Morphometric factors in the formation of Great Lakes coastal wetlands

Transcription

1 Morphometric factors in the formation of Great Lakes coastal wetlands C. E. Herdendorf Department of Geological Sciences, The Ohio State University, Columbus, Ohio 43210, USA; The Great Lakes basins were carved from ancient river valleys by continental ice sheets that receded from the region less than 10,000 years ago. Not only did the glaciers create the basins now holding the lakes, but they are responsible for many of the shallow depressions in the coastal margin that have since developed as coastal wetlands of various types. For the past four thousand years, coastal processes in the lakes have further modified the shore topography to form embayments, coastal lagoons, estuaries, deltas, and solution basins where thousands of hectares of wetlands have become established. This paper will explore the origin of the various morphometric forms which these wetlands have taken and their characteristic hydrologic processes. Keywords: estuaries, geomorphology, karst, lacustrine, palustrine, physiography Physiography of the Great Lakes The five adjoining Laurentian Great Lakes Superior, Michigan, Huron, Erie, and Ontario extend 1,370 km from westernmost point to easternmost point and 1,130 km from north to south (Figure 1). With a total surface area of 244,160 km 2, this is the largest freshwater system on earth. The total shoreline of these lakes measures 17,017 km and is nearly equally divided between Canada and the United States, although Lake Michigan is totally within the United States and Lake Huron s Georgian Bay lies completely in Canada. The lakes in this immense system contain about 22,700 km 3 of water or nearly one-fifth of the all the freshwater on the planet. Lake Superior contains 53% of that water; Lake Michigan, 22%; Lake Huron, 16%; Lake Erie, 2%; and Lake Ontario, 7%. The Great Lakes are located in zones of weaker sedimentary rocks that were excavated for many millennia by steam erosion. Major valleys were deepened and reshaped by glacial ice during the Pleistocene Epoch. The lakes originated late in this epoch when the margin of the waning ice sheet retreated northward into the newly carved lake basins, some of which were dammed by glacial end moraines. The early ice-margin lakes expanded as the glacial ice masses shrank. However, as new and lower outlets were uncovered to the north, the lakes drained to ever lowering levels except during periods of minor readvances of the ice front (Hough, 1962). Following deglaciation, the Earth s crust rebounded from the hundreds of meters of depression experienced under the weight of the ice masses, causing old outlets to be closed and the levels of the lakes to again rise, but not as high as their initial levels. Continued uplift of the land to the north and erosion of the shores and outlet channels have continued to cause slow changes to the configuration of the lakes. The watershed of the Great Lakes is about 764,000 km 2 and extends over parts of three different physiographic (landform) provinces Canadian Shield, Central Lowlands, and St. Lawrence Lowlands. The streams that flow into the lakes reflect the character and variations of these regions. The rivers that enter Lake Superior and the northern parts of Lakes Michigan and 179 Aquatic Ecosystem Health & Management, 7(2): , Copyright C 2004 AEHMS. ISSN: print / online DOI: /

2 180 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Figure 1. St. Lawrence Great Lakes and drainage basin (NOAA, Great Lakes Environmental Research Laboratory). Huron change elevation rapidly as they descend from the rocky cliffs of the Canadian Shield to the lakes in many falls and rapids. Rivers flowing into the southern Lakes Michigan, Erie, and Ontario originate in the Central Lowlands and are more likely to flow gently through well-defined channels and to have broad floodplains. The St. Lawrence Lowlands is restricted to the wide, flat valley of the river for which it is named. Lake Superior With a volume of 12,230 km 3 and a surface area of 82,100 km 2, Lake Superior is the largest of the Great Lakes. The lake bottom is divided into two basins; the Keweenaw Peninsula and a prominent north-south submerged ridge at depths of 150 to 180 m separate the eastern and western basins. The western basin is characterized by a comparatively smooth bottom consisting of thick lake sediments and glacial deposits, while the eastern basin is more rugged with numerous northsouth ridges of bedrock flanked by sediment-filled valleys, thought to be the remnants of a preglacial drainage system. The Keweenaw Peninsula, Apostle Islands, Isle Royale, and connecting submarine ridges are outcrops of ancient Precambrian volcanic and sedimentary rocks which are more resistant to erosion. The southern border of the eastern basin consists of Paleozoic strata, most noteworthy being the colorful sandstone cliffs of Pictured Rocks National Lakeshore. Lake Superior lies almost wholly within the Precambrian Canadian Shield, the Paleozoic Central Lowlands rocks of the southeastern shore being the only exception. An escarpment borders the shore of Lake Superior which rises 120 to 240 m above the surface of the lake on all sides. Interspersed along this precipitous coast of spectacular cliffs are small, rocky, pocket beaches. Offshore the lake bottom rapidly drops to depths greater than 60 m. In the vicinity of Whitefish Point the bottom slope is more gentle and the shore is characterized by shallow reaches composed of sand, derived from

