Rock planting is a simple and effective way of establishing eelgrass in high energy rocky environments.It all starts with selecting the perfect site…Once you have that, you’re half way there!Obviously, it is not always easy to find these sites and that is the real challenge.I couldn’t possibly cover all that goes into the site selection process in a blog post, so I won’t even try.We’ll just assume for now that you have such a site.
The following photos are from our field work yesterday off of GreatGullIsland where we have initiated a large-scale planting effort based on the success of our test plantings.These are the steps we take following collection of the donor plants from a suitable location.Again, this will not be covered in this post.
Step1. Chose your weapon!I prefer that old fashioned crow bar (above) while others on the crew use l
arge screwdrivers or short sections of rebar.
Step 2. Flip the rocks in preparation for planting.
Step 3. Place the plants in groups of 6 to 12.
Step 3a. Plant in groups…to speed coalescence. 1 meter OC spacing is ideal if there are enough rocks.
Step 4. Monitor. The plantings should look like this after a couple months. Notice how the shoots are growing away from the rock they were planted under. (same site, but from a previous planting).
Step 4a. Monitor more!…Eventually the rocks disappear as they get buried under sand and gravel that accumulates as the eelgrass shoot density increases. The plantings should like this after about three years! (different site same method).
The weather this week has allowed us to get back out in the field once again as the season races towards winter…we need a few more good weeks to finish out or field work!
On Monday Kim, Ali and I were able to get out to PlumIsland and check on the status of plantings there.The story was mostly good with a little bit of not so great news.
I’ll begin with the not so good news…
Our plantings off of FortTerry on PlumIsland (south side of the island) were looking quite battered and beaten from the heavy winds and storms we had over the last week or so (above).It still amazes me that there can be so much erosion and scouring to the bottom in 12 feet of water!I can’t imagine what the waves must have been like!We do still have plenty of plants here, but we lost many and those that remain appear pretty battered.There was also some burial as sand waves passed through the planting area.On another note, we still haven’t been able to find the temperature logger that was attached to a half cement block that was washed away during one of the last storms…maybe this site is too energetic.We are not planning any more plantings this year and instead we will just watch and wait to see how the plants fair through the winter.I REALLY want this site to work as it has so much potential for large-scale planting.For now, I will cross my fingers!
Now onto the good news…
After FortTerry, we headed east to the north side of GreatGullIsland and although the waves were very heavy and the vis was poor, we were could see that the plants looked great here (above).Everywhere I looked, there seemed to be groups of emerald green plants.This year we have really focused on planting in tighter groupings to speed coalescence and I think this is will pay off in the end.At past rock planting sites it has taken approximately three years for coalescence to occur, but I’m hoping that with this spacing this will begin to happen within the second growing season.Then again, we will get less bang for our buck per planting unit, but we’ll see how this works…we can always go back to the original method.
At Great Gull, there was no indication of damage or loss and we even had a few Lacuna egg masses visible on the blades…a good sign.I fully expect this site to fair as well as our plantings on the south side of the island that are doing incredibly well at this point after three years…
Once back in the boat we headed west to the north side of PlumIsland to visit the RadiatorBeach site, the deepest of our plantings this season (top photo).Here again we were happy to find the plantings doing very well with no signs of loss or damage even at our deepest stations below 20ft!Some of the plants here were shorter than the last time we visited, but this is just the winter growth habit taking over as the temperature drops and the water clarity increases.
Today, we’ll be splitting into two teams: My team, including Neal and Ali will be planting more plants at Great Gull while Steve and Kim will be monitoring the recovery of the natural meadow at Orient Point.We also hope to get in tomorrow and we have a big day planned for Friday with visits to points west in LIS.
Enhancing the "Unobtrusive Charisma" of Long Island's seagrass ecosystems one post at a time...
About seagrassli
What is Seagrass? Seagrassn: "Rooted submerged marine or estuarine macrophytes of several species. Habitats created by seagrass meadows are among the most diverse and productive estuarine environments." (NOAA) On LI eelgrass (Zostera marina) is the dominant species and the focus of our work. -ChrisP
I am currently the Eelgrass Program Manager at CCE in Southold. I began working for Cornell 19 years ago. My original work focused on salt marsh restoration and ecology, but in '94 I began to work with eelgrass. Since that time we have built a considerable restoration and monitoring program. Current work involves refining site selection criteria and developing labor-saving planting methods for use in local waters and throughout the World.