Effects of recent seagrass species change on habitat structure and function:

Preliminary research proposal

Emily FrenchSummer 2013

Change in seagrass species in the Chesapeake Bay

• Z. marina declining in the Chesapeake Bay, only occupies 65% of area it did 20 years ago

Modified from Orth et al. 2001

www,helcom.com/fi

www.kinrm.sa.gov.au

Change in seagrass species in the Chesapeake Bay

• Deteriorating water quality causing Z. marina to die back

• Disturbances can allow opportunistic species to thrive

• R. maritima is the second most prevalent grass in the polyhaline Bay, is a good colonizer that thrives when conditions are right

• R. maritima could be a potential replacement in areas where grasses co-occur

Hot off the press!

R. Maritima vs. Z. marina

R. Maritima vs. Z. marina

R. Maritima vs. Z. marina

R. Maritima vs. Z. marina

Evidence near the York River, VA

Orth lab 2012, unpublished data

Evidence near the York River, VA

Orth lab 2012, unpublished data Moore et al. in press

Research Questions

1. How do the structural components of Z. marina beds compare to those of R. maritima?

2. Does habitat value for associated faunal communities vary between R. maritima- dominated, Z. marina-dominated, and mixed species areas?

3. Are there sediment biogeochemical, microbiological , or erosion potential differences between the R. maritima-dominated, Z. marina-dominated, and mixed species areas?

Sites: Lower, polyhaline Chesapeake Bay

• Three Sites: Mobjack Bay between the Severn and Ware rivers, Goodwin Islands, Poquoson flats

• Three sampling areas within each site: Z. marina- dominated, R. maritima- dominated, mixed

• Five replicates within each sampling area (n=5)

Methods• 5 replicates of each

of the sample types will be taken within each of the sample areas.

• Meter square quadrat will be haphazardly tossed within 10 m of the PVC pole marking the sampling area.

Methods

1. Percent cover2. Biomass core3. Sediment core-

sediment characteristics

4. Sediment core- microbial community

5. Faunal grab6. Epiphytes7. Erodibility

Sample types:

Methods

1. Percent cover2. Biomass core3. Sediment core-

sediment characteristics

4. Sediment core- microbial community

5. Faunal grab6. Epiphytes7. Erodibility

Sample types:

Methods

1. Percent cover2. Biomass core3. Sediment core-

sediment characteristics

4. Sediment core- microbial community

5. Faunal grab6. Epiphytes7. Erodibility

Sample types:

Methods

1. Percent cover2. Biomass core3. Sediment core-

sediment characteristics

4. Sediment core- microbial community

5. Faunal grab6. Epiphytes7. Erodibility

Sample types:

Community 1

Community 2

http://biology.clc.uc.edu/

Methods

1. Percent cover2. Biomass core3. Sediment core-

sediment characteristics

4. Sediment core- microbial community

5. Faunal grab6. Epiphytes7. Erodibility

Sample types:

Methods

1. Percent cover2. Faunal grab3. Sediment core-

sediment characteristics

4. Sediment core- microbial community

5. Biomass core6. Epiphytes7. Erodibility

Sample types:

www.kinrm.sa.gov.au

Methods

1. Percent cover2. Faunal grab3. Sediment core-

sediment characteristics

4. Sediment core- microbial community

5. Biomass core6. Epiphytes7. Erodibility

Sample types:

http://gescience.com/UGEMS.html

Timeline

• June 2013- Preliminary sampling at the height of Z. marina biomass

• August 2013- Second sampling at the height of R. maritima biomass

Thanks!• Moore lab: Ken Moore, Erin Shields, Betty Neikirk, Steve

Snyder• Orth lab, Song lab, Duffy lab• CB-NERRS WQ lab

Questions or suggestions?