3 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) nearby glacial deposits, that have been transported into the area by alongshore currents (Upchurch, 1976). The maximum depth of the lake, 406 m, is located east of Keweenaw Peninsula. Lake Superior owes its origin to a combination of events. First being the formation of a midcontinent rift and associated igneous activity in the Precambrian Era. This rift was later filled with soft sedimentary rocks which eventually became eroded into a ridge and valley system. The older, harder rocks around the edges of the Superior basin (lava flows, gabbros, and granites) form parts of the bordering escarpment and Keweenaw Peninsula. Faulting may have also weakened the bedrock and formed graben-type fault-block depressions. Lastly, as continental glaciers swept across Canada and into the Superior basin, they were guided by the valleys. The immediate cause of the present submarine topography was deepening by successive lobes of glacial ice that occupied the bottom of the rift zone, thus eroding the softer sediments but modifying only to a moderate degree the resistant Precambrian rocks of the sides. As they retreated, the glaciers and glacial lakes covered the bottom surface with a thin layer of drift and sediment. Irregularities and deep canyons in the western part of the lake basin were filled with sediment, yielding a smooth bottom, whereas, depressions in the eastern part of the lake were not filled, leaving the many irregular north-south submarine canyons and ridges. While the glacial lakes were receding and establishing a series of temporary levels, waves carved ancient lake terraces into the shoreline resembling gigantic stair steps. Several channels have drained Lake Superior at different times. Outcrops of sandstone in the St. Marys River, the present outlet, form a natural weir that restricts the discharge of the lake. The water level in Lake Superior, at an average elevation of 183 m above sea level, is now controlled by engineering works constructed across the rapids at Sault Ste. Marie. Lake Michigan The third largest in area and second in volume of the Great Lakes, Lake Michigan has a surface area of 57,750 km 2 and a volume of 4,920 km 3. The bottom of the lake is characterized by three basins. The southern basin is separated by a limestone sill extending from Sheboygan, WI to Ludington, MI that is covered by a veneer of glacial morainic material. The southern basin has a relatively smooth bottom, over 500 feet deep, that consists of silt and clay lake sediments over Devonian- Mississippian shales. North of the sill, which rises to a depth of m at mid lake, a deep north central basin drops to the lake s maximum depth of 281 m. The bottom of this basin has an irregular floor caused by outcrops of resistant Devonian limestones separated by Devonian declivities (Upchurch, 1976). A northeastern basin consists of numerous north-south trending valleys and ridges similar to those of eastern Lake Superior. This basin contains a number of islands and its bottom is characterized by a number of deep troughs, 75 to 150 m deep, separated by ridges with only 8 to 15 m of water over them (Hough, 1958). Green Bay, with a surface area of 4,100 km 2, constitutes a fourth physiographic element of Lake Michigan. Green Bay is a relatively shallow embayment, mostly less than 30 m deep, that is separated from the main lake by the Door Peninsula (a western extension of the crescent-shaped cuesta known as the Niagara Escarpment that also separates Georgian Bay from Lake Huron and Lake Erie from Lake Ontario). Lake Michigan lies wholly within the Paleozoic bedrock province. Rock exposures are not common around the lake because glacial deposits mantle the bedrock almost everywhere. However, exposures are sufficient to show that Paleozoic rock formations control the major topographic feature of the lake basin. Silurian-aged Niagaran Dolomite forms the cuesta that bounds the lake on the west and north and dips under the lake toward the center of the Michigan structural basin centered under the Lower Peninsula of Michigan. Middle Devonian-aged Traverse Group limestones form the shore from the Straits of Mackinac to the headlands of Grand Traverse Bay. The shoreline of Lake Michigan ranges from Paleozoic bedrock that forms precipitous cliffs and glacial debris along the northern and western shores, to expansive sandy beaches with enormous dune ridges on portions of the eastern and southern shores. Offshore slopes are gentle in most areas. Lake Michigan was formed during the Pleistocene ice age when continental glaciers gouged out the lowlands between present-day Michigan and Wisconsin, and removed the overburden and softer rock formations, leaving ridges of harder, more resistant rocks. As the glaciers retreated, morainic drift buried the rock outcrops and filled many of the preglacial valleys and ice scoured troughs with glacial till, outwash deposits, and glacial lake sediments. A major outlet for ancient glacial lakes in the basin was near Chicago which drained to the Gulf of Mexico. As lower post-glacial levels were established in Lake Michigan, this outlet was abandoned as flow to the north through the Straits of Mackinac dominated. Because Lakes Michigan and Huron have tihis relatively deep connection, they are

4 182 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) hydrologically the same lake, with the same average surface elevation, m above sea level. Lake Huron This lake has the second largest surface area, 59,500 km 2, and the third largest volume, 3,537 km 3 of the Great Lakes. The lake bottom is composed of three basins. The eastern basin (Georgian Bay), is separated from the main lake by the Niagara Escarpment, which forms the Bruce Peninsula, Manitoulin Island (world s largest freshwater island), Cockburn Island, and Drummond Island. Georgian Bay, at 16,300 km 2, is underlain by shales that are less resistant to erosion than the limestones and dolomites that form the escarpment. Lake Huron proper is nearly equally divided into two basins by a ridge that extends southeast from Alpena, MI to Kincardine, ON. This ridge is a cuesta of Devonian limestone with the basins on each side underlain by softer shales and sandstones (Upchurch, 1976). The deepest point in Lake Huron, 229 m, occurs north of the ridge in the northern or main basin about 37 km southwest of the northern tip of Bruce Peninsula. The irregular bathymetry of the northern basin is attributed to the presence of Silurian reefs and the possible collapse of strata resulting from solutioning of Silurian salt beds (Lewis and Herdendorf, 1976). Saginaw Bay, a 3,400 km 2 shallow extension of the southern basin, formed in less resistant Mississippian and early Pennsylvanian rocks to the northwest of Michigan s thumb area. The periphery of Lake Huron, from the shoreline out to about 20 km, generally consists of a sand and gravel bottom. The presence of some coarse gravel and boulders of igneous, metamorphic, and sedimentary rocks represents lag deposits from glacial till (Lewis and Herdendorf, 1976). Dark gray to brown silty clay occupies the deeper parts of the basin. Saginaw Bay s bottom is predominately composed of silty clay, but fine-grained sand is also found throughout the bay. In Georgian Bay, bedrock outcrops and boulder debris are common around the flower pot islands and submerged reefs from depths of 5 to 30 m; mud covers the deeper bottoms. The Lake Huron shoreline is diverse. Sandy beaches with dune ridges occur where morainal or glacial lake deposits serve as sediment sources. Consequently, the shore of the southern basin and southwestern shore of the northern basin are low and have well-developed beaches. Areas bordered by erosion-resistant rock, such as the Paleozoic limestones and dolomites of the Bruce Peninsula and Manitoulin Island, ON, and Presque Isle, MI, and by the Precambrian crystalline rocks of the North Channel shores, have sheer cliffs and small, rocky, pocket beaches. During the Pleistocene ice age, continental glaciers deepened pre-glacial lowlands and gouged out softer rock formations on the north and east sides of the Michigan highlands to form Lake Huron. The transgressing glacier stripped soils from the rock surface and exposed the Niagara Escarpment. Retreating glaciers filled depressions with drift and glacial lake deposits. These ancient lakes are evidenced by abandoned beach ridges and terraces carved into the shoreline. The outflow from Lake Huron passes through an outlet channel composed of the St. Clair River, Lake St. Clair, and Detroit River. There are no artificial controls in the channels between Lake Huron and Lake Erie, but dredging operations in these waterways over the years have deepened the natural channels resulting in a substantial lower of the levels of Lakes Huron and Michigan. Lake Erie Relatively narrow and shallow Lake Erie is the fourth largest of the Great Lakes by surface area at 25,657 km 2 and smallest by volume at 483 km 3. The lake is oriented with its long axis in a east-northeast direction and is naturally divided into three basins: western, central, and eastern. The western basin, lying west of a line from the tip of Point Pelee, ON, to Cedar Point, OH, is the smallest and shallowest basin with most of the bottom depths between 8 and 11 m. In contrast with the other basins, a number of bedrock islands and shoals are situated in the western basin and form a partial divide between it and the central basin. The bottom is flat except for the steep-sided islands and shoals in the eastern part. The deepest soundings are 19 m in a small depression north of Starve Island Reef and 16 m in another depression south of Gull Island Shoal (Lewis and Herdendorf, 1976). The central basin is separated from the eastern basin by a relatively shallow sand and gravel bar between Erie, PA and the base of Long Point, ON. The central basin has an average depth of 19 m and a maximum depth of 26 m. Except for the rising slopes of a low morainal bar extending south-southeast from Point Pelee, ON, the bottom of the central basin is extremely flat. The eastern basin is relatively deep and bowl-shaped. A considerable area lies below 37 m, and the deepest sounding of 64 m is about 13 km east-southeast of Long Point, ON. The varying depths of the Lake Erie basins are attributed to differential erosion by preglacial streams, glaciers, and postglacial lacustrine processes. The strata of the central and eastern basins of Lake Erie

