Spring recap

Jill Carr measuring canopy height at a Nahant reference bed.

Despite all the bad weather that we've had, it was a very busy and productive spring for the MarineFisheries HUB3 eelgrass restoration project.  Our work has shifted from Salem Sound to Boston Harbor, and the spring was spent planting and monitoring at six sites that were selected last fall.  The sites that were selected for restoration are Green Island, Great Brewster Island, Gallops Island, Long Island, Governors Island Flats, and Deer Island Flats.  All of our harvesting for the Boston Harbor restoration will take place in expansive natural eelgrass beds near Nahant.  We also began monitoring at three reference beds; two near Nahant and one east of Logan Airport.  As noted in a May post, during our initial assessment of the reference beds and harvest sites, it appeared that some of the natural beds had suffered some damage from winter storms that battered the area.  While we don’t have enough data to say for sure, the beds do seem to be rebounding as seedlings are growing and filling in some of the bare areas.    

Boston Harbor restoration, reference, and harvest sites.

The Boston Harbor sites are set up in a similar layout to our six plots per ¼ acre sites in Salem Sound.  The plots that were planted this spring will act as test plots and five additional plots will be added to the sites that are deemed successful based on the initial plots.  Our goal is to get at least 1 acre planted in Boston Harbor.  We are planning to use volunteers for large scale planting days again as last year’s volunteer days with Salem Sound Coastwatch and The New England Aquarium’s Live Blue Ambassadors program were a huge success.

Earlier in the spring, we looked at two of our restoration sites that were planted last year in Salem Sound.  Both the Woodbury Point site and the Middle Ground site survived the winter and appeared to be expanding.  A full monitoring event is planned for all of the Salem Sound sites in late July so that we can determine the actual one year success of those sites.

We are all keeping our fingers crossed for the weather to begin to improve.  We have a lot of work to do throughout the summer, so stay tuned for further updates.

Declining density and extent of eelgrass at Salem Sound and Nahant could be due to storm damage

Hi! Back in the water again after a long winter in the office...

Nahant

So far we have been to the Nahant meadow twice this spring.  The first time in April we came to retrieve a hobo temp/light monitor and harvest for plantings in Boston Harbor outer islands. Notes from August 2012 at that site indicate that plants were tall and lush, 75% cover and approximately 80shts/m2 with many reproductive shoots.  The meadow was continuous with few open patches.  But in April, we observed a low density patchy bed with large eroded areas and other areas of deep sand waves.  Our screw anchor, installed back at the end of August 2012, was buried up to the eye. 

We were back at the Nahant eelgrass meadow last week looking for a site to establish a monitoring station.  We ran a drop camera along several transects spaced throughout the DEP mapped area.  We were surprised and disappointed to find a large portion of the area mapped by DEP in 2006 is now gone and the remaining grass is mostly patchy, similar to what we saw in April.  The southeast lobe of the bed persists, but has contracted from it's 2006 extent.  Check out the rough map below digitized from our field notes, showing the remaining meadow, and an area of patchy grass and other sections of the bed that are now only sand waves.

We plan to return with divers for a closer look to help determine what might have occurred.  From the camera view it appeared that sand waves had swept over the bed, possibly burying the grass.  This meadow has long been a lush dense meadow and one of the few remaining north of Boston of this size (in MA).  Many groups have used this bed as a reference bed and donor bed for eelgrass projects in Boston.  The green dots on the map above show the locations where we are investigating possible establishment of a new SeagrassNet, long term monitoring station.

Salem Sound

At our SeagrassNet site in Salem Sound (Misery Island, Beverly) we also found low density and evidence of erosion.  It looked like much of the sand had been washed away leaving a hard-packed clay.  There is still grass clinging to the clay, so hopefully as the season progresses it will fill back in.  I think we are seeing the effects of a late winter with several storms, including NEMO in February 2013.

Sand eroded away leaving hard-packed clay over much of the shallow side (transect A) of the meadow

SeagrassNet quadrat showing low density eelgrass and eroded areas of clay

erosion around a small eelgrass clump near transect A

Taking a biomass sample on Transect B