Biodiversity and Conservation: A Hypertext Book by Peter J. Bryant

Chapter 22: HABITAT POLLUTION 

Florida Coastal Zone Color Scanner Image (CZCS) of a Gymnodinium breve bloom, from the USF/DMS - REMOTE SENSING LABORATORY

 

Check the Environmental Scorecard for your home town!

Pollution is an increasingly important factor determining the health and distribution of wildlife and biodiversity. We will discuss a few examples where the biological effects have been demonstrated or at least strongly suspected.

CHLORINATED HYDROCARBONS

PCBs (polychlorinated biphenyls)

These compounds were manufactured beginning in the 1930's as non-flammable insulators and heat-dissipators in capacitors and transformers, hydraulic fluids, paint additives and plasticizers. PCB's have been found to cause liver damage, affect calcium metabolism, and to interfere with reproduction in seals by causing pathological changes in the reproductive system. Production of PCB's was stopped in 1977 and open disposal was banned in 1979, but due to their stability and bioaccumulation, they are still being detected at high levels in animal tissues. This is a global problem; the highest levels of industrial chemicals and pesticides, including PCBs, in human samples are found in Arctic people, particularly Greenland's Inuit.  Killer whales off the coast of Washington State and Vancouver Island have the highest levels of PCBs found in wild mammals (up to 250 parts per million), and their populations are declining. Western Aleutian sea otter tissue contained twice the concentration of PCB than typically found in otters living along the central California coast, and 40 times as much as in otters from a relatively uncontaminated site in southeast Alaska.

The PCBs That are showing up at such high levels in the Arctic are probably not coming from local sources but are being concentrated at high latitudes by the phenomenon of global distillation.  Many organic materials including PCBs evaporate rapidly from the soils of warm latitudes, but then condense and come back to the surface in rain and snow at high latitudes.

Dioxin

For 30 years, efforts to re-establish reproducing populations of lake trout in four of the five Great Lakes failed. The reason for this might be the high levels of dioxin and related chemicals in these waters. Dioxin, the chemical that led to the evacuation of Times Beach and Love Canal, is formed during the incineration of chlorine-containing wastes, the manufacturing of polyvinyl chloride (PVC) plastics, the production of chemicals like herbicides, pesticides and chlorinated benzenes, and the chlorine-bleaching of wood pulp and paper. The levels in Lake Ontario were high enough from 1945 to 1975 to have resulted in zero survival of young trout. Female fish accumulate dioxin-like chemicals in their bodies and transfer some of these toxins to their eggs, and this can cause the fish's offspring to die soon after hatching.

Dioxin and related chemicals can cause a range of adverse health effects in humans including reproductive and immune system disorders, alteration of fetal development, and cancer (EPA Science Advisory Board, October 1995).  Dioxin was the contaminant in the herbicide Agent Orange, used as a defoliant in the Vietnam war and thought to have caused numerous health problems in veterans of that war.

Dioxin scare

The pulp and paper industry has historically discharged dioxin and other environmental toxins into rivers and streams.  Legislation enacted by both the United States and Canadian governments restricting those activities and the installation of state-of-the-art pollution-control technologies have drastically lowered the pollutants in paper mill effluent.  These measures have been costly but have succeeded in lowering the levels of dioxin and similar compounds to undetectable levels.  As a result, the general consensus among business, scientific, and environmental interests was that the pulp and paper pollution problem had been solved.  There has even been talk about relaxing some of the more stringent regulations.

A 1997 study by Canadian researchers brings all of that into doubt, however.  Baby Chinook salmon exposed to low levels of supposedly non-toxic pulp mill effluents routinely released into Canada's upper Fraser River in British Columbia showed evidence of serious genetic damage.  This was surprising given that the Prince George paper mill there is outfitted with the most modern anti-pollution technology and operates in accordance with British Columbia pollution guidelines that are among the most stringent anywhere.  This situation is illustrative of a common problem in managing our environment: our basic understanding of how ecosystems function and how external events influence them is seriously inadequate.  For example, the current standard for non-toxicity of pulp and paper mill effluent is the ability of fish to survive for four days in pure effluent.  This assays acute toxicity but fails to address the impact of long-term exposure of living organisms to low levels of pollutants.  The Fraser River study clearly shows that chronic exposure to unknown toxins or to undetectable levels of known toxins can have serious effects.

