktonic) or attached to submerged surfaces (filamentous or "rooted"). -*means of dispersal*: multiply rapidly in warm weather; -*potential problems*: free-floating algae responsible for many nuisance algal blooms (release toxin, low DO, blue-green algae); removing rooted algae can allow worse species to come in so don't mess with them. List the advantages and disadvantages of chemical control of aquatic plants and algae *Advantages*: -offer longer-lasting control than some mechanical methods -less physical labor -ultimately cost less -important tool for specific nuisance plants/algae such as Eurasian watermilfoil and purple loosestrife *Disadvantages*: -restrictions on water use -oxygen depletion and fish kills -sudden nutrient release into water can lead to other plant or algae problems -risk to people and nontarget organisms Describe the beneficial roles of Wisconsin's fish populations. -maintain balanced communities by feeding on aquatic plants, insects, and other fish & provide a food source for natural predators -fishing for food/sport is popular in WI and ddepends on healthy populations -fish farms and hatcheries raise fish for food, feed, fertilizer, bait, and to release List 5 types of situations in which fish control may be warranted -eliminating undesirable or competing fish from fish rearing ponds -removing exotic and other undesirable species from a waterbody -thinning stunted fish to bring a population into balance -eliminating fish from a hatchery water supply to prevent a potential reservoir of disease-causing organisms -treating fish spawning sites to prevent overpopulation of an individual species Explain why post-treatment management can be important in the long-term success of a pesticide treatment project. -because when fish populations are lowered, density-dependent population growth allows the population to rebound if not managed post-treatment Know the Law: Who do you need to get approval from to conduct any chemical treatment for fish control? WI DNR Aquatic Plant Management Program List the 2 main reasons why mosquito control may be warranted. -nuisance -disease Describe the 4 stages of the mosquito life cycle, including the main structural features of each - *egg*: laid in water, hatch in ~3 days, some laid on dry land and hatch when flooded -*larva*: "wiggler", 4 instars with molting in between each, filterers, air tube to breath from surface -*pupa*: comma shaped, non-feeding, lasts a few days, contain respiratory trumpets, "tumblers" -*adult*: 1 pair wings, elongated probiscis, pair of antennae, males have bushy antennae while females have short and sparse antennae List the types of info you need about a mosquito species before you can develop an effective program to control it. -the types and locations of breeding sites -# of generations per year -host preference of the females (what animals they prefer to get blood from) -seasonal population levels and how rainfall affects them -their flight range -common resting areas -whether the species can transmit pathogens that may be present in your area -whether the mosquitoes carry pathogens that are present