Aquatic Plants in BBL


Eurasian Water Milfoil	Coontail

A wide range of aquatic plants can be found growing in, on, and around a body of water. Based on their various adaptations, some will be found rooted in flowing waters while others can only survive in placid, stagnant areas. Within a natural, well-balanced system, these plants provide food and cover for fish, waterfowl and aquatic vertebrates. They produce oxygen and help stabilize bottom sediments. Like terrestrial plants, aquatic vegetation requires a carbon source, sunlight and nutrients. Dissolved carbon dioxide, bicarbonates and carbonates, typically quite abundant in water, provide a source of carbon for the growth and food production process known as photosynthesis. The energy driving this process is derived from sunlight. Therefore, the depth of the sunlight penetration will limit the depth to which aquatic plants can grow. At the same time, the amount of nutrients available (mainly nitrogen and phosphorous) will limit the quantity of vegetation, which will grow.

Aquatic plants derive their nutrients from the sediments and/or the water column. These nutrients are cycled between the sediments and the water on an annual basis. Adding to this nutrient enrichment of a lake, a process known as eutrophication, are inputs from external sources. Nutrients and sediments are contributed by man's agricultural, domestic and industrial activities through sources such as domestic waste discharges, construction site erosion, lawn and garden fertilizer runoff, and septic tanks. The most noticeable symptom resulting from eutrophication is the development of prolific aquatic plant growth. Eight types of aquatic plants have been identified in Big Bear Lake, of which coontail and milfoil are the most abundant and the most troublesome to navigation, fishing and aesthetics.

FLOATING AQUATIC PLANTS IN BIG BEAR LAKE
Plants with leaves that float on the surface and are rooted on the bottom are included in this category. Free-floating surface plants, which derive their nutrients directly from the water through the cell wall or by means of a well developed root system, are also in this group.

Smartweed (Polygonum hydropiperoides Michx): This is a flowering plant, which can form dense strands covering large areas of the Lake. The five parted flowers bloom from July to September and their color varies from white to pink. This plant grows in wet soil or standing water and it provides a food source for waterfowl.

SUBMERGED WEEDS IN BIG BEAR LAKE
Plants which are generally rooted at the bottom and are completely underwater are in this category. Submerged weeds are usually flaccid and lack rigid cellular tissue. Flowers, if present, may extend above the water surface.

Coontail (Ceratophyllum demersum): This plant is easy to recognize as it resembles the plants often seen in home aquariums. It is submersed without roots, and the leaves are dark green in color and arranged in whorls on the stem. Coontail can be distinguished from milfoil by the forking of the leaves rather than the feather-like divisions. The spacing between leaf whorls is highly variable. Consequently, plants may be bushy or extremely long and sparse.

Eurasian Water Milfoil (Myriophyllum spicatum): This species is an exotic plant, introduced to the U.S. by the aquarium industry. It is rapidly becoming a major nuisance throughout North America. It is capable of rapid dispersion, principally by fragmentation of the plant parts. Each fragment is capable of growing roots and eventually developing into a new plant. Removal of fragments from boat trailers and along shorelines is advised to prevent its spread into new areas. Eurasian Water Milfoil is quite competitive with native species and may completely dominate a plant community within a few years after introduction. As this weed replaces native aquatic vegetation, it can alter physical, chemical and biological processes in the entire ecosystem. Due to the plant's ability to form dense growths, water use activities may become severely impaired. Studies have documented dramatic changes in water temperature and dissolved oxygen in Eurasian water milfoil beds that are detrimental to many species of fish.

Curly Leaf Pondweed (Potamogeton crispus): The leaves are thin and membranous with veins plainly visible. Minute teeth are visible along the entire margin of the leaf and the weed commonly grows early in the spring and dies back during midsummer. Fruits are borne in spikes above the water surface and leaves are alternately arranged on the stem. This plant tends to grow profusely early in the season, often shading and inhibiting other weed growth. Re-growth of this weed rarely occurs in the same season after control has been achieved.

American Elodea (Elodea canadensis): This weed has broad oval leaves, usually four in number, arranged in whorls around the stem. Whorls are compact near the growth tip, with spacing between the whorls gradually increasing further down the stem. Fragmented portions can develop into new plants.