Organophosphates

Wild bird populations have also suffered through exposure to another type of pesticide, organophosphates.  For example, most states in the U.S. have banned the organophosphate fenthion, but Florida continues to spray the pesticide over 2 million acres each year and, as a result, thousands of birds are dying each year.  Take action!

 

 

The 1990 amendments to the Clean Air Act set up a mechanism to reduce sulfur dioxide and nitrogen oxide emissions, with two phases starting in 1995 and 2000. They set up a system of tradable emissions allowances, under which each utility will receive permits to release an amount of sulfur dioxide, with the allowance decreasing each year. If they don't use their allowance they can sell the credits to other utilities. So there is a big financial incentive for reducing emissions, and the program is succeeding in reducing emissions.  The Environmental Protection Agency manages these programs.

A study in 1999 showed that some areas in Europe and N.E. North America are beginning to show slight signs of recovery from acid rain damage.  Lakes in most areas except Great Britain showed a 1-6% reduction in sulfate during the 1990's. 

HEAVY METALS

In the mid-1970's, farmers on the west side of California's Central Valley found that their crops were dying of selenium poisoning. This was because the soil is high in selenium and drainage is poor. So they built drainage systems to carry the irrigation wastewater into evaporation ponds. One place where this happened was at Kesterson Reservoir, adjacent to Kesterson National Wildlife Refuge. At the reservoir, the water was simply allowed to evaporate. At first, wildlife officials thought that this plan would be beneficial to wildlife in that it would provide additional waterfowl habitat. In fact, it created a poison trap.

In 1983, biologists began to find several problems at Kesterson. Large numbers of bird eggs failed to hatch, and the embryos showed gross deformities. A flock of tricolored blackbirds showed complete breeding failure -all of their eggs failed to hatch. Eventually, thousands of dead adult birds were found.

After two years of research the state declared that high levels of selenium were responsible for the abnormalities and mortality:

 

 

Selenium levels (ppb): 

 

Water 

Soil 

Normal levels 

10 

4 

Kesterson 

3000 

250

Selenium is a normal component of soils and in fact is required, in small amounts, for life. But at high levels it is toxic. Cadmium, arsenic, boron, uranium and pesticides also get concentrated and may be contributing to the problem. Detailed reports are available.

The Kesterson problem was solved (actually, postponed) by draining the ponds (into the San Joaquin river) and covering the area with dirt.

In 1989 similar problems showed up at ponds next to the Kern National Wildlife Refuge in the Tulare basin, and the deformity rates were five times as high as at Kesterson. The problem was similar in that the lack of natural wetlands forced the birds to use the contaminated ponds. Similar problems have started showing up at Stillwater National Wildlife Refuge in Nevada, the Kendrick Reclamation Project in Wyoming and the Middle Green River in Utah. Dozens more sites are being investigated.

One potential solution to the selenium accumulation problem has been devised and experimented with by Dr. Bill Frankenberger at U.C. Riverside. He has isolated strains of fungus that can convert selenium into a non-toxic gas, and developed strains that can carry out this conversion at 200 times the normal rate. Unfortunately, this is illegal because of EPA regulations that restrict the transfer of toxic materials.

Heavy metals may claim Doņana birds, ENN Daily News -- 3/16/99

OIL SPILLS

Oil spills, usually resulting from tanker accidents, often occur near coasts and therefore have a devastating effect on local wildlife, especially seabirds. Areas of heavy shipping, such as the St. Lawrence River and other estuaries, are especially threatened by these accidents.

