Trading Ecosystems the ecological implications of marsh conversion

Trading Ecosystems: the ecological implications of marsh conversion Graham R. Daborn Symposium on the Protection of Agricultural Heritage Acadia University 17 April 2010

Sherman Bleakney “Henceforth thou art the Genius of the shore, In thy large recompense, and shalt be good To all that wander in that perilous flood. ” John Milton Lycidas (1638) L. 182 -185.

The Bay of Fundy is continually changing

Pre-1604 • > 100, 000 acres of marsh Morris Map 1724

Arrival of the Acadians • First dykes constructed at Port Royal 1635 -1640

Acadian Conversions to 1755 • By 1755 many thousands of acres of alt marsh had been dyked in the areas of Annapolis, Grand Pré, Truro, Beaubassin, Missiguash, Shepody, Tantramar etc.

Acadian uses of dyked lands • A great variety of crops were raised: hay, wheat, peas, oats, barley, corn, carrots, beets, parsnips, onions, chives, cabbage, turnips etc.

Post-1755 history • With the Expulsion, marsh conversion did not stop; the Planters took over. • NS 1760 “Act for Appointing Commissioners of Sewers” included “Whereas great quantities of marsh, meadows and low ground…are spoiled by overflowing of the sea…the new settlers…be encouraged…to raise dykes and remove such obstructions as prevent these lands from being immediately useful; . . ”

th 19 • • & th 20 centuries Wellington Dyke #1 1816 -1823 Aulac 1825 Saxby Gale 1869 Maritime Dykeland Rehabilitation Committee 1943 • Habitant Aboiteau 1944 • Wellington Dyke #2 • Maritime Marshlands Rehabilitation Act 1949

Does it matter?

Fundy Marshes • A rich, low diversity plant association dominated by Spartina patens (marsh hay), • Spartina alterniflora (marsh cord grass), Juncus spp. , Limonium spp. (sea lavender) etc.

Animals of the marsh

Animals of the marsh

Fundy Marshes in Summer

Fundy in Winter

Are Fundy salt marshes stable?

Fort Anne • Shoreline erosion exposed timbers laid down in 1740 s

1955 Limit of marsh

1996 1992 Windsor Causeway (1970) 2003

Annual production of S. alterniflora marshes in North America 1200 Windsor Grande Pre

Fundy Salt Marshes

Conclusion • Fundy salt marshes are among the most productive in North America. • Fundy salt marshes act as ‘soft’ shoreline defenses, constantly adjusting to sea level rise. • If ‘let out to sea’, dyked lands will take a long time to recover their original function: therefore, if they are used productively, there may be no net benefit to removing the dykes. • If not used productively, why not return them?

“…. . take heed lest passion sway Thy judgement to do aught which else free-will Would not admit; …. ” John Milton ‘Paradise Lost’ VIII: 635 -637.