Written by Gerry Smith
posted on September 13, 2017 12:38
The natural world is ever fluctuating within limits. This was once true of water levels on the Eastern Great Lakes and St Lawrence River before humans intervened with their water control structures. While these alterations made water bodies more useful for our species purposes, this impacted aquatic ecosystems in adverse ways many of which we still do not fully understand. The conversion of the River to the “Seaway” changed wildlife habitat in numerous ways. Perhaps the most serious was the damping down of natural water level fluctuations. Natural systems are dynamic and these fluctuations served to revitalize wetlands and other riverine habitats throughout our region. The more static conditions of the last sixty years altered habitats for a number of species in highly adverse ways.
Photo by Julie Covey
The natural regime prior to 1957, permitted diversification caused by large water level changes and provided higher quality bird habitats than the man made management pattern. During periods of low water, marshes and shoreline fringes would often burn. In high water years, areas would be flooded out. Both regimes significantly changed local vegetation patterns by reducing cattail and encroaching woody plants. A higher percentage of sedge meadow and open water then developed within wetlands.These habitats are favored by many bird species that are habitat limited by cattail monoculture. The excessive cattail mats currently dominating many wetlands along the river and Eastern Lake Ontario are a problem for several bird species.
Hopefully IJC plan 2014 will contribute to an improved degree of fluctuation in future water levels and greater wetland diversification.While many residents and land owners understand that sixty years of near static water level management was a disaster, others do not. Particularly in the Eastern Lake Ontario dune lands, just south of The Thousand Islands Region, many landowners impacted by the current high water event are hysterical. These dynamic systems are being severely impacted at the moment but because of their characteristics will recover with the next lower water period. The only real “problems” are human ones resulting from structures being built where they never should have been. From my perspective these problems pale in comparison with the many benefits that will come from greater water level fluctuations.
Those dune systems mentioned earlier continue to take a pounding from temporary high water erosion. That erosion will result in moving sand around and creating new patterns of sand Flats and foredunes. The small population of the federally endangered Piping Plover present will benefit from these habitat alterations. While being unable to nest in 2017, because of high water, a short-term problem, these birds will find fresh new high quality nesting areas in future years. The dunes will change, recover and this dune dependent species will hopefully increase its local population.
Wetland birds such as Black Tern and Pied- billed Grebe should also benefit throughout the St Lawrence River-Eastern Lake Ontario Region. As previously noted, flooding of marshes should reduce cattails and create more sedge meadow areas. These declining bird species will greatly benefit as this habitat type is essential for nesting and feeding. Other aquatic habitat users such as Great Blue Heron, American Bittern and Common Tern should also benefit. These birds feed in wetlands and its likely open water meadows would increase access to prey items. Marshes with greater habitat diversity benefit many fish and wildlife species and human inconveniences caused by greater fluctuations in water levels are a small price to pay for healthier ecosystems.
Other high water benefits to birds are harder to characterize because they are more subtle. Removal of vegetation from low lying shoals is a two edged sword. Roosting gulls and Terns may appreciate fewer shrubs that could obscure an incoming falcon but flocking swallows will miss these feeding perches. Ospreys appear to have had a banner year in 2017 , at least at mainland nests, raising many young. Did high water effects on fish distribution play any role in their success? Could our nesting Spotted Sandpiper population find any place at all to nest? The bottom line is that water level fluctuations impact different species in different ways at different times, short- term and long-term. Completely understanding these complex relationships,particularly with humans befuddling the picture, is a real challenge
One thing is very clear, birds and most is the natural world is adapted to fluctuations in their environment. The problems of severe population declines etc occurs when forces, most often human caused, change the environmental rules. In this case, water level variations limited to a smaller than normal range ,for our species purposes, has had unforeseen consequences for other organisms in our region. Undoubtedly the drastic decline of populations of our lovely marsh Tern, the Black, is in part due to alteration of its breeding habitat by sixty years of narrowly focused ware level management. I have no doubt that the mistakes of the past have played a role in the decline of other riverine associated bird species.
So when one’s dock is under water, floating away, or out of water, try not to curse the fates. Instead remember what you view as misfortune may be contributing significantly to the well-being of our fellow travelers in the natural world. Birds will be much better off and so will we when humans understand to work with the rhythms of natural systems rather than against them.
Plan 2014 is at least a start in that direction.
By Gerry Smith
Gerald A. "Gerry" Smith, is an ornithologist who can often be found leading fellow bird enthusiasts, on guided Thousand Islands Land Trust (TILT) tours throughout the year. He is a graduate of the biology program at SUNY Oswego, and is one of the founding members of Derby Hill Bird Observatory, along Lake Ontario. He was the first staff ornithologist at Derby Hill, for the Onondaga Audubon Society. Gerry was President of the Onondaga Audubon Society and in 2010, he also published the popular guide book, "Birding the Great Lakes Seaway Trail.”
TI Life Series on River Birds by Gerry Smith:
April 2017 The Devil Bird in the St. Lawrence River
March 2017 River Birds: The Bad, Part III
February 2017 River Birds: 40 Years of Change, Part II, Mixed News
January 2017 River Birds; 40 Years of Change, Part 1: Good News