In the U.S., the Oil Pollution Act of 1990 came about in response to one of the worst oil spills, the sinking of the Exxon Valdez.  The Act created a trust fund available to fund up to one billion dollars per Spill. 

The chances of a catastrophic oil spill on the North coast of Alaska have been increased greatly by the Bush administration's decision to open up the National Petroleum Reserve-Alaska for oil drilling.  This area is located just west of the Arctic National Wildlife Refuge, which supports large populations of caribou, polar bears, Arctic wolves, and millions of migratory birds.

Two fifths of world's African penguins threatened by oil spill

DIE-OFFS

ENDOCRINE DISRUPTING CHEMICALS

Another biologically active category of chemical pollutants are the endocrine-disrupting chemicals. These chemicals mimic the effects of the body's own hormones and can impair the immune system as well as sexual development and fertility.  Some investigators believe they also cause breast, ovarian and testicular cancer in humans and may account for a 50 percent drop in sperm counts in Europe and North America.

Chemicals in this group include many pesticides (DBCP, DDT, DDE, kepone, heptachlor, chlordane, dieldrin, mirex, lindane and toxaphene), dioxins, PCBs, Bisphenol-A, and phthalates, many of which mimic the female hormone estrogen.  Most are long-lived compounds and can bioaccumulate in the environment.  In a study of Japanese rivers, lakes and groundwater reported in 1998, eleven suspected endocrine disrupters were found in varying levels at 122 of 130 sites. 

In a study reported by The Worldwide Fund for Nature, "significant levels" of 16 different phthalates were found in newborn babies. Read about how these chemicals might be affecting human development, and what could be done to alleviate the problem.

Most of us have at least 300 to 500 measurable man-made chemicals in our body tissue, chemicals that wouldn't have been found 50 years ago because they didn't exist.  Many of these are present at concentrations a thousand times higher than our body's own chemical messengers.  The chemical industry produces about 1000 new chemicals every year.

Our Stolen Future Home

The U.S. Environmental Protection Agency (EPA)

EPA's purpose is to ensure that:

 

All Americans are protected from significant risks to human health and the environment where they live, learn and work. 

National efforts to reduce environmental risk are based on the best available scientific information.

Federal laws protecting human health and the environment are enforced fairly and effectively.

Environmental protection is an integral consideration in U.S. policies concerning natural resources, human health, economic growth, energy, transportation, agriculture, industry, and international trade, and these factors are similarly considered in establishing environmental policy. 

All parts of society-communities, individuals, business, state and local governments, tribal governments-have access to accurate information sufficient to effectively participate in managing human health and environmental risks. 

Environmental protection contributes to making our communities and ecosystems diverse, sustainable and economically productive. 

 

The United States plays a leadership role in working with other nations to protect the global environment.  

The EPA's Pesticide Program

 

Over 20,000 pesticide products have been registered for use in the United States. 

 

EPA is responsible for regulating the sale and use of pesticides, and the allowable levels in or on food.

EPA is responsible for registering, or licensing pesticide products - based on assessment of the potential effects on human health and the environment, when used according to label directions.  

The EPA's 1999 Annual Plan

$7.8 billion and 18,375 FTE 

includes $41.3 million to ensure safe handling and use of the approximately 2,000 chemicals and 40 genetically engineered micro-organisms expected to enter commerce each year 

EPA's "Toxics Agenda" identifies chemicals that may pose risks to humans and the environment. 

New program to address the health threat presented by persistent, bioaccumulative, and toxic (PBT) pollutants and to prevent new PBTs from entering the marketplace.  This initiative is funded at $13 million in the 1999 Annual Plan ($10 million more than in 1998).

