Living Shorelines and Sea Level Rise on New Jersey’s Delaware Bayshore

Living Shorelines and Sea Level Rise on New Jersey’s Delaware Bayshore


Sea level rise has been affecting
communities on the Bayshore now for several years. Driving down the Bayshore,
you see evidence of overwash of sea water and sand and sediment into the
road. The homes are up on stilts now and having septic problems. Communities that
have been dependent upon fishing and farming are struggling to find ways to
persist in the face of rising sea levels. Sea level rise is eroding their
shorelines, flooding their towns, flooding their agricultural fields. So
unfortunately the communities are really struggling with leaving, staying that
kind of debate as far as living along the coast. Many communities exist
right up to the water’s edge. For example, the fishing communities are seeing a
loss of the shoreline, which means that they can’t maintain their marinas there. Communities that have housing or other buildings built up to the Bayshore are seeing again the shoreline erode actually moving underneath some of
these structures now making them much more susceptible to storm damage and
erosion. Towns are trying to protect the shoreline so that they can protect the
roads, the infrastructure, the farm fields against rising seas and riding tides. So
it’s a real struggle. One of the sites that we’ve been trying
to install a living shoreline is a location called Money Island.
It’s also near a community called Gandy’s Beach. And between those two small
communities is a large expanse of marsh. Money Island is situated right in the
middle of the Delaware Bay oyster beds, which is a primary area for crabbing and
fishing for flounder or fluke, for weak fish, but it’s called Money Island
because the boats are landing their catch and they’re making their money there.
It’s served by a number of commercial docks.
There’s a single road that comes out for that across this small spit of marsh. We
picked this area because it’s key to the fishing community, and if we lose the
road going out to that then this fishery will have to find another port. Living
shorelines are more helpful than traditional bulkhead-type structures
because they absorb wave energy more than they reflect it. Bulkheads often
cause more erosion at the base, and they also have less habitat benefit for the
creatures that live in the area where it’s being installed. So it’s less
friendly to the habitat and also sometimes even less effective. A
traditional breakwater is sort of a sterile structure. It doesn’t support a
lot of life. A natural shoreline does that, and certain components of natural
shorelines can be engineered, if you will, to help protect the shoreline so
that it isn’t susceptible to storms, it’s not susceptible to the same level of erosion,
or when those things happen it will regrow. It’s a living sort of structure
as opposed to a static solid piece of structure like a bulkhead or a pile of
rocks. Marshes are natural buffers. That’s what they’re there for. They move, they change, they erode, but the goal is that they can
recover and keep pace with sea level rise.
What’s happening recently is we’re seeing sea level go up at a much faster
pace, and that’s drowning the marshes, which means that now that water is
moving into the forests, into the farm fields, into the roads, into the cities.
And so we’re trying to find a way that we can accelerate the rate at which the
marshes increase to keep pace with that sea level rise. So the living shoreline,
the oyster castles, which are shell and concrete blocks that are stackable and
buildable and also the shale bags, those bigger structures, help slow down wave
energy, which allows sediment to fall out and help add some height to the
shoreline. And then behind that there’s coconut fiber logs that are installed
and planted with Spartina grass. All that stabilizes the sediment even more. One of
the main benefits of doing this is that you maintain the connection between the
aquatic environment and the terrestrial environment. There’s an interface there
where those two things meet and that interface allows life and living
processes to move from aquatic environments into terrestrial
environments. Oysters and ribbed mussels will recruit to these structure. They
live at the base of the Spartina grass, and they have these byssal threads, the
mussels do, which are like stringy rubber bands that help also solidify things. The
oysters build structure. They’re reef builders, so as they attach to our
castles and our shell bags they’re concreting things together. And oysters
filter the water. They create habitat for all different fish and critters to hide
in. It’s a living structure. We want to enhance the habitat. We want to improve
the habitat. We want the habitat that we put out there to be at least as
productive as a natural habitat is, if not even more productive in terms of the
number and the kinds and types and abundance of species that grow and live
there. You know, one of the areas of growth for
food production systems, agricultural systems in New Jersey, is aquaculture and
in particular shellfish aquaculture. And along the Bayshore region, they
predominantly do this by building short racks and putting bags on top of them.
And those actually act as a breakwater structure. The farms themselves actually
can have a positive impact on protecting the shoreline. And there’s a nice
interaction, a nice synergy there then between building a living shoreline and
having a farm out in front of it. And so those two things fit together very
nicely. Another thing that happens as the sea level rises is it starts to invade
our farmlands, our agricultural fields. It also can increase the penetration into
our freshwater aquifers, something we call saltwater intrusion. As you can
imagine, what might happen then is once salt gets into these otherwise upland
terrestrial freshwater habitats it’s just like if you have a garden. You’re
not going to put saltwater in your garden. It’s going to kill those plants.
The same thing happens there. If you drive along the Bayshore today, you will
see what we call bone forests, and they are stands of trees without any leaves
on them. All you see is just the leftover trunks. That’s what’s going to happen to the
agricultural fields. That salt is going to stay in the fields and stay in those
soils, and it won’t become farmable unless we have some sort of salt
tolerant crop that we can put in there. I first moved to the Bayshore here in
1989. I’ve seen quite a lot of changes in the Bayshore here. Those
communities that have been dependent upon fishing and farming, you know, those sort
of things, are struggling to find ways to persist in the face of rising sea levels.
Communities here along the Delaware Bayshore are rich in culture and history.
There’s a lot of neat stories and folktales that go back to how the community
survived mostly relying on the bay and its resources for their well-being.
So it’s important to these people to maintain that. The saltwater is intruding
into the forests and the farm fields and the communities, and agricultural land
can’t move inland further because that’s where there’s a town or city or
residential development. So we’re getting squeezed sort of on
both ends. So protecting these shorelines is critical.