HMCA Climate Change Threats
Water Level Change
Lake levels are projected to increase in variability, resulting in more extreme highs and lows. Water level regimes define wetland processes, soil moisture conditions, vegetation dominance, and shoreline conditions. Water level changes need to be gradual to optimize wetland function and structure, therefore both extreme scenarios will alter species found within a wetland, and result in a decline in biodiversity and ecosystem services.
Increased Storm Events
Climate change will also result in an increase in both the frequency and intensity of storm events. These extreme storm events produce intense waves that can cause coastal structures to breach. The barrier beach was the first line of defense against wave action, but without this protection, structures that were not built to withstand Lake Erie are compromising the controlled wetland cells, and surrounding homes and businesses.
The increased frequency and intensity of storm events can lead to increased sediment and nutrient runoff, which will result in water quality impairments such as high turbidity, eutrophication, and algal blooms. Excess sediments will lead to the burial of plant communities, a decrease in light penetration and photosynthesis, and a lack of oxygen.
Decrease in Winter Ice Cover
Warming air and water temperatures will reduce winter ice cover, which is imperative in protecting shorelines from extreme storm surges as the ice prevents sediment loss from wave action. The absence of ice will also leave shoreline properties vulnerable to flooding. In the past this has resulted in the construction of shoreline protection structures, which in turn disrupt longshore drift, cuts off sediment supply, and disrupts normal processes of wind, wave, and current movement.