This story was produced by way of a partnership with Local weather Central, a non-advocacy science and information group. John Upton and Kelly Van Baalen of Local weather Central contributed reporting.
SCARBOROUGH, Maine — Just a little brown chook with orange facial markings led Andrew Mackie to journey lots of of miles from his residence state of New York to Scarborough Marsh 30 years in the past.
The avid birder got here to see the saltmarsh sparrow, a secretive creature about 5 inches lengthy and weighing half an oz.. It breeds in salt marshes from Maine to the Chesapeake Bay, nesting in saltmeadow cordgrass simply above the excessive tide line and the ocean waters that stand up twice a day. Its hardiness and elusiveness attracted Mackie.
“It tends to be a skulker down within the salt marsh, so it’s not coming as much as sit on phone strains,” mentioned Mackie, now the chief director of the Scarborough Land Belief. “You need to be an actual chook lover to wish to discover that chook.”
The saltmarsh sparrow is greater than a rarity for intrepid birders. Its presence signifies that the marsh is wholesome, a house to wildlife, a spot to recreate and hunt and a buffer in opposition to air pollution and storm surge. Rising seas are threatening the marsh, and in flip, the saltmarsh sparrow. Their numbers are declining, with solely about 1,600 of them left in Maine, which has prompted a state preservation effort.
However the broader race to save lots of the three,200-acre Scarborough Marsh — Maine’s largest contiguous salt marsh — is working into the dual challenges of rising seas and excessive growth within the fast-growing Portland suburban space, giving the marsh little room to develop and placing it susceptible to shrinking.
Salt marshes comprise lower than 1 % of Maine’s land space, primarily within the southern a part of the state, however their worth is in depth. They shield adjoining land and buildings from ocean flooding throughout storms. They take in carbon and filter sediments and pollution from water. They’re looking and fishing grounds, a recreation space and nurseries for fish and different animals.
Since colonial instances, Maine has misplaced an estimated one-fifth of its wetlands to growth and farming. Whereas regulatory protections have stemmed these losses, the vital habitat faces new threats as sea-level rise accelerates and overtakes its seaward aspect.
Maine’s four-year local weather motion plan recommends that the state decide to managing no less than 1.5 toes of sea-level rise by 2050 and three.9 toes by 2100. A 1.5-foot rise may submerge 67 % of Maine’s coastal sand dunes and cut back the dry seashore space by 43 %, considerably impacting coastal tourism, a serious financial driver right here.
Marshland can also be threatened by the consequences of heat-trapping air pollution, regardless that it could actually develop vertically and migrate inland as seas rise. Scarborough Marsh already has some areas that present the place such inland migration has overtaken outdated forests and led to “ghost forests,” stands of useless bushes killed by saltwater.
Pure progress reminiscent of roots and above-ground vegetation add biomass to construct the marsh up yearly, serving to it struggle in opposition to sea water incursion. However rising seas can outpace the flexibility of marsh vegetation to maintain up. Buildings, roads and different infrastructure additionally block a marsh’s means emigrate.
Scarborough Marsh faces such challenges. The realm round it’s extremely developed with homes and industrial buildings. Roads and different obstacles hinder water circulation. The dearth of open land for migration means it’s unlikely for even aggressive conservation efforts to maintain up with the rising tides, Mackie mentioned.
A current evaluation by Local weather Central, a non-advocacy science and information group, confirmed that halting coastal growth and aggressively lowering air pollution may restrict coastal wetland losses within the continental U.S. to 10 % this century. With ongoing coastal growth and excessive sea-level rise, however, three quarters of marshland may very well be misplaced throughout the identical timeframe.
Right here in Cumberland County, the place marshes are already ringed by neighborhoods and roads, Local weather Central’s evaluation confirmed efforts to preserve undeveloped land may see the overall marsh space develop by 24 % by 2100 even when seas rise quickly. Aggressive growth alongside fast sea-level rise, in contrast, may trigger 14 % of the marsh space to be misplaced.
