Lake Apopka Re-establishing Fish and Wildlife Habitat in a Highly - PowerPoint PPT Presentation

Lake Apopka – Re-establishing Fish and Wildlife Habitat in a Highly Degraded, Hypereutrophic Water Body Bruce V. Jaggers, Ed Hayes Florida Fish And Wildlife Conservation Commission Eustis, Florida

Goal  Current Condition - Less than 1% aquatic vegetation in lake portion of Apopka.  Goal – Re-establish 10% aquatic vegetation in Lake Apopka in 10 years (Tiger Team).

Challenges  Poor light penetration – secchi typically 1 foot or less.  Large deposits of flocculent mud.  Limited littoral areas – 20,000 acres of marshes cut off from lake by levees.  Functions as a Reservoir – 5 feet of water 50 feet from levees at minimum desirable lake level.  Extreme wind fetches – Over 10 miles in distance across the lake.

North Shore Marshes – 20,000 Acres

Opportunities  Lake Levels 2 feet below low pool (opportunity to establish plants in ~3 feet of water).  Suitable substrates for planting (firm peat deposits).

Decision Point  Focus on planting spatterdock ( Nuphar spp.) and giant bulrush ( Schoenoplectus californicus ). Native aquatic species able to establish and survive in deeper water.  Establish submersed plants (SAV) behind “wave breaks” created by initial plantings.

Planting Scheme

Spatterdock Planting Zones Spatterdock Spatterdock

Questions  What methods do we use for large-scale spatterdock plantings? Has this been done before?  Will plants survive and establish in Apopka?

Evaluated Techniques (2012)  Bare root plants (small rhizomes).  Wild harvest plants (large rhizomes).  Nursery grown plants (UF greenhouse).

Decision Point  Focus on planting wild harvest and nursery grow-out plants (2013 & 2014).  Best outcome considering plant survival, logistics and cost.

Spring/Summer/Fall 2013 Planted 25,000 wild harvested spatterdock. Planted 10,000 nursery grow-out spatterdock. Planted 500 UF greenhouse spatterdock. Laughlin Road Site

Spring/2014 Planted 50,000 wild harvested spatterdock. Planted 10,000 nursery grow-out spatterdock. Planted 300 UF greenhouse spatterdock.

Spatterdock Survival Estimates  Wild harvest ~60% survival.  Nursery grow-out ~75% survival.  UF greenhouse grow-out ~80% survival.  Total # spatterdock plants installed – 96,000

Costs to Plant Spatterdock  Wild harvest - $2.58/plant.  Nursery grow-out - $6.80/plant.  UF greenhouse grow-out - ~$27.80/plant.  Total Spent (as of May 2014) - $327,753

Progress Toward 10% Goal (as of May 2014)  ~450 acres aquatic plants (1.5% of lake)  Next step – test plots of SAV planted in protected spots behind emergent plants

Spatterdock Wild Harvest Plants Laughlin Road Site

Wild Harvest Methods

Nursery Methods – Pond Grow-out

Nursery Methods – UF Greenhouse

Question  Why the difference in survival between wild harvest plots? E.g. 30 – 85% survival in individual plots.  Substrate conditions and water levels appeared to be similar between 7 plots.

Keys To Successful Plantings  Large rhizomes (wild harvest plants or plants grown out in nursery).  Current low water levels (below regulation schedule).  Sites with suitable substrates available.  Nutrients available for good plant growth.

Constraints To Successful Plantings  Deep water (even at water levels below regulation schedule).  Poor light penetration.  Wind/wave energy generated on large lake (initial plantings have survived winter storms so far).  Availability of plant material to transplant. Long transport distances.

Wild Cards  Water Levels/Water Storage (water levels in planting zones 6 feet at upper end of regulation schedule).  Wind/wave energy generated on a 30,000 acre water body (initial plantings have survived winter and summer storms so far).  Tropical storm after 1970’s effort!  Toxicity of some sediments?

High Sediment Sulphides Concentrations Causing Plant Damage?

QUESTIONS?