How the Ecology and Biology of Florida s Seagrasses Drive the Reality of Regulatory Options

Transcription

1 How the Ecology and Biology of Florida s Seagrasses Drive the Reality of Regulatory Options CSA Ocean Sciences Inc. Mark S. Fonseca Ph.D. Science Director CSA Ocean Sciences Inc.

2 Outline What are seagrasses? Challenges to restoration / what have we learned? Evaluation criteria Conclusions challenges in the 21 st century

3 What are Seagrasses? q Flowering, vascular plants not algae q 6 to 8 species in Florida: Halophila decipiens paddle grass Halophila engelmannii star grass Halophila johnsonii (?) Johnson s seagrass Ruppia maritima widgeon grass Halodule wrightii (cuban) shoal grass Halodule beaudettii (?) shoal grass Syringodium filiforme manatee grass Extreme pioneering often annual pioneering Putative H. beaudettii Euryhaline / sheltered Thalassia testudinum turtle grass climax

4 Thalassia Halodule One meter Syringodium Halophila decipiens One meter One meter

5 Challenges Larger Issues Habitat restoration rarely a net gain Avoidance > minimization > mitigation Seagrass niche is full Biggest gains past, large-scale modifications watersheds, borrow pits, roadways, scarring Flynn vs. FDEP State of Florida Division of Administrative Hearings Regulatory Issues Consistency Trade-offs of seagrass loss for conservation off-site = net long term loss Prop scars not much lift Spatially & temporally dynamic cover defining habitat UMAM process not designed for seagrass o Complicates performance and compliance levels Maintenance dredging conundrum Bird stakes & carbonate sediments (south Fl and Halodule)

6 Key Pitfall is Site Selection (follows (Addy 1947) Depth similar as natural beds Anthropogenically disturbed No rapid or natural recolonization Track record Sufficient area Similar quality habitat restored No chronic or acute disturbance (storms, bioturbation)

7 Site selection What have we learned? Stalled at simple observations of depth, and human causality Methods - most of them work Extreme expectations too much like crops Defining success: persistence and acreage Impediments to success Disturbance (water clarity, storms and bioturbation) Grazing Applying seagrass biology and ecology Spreading rates, vegetative vs. seeding Compressed succession Landscape pattern Economics

8 Evaluation Criteria Success = Coverage and persistence Other measures.. Interesting research Do not guide interim action Unreliable indicators f (small scale gradients) blade width leaf length epiphytes rhizome length biomass

9 How much acreage? HEA and UMAM Similarities Assessment tools for habitat impacts and mitigation Calculate amount of mitigation required Consider the change in the value of services over time

10 Habitat Equivalency Analysis Quantitative assessment based on a recovery function 2 primary components Amount of injury (area and severity) Lost services vs natural recovery + restoration (all discounted over time) Units = acre-years of service No formal risk assessment or preservation factor

11 Uniform Mitigation Assessment Method Qualitative assessment Relative to fish and wildlife utilization Units = functional loss and relative functional gain (RFG; dimensionless) RFG = mitigation Δ (with vs without project) adjusted for Time Risk Preservation (if applicable) Currently under review for seagrass/benthic habitats

12 Assessment uncertainties Spatially and temporally dynamic habitat vs 30 min assessment Natural growth variations f (habitat conditions) Functional roles Open system for wildlife/fish utilization Separating anthropogenic degradation vs natural variation

13 Conclusions What are the challenges/opportunities in the 21 st century? 1. Understanding disturbances, defining extremes, 2. Species definitions 3. Forecasting site suitability 4. Applying economics 5. Applying landscape principles draw from terrestrial ecology 6. Using genetic information at the scale of action 7. Managing non-charismatic seagrass species 8. Effective use of information A. Uhrin

14 Google: Seagrass guidelines

15 A. Uhrin CSA Ocean Sciences Inc SW Kansas Avenue Stuart, Florida

16 Seagrass restoration costs 1.5 acre (0.607 HA) project Map & Ground truth = 6 Planting = 19 Monitoring = 59 Contractor = 8 Gov t. oversight = 9 TOTAL COST ~= $ K In 2013 dollars $ K per acre Source: United States vs. Salvors Inc.

17 Planting unit size affects survival ~ Survival (days) Sod 25 x 25 cm ( m 2 ). Bare root Sod Mega sod Mega sod 3.5 x 3.5 m (11 m 2 ) 50 0 Bare root units 10 x 10 cm (0.01 m 2 ) Planting unit size (m 2 )