SAV Habitat Requirements and Restoration Targets: Technical Synthesis III

SAV Habitat Requirements and Restoration Targets: Technical Synthesis III

Lee KarrhSAV workgroup chair

MD-DNR

A brief history• TechSyn 1 was published in

1992, – Largely water column based– Simple pass/fail evaluation of

each habitat requirement (HR)– Fixed restoration depths (1

and 2 meter)• TechSyn 2 was published in

2000– Created a model to combine HRs– Attempted to model attenuation at

the leaf surface– Evaluated light availability at the

leaf surface for multiple restoration depths, as opposed to 1 or 2 meters only

From: Batuik et al., 1992

Summary of TS1 and TS2 Habitat Requirements

Why is TS3 necessary?• For direct restoration projects,

even places that met existing habitat requirements had poor success

• The Watershed Model (version 5.3) did not adequately estimate observed SAV abundances in calibration runs using existing HRs

Cerco, 2010

Pertinent conclusions from STAC review of SAV restoration

• Evaluate extremes of temperature and clarity rather than just average conditions;

• Consider the interacting effects of multiple stressors (particularly temperature, clarity and salinity) and temporal dynamics and sequencing

• Develop SAV restoration strategies that are responsive to climate change

Pertinent From STAC Review of SAV module of the Model

SAV potential: A. Improve model relationships between TSS (particle size, organic content, etc.) and epiphyte loads (biofouling, periphyton). B. Test the ability of the model to duplicate case study areas where there have been observed improvements in habitat conditions and SAV resurgence. C. Quantify the effects of other stressors (salinity, sediment biogeochemistry) on SAV biomass dynamics. D. Incorporate multiple species (including non-native) potential with species-specific physiology into each SAV cell rather than generic SAV. E. Further develop SAV to habitat feedbacks.

SAV area: A. Refine how bottom sediment properties affect species-specific SAV recruitment and survival. B. Improve simulations of year-to-year variations in SAV species-specific recruitment potential including colonizer species. C. Include biological disturbance components of mortality. D. Refine relationships between SAV canopy height and SAV light requirements.

TS3 will allow us to:• Review current habitat requirements and water clarity

standard and determine if they are stringent enough to allow for the resurgence of SAV. – Are 13% and 22% of incident light at the plant sufficient?– Revisit ambient nitrogen, phosphorous and chlorophyll habitat

requirements in relation to anticipated reductions in loadings via TMDL/WIP process, provide guidance to Water Quality Standard development

• Improve modeling results for SAV growth in linked Watershed/Hydrodynamic Model (the Chesapeake Bay Model)– Modeling results to date have been too poor to incorporate into

model runs• Will global change require different habitat requirements

in the future?

• Revised/re-considered habitat requirements will improve direct SAV restoration (i.e. planting/seeding)– As recommend by STAC review of 2011

• Revised habitat requirements will provide greater explanatory power when preparing SAV information for managers and the public (i.e. Bay Barometer, report cards etc.)

• Use ecosystem services evaluation– Evaluate effectiveness of TMDL/WIP process relative

to SAV– Quantifying water quality feedbacks due to SAV to

allow Chesapeake Bay Model to account for water quality improvement as SAV is restored (currently not a component of the Model)

– Determine economic value of SAV for management and public informational products

Topics to be addressed• SAV Restoration

– SAV habitat requirements (light, sediments, waves)– Habitat criteria for established versus restored SAV beds– Impact of pioneer species on SAV resurgence/restoration– Feedbacks and resilience of SAV populations (genetics) and communities– Large versus small scale restoration– Shoreline hardening effects on SAV

• Global change– Temperature– Sea level rise, coastal erosion and sustainable shorelines– CO2 levels– Precipitation (variable river flow) and global dimming (incident light)

• Ecosystem services provided by SAV in Chesapeake Bay– Ecological functions of SAV (interactions with fisheries, nutrient uptake, carbon

sequestration, wave/resuspension reduction, habitat value, improving habitats for other species, water quality challenges (i.e. DO improvements)

– Economic impact of SAV serving the above functions• Identification of knowledge gaps in SAV research, restoration and management

PARTICIPANTSAnalysis/Synthesis Partners• Tom Arnold Dickinson College• Katia Engelhart University of Maryland Center for Environmental Science, AL• Maile Neel University of Maryland College Park• Chuck Gallegos Smithsonian Environmental Research Center• Brooke Landry Maryland Department of Natural Resources• Mike Kemp University of Maryland Center for Environmental Science, HPL• Chris Kennedy George Mason University• Evamaria Koch University of Maryland Center for Environmental Science, HPL• Ken Moore Virginia Institute of Marine Science• Bob Orth Virginia Institute of Marine Science• Chris Patrick Smithsonian Environmental Research Center• Nancy Rybicki US Geological Survey, Reston, VA• J. Court Stevenson University of Maryland Center for Environmental Science, HPL• Chris Tanner St. Mary’s College• Lisa Wainger University of Maryland Center for Environmental Science, CBL• Don Weller Smithsonian Environmental Research Center• Richard Zimmerman Old Dominion University

RESOURCE MANAGEMENT Partners• ???? NOAA Chesapeake Bay Program• Rich Batiuk US EPA Chesapeake Bay Program• Michelle Gomez US ACE Baltimore District• Rick Ayella MDE• Lee Karrh MD-DNR• Rusty Butt DEQ• Leslie Orsetti DC Fisheries• Anne Swanson Chesapeake Bay Commission