5 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) dip slightly to the southeast and have a general eastwest strike direction roughly paralleling the lake. Lake Ontario is separated from Lake Erie by the resistant Silurian limestones and dolomites of the Niagara Escarpment. The central and eastern basins of Lake Erie are underlain by nonresistant shale, shaly limestone, and shaly sandstone of Upper Devonian age. The southward advance of Pleistocene glacial ice was obstructed by the Mississippian Escarpment and the ice was directed westward along the outcrop of the softer Upper Devonian shales. These shales were deeply eroded to form the narrow eastern basin. Farther west, where the dip of the beds is less and the width of the soft shale belt is greater, glacial erosion resulted in the broader, but shallower central basin. The Devonian shales trend inland between Cleveland and Sandusky and the shallow western basin is underlain by Silurian and Devonian limestone and dolomite on the northward plunging end of the Findlay Arch. Glacial erosion had relatively slight effects on these resistant rocks. The islands in western Lake Erie are arranged in two north-south belts that correspond with the outcrop patterns of the two most resistant rock formations. The Kelleys Island-Pelee Island belt is underlain by Columbus Limestone and the Bass Islands are underlain by Put-in-Bay Dolomite. The bottom sediments of Lake Erie consist of silt and clay muds, sand and gravel, peat, compact glaciolacustrine clays, glacial till, shoals of limestone and dolomite bedrock and rubble, shale bedrock shelves, and erratic cobbles and boulders composed chiefly of igneous and metamorphic rocks. The distribution of bottom sediments is related to the bottom topography. The broad, flat areas of the western and central basin, and the deep areas of the eastern basin have mud bottoms. Midlake bars and nearshore slopes are comprised of mostly sand and gravel or glacial till. Rock is exposed in the shoals of western Lake Erie and along the south shore of the eastern basin. Most of the shoreline of Lake Erie consists of low marshy coasts or high bluffs of clay-rich glacial till or shale. Along the wetlands the shores are commonly protected by barrier beaches or dikes, whereas the bluffs are commonly fronted by narrow cobble and shingle beaches. The western Lake Erie Islands and peninsulas, and the eastern basin s northeast shore are bound by Silurian-Devonian limestone and dolomite cliffs and rocky shelving bottoms. In general, sand is limited along the shoreline, but extensive dune and beach deposits are found at several places. Notable dunes have been formed at the base and southwest side of Long Point, Point Abino, and Sturgeon Point, all in eastern Lake Erie. These dunes are formed presumably under the influence of the prevailing southwest winds. Littoral currents have concentrated sand in spits and baymouth bars at such places as Point Pelee, Point Aux Pins, and Long Point, ON; North Cape, MI; East Harbor and Cedar Point, OH; and Presque Isle, PA. The natural outlet for Lake Erie is the Niagara River which has a length of 60 km and a total drop of 99 m to Lake Ontario. Navigation to the east of Lake Erie is via the Welland Canal and New York State Barge Canal. Lake Ontario This lake is the smallest of the Great Lakes with a surface area of 19,000 km 2 and fourth largest by volume at 1,637 km 3. Lake Ontario is elongated approximately east-west and has a surface elevation 75 m above sea level. The lake is 245 m deep at its deepest location, where the bottom is 170 m below sea level (a feature known as a cryptodepression), lower than the bottom of any of the other Great Lakes except Lake Superior at 223 m below sea level. Lake Erie is the only one of the Great Lakes that does not possess such a feature. Four depositional basins have been identified in Lake Ontario, three of which are separated by glacial moraines (west to east, Niagara basin, Mississauga basin, and Rochester basin) and a fourth which is isolated by a bedrock sill (Kingston basin). Bottom gradients along the south shore are quite variable, ranging from 1.9 m km 1 near the Niagara River mouth to 11.7 mkm 1 near Rochester (Lewis and Herdendorf, 1976). The Lake Ontario basin is a lowland bordered on the north by an escarpment of the Canadian Shield, on the east by the Adirondack Mountains, on the south by the Appalachian Plateau, and on the west by the Niagara Escarpment. The Niagara Escarpment is 60 m high at Niagara Falls, but decreases in height along the south shore of Lake Ontario. Near Oswego, NY, glacially deposited ridges, known as drumlins, form dramatic cliffs that are separated by lush wetland lagoons. On the north shore, east of Toronto, ON, the high bluffs of gray glacial till at Scarborough are eroding at an rapid rate. As continental glaciers of the Pleistocene ice age crossed the basin, they gouged out the soft red shales of the Queenstone Formation to form the lake depression. The depth of scour and shape of the depression were influenced by hard limestone formations along the north shore of the lake. The retreating glaciers deposited sediment (till) in the lake creating the morainal ridges separating the depositional basins and along the shore forming the drumlins and high bluffs.

