Introduction

In this endeavor, I will attempt to give insight into some of the reasons why the U.S. duck population has dropped over the past year and even the past decade or so.  One important aspect to keep in mind, is that there are a multiple of factors and interactions involved.  Meaning that no one factor is the main cause of the drop in the duck population; it is a number of factors interacting with each other that has resulted in the duck decline in the United States.  I feel that in order to explain phenomena about a species, one has to understand their environment.  As a result, we will examine the environment in which ducks spend their time and energy.  

Duck Numbers are Declining

The total duck population in the United States has dropped from a total of 36 million in 2003 to a disappointing 32 million this year.  This was a significant 11% decline from a year ago, according to the spring waterfowl breeding and habitat survey.

Why are Duck Populations Declining?

Recent reports have attributed the 11% decline in ducks from a year ago to severe droughts.  As a result, droughts have led to a decrease in may ponds, which put a damper on spring breeding for ducks. Moreover, there is evidence that wetlands (refuge for ducks) has been declining as well.  According to the Nation Wetlands Inventory, we have lost 644,000 acres of wetlands over the past decade.  This represents an 80% reduction from the previous decade.  There seems to be a relationship with the decline in both wetlands and the duck population in the United States.

What Are Wetlands?

Why Are Wetlands Important?

Threats To Wetlands

Duck Numbers

Wildlife Protection

What Are Wetlands?

Generally, wetlands can be defined as areas where water covers the soil or is near the surface at various times throughout the year.  Specifically, the Commonwealth of Pennsylvania defines wetlands as: "Those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions" (Fearon, 2003). Many wetlands are seasonal, meaning they are dry one or more seasons every year.  The timing of wetlands manifestation determines its role in the environment. Wetlands contain unique types of soils and are home to ducks, plants, and many thousands more who have adapted to the wet environment.  Some common names for wetlands include: bogs, swamps, and marshes.  A bog is a wetland that primarily contains decomposed plant material called peat or muck.  Mosses are very commonly found in bogs.  A swamp is a wetland that primarily contains bushes and trees.  Swamps can be classified by the type of tree that dominates that particular area.  For example, you may have heard of cedar or spruce swamps.  Marshes are a type of wetland that consists of bulrushes, cattails, and other grasses that are rich in nutrients.  Marshes usually form at the mouth of a river or stream where drainage is poor.

Where Are Wetlands?

There are two general geographic locations for wetlands.

1. Coastal Wetlands- Areas where the sea water mixes with fresh water. These areas include: Atlantic, Pacific, Alaskan, and Gulf coasts.

2. Inland Wetlands-  Areas on food plains near streams, rivers, lakes, ponds. 

Why Are Wetlands Important?

Wetlands are home to thousands of animals and plants. Many plants and animals live no where else but in wetlands. Ducks depend on wetlands for nesting, feeding, rest, and an environment to reproduce as well as raise their ducklings.  Wetlands play a substantial role in cycling nutrients throughout the ecosystem.  They protect land damage from erosion caused by flooding and storms.  An example is that wetlands soils absorb and hold water from precipitation and then release it slowly back into streams and rivers.  Also, wetlands help filter water and pollutants from the environment.  For example, chemicals from farms, lawns, and businesses. Wetlands are said to be "wildlife supermarkets", because they form the base of many food webs.  Plants who are the major organisms in wetlands, are responsible for this product. Moreover, some organisms eat plants or plant parts that are above the surface.  Decomposing plants provide food for bacteria, fungi, and various other wetland invertebrates.  As a result, these organisms provide food for many wetland vertebrates.  If you are not convinced yet that wetlands are important, then this might.  More than 120,000 species of birds just in Pennsylvania, perform most of their life functions on wetlands (Fearon, 2003).  In addition, 50% of birds in North America depend on wetlands.

What Happens When Wetlands Are Lost?

When wetlands are degraded or lost, the plants and animals who rely on them are harmed or jeopardized. For example, plants and animals may become endangered or threatened. Endangered species are those that might soon become extinct. Threatened species are those that may soon become endangered.  If wetlands degradation and loss continues, ducks as well as many other plants and animals could possibly be classified as endangered or threatened species. 

