09/10/11

How Do Hurricanes Affect Wildlife?

After Hurricane Irene, Susan posed the question to me: what happens to wildlife during a hurricane? I decided to try and find out the answer to this.  Because Irene affected such an enormous area—from North Carolina to New England—it’s difficult to generalize. I began with the National Wildlife Federation’s Seven Things to Know about How Hurricanes Affect Wildlife, which I’ve summarized below. Please see the NWF site for more information.

Wind Dislocation

The powerful winds in a hurricane can blow birds off course and push them away from their home habitat. While songbird and woodland birds can cling to branches, and woodpeckers and other cavity nesters ride out the storm inside trees, sea birds and waterfowl are exposed to the high winds.

Other tree dwelling animals are also effected. During Irene, many baby squirrels were orphaned after being blown out of their nests in trees.

Courtesy www.humanesociety.org

Tree Loss

Loss of coastal forests and trees can be devastating to wildlife dependent on the trees for food and habitat. High winds will often strip trees and bushes of food for wildlife: fruits, seeds, and berries.

Dune and Beach Loss

Storm surges, wave action, and winds can cause beach and dune erosion, which has severe effects on species, especially those that live in ecological niches in the sandy areas and dunes of coastal barrier islands.  Sea turtle nests, for example, can be washed out, or a water surge, called a “wash over” that can submerge these nests. Tern and plover nesting areas may also be affected. In some cases, the storm can cause an entire beach area to disappear.

Saltwater Intrusion

The sustained and powerful winds of a hurricane may cause salty ocean water to pile up and surge onshore.  These storm surges can be huge. Hurricane Irene’s surges brought water levels that were as much as 8 feet above normal high tide. In addition to the physical damage this causes, the salt contained in sea water dramatically shifts the delicate balance of freshwater and brackish wetland areas. Creatures and vegetation that are less salt-tolerant may be harmed and many may not survive this influx of sea water.

Freshwater Flooding

Heavy rains generated by hurricanes dump water in coastal area river basins (called watersheds) and this, in turn, can send vast amounts of fresh water surging downstream into coastal bays and estuaries.  This upsets the delicate and finely tuned freshwater/salt water balance that can be so vital for the health of these ecosystems.

Turbidity

Heavy rainfall in upstream areas also washes soil, sediment, and pollutants into coastal and marine environments.  Similarly, sediment can wash over coral reefs, blocking needed sunlight.

Marine and Aquatic Species

Hurricane Irene generated massive waves and violent action on the surface.  When hurricane Andrew hit Louisiana the government estimated that more than 9 million fish were killed offshore.  Similarly an assessment of the effect of that same storm on the Everglades Basin in Florida showed that 182 million fish were killed.

Close to Home

Where I live in Hoboken, New Jersey, many of the city’s residents (including my family) were subject to a mandatory evacuation because of the danger of flooding; in worst case scenarios, possible storm surges were predicted to cause water to rise to the second story of the city’s apartment buildings. While the flooding wasn’t as severe as predicted, we did notice that the water on the sidewalks, in our basements, and backyards smelled toxic. Considering that this water flows into storm drains and eventually into waterways is disturbing. This “witch’s brew,” as it was called in various news reports, consisted of raw and partially treated sewage, chemicals from industrial facilities, bacteria, oil, and gasoline.

This commentary by Jeff Tittel in the New Jersey Newsroom.com about the possibility of this toxic brew being released during hurricanes from New Jersey’s many superfund sites was disturbing:

The New Jersey DEP only has one inspector reviewing institutional controls and caps and ensuring flooding and other impacts do not impact the controls. We have 118 superfund sites, 16,000 contaminated sites, and 7,000 sites that have been remediated, some of which are very complex. There are about 500 toxic sites near our rivers and about 3,500 are located near groundwater sources and 500 near major water supply wells. Flooding and polluted stormwater could result in toxins from these sites entering our waterways.

The other day I heard about a woman in Hoboken who sloshed around in the water in flip flops the day after the hurricane and who now has a serious infection. I could smell this toxic brew right in my own flooded basement and backyard. This can’t be good for wildlife (or for people either).

Hoboken after Hurricane Irene. Photo by Mary Jo Rhodes

How did Hurricane Irene affect the environment and the wildlife in your area?