6 184 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) The St. Lawrence River is the natural outlet for the Great Lakes, flowing about 1,300 km from Lake Ontario across the St. Lawrence Plain into the Atlantic Ocean at the Gulf of St. Lawrence. This plain is a lowland between the Adirondack Mountains of New York and the Canadian Shield. The broad, multiple-channel river head is broken into by numerous islands (Thousand Islands region). Downstream the channel narrows abruptly where the river flows over hard, resistant Precambrian rocks protruding south from the Canadian Shield. The lower course of the river is a long, hornshaped, tidal estuary which opens into the Gulf of St. Lawrence. Outflow of Lake Ontario typically ranges from 4,250 to 8,500 m 3 s 1. Morphometric types of Great Lakes coastal wetlands The Great Lakes are noted for their severe westerly and northeasterly storms and the resultant wave attack and dramatic fluctuations of water levels at their shorelines, as much as 2 m within a few hours. In most reaches of the Great Lakes, the high energy produced at the shore by these storms precludes the development of fringing coastal wetlands. Only where some natural or artificial protection is available against the harsh coastal process of wave attack, erosion, ice scour, and rapid transportation or deposition of sediments can coastal wetlands become established and continue to thrive. Certainly coastal wetlands can survive water level fluctuations, and are often rejuvenated by them, but generally quiescent conditions and the absence of marked turdidity favor their formation. Fortunately a number of morphometric situations occur along the shorelines of the Great Lakes which have created these favorable conditions and tend to foster wetland development. The following categories of coastal wetlands are based on the type of morphometric feature which has created the necessary protection for the establishment of wetland vegetation. For the purpose of this paper, coastal wetlands are considered as those situated within at least 300 m of the high water mark of one of the Great Lakes or their connecting waterway, including the St. Lawrence River within the boundaries of New York and Ontario. For a wetland that occurs within this coastal margin but extends inland beyond the 300-m limit, the entire contiguous wetland is here considered to be a coastal wetland. Thus, wetlands located wholly or partly within 300 m of a coastal body of water, such as a bay, lagoon, estuary, harbor, or small lake with a direct connection to a Great Lake, are here included. Great Lakes coastal wetlands can be classified into at least seven morphometric groups: (1) coastal lagoon wetlands, (2) estuarine wetlands, (3) delta wetlands, (4) kettle lake wetlands, (5) solution basin (karst) wetlands, (6) riverine wetlands, and (7) diked wetlands (Figure 2). This classification scheme cuts across several of the functional or ecological systems (lacustrine, palustrine, and riverine wetlands) proposed by the U.S. Fish and Wildlife Service (Cowardin et al., 1979) for the Great Lakes. For example, portions of coastal lagoons, freshwater estuaries, and deltas may be within the lacustrine system, while more elevated portions of the same morphometric wetland might be classified within the palustrine or riverine systems. The relationships of these two classification schemes are further discussed at the end of this section. Table 1 presents a listing, by lake, of 309 significant coastal wetlands or wetland complexes of the Great Lakes. The table contains an estimate of the surface area of each wetland or wetland complex, as well as an attempt to place each in a morphometric category. Significant is here defined as wetlands over 40 ha (100 acres) in size or, if smaller, a particularly good example of a morphometric type. Coastal lagoon wetlands This category includes the protection afforded to wetland development by a variety of embayments and isolated raised depressions within the shorelands of the Great Lakes that were primarily created or modified by coastal processes during the present or predecessor lake stages. These processes include wave attack and erosion, sediment transport and deposition by alongshore currents, ice shove, dune-forming wind, and mass wasting of bluffs. Offshore bars, barrier beaches, and sand spits are also created by these agents that result in quiescent regions where aquatic macrophytes can flourish. In large bodies of water such as the Great Lakes, the shifting of sediments by nearshore currents can form basins where wetlands eventually develop. If sediments are deposited across the mouth of an embayment, a tributary outlet or a freshwater estuary, the blockage may result in the formation of a new pond or lagoon. Wave activity, too, has formed bars of sand and gravel, which likewise have closed off the mouths of embayments. The usual way in which a lagoon capable of supporting a wetland is formed is by accretion of a bar across some irregularity or indentation of the coastline. The term bar is used here in a generic sense to include the

7 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Figure 2. Morphometric classification of Great Lakes coastal wetlands. various types of submerged or emergent embankments of sand and gravel built on the lake bottom by waves and currents. One of the most common types of bars associated with wetlands in the Great Lakes is a spit. This feature is a sand ridge attached to the mainland at one end and terminating in open water at the distal end. Spits that have extended themselves across or partially across embayments are termed baymouth or barrier bars. Commonly the axis of a spit will extend in a straight line parallel to the coast, but where currents are deflected landward a recurved spit or hook can result. Several stages of hook development may produce a compound recurved spit with a series of ponds separated by beach ridges. Such ponds have provided excellent sites for wetland development along the Great Lakes. Kormondy (1969, 1984) described wetland succession in beach ponds on a 6.4 km-long spit in Lake Erie known as Presque Isle near Erie, PA. Owing to a combination of its sandy shore and exposure to violent lake storms, this spit developed as a series of hooks with the establishment of numerous, fingerlike beach ponds over the past several thousand years. The ponds were created when an elevated bar of sand developed, thereby isolating a small portion of the lake; the ponds were seldom more than 100 to 200 m long, 10 to 20 m wide, and 1 m deep. Some of the ponds were destroyed in a few days, months, or years by subsequent storms which either breached the sand bar or blew enough sand to fill in the depression. The better protected ponds survived these geological processes only to be subjected to a biological fate, wetland succession. A four-year-old pond is characterized by sparse pioneer vegetation, such as stonewort, algae, bulrushes, cattail, and cottonwood seedlings. At 50 years, filling has occurred in the basin and encroaching vegetation has reduced the open water portion to about half of its former area. The major vegetation consists of water milfoil, cattail, bulrushes, bluejoint, willow, bayberry, and cottonwood. After 100 years the open water portion is almost obliterated and the vegetation has increased in complexity and the dominant forms include water