EPA's Strategy for Persistent, Bioaccumulative and Toxic pollutants (PBT) When a company or individual introduces a new chemical or a significant new use of a chemical, they must obtain a permit from the EPA. Candidates for listing in the PBT category are identified by their similarity to known PBTs.  They must be tested by conventional toxicity tests as well as by new testing procedures, including tests of:

biodegradability in a single-organism test

biodegradability in a laboratory microcosm including intact benthic sediment and overlying site water

bioaccumulation potential

chronic toxicity to fish (rainbow trout) and daphniids

additional testing to evaluate other biota (e.g., avian, sediment dwelling organisms) or other effects (e.g., endocrine disrupting potential) where appropriate.

The EPA plans to develop and implement national action plans to reduce priority PBT pollutants, of which the first twelve have been identified:  

EPA's First 12 Priority PBT Pollutants 
From the Canada- U.S. Binational Toxics Strategy

aldrin/dieldrin 
benzo(a)pyrene 
chlordane 
DDT
hexachlorobenzene
alkyl-lead

mercury & compounds
mirex 
octachlorostyrene 
PCBs
dioxins & furans
toxaphene

INTERNATIONAL AGREEMENTS

The United Nations is developing international agreements for the control of Persistent Organic Pollutants, including many of the same chemicals that are on the EPA list.  President Bush has announced that he intends to sign the first global treaty on toxic chemicals--the Stockholm Convention on Persistent Organic Pollutants (POPs). This is one of four significant international treaties on chemicals in the environment.

At the same time, the agreements of the North American Free Trade Association and the World Trade Organization are encouraging much heavier pesticide use by increasing competition between growers in different countries, reducing food safety inspections, eliminating labeling of eco-friendly products (e.g. shade-grown coffee) and prohibiting regulations that discriminate on the basis of the way products are made.

NOISE POLLUTION

Noise can be very disruptive to the behavior patterns of animals that are required for their reproduction and survival.  One form of extremely loud noise pollution, the experimental Low Frequency Active Sonar (LFAS) being developed by the U.S. Navy for detection of enemy submarines, is so loud that biologists fear it may not only disorient marine mammals but may also do physical damage to their ear structure. The system generates sounds that can reach 165 decibels at 40 miles from the source, and 140 decibels more than 300 miles away. Several examples of marine mammal strandings have been associated with LFAS and other types of sonar use.  Killer-whale biologist Ken Balcomb observed a stranding of a beaked whale in the Bahamas, and obtained evidence for ear damage this animal.  He had great difficulty convincing government authorities that this could be caused by naval sonar activities.

The Navy's deployment of LFAS has been challenged in a successful lawsuit by the Natural Resources Defense Council, the Humane Society, the League for Coastal Protection, the Cetacean Society International, and the Ocean Futures Society and its president, Jean-Michel Cousteau.  In October 2002, a federal court ruled in favor of the suit.  In announcing a preliminary injunction against deployment of the system, U.S. Magistrate Judge Elizabeth LaPorte found that the National Marine Fisheries Service and Navy were likely to have violated several federal statutes, including the Marine Mammal Protection Act (MMPA), the Endangered Species Act (ESA), the National Environmental Policy Act (NEPA), and the Administrative Procedure Act (APA).  The court ordered the Navy to meet with the plaintiffs to discuss how the system might be deployed, on a more limited basis, while the lawsuit is pending. Act now!

The general level of background noise in the ocean is also increasing and threatening to disrupt communication between marine mammals.

Some things you can do: Simple Lifestyle Changes

Additional Links

RACHEL | AMAP | Calpirg Report index | Pesticide Action Network of North America: Hooked on Poison | Californians for Pesticide Reform (CPR) | Northwest Coalition for Alternatives to Pesticides (NCAP) Home Page | Pesticides, Human Health and the Environment | US EPA Assessing Health Risks from Pesticides

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Chapter 23: CAPTIVE BREEDING AND REINTRODUCTION

Copyright Š2002 Peter J. Bryant (pjbryant@uci.edu), School of Biological Sciences,
University of California, Irvine, Irvine, CA 92697, USA.
Phone (949) 824-4714 Fax (949) 824-3571
A Project of the Interdisciplinary Minor in Global Sustainability