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LakeAnnaLifeTimesAugustSeptember2015 5 overheard IS IT FACT OR FICTION First Hydrilla Treatment Completed In recent years Lake Anna has seen the reemergence of the submerged aquatic weed known as hydrilla. While the total coverage is currently miniscule compared to the entire lake hydrilla can propagate rapidly. Hydrilla might not seem like a ma- jor issue now but the threat of infestation levels and the course of action to control it early have activated a number of area residents each with their own idea of the correct future path. While there are a number of native grasses that grow in Virginia waters hy- drilla is an exotic brought in to the U.S. many years ago by tropical fish dealers. Since its escape from fish tanks hydrilla has managed to find its way into many of the countrys lakes and waterways. Some- times it grows within ecological limits. Sometimes it grows like kudzu spreading quickly in relatively shallow clear water forming dense mats that can make boat- ing difficult. Hydrilla can establish and then displace native aquatic plants such as pondweeds and eelgrass. While all aquatic plants have developed adaptations for life in the aquatic environment hydrilla seems to be a couple of steps ahead of other sub- mersed plants. Research has identified many of the characteristics that enable hydrilla to ex- ist and compete so effectively. The growth habit of hydrilla enables it to compete ef- fectively for sunlight. It can elongate very rapidly up to one inch per day until it nears the water surface. Near the water surface it branches profusely and produces great- er stem density than other submersed aquatic plants. One half of hydrilla standing crop occurs in the upper 0.5 m of water column. By pro- ducing this mat of vegetation on the water surface hydrilla is able to intercept sun- light to the exclusion of other submersed plants. Hydrilla makes efficient use of available nutrients. Hydrilla tissue is composed of approximately 90 water. Therefore the plants can produce a great deal of fresh plant material from a limited supply of the essential plant nutrients carbon nitrogen and phosphorus. Hydrilla is able to grow under a wide range of water chemistry conditions. It is commonly found in oligotrophic low nutri- ents to eutrophic high nutrients waters. It can grow in water up to about 7 the salinity of seawater or higher and it toler- ates a wide range of pH but tends to grow better at pH 7. Hydrilla is adapted to use low light levels for photosynthesis. This means that hyd- rilla can begin to photosynthesize earlier in the morning and thus successfully com- pete with other aquatic plants for limited dissolved carbon in the water. The low light requirement 1 of full sunlight or less also allows hydrilla to colonize in deeper water than other aquatic plants. Licensed applicator John Kauffman and Tom Guntner at work treating hydrilla on August 25. Larry Zemke photo Wake Surfing Examined Wakesurfing is a relatively new water sport that has become pop- ular on Lake Anna. Enthusiasts utilize a specialized wake surfing boat that creates a two- to three- foot wake so they can surf it on a wakesurfing board. The boards are smaller and differently shaped than typical surfboards employing padded kick bumps that enable the rider to master jumps spins and other tricks. Its said to be a lot of fun and easier on the joints than its counterpart wakeboarding. While this might sound like just another way to enjoy the water to some to others wakesurfing has become a nuisance a danger to boaters and a major source of ero- sion to the lakeshore. Early last fall in 2014 the Lake Anna Advisory Committee LAAC began to hear from a number of attendees to their meetings that described what they felt was a growing danger to the boating public from wakesurfing. The Lake Anna Civic Association had also logged similar complaints. Reports of boats being swamped and docks being over-washed by the over-sized wakes accompa- nied reports of increased shore- line erosion. With these concerns in mind the past chairman of the LAAC appointed a LAAC Wake Surfing Subcommittee asking them to re- search the situation. Fast forward to the July 22 meet- ing of the LAAC where the Wake Surfing Subcommittee presented their findings and recommenda- tions and youll see where some serious battle lines were drawn among lake users. Subcommittee chair Jean Mc- Cormick recommended LAAC ask Orange Louisa and Spotsylvania Counties to support their recom- mendation that the existing Spotsylvania and Louisa ordi- nances be changed to establish 200 feet for wake surfing and 100 feet for other towing activities as the common rule with Class 4 as the common misdemeanor type for violation and that Orange County enact a similar ordinance for consistency of expectations and enforcement on Lake Anna. Current Spotsylvania and Louisa ordinances are inconsistent. The Virginia regulation is 50 feet. The subcommittee saw confusion in the laws and heard law enforce- Hydrilla has been found growing at a depth of 15 meters in the Crystal River and commonly occurs in water three me- ters deep in Florida lakes. The bright green water weed is also very efficient at reproducing itself and maintain- ing itself during adverse conditions. It can reproduce itself in four different ways in- cluding fragmentation tubers turions and seed. Almost 50 of hydrilla fragments that have a single whorl of leaves can sprout a new plant that a new population can grow from and greater than 50 of frag- ments with only three whorls of leaves can sprout. This means that small amounts of hydrilla on boat trailers bait buckets dra- glines and from aquariums can spread the plant from place to place. Hydrilla is one adaptive plant that has cost lake managers billions of dollars to control. You can see why folks around a clear lake like Anna might be a little nervous when it shows up again after 25 years. All that being said hydrilla also has a number of beneficial aspects to the lakes and rivers it inhabits. Since it uses nutrients so efficiently hyd- rilla acts as a natural filtering agent clear- ing and often cleaning water of suspended particles and silt. Aquatic life generally thrives in the underwater weedbeds. Hyd- rilla like all plants also gives off oxygen as it grows a good benefit during hot sum- mer low oxygen levels in lakes. Addition- ally everything from aquatic invertebrates think nymphs and other water bugs and microscopic life to juvenile fish to adult fish seek the sanctuary and oxygen of a hydrilla bed. In general homeowners and recreation- al boaters are not fans of hydrilla. Many anglers will argue its a welcome addition to the water they enjoy fishing that only im- proves catch rates and fish stocks. To further understand Lake Annas his- tory with hydrilla we turn the pages of his- tory back to the late 80s when hydrilla first found its way into the lake. Then it spread rapidly 900 acres from the Cool- ing Lagoons hot side into the main lake creating a testy situation between home- owners and the counties around the lake. Eventually Dominion made the decision to stock approximately 6300 sterile grass eating carp another exotic species into the Cooling Lagoons. With the assistance of the Virginia Department of Game And Inland Fisheries VDGIF and the Lake Anna Civic Association the carp were continued on next page continued on page 7