8 186 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Table 1. Significant wetlands of the Great Lakes. Data sources: Ball et al. (2003), Duffy et al. (1987), Geis and Kee (1977), Glooschenko et al. (1987), Herdendorf et al. (1981a,b,c,d,e,f), and Herdendorf et al. (1986). Morphometric Wetland Name Location Type Area (ha) Lake Superior & St. Marys River Agate Harbor Wetlands Keweenaw County, MI Coastal lagoon 82 Agawa Bay Algoma County, ON Coastal lagoon 300 Allouez Bay/Nemadji River Douglas County, WI Coastal lagoon/estuarine 187 Apostle Islands Wetlands Ashland & Bayfield Coastal lagoon 705 Counties, WI Au Train Bay & Point Alger County, MI Coastal lagoon/riverine 255 Bark Bay Wetlands Bayfield County, WI Coastal lagoon/estuarine 275 Batchawana Bay Algoma County, ON Coastal lagoon 500 Bear Lake Wetland Houghton County, MI Coastal lagoon 123 Bibon Lake/Flag River Bayfield County, WI Coastal lagoon/riverine 376 Big Bay Wetland Keweenaw County, MI Coastal lagoon 132 Big Bay Wetlands Marquette County, MI Coastal lagoon 164 Big Garlic River Wetland Marquette County, MI Coastal lagoon/estuarine 182 Black Bay Thunder Bay County, ON Coastal lagoon 900 Blind Sucker River Luce County, MI Coastal lagoon 108 Brewery Creek Keweenaw County, MI Coastal lagoon/riverine 81 Cedar Swamp Keweenaw County, MI Coastal lagoon 212 Chequamegon Wetland Ashland County, WI Coastal lagoon/estuarine 3,850 Dollar Bay Wetland Houghton County, MI Coastal lagoon 82 Fish Creek Wetland Ashland & Bayfield Coastal lagoon/estuarine 316 Counties, WI Flintsteel River Wetlands Ontonagon County, MI Coastal lagoon/riverine 196 Gogomain River Wetland Chippewa County, MI Coastal lagoon/estuarine 397 Goulais Bay Algoma County, ON Coastal lagoon 500 Grand Island Wetlands Alger County, MI Coastal lagoon 285 Grand Traverse Bay Keweenaw County, MI Coastal lagoon 277 Gratiot River Wetland Keweenaw County, MI Coastal lagoon/riverine 42 Graveyard Creek Wetland Iron County, WI Coastal lagoon/riverine 51 Huron Mountains Wetlands Marquette County, MI Coastal lagoon 75 Isle Royale Wetlands Keweenaw County, MI Coastal lagoon 1,037 Izaak Walton Bay Wetlands Chippewa County, MI Coastal lagoon/riverine 211 Keweenaw Bay Wetlands Baraga County, MI Coastal lagoon 482 Lac LaBelle Wetlands Keweenaw County, MI Coastal lagoon 854 Lake George Algoma County, ON Coastal lagoon/riverine 927 Lake Lily Wetland Keweenaw County, MI Coastal lagoon 59 Lake Nicolet Wetland Chippewa County, MI Riverine 102 Laughing Whitefish Point Alger County, MI Coastal lagoon 68 LeChance Creek Wetland Houghton County, MI Coastal lagoon 192 Lightfoot Bay Wetland Baraga County, MI Coastal lagoon 175 Michipicoten Bay Algoma County, ON Coastal lagoon 400 Middle Bay Wetland Marquette County, MI Coastal lagoon/estuarine 103 Mud Lake Wetland Keweenaw County, MI Coastal lagoon 142 Munuscong Lake Wetlands Chippewa County, MI Coastal lagoon/riverine 1,170 Neebish Bay Wetlands Chippewa County, MI Coastal lagoon/riverine 800 Nipigon Bay Thunder Bay County, ON Coastal lagoon 900 (Continued on next page)

9 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Table 1. Significant wetlands of the Great Lakes. Data sources: Ball et al. (2003), Duffy et al. (1987), Geis and Kee (1977), Glooschenko et al. (1987), Herdendorf et al. (1981a,b,c,d,e,f), and Herdendorf et al. (1986). (Continued) Morphometric Wetland Name Location Type Area (ha) Oliver Bay Wetlands Keweenaw County, MI Coastal lagoon 192 Oskar Wetland Houghton County, MI Coastal lagoon 109 Pendills Bay Wetlands Chippewa County, MI Coastal lagoon 136 Pictured Rocks Wetlands Alger County, MI Coastal lagoon 359 Powell Point Wetlands Alger County, MI Coastal lagoon 217 Raber Bay Wetland Chippewa County, MI Coastal lagoon/riverine 645 Raspberry Bay Wetland Bayfield County, WI Coastal lagoon/estuarine 57 Salmon Trout River Marquette County, MI Coastal lagoon/riverine 599 Sand River Wetland Bayfield County, WI Coastal lagoon/estuarine 95 Shot Point Wetland Marquette County, MI Coastal lagoon 146 Sioux River Wetland Bayfield County, WI Coastal lagoon 82 Siskiwit Bay Wetlands Bayfield County, WI Coastal lagoon/estuarine 101 St. Joseph Island Algoma County, ON Coastal lagoon/riverine 2,257 St. Louis River Wetlands St. Louis County, MN Estuarine 443 Sturgeon & Snake Rivers Baraga & Houghton Delta/riverine 3,300 Counties, MI Sugar Island Wetlands Chippewa County, MI Coastal lagoon/riverine 1,318 Tahquamenon Bay Chippewa County, MI Coastal lagoon 2,400 The Marshes Keweenaw County, MI Coastal lagoon 267 Thunder Bay Thunder Bay County, ON Coastal lagoon 1,500 Torch Bay & Lake Houghton County, MI Coastal lagoon 486 Whitefish Bay & Point Chippewa County, MI Coastal lagoon 700 Yellow Dog Point Wetlands Marquette County, MI Coastal lagoon 101 Lake Huron, Georgian Bay & North Channel Albert Sleeper Wetland Huron County, MI Coastal lagoon 700 Au Sable Point Wetland Iosco County, MI Coastal lagoon 53 Bell River Wetland Presque Isle County, MI Coastal lagoon/estuarine 136 Black Lake Wetland Presque Isle County, MI Coastal lagoon 211 Bois Blanc Island Wetlands Mackinac County, MI Coastal lagoon 860 Cheboygan Wetlands Cheboygan County, MI Coastal lagoon 98 Daie du Dore Wetland Bruce County, ON Coastal lagoon 95 Drummond Island Wetlands Chippewa County, MI Coastal lagoon 747 East Saginaw Bay Wetland Huron & Tuscola Coastal lagoon 6,770 Counties, MI Edgewater Wetlands Cheboygan County, MI Coastal lagoon 46 Gore Wetlands Huron County, MI Coastal lagoon 179 Greenbourgh Harbour Bruce County, ON Coastal lagoon 27 Hardwood Point Wetland Huron County, MI Coastal lagoon 79 Hill & LaSalle Islands Mackinac County, MI Coastal lagoon 41 Hog s Bay Marsh Simco County, ON Coastal lagoon 32 Howdenvale Bay Fen Bruce County, ON Kettle 37 Long Lake Creek Wetland Alpena County, MI Coastal lagoon 45 Marquette Island Wetlands Mackinac County, MI Coastal lagoon 99 Matchedash Bay Marsh Simco County, ON Coastal lagoon 807 (Continued on next page)

