Successful Eelgrass Restoration: Case Studies in Urban Systems

1. Successful Eelgrass Restoration: Case Studies in Urban Systems Ashley Bulseco-McKim November 19, 2012

2. Outline • Overview of restoration techniques • Case studies in urban systems • What worked? What didn’t work? • Recommendations

3. Restoration Efforts NH/ME: Short(s), Davis, Kopp et al. Boston Harbor: Leschen, Evans, Estrella, Ford et al. Rhode Island: Nixon, Granger, Harris et al. Washington: Thom Long Island: Churchill, Dennison, Pickerell et al. Chesapeake Bay: Orth, Marion, Kemp, McGlathery, Reynolds New Jersey: Campanella, Bologna, Simmena et al. Heck, Duarte North Carolina: Fonseca, Thayer et al.

4. Transplanting Techniques • Hand planting • Core/plug method • Bare-root technique • Horizontal rhizome method (Davis & Short 1997) • Framing • TERFSTM • Checkerboard planting • Seeds • Traditional • Buoy • Mechanized

5. Hand-Planting • Core/Plug method: extracts cores with sediment intact (instrusive) • Bare-root technique: removes shoots with small amount of rhizome • Horizontal rhizome method: Two shoots are aligned parallel, pointing in opposite directions, and are pressed horizontally in the top 2 cm of sediment (not good for siltyclay) http://projects.ups.edu http://morro-bay.com

6. Transplanting Techniques • Hand planting • Core/plug method • Bare-root technique • Horizontal rhizome method (Davis & Short 1997) • Framing • TERFSTM • Checkerboard planting • Seeds • Traditional • Buoy • Mechanized

7. Frame: “TERFSTM” – Transplating Eelgrass Remotely w/Frame Systems (UNH) • 60 x 60 cm frame that holds 50 eelgrass shoots each • Volunteers attached shoots to the frame using dissolving ties • Distributed by either wading or throwing over the side of a boat, held down to the sediment surface with bricks (roots in sediment, blades in water column) • Left for 3-5 weeks • Too early: not enough time for roots to penetrate sediment • Too late: blades will entangle the frame • Re-use frames after removal Short et al. 2002

8. Frame: “TERFSTM” – Transplating Eelgrass Remotely w/Frame Systems Short et al. 2002

9. Frame: “TERFSTM” – Transplating Eelgrass Remotely w/Frame Systems Short et al. 2002

10. Frame: PVC/jute • Alternatives to TERFSTM • 0.25 m2 square of PVC pipe with jute mesh streched over • Eelgrass shoots tied to intersections • Mesh cut away after establishment • Good for community-based efforts Leschen et al. 2010

11. Frame: Checkerboard Pattern • Checkerboard plot 30-50 meters apart • Designed to cover • more ground • The void allows for further growth of eelgrass • If too close together, you would increase initial effort Leschen et al. 2010

12. Transplanting Techniques • Hand planting • Core/plug method • Bare-root technique • Horizontal rhizome method (Davis & Short 1997) • Framing • TERFSTM • Checkerboard planting • Seeds • Traditional • Buoy • Mechanized

13. Seed:Manual Planting • Classic method of collecting reproductive shoots • Hold in seawater until seeds mature and are released • Broadcast over large areas relatively quickly, but unpredictable germination timing and high time commitment (Leschen et al. 2010) Pickerell et al. 2005

14. Seed: Buoy-Deployment • Reproductive shoots are collected and immediately transferred to net • 9 mm net • Lobster buoy • Cement block (anchor) • Polypropylene line • Garden hose • Wire tie (adjust to water depth) • Efficient, but where do seeds go? Pickerell et al. 2005

15. Seed: Mechanical Planting • Planter: Benthic sled • Seed hopper • Peristaltic pump • Gel mixture of seeds andKnox ® gelatin • Injection nozzles • Buries seeds in the sediment • Variable effectiveness – is it worth the cost? Orth et al. 2009

16. Seed: Genetic Diversity • Hand-planting and frames rely on adult eelgrass shoots which may lead to loss of genetic diversity (Williams 2001) • Genetic diversity is important in ecosystem restoration because genetically diverse assemblages may be more resistant to disturbances and climate change • In Chesapeake Bay/Virginia Bay, found both donor beds and restoration sites had the same level of genetic diversity Orth et al. 2012

17. Other Restoration Techniques • Community-based restoration • Emphasis on site-selection • Long-term monitoring – important to assess success & failures, structural attributes, and functional attributes • Structural attributes: biotic and abiotic components • Functional attributes: ecosystem services e.g. energy flow, biogeochemical cycling, trophic relationships, growth rates, materials exchange • Important to understand how restoration sites compare to natural sites in regards to these factors

18. UNH Community-based Restoration • Make eelgrass restoration more accessible • The success of a community project relies on community involvement • Volunteers leave with an interest in coastal restoration and will advocate for it in the future Short et al. 2002b

19. Site Selection Model • PTSI, test-transplants, TSI • Multiplicative Index Short et al. 2002a

20. Case Study: Boston Harbor, MA • Goal: to restore eelgrass from spring ‘04 to fall ’07 to mitigate impacts from HubLine pipeline • Deer Island secondary wastewater treatment facility • Natural repopulation unlikely due to wind-driven current patterns (seeds wouldn’t reach estuary) • = good candidate Leschen et al. 2010

21. Methods • Short et al. 2002 site-selection model • Used frames (checkerboard pattern), hand-planting (horizontal rhizome), and seeds (manual) to test effectiveness – Lynn Harbor • Monitoring Leschen et al. 2010

22. Results • Preliminary: sites > 57% silt/clay failed & < 35% silt/clay successful • Medium-scale: TERFSTM attracted burrowing crabs so adapted to PVC/jute – four sites to test • Large-scale: planted sites comparable to or exceeded natural beds in biomass and density • Within 1 year, impossible to differentiate between plots planted with different methods • Overall: successfully restored over 2 ha of eelgrass to Boston Harbor Leschen et al. 2010

23. What we’ve learned (Leschen et al. 2010) What worked? What didn’t work? • Horizontal rhizome method worked well but required SCUBA • PVC/jute frames good for community involvement (> 150 volunteers) but less efficient • Checkerboard planting minimized human effort • TERFSTM attracted crabs • Seeds distributed on sediment surface were not successful (but better if scratched into the sediment) • Not enough information on sediment requirements for eelgrass – wide range in literature! Leschen et al. 2010

24. Recommendations (Leschen et al. 2010) • Need better information on physical requirements (e.g. wave exposure and sediment characteristics) to be used in site selection model • Because of imbalance between amount of eelgrass lost and eelgrass restored, we need to consider other management at the same time (4 ha gained, 760 ha lost) = “watershed approach” • Areas with compromised water or sediment quality may not be ready for eelgrass transplantation, and alternative mitigation strategies might be more far-reaching (e.g. minimizing boat impacts)

25. Recommendations (Neponset) • Adapt Short et al. 2002 model for site selection • Use a combination of transplant methods(or experiment before large-scale transplant) • Gain a better understanding of sediment characteristics • Gain a better understanding of wave exposure • Survey types of bioturbators • Involve the community • Long-term monitoring

26. References • Leschen et al. 2010 • Orth et al. 2008 • Orth et al. 2012 • Pickerell et al. 2005 • Short et al. 2002a • Short et al. 2002b • Note: literature cited in text includes hyperlinks to PDFs

29. Recommended Requirements for Eelgrass