Sago Pondweed (Potamogenton pectinafus): These plants are bushy in appearance with narrow thread-like leaves alternately arranged on the stem. Nutlets are arranged like beads spaced on a string and emerging from the water. The leaves are alternately arranged on the stem. In waterfowl areas, these plants are a valuable food source.

Leafy-Pondweed (Potamogenton foliosus): This plant has short, grass like submerged leaves. Clumps of 4-8 fruiting bodies are attached to the center stem by a short seed stalk. It grows from shallow water to a depth of four feet. In waterfowl areas, these plants are a valuable food source.

Widgeon Grass (Ruppia maritime): The leaves are thread-like and narrow, extending from an extensive buried root system. It has four to six fruits borne in clusters on short stalks at the top of the plant. This plant is a prime waterfowl food and is desirable in some locations.

Spikerush (Eleocharis spp.): The stems are green and leafless, varying in length from 5 inches to 4 feet with varying diameters. It grows in clumps, similar to turf. The mature stems are tipped with a brown to black, scaly, lance-shaped spikelet. It reproduces from rootstocks and seeds, and is usually found on muddy or sandy shores and shallow water, but submerged forms do occur.

Algae are primitive plants closely related to the fungi. They exhibit no true leaves, stems or root systems and reproduce by means of spores, cell division or fragmentation. Some 17,400 species of algae have been identified and thousands more probably exist. These organisms have adapted to many different habitats and exhibit a wide range of characteristics. They can be found in many places from hot springs to glaciers, fresh water to salt water and sandy beaches to rice paddies.

Planktonic Algae – common genera: Anabaena, Chlorella, Pediastrum, Scenedesmus, Oocystis: These are microscopic plants usually suspended in the upper few feet of water often reaching bloom proportions. The water appears pea soup green or brownish and natural die-off may cause a summer kill of fish due to oxygen depletion. Some species may be toxic to livestock, wildlife or man, or impart taste and odor problems. At the mercy of wave and current action, planktonic algae will sometimes accumulate along the shore or in backwater areas around Big Bear Lake.

Filamentous Algae – common genera: Spirogyra, Cladophora, Rhizoclonium, Mougeotia, Zygnema and Hydrodictyon:This algae is also known as “pond scum” or “moss” because it forms greenish mats upon the water’s surface. Filamentous algae usually begins its growth along the edges or bottom of the body of water and “mushrooms” to the surface buoyed by the oxygen it has produced. Individual filaments are a series of cells jointed end to end which give the thread-like appearance. They also form fur-like growths on the bottom of logs, rocks and even on the backs of turtles. The texture of these growths may be slimy, cotton-like or coarse. Common names such as frog spittle and water net have been given to a few forms. Filamentous algae often appears in large mats which provide a smothering action when hovering over milfoil plant masses. The algae reduces the sunlight and causes other problems which inhibit the growth of milfoil. Therefore, this algae, although sometimes a functional and aesthetic aquatic nuisance, must sometimes be viewed as a positive biological control agent for vascular aquatic plants. The District monitors algae carefully and control measures vary from year to year depending on the severity of the problem.

Toxic Algae: Death and sickness to pets, livestock, wildlife and even man have been attributed to the presence of certain algae, mostly blue-green-forming species, in water supplies. Lethal substances produced by these algae are retained in the cell and released after death or are secreted from living cells. It is important that wildlife specialists, pond owners and lake property owners are aware of this potential danger. The only type of toxic algae identified in Big Bear Lake is blue green algae which can be found in stagnant, shallow areas of the Lake. On the average, one or two blooms occur each season and sometimes an application of the chemical Cutrine is applied until the algae is controlled.

Blue Green Algae (Lyngbya spp.): The species which are particularly troublesome to control are those which grow in colonies forming small spongy masses of mucilage. These blue-green, black or gray clumps made up of thousand of individual cells will lay on the bottom or float to the surface. Because of the protective mucilage, chemical control is difficult.

Aquatic Plants and Algaes Present in Big Bear Lake

Aquatic Plants and Algaes Present in
Big Bear Lake