10 188 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Table 1. Significant wetlands of the Great Lakes. Data sources: Ball et al. (2003), Duffy et al. (1987), Geis and Kee (1977), Glooschenko et al. (1987), Herdendorf et al. (1981a,b,c,d,e,f), and Herdendorf et al. (1986). (Continued) Morphometric Wetland Name Location Type Area (ha) McLeod Bay Wetland Cheboygan County, MI Coastal lagoon/estuarine 336 Misery Bay Wetlands Alpena County, MI Coastal lagoon 763 Mismer-Hessel Bay Mackinac County, MI Coastal lagoon 186 Mulligan Creek Wetland Presque Isle County, MI Coastal lagoon 146 North Thunder Bay Alpena County, MI Coastal lagoon 260 Old Shore Wetland Huron County, MI Coastal lagoon 42 Oliphant Wetland Bruce County, ON Coastal lagoon 173 Pointe Aux Barques Huron County, MI Coastal lagoon 776 Port Franks Wetland Lambton County, ON Estuarine 123 Prentiss Bay Wetland Mackinac County, MI Coastal lagoon 57 Sandy Point Wetlands Huron County, MI Coastal lagoon 675 Schnitzelbank Creek Arenac County, OH Coastal lagoon 1,068 Skipness Wetland Bruce County, ON Riverine 83 South Thunder Bay Alcona & Alpena Counties, MI Coastal lagoon 2,930 Squaw Bay Wetland Alpena County, MI Coastal lagoon 314 St. Martin Bay & Point Mackinac County, MI Coastal lagoon 1,760 St. Martin Island Wetland Mackinac County, MI Coastal lagoon 40 Stokes Bay/Gauley Bay Bruce County, ON Coastal lagoon 237 Sturgeon Bay Wetland Simco County, ON Coastal lagoon 192 Sucker Creek Wetland Bruce County, ON Estuarine 146 Swan Lake Wetland Presque Isle County, MI Coastal lagoon/estuarine 312 Tawas Point Wetland Iosco County, MI Coastal lagoon 332 Thompsons Harbor Presque Isle County, MI Coastal lagoon 130 Tobico Marsh Bay County, MI Coastal lagoon 229 Waterfowl Bay Wetland Huron County, MI Coastal lagoon 128 West Saginaw Bay Wetland Arenac & Bay Counties, MI Coastal lagoon 3,790 Whitestone Point Wetland Arenac County, MI Coastal lagoon 217 Wreck Point Wetland Presque Isle County, MI Coastal lagoon 81 Lake Michigan & Green Bay Arcadia Lake Wetland Manistee County, MI Estuarine 146 Atkinson Marsh Brown County, WI Coastal lagoon/estuarine 206 Baileys Harbor Swamp Door County, WI Coastal lagoon/estuarine 2,044 Bar Lake Wetlands Manistee County, MI Coastal lagoon 480 Bass Lake Wetlands Mason & Oceana Counties, MI Coastal lagoon 67 Beaver Island Wetlands Charlevoix County, MI Coastal lagoon 1,526 Betsie River Wetland Benzie County, MI Estuarine 154 Big Stone Pond Emmet County, MI Coastal lagoon/riverine 75 Border Wetland Delta County, MI Coastal lagoon 43 Cedar River Wetlands Menominee County, MI Coastal lagoon/riverine 630 Charles Pond Oconto County, WI Coastal lagoon 69 County Line Swamp Manistee/Mason Counties, MI Coastal lagoon 59 Dead Horse Bay Brown County, WI Coastal lagoon 134 Deepwater Point Wetlands Delta County, MI Coastal lagoon 111 Egg Harbor Wetland Door County, WI Coastal lagoon 53 Ford River Wetlands Delta County, MI Coastal lagoon/delta 157 Gallien River Wetland Berrien County, MI Coastal lagoon/estuarine 178 (Continued on next page)

11 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Table 1. Significant wetlands of the Great Lakes. Data sources: Ball et al. (2003), Duffy et al. (1987), Geis and Kee (1977), Glooschenko et al. (1987), Herdendorf et al. (1981a,b,c,d,e,f), and Herdendorf et al. (1986). (Continued) Morphometric Wetland Name Location Type Area (ha) Garfield Wetlands Mackinac County, MI Coastal lagoon 81 Good Harbor Bay Leelanau County, MI Coastal lagoon 118 Grand Mere Lakes Berrien County, MI Coastal lagoon 103 Grand Traverse Bay Grand Traverse County, MI Coastal lagoon 74 Granskog Creek Wetlands Delta County, MI Coastal lagoon 295 Hamlin Lake Wetlands Mason County, MI Estuarine/riverine 326 Henderson Lake Wetland Delta County, MI Coastal lagoon 102 High/Hog/Garden Islands Charlevoix County, MI Coastal lagoon 193 Horseshoe Point Wetlands Door County, WI Coastal lagoon 110 Illinois Beach Wetlands Lake Co., IL & Kenosha Co., WI Coastal lagoon 1,176 Indiana Dunes Wetland Porter County, IN Coastal lagoon 163 Kangaroo Lake Wetlands Door County, WI Coastal lagoon 65 Kewaunee River Wetlands Kewaunee County, WI Estuarine 146 Lake Calumet Wetlands Lake Co., IN & Cook Co., IL Estuarine 428 Lilly Bay Wetland Door County, WI Coastal lagoon/riverine 170 Little Harbor Wetlands Schoolcraft County, MI Coastal lagoon 56 Little Sturgeon Bay Door County, WI Coastal lagoon/diked 127 Little Sucker Creek Wetland Emmet County, MI Coastal lagoon/estuarine 76 Little Tail Point Wetland Brown County, WI Coastal lagoon 85 Long Tail Point Wetland Brown County, WI Coastal lagoon 66 Lower Millecoquins River Mackinac County, MI Coastal lagoon 42 Mackinaw Wetland Emmet County, MI Coastal lagoon 76 Manistee Lake & River Manistee County, MI Estuarine/riverine 3,800 Martin Bay Wetlands Delta County, MI Coastal lagoon 208 Mattix Creek Wetland Mackinac County, MI Coastal lagoon/riverine 594 McGeach Creek Wetland Charlevoix County, MI Coastal lagoon/riverine 216 McNeil Creek Wetland Mackinac County, MI Coastal lagoon/riverine 149 Muskegon Lake & River Muskegon County, MI Estuarine/riverine 2,450 North Bay Wetland Door County, WI Coastal lagoon 870 Oconto Marsh Oconto County, WI Estuarine/riverine 3,792 Ogontz Bay Wetlands Delta County, MI Coastal lagoon/estuarine 712 Paquin Creek Wetland Mackinac County, MI Estuarine/coastal lagoon 168 Pensaukee River Wetlands Oconto County, WI Estuarine 198 Pentwater Lake & River Oceana County, MI Estuarine/riverine 122 Pere Marquette River Mason County, MI Estuarine/riverine 2,500 Peshtigo River Wetland Marinette County, WI Delta 2,040 Pigeon River/Sloan Pond Ottawa County, MI Coastal lagoon/riverine 63 Point au Sable Wetlands Brown County, WI Coastal lagoon 45 Point Aux Chenes Wetlands Mackinac County, MI Estuarine/coastal lagoon 1,229 Point Beach Wetland Manitowoc County, WI Coastal lagoon/estuarine 603 Point O Keefe Wetlands Schoolcraft County, MI Coastal lagoon 43 Point Patterson Wetlands Mackinac County, MI Estuarine/coastal lagoon 599 Port Oneida Wetland Leelanau County, MI Kettle 110 Portage Bay Wetlands Delta County, MI Coastal lagoon/estuarine 432 Portage Marsh Delta County, MI Coastal lagoon/estuarine 527 (Continued on next page)