Threats To Wetlands 

1. Global Warming

Global warming is a theory that the earth is getting gradually warmer as time goes on.  The hazardous effect of global warming is increasingly dry seasons.  Dry seasons can result in disaster for wetlands due to the increase in water evaporation.  Some wetlands might completely dry up and be lost forever.  Computer aided models predict that global warming will result in more frequent as well as more severe droughts.  Increasing temperature will result in increasing evaporation and plant transpiration.  Ultimately, there will be a reduction of water in lakes, ponds, soils, and wetlands.  To add further support to the theory of global warming, the U.S. Environmental Protection Agency (EPA) reports that over the past century, wetlands have decreased by 70%.

2. Agriculture

Agriculture can have a severe impact on wetlands.  Drainage runoffs from fields which contain hazardous chemicals and fertilizers end up in rivers, streams, and lakes.  The result equals pollution for wetlands and a poor quality of water. Pollution can have devastating effects such as poisoning or even kill wildlife.  Also, wetlands can be degraded when food and forest products are harvested.  

3.  Silviculture

Silviculture effects habitat by altering the composition and structure of forests and particularly wetland vegetation.  Studies have indicated a decrease in wetland plants as the result of clear-cut harvesting.

4. Urbanization And Rural Development

Urbanization and rural development have had the most severe impact on wetlands over the past decade. Urbanization is the growth in proportion of the population living in urban communities.  One effect of urbanization is the material concrete, which we use to build sidewalks and many other structures. Concrete increases the amount of runoff water which in turn, increases sediments, pollutants, salts, and pesticides into nearby wetlands.  The construction of roads and bridges over wetlands increases the amount sediment deposited and restricts the movement of species.  Chemicals and salt put down on these roads and bridges for maintenance purposes add to further wetland destruction. Canals, levees, and ditches divert water from its natural flowing tendency increasing the rate of water moving into and out of a particular wetland.  The increase in the movement of water hinders wetlands ability to act as a flood control buffer. The construction of buildings, factories, and housing developments have greatly reduced wetland acreage.  Landfills have posed risk to wetlands.  Waste is another by-product of urbanization that is disposed of sometimes as close as a half mile away from certain wetlands. Many materials leak out of landfills and reek havoc on wetlands.

Bibliography

1.   Cook, S. (2001).  Expert takes aim at duck decline.  Duluth News-Tribune, MN (2001, September 26).

2.   Cook, S. (2002).  Mallard population continues to drop; breeding area remain dry.  Duluth News-Tribune, MN (2002, July 17).

3.   Delta Waterfowl.  (2004). Breeding population of ducks down 11% from last year.                                                                                                       <http://www.deltawaterfowl.org/home/archive/2004/040712_numbers.html> (2004, Septemer 9).

4.   Ducks Unlimited Canada. (2004). Ducks and Geese Finding Good Nesting Habitat This Spring Parts of Southern Prairies Still Dry.  Environment   Customwire.  (2004, May 31).

5.   Fearon, G. (2003).  Environment and ecology for Pennsylvania. 3rd. ed.  Parsippany, NJ, Pearson Education Inc.

6.   Forest Conservation Portal. (2004).  U.S. duck population drops by 11%.  Forest Conservation Archives. <http://forests.org/articles/reader.asp?linkid=33530> (2004, September 12).

7.   Riepenhoff, R. (2001).  Longtime duck hunter worried by decline in vegetation.  Milwaukee Journal Sentinel, The WI (2001, October 17).

8.   United States Environmental Protection Agency. (2004).  Global warming poses threat to pothole wetlands and waterfowl.  Inside the Greenhouse. <http://www.epa.gov/globalwarming/greenhouse/greenhouse10pothole.html>  (2004, September 15).

9.   U.S. Fish and Wildlife Service. (2004).  Wetlands status and trends. Nation Wetlands Inventory. <http://wetlands.fws.gov/statusandtrends.htm> (2004, September 15).

10.  U.S. Fish and Wildlife Service. (2004).  Why map wetlands?  <http://wetlands.fws.gov/whymap.htm> (2004, September 15).

11.   Votteler, T.H., & Muir, T.A. (2002).  Wetland protection legislation. National Water Summary on Wetland Resources. <http://water.usgs.gov/nwsum/WSP2425/legislation.html>  (2004, September 26).