Conservation teams and the state’s fish and wildlife division typically buy land to open up pathways for marsh migration. Nevertheless, the sparse land that is likely to be in the stores from non-public homeowners is pricey as a result of it’s close to the ocean. Mackie mentioned the land belief has recognized 5 parcels that it’s trying to purchase that common 15 acres every.
“There’s not a whole lot of undeveloped land round as a result of the marsh is hemmed in by growth,” Mackie mentioned. “We and our companions have recognized some parcels we want to purchase.”
Parcels shall be recontoured to a better elevation appropriate for salt marsh formation, he mentioned. Some communities plan to construct sea partitions to stop flooding, however that technique could be counterproductive round a marsh, which acts like an enormous sponge to soak up water.
On the identical time, the land belief is delicate to the necessity for housing and growth throughout a nationwide housing disaster that Maine has skilled most in populated southern areas.
“Our place is that we want balanced progress with defending our pure lands and sources which are vital to our livelihood, our sustainability,” Mackie mentioned.
The Maine Division of Inland Fisheries & Wildlife, which owns a complete of 110,000 acres throughout Maine with 60 totally different wildlife administration areas, can be a serious associate in land purchases. It owns 269 tidal marshes totaling 22,372 acres throughout the state. Of these, it owns and manages greater than 95 % of Scarborough Marsh.
When it appears at property, the division considers species, public entry and connectivity of the habitat so aquatic species can transfer by way of it, Bethany Atkins, land acquisition and habitat grants biologist on the division, mentioned.
“We solely work with landowners who wish to promote to us,” she mentioned.
Since it will likely be a problem to purchase sufficient land for migration, one of the best state of affairs is the marsh floor maintaining with the rise of the ocean, mentioned Steve Pinette, president of the Associates of Scarborough Marsh, which additionally has recognized a number of 10- to 20-acre parcels that must be bought.
A drive up coastal Route 1 offers a glimpse of the problems the marsh faces. A piece of the street, which runs by way of the western a part of the marsh, floods often throughout astronomical excessive tides and prevailing winds, Jami Fitch, sustainability coordinator with the city of Scarborough, mentioned. Some 30,000 autos journey on Route 1 each day, making the flooding a severe concern for the city and the state.
Elements of Route 1 and Route 9, one other busy street perpendicular to it and working east-west by way of the marsh, are being prioritized by the city and state for doable elevation. Farther south, one street close to the Rachel Carson Nationwide Wildlife Refuge in Wells is likely to be left for that marsh to take over.
“These are the issues we’re keen to think about,” Scarborough City Supervisor Thomas Corridor mentioned. “We’ll both make main investments to reconstruct areas or allow them to return to nature.”
Growth doesn’t should occur proper on the sting of the marsh for it to have an effect, Corridor mentioned. Stormwater have to be monitored fastidiously and chemical substances going into rivers that feed into the marsh have to be minimized, together with garden fertilizers.
The most important problem for the marsh’s longevity is addressing tidal flows and making them as pure as doable, Ryan Robicheau, wildlife administration supervisor on the Maine Division of Inland Fisheries & Wildlife, mentioned. The division is beginning an evaluation to grasp the elements that play into the well being of the marsh and prioritize funding over the subsequent three to 5 years.
If the marsh is inundated with an excessive amount of sea water, it may begin changing to open water or a mudflat, state marine geologist Peter Slovinsky mentioned. The character of the marsh additionally may change. Extra of it may flip into the low marsh on its seaward aspect that floods extra often, displacing habitat, together with saltmarsh sparrow nests.
Slovinsky mentioned the marsh is a pure rearing floor for a wide range of industrial fish, together with cod. The small fish are eaten by birds and bigger fish like migrating striped bass, bluefish and flounder.
“The marsh is intrinsically linked to the meals net,” he mentioned. “And the financial vitality of the neighborhood is barely going to be nearly as good as its environmental vitality,” he mentioned.
Like many who spend time there, Pinette of Associates of Scarborough Marsh has developed a visceral connection to the marsh, one which contributes to its inherent worth.
“In sure elements of the marsh you hear nothing, and you might be surrounded by vegetation and bushes,” he mentioned. “It may very well be prefer it was in colonial days.”