12 190 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Table 1. Significant wetlands of the Great Lakes. Data sources: Ball et al. (2003), Duffy et al. (1987), Geis and Kee (1977), Glooschenko et al. (1987), Herdendorf et al. (1981a,b,c,d,e,f), and Herdendorf et al. (1986). (Continued) Morphometric Wetland Name Location Type Area (ha) Rocky Point Wetlands Door County, WI Coastal lagoon 563 Rowleys Bay Wetlands Door County, WI Coastal lagoon 219 Rupert Bayou Mason County, MI Coastal lagoon/estuarine 110 Sand Bay Wetland Door County, WI Coastal lagoon 49 Sand Bay Wetlands Delta County, MI Coastal lagoon 73 Seul Choix Point Wetlands Schoolcraft County, MI Coastal lagoon 2,361 South River Bay Wetland Delta County, MI Coastal lagoon 45 Squaw Point Wetland Delta County, MI Coastal lagoon 295 Stony Lake & Creek Oceana County, MI Estuarine/riverine 157 Stony Point Wetland Schoolcraft County, MI Coastal lagoon 1,762 Sturgeon River Wetland Delta County, MI Coastal lagoon/estuarine 2,710 Sucker Lake Wetland Delta County, MI Coastal lagoon 118 Sutton Bay Wetland Leelanau County, MI Coastal lagoon 42 Threemile Creek Wetland Kewaunee County, WI Coastal lagoon/riverine 65 Toft Point Wetland Door County, WI Coastal lagoon 40 Torch Lake Wetlands Antrim County, MI Coastal lagoon/riverine 416 Trails End Wetland Emmet County, MI Coastal lagoon 149 Upper Big Bay de Noc Delta County, MI Coastal lagoon/riverine 3,687 Washington Island Wetland Door County, WI Coastal lagoon 109 West Moran Bay Wetland Mackinac County, MI Coastal lagoon 522 Whiskey Creek Wetland Charlevoix County, MI Coastal lagoon/riverine 232 White Lake & River Oceana/Muskegon Counties, MI Estuarine/riverine 1579 Whitefish Bay Wetlands Door County, WI Coastal lagoon/estuarine 61 Whitefish River Wetlands Delta County, MI Coastal lagoon 259 Whitney Slough Brown County, WI Coastal lagoon/diked 185 Lake St. Clair, St. Clair River & Detroit River Algonac Wetland St. Clair County, MI Riverine 140 Canard River Marshes Essex County, ON Estuarine/diked 416 Clinton River Wetland Macomb County, MI Coastal lagoon/estuarine 237 Detroit River Islands Wayne County, MI Riverine/coastal lagoon 239 Mitchell Bay/Thames River Kent County, ON Coastal lagoon/estuarine 6,280 Rockwood Wetland Wayne County, MI Coastal lagoon/diked 73 St. Clair Flats St. Clair County, MI Delta 14,000 Walpole Island Wetland Lambton County, ON Delta 16,000 Lake Erie & Niagara River Bay View Wetland Erie County, OH Coastal lagoon/diked 259 Big Creek Marsh Essex County, ON Estuarine 1,000 Big Creek Wetland Haldimand-Norfolk, ON Estuarine 770 Catawba Island & Harbors Ottawa County, OH Coastal lagoon/solution 850 Cedar Creek Essex County, ON Estuarine 250 Cedar Point Wetland Lucas County, OH Coastal lagoon/diked 644 East Sandusky Bay Erie County, OH Coastal lagoon 800 Fish Point, Pelee Island Essex County, ON Coastal lagoon 45 Grand Island Wetlands Erie County, NY Riverine 144 Grand River Marshes Dunnville/Port Maitland, ON Estuarine/riverine 1,076 (Continued on next page)

