Visualizing Environmental Science

390 CHAPTER 15 Biodiversity and Conservation

plants stored in this manner remain stagnant in an evolu-

tionary sense. Thus, they may be less fit