Conserving Wildlife, Delaware Bay

The Folly of Unpreparedness

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The Folly of Unpreparedness

The catastrophic storms that pounded Texas, Florida and Puerto Rico last year should have reminded the people of NJ of the destructive force of coastal storms and the folly of unpreparedness.  Sadly we have not.  While some rules have changed since Hurricane Sandy and billions of taxpayer funds have restored shoreline habitat to create a more secure coast many areas remain vulnerable.

This is particularly true along the shoreline of Delaware Bay.  To start with,  little of the billion in Hurricane Sandy funds flowed to the communities of the Delaware Bay despite towns like Fortescue and Reeds Beach sustaining significant storm-related damage.  Most had to limp back to life with barely a flicker of attention from NJ state or federal agencies.  Virtually nothing has been done to prepare for the inevitable next storm.

Filling the gap left by state and federal agencies, a team including American Littoral Society and this author’s restoration business,  restored seven damaged beaches and created experimental techniques to make the beach and marsh more resilient to the next destructive storm.  We focused our projects on wildlife conservation goals, but we also helped communities recover.  in the process, we studied the ecology of beaches and the extensive Delaware Bay marsh, an important defense against storm surge and flooding.  We learned new and vital lessons for the future of the bay.

threats to horseshoe crabs

The infrastructure on Fortescue has been in decline for decades, just as it is in many communities along the bay. Hurricane Sandy dealt a mortal blow to many of the bays defenses. Derelict bulkheads and rubble trap horseshoe crabs who die a slow death if not rescued by the next high tide or volunteers

 

fortescue suffered from Hurricane Sandy but Received no help

Hurricane Sandy hit Fortescue ferociously, causing damage on a scale similar to much of New Jersey’s Atlantic coast. But inexplicably, it was left out of the federal largesse that benefits the primarily rich communities of Atlantic coast.

 

The Little Known Impact of Salt Hay Farming

We soon found the ecological story more complicated than it first appears.  It is little known and poorly understood that the centuries-old practice of salt hay farming once pervasive on the bay now threatens thousands of acres.  Since the first days of settlement, the Bay’s marshes were impounded by early settlers to increase the area of arable and pasture land.  They built elaborate networks of dikes that covered a large portion of the bay’s 200,000 acres of inter-tidal wetlands.

Centuries of harvesting hay and restricting tidal flushing increased decomposition and compaction. Marsh elevation lowered substantially below the normal height, always equal to the mean high tide line.  In a way, farmers created a kind of depression surrounded by dikes.  When costs no longer equaled income, farmers abandoned their diked marshes and water filled the depressions, increasing tidal flow by millions of gallons.    The increased flow of water eroded creek edges and inlets.  Sandy beaches disappeared and mud replaced vegetation in the marsh.   Joe Smith and I published this (inset) peer-reviewed scientific paper on the subject. See also the aerial photos below of one area in the middle bay that went from diked marsh to an open bay.

The impact of this negligent abandonment left many communities on the Bayshore both ecologically and economically vulnerable. Eroding marshes allow destructive storm surge to reach closer to settled areas.  Damaged wetlands along navigable waterways allow shipping channels to fill with sentiment and move, both increasing the cost of maintenance and the danger to commercial and recreational boats.  Unfortunately the agencies are of little help, in fact, they barely recognize the problem.

Cox Meadow on Delaware Bay

cox meadow on Delaware Bay

cox meadow on Delaware Bay

The upper aerial photo from 1977 shows the outline of earthen dikes used by farmers to control the tide since colonial times. Lacking tide, marsh decomposition reduces the elevation to less than mean high tide.  As farmers abandoned the impoundments, the sea overwhelmed the damaged marsh.  The middle photo from 1995 shows the destruction wrought by surging storm waters laying waste to both the outer beaches and the marsh. The lower photo shows  the whole farm turned into an intertidal mudflat by 2013

Living Shorelines Work but Not in the Worse Conditions

The bay needs more beach and marsh restoration to bring back full productivity and this has been the focus of the American Littoral Society’s work.   More immediately though, communities need infrastructure to help defend homes from destructive storms.  Most people think of the shoreline infrastructure as just jetties and bulkheads made of pilings and rock.  Such hardened structures riddle our Atlantic coast, some achieving their purpose of protection; many only failed experiments in engineering. Nearly all impair the ecological function of valuable marine ecosystems.

There are alternatives.  Engineers and biologists have experimented with a  living approach to protecting marsh edge with cultivated mussel or oyster beds. But these approaches can protect marsh and beach in limited conditions.  They cannot withstand the wave environment of the Delaware Bay where wind can create relentless waves that are both short in amplitude and steep.    Moreover, the middle third of the bay suffers a direct exposure to the ocean swell coming from the mouth of the bay.  The swell sometimes teams with the wind creating a furious white capped tumult that can tear apart an intact marsh let alone one impaired by farming.  The bay is well known to seasoned sailors ( of which I am one) for it’s mercurial nature: in one moment a placid sea, in another a raging seascape under a clear blue sky.

In other words, the swell, wind and sea level rise conspire to erode the Bayshore.  But the greatest impact is to hasten the erosion of previously farmed wetlands placing much of the bayshore in grave danger.  Small mussel and oyster beds cannot stand up to these conditions in most high energy circumstances, like Fortescue Beach or the Mouth of the Maurice River.   In these conditions living shoreline, solutions must be augmented with harden structures.

Infrastructure that Maintains Ecological Function and Protects

But done extensively hard structures, like rock jetties and bulkheads, would ruin the fragile ecological system of Delaware Bay. So how can we protect the ecologically important shoreline of Delaware Bay and still protect communities virtually abandoned by the state agencies?  Keep in mind that many community beaches like Reeds Beach NJ, also provide rich habitat for horseshoe crabs who breed eggs into the sands just in time for shorebirds on their way back to the Arctic.  Any protection for communities must include protection for crabs which typical hard structures do not.

Fortunately, there is a third alternative: infrastructure that maintains ecological function and passes the engineering muster necessary to ensure protection.  This third choice creates a critical new step in the fight against the impact of climate change and increasing frequency of coastal storms.  Essentially it blends new engineering concepts with age-old land management techniques.

Our team has created infrastructure designs for several areas critical to Delaware Bay communities that break away from both fully hardened and soft or living solutions.  First, we propose new methods of disposing of sediments from channel or marina dredging projects, to restore elevation of damaged of salt hay farms and eroded beaches.  Our experiments have shown enormous benefits to fish, horseshoe crabs and birds.  Our rebuilt marsh will come in at about the same cost or cheaper than current methods of sediment disposal,  where these ecologically valuable materials end up disposed of as waste.

We also engineered hardcore oyster reefs, breakwaters that can resist the most of what the bay develops. The breakwaters can also provide calm waters that promote exceptional horseshoe crab breeding.  Additionally, the outer layer promotes an oyster set and ultimately a thriving oyster bed that recreates the long ago destroyed beds that once protected the Bayshore ( see the map below).  It also produces abundant marine life the lifeblood of the bay’s fishery.  In total these semi-hard structures delivery both protection and ecological benefit.

We could deploy hardcore breakwaters constructed as oyster reefs to protect beaches, while new solid containment dikes rimmed with mussels can be filled with sediment to restore drowned marshes.  Long-term dredging plans coupled with large-scale landscape-level restoration of both ecologically valuable beach and marsh will make waterways safe and resilient and upland areas secure from storm surge.  All of this is possible if funded.

 

A living shoreline of marsh or natural beach protects shorelines and maintains ecological productivity. It cannot stand up to high energy storms forcing communities to resort to “hard” solutions – bulkheads and jetties that destroy ecological function. ( Image from NOAA) 

The American Littoral Society developed a new living shoreline using waste couch shell to recreate the oyster beds that once ringed the shoreline. Within the same year of construction, oyster spat settles on the shell and grows into oysters. Although still in the experimental stage the reefs provide good protection at lower tide stages.

 

 

1776 nautical chart

This nautical chart from the 1700’s shows a rim of extensive shallow areas along the shoreline of Delaware Bay.  The shallows of Delaware Bay blossomed with oysters.  The oyster market anchored the economy of coastal NJ and Delaware.  They also protected the shoreline from erosion.  

 

Natural Infrastructure to Restore Delaware Bay

Making a natural infrastructure project successful requires more than construction. It has to be imagined within an adaptive management framework.  It’s an age-old concept. One constructs. Then she monitors the progress of construction, redirecting resources as needed and when complete use the experience to better construct.  Oddly the concept is surprisingly absent from most land restoration projects. Usually, an agency contracts an engineer for plans, then contracts a construction firm to carry out the plans.  They may contract someone to monitor outcomes, but she would have no role in the design or the execution of the project.

Imagine a farmer planning his crop, then planting it but never looking at it until he’s ready to harvest.   If he did, there would very likely be nothing.

Our team builds continuous monitoring of all the vital signs of restoration success into our project, regardless of the outcome.  We use the results to adjust methods while the project proceeds and this helps to better accomplish the project’s goals.  This objective experience helps guide future projects,

Agencies have gilded this lily with Bayesian statistics and complex sampling schemes giving managers the idea that rigor is only possible with statistical expertise.  In fact, restoring habitats is a craft just like constructing an energy efficient building or raising crops organically.  Managers need to experiment with restoration to figure new techniques or modify old ones.  They must monitor key variables to ensure progress and if none then insist on mid-project course corrections, with or without statistical advice.  Data are key to assessing effectiveness and cost to improve the habitat over the long term.

The restoration of damaged natural systems on Delaware Bay can revitalize an area that seems paralyzed by serial restoration failures and the overwhelming threat of climate change.  Few people realize the Delaware Bay marsh is among the most productive wetland in the eastern US.  Numerous scientific publications have demonstrated that its natural marsh, with its broad tidal range and exceptional productivity, can accrete sediment at levels equal to most estimates of sea level rise.  In other words, there is hope for a future beyond climate change, if only we can act to restore valuable habitat now.