13 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Table 1. Significant wetlands of the Great Lakes. Data sources: Ball et al. (2003), Duffy et al. (1987), Geis and Kee (1977), Glooschenko et al. (1987), Herdendorf et al. (1981a,b,c,d,e,f), and Herdendorf et al. (1986). (Continued) Morphometric Wetland Name Location Type Area (ha) Hillman Marsh Essex County, ON Estuarine 362 Huron River Wetland Erie County, OH Estuarine 280 Lighthouse Point Essex County, ON Coastal lagoon/diked 85 Long Point Sandspit Haldimand-Norfolk, ON Coastal lagoon 6,230 Maumee River & Bay Lucas & Monroe Counties, OH/MI Coastal lagoon/estuarine 680 Mentor Marsh Lake County, OH Coastal lagoon 294 Mouillee Marsh Monroe & Wayne Counties, MI Coastal lagoon/estuarine 553 Muddy Creek Bay Sandusky/ & Ottawa Counties, OH Coastal lagoon/diked 1,328 Nanticoke Creek Haldimand-Norfolk, ON Riverine/estuarine 311 Old Woman Creek Erie County, OH Estuarine 63 Ottawa Wetlands Ottawa County, OH Coastal lagoon/diked 1,788 Otter Creek Wetland Monroe County, MI Estuarine 67 Peripheral Marsh Haldimand-Norfolk, ON Coastal lagoon 1,385 Point Pelee Sandspit Essex County, ON Coastal lagoon 1,012 Presque Isle Wetlands Erie County, PA Coastal lagoon 166 River Raisin Wetland Monroe County, MI Estuarine 52 Rondeau Bay & Sandspit Kent County, ON Coastal lagoon 1,201 Swan Creek Wetland Monroe County, MI Estuarine/coastal lagoon 150 Toledo Beach Wetland Monroe County, MI Coastal lagoon 125 Toussaint River Wetlands Ottawa County, OH Estuarine/coastal lagoon 1,076 Turkey Point Marsh Haldimand-Norfolk, ON Coastal lagoon 3,088 Wainfleet Bog Niagara Regional Muni., ON Kettle 1,006 Willow Point Wetland Erie & Sandusky Counties, OH Diked/solution 91 Lake Ontario & St. Lawrence River Albury Swamp Prince Edward County, ON Coastal lagoon 435 Bainsfield Bay Marsh Glengarry County, ON Riverine 472 Barnett Marsh Jefferson County, NY Coastal lagoon 71 Beaver Creek Wetland Wayne County, NY Coastal lagoon/estuarine 164 Big Island Marsh Prince Edward County, ON Coastal lagoon 772 Big Sand Bay Prince Edward County, ON Coastal lagoon 195 Black Creek Wetland Cayuga County, NY Coastal lagoon/estuarine 206 Black Pond Wetland Jefferson County, NY Coastal lagoon 178 Black River Bay Jefferson County, NY Coastal lagoon 315 Blind Bay Jefferson County, NY Coastal lagoon 38 Blind Bay St. Lawrence County, NY Coastal lagoon 34 Braddock Bay Wetland Monroe County, NY Coastal lagoon/estuarine 240 Buck Pond Wetland Monroe County, NY Diked 144 Butterfly Swamp Oswego County, NY Estuarine/coastal lagoon 164 Chalk Lake & Lynde Creek Durham Regional Muni., ON Kettle/estuarine 110 Charlottenburgh Marsh Glengarry County, ON Riverine 851 Chaumont Bay Wetland Jefferson County, NY Coastal lagoon 78 Chippewa Creek Marsh St. Lawrence County, NY Estuarine 275 Cobourg Marsh Northumberland County, ON Coastal lagoon 78 Cootes Paradise Hamilton Regional Muni., ON Coastal lagoon 122 Cranberry Marsh Durham Regional Muni., ON Delta 33 (Continued on next page)

14 192 Herdendorf / Aquatic Ecosystem Health and Management 7 (2004) Table 1. Significant wetlands of the Great Lakes. Data sources: Ball et al. (2003), Duffy et al. (1987), Geis and Kee (1977), Glooschenko et al. (1987), Herdendorf et al. (1981a,b,c,d,e,f), and Herdendorf et al. (1986). (Continued) Morphometric Wetland Name Location Type Area (ha) Cressy Swamp Prince Edward County, ON Coastal lagoon 104 Crooked Creek Wetland St. Lawrence County, NY Estuarine 344 Deer Creek Wetland Oswego County, NY Estuarine/coastal lagoon 546 Delaney Bay Jefferson County, NY Coastal lagoon 85 Densmore Wetland Jefferson County, NY Coastal lagoon 40 Doran Creek Marsh Dundas County, ON Riverine 42 East Bay Wetland Wayne County, NY Coastal lagoon/estuarine 507 Eel Bay Marsh Jefferson County, NY Coastal lagoon 69 Fifteen Mile Creek Niagara Regional Muni., ON Estuarine 23 Flynn Bay Marsh Jefferson County, NY Coastal lagoon 96 Fox Island Wetland Jefferson County, NY Coastal lagoon 69 French Creek Marsh Jefferson County, NY Coastal lagoon 261 Frenchman s Bay Durham Regional Muni., ON Coastal lagoon 45 Galloo Island Wetland Jefferson County, NY Coastal lagoon 83 Goose Bay Marsh Jefferson County, NY Coastal lagoon 208 Grenadier Island Wetland Leeds County, ON Riverine 868 Hoople Creek Wetland Stormont County, ON Riverine 169 Huyck s Bay Prince Edward County, ON Estuarine 245 Irondequoit Bay Wetland Monroe County, NY Coastal lagoon/estuarine 67 Jacques Cartier Wetland St. Lawrence County, NY Riverine 59 Jones Creek Marsh Leeds County, ON Riverine 140 Little Sucker Brook St. Lawrence County, NY Estuarine 57 McCrae Marsh Jefferson County, NY Coastal lagoon 71 Moon Beach Wetland Cayuga County, NY Coastal lagoon 56 Mud Creek & Bay Jefferson County, NY Estuarine 127 Mullet Creek Wetland Jefferson County, NY Coastal lagoon 208 North Walcott Wetland Wayne County, NY Coastal lagoon 94 Oak Island Wetland St. Lawrence County, NY Riverine 57 Oshawa Marsh Durham Regional Muni., ON Coastal lagoon 105 Payne Beach Wetland Monroe County, NY Coastal lagoon 51 Point Peninsula Marsh Jefferson County, NY Coastal lagoon 134 Port Bay Wetland Wayne County, NY Coastal lagoon/estuarine 168 Presqúile Bay Marsh Northumberland County, ON Coastal lagoon 970 Ray Bay Wetland Jefferson County, NY Coastal lagoon 96 Red Creek Wetland Cayuga County, NY Coastal lagoon/estuarine 139 Rift Marsh Jefferson County, NY Coastal lagoon 49 Riverside Marsh Dundas County, ON Riverine 134 Root Swamp Wayne County, NY Coastal lagoon 73 Rouge River Wetland Durham Regional Muni., ON Estuarine 56 Round Pond Wetland Monroe County, NY Coastal lagoon 91 Sage Creek Wetland Oswego County, NY Estuarine/coastal lagoon 39 Sandy Creek/Colwell Pond Jefferson County, NY Coastal lagoon 911 Sawguin Creek Marsh Prince Edward County, ON Riverine 1,956 Snake Creek Wetland Oswego County, NY Estuarine/coastal lagoon 55 Sodus Bay Wetland Wayne County, NY Coastal lagoon/estuarine 299 Southwick Beach Marsh Jefferson County, NY Coastal lagoon 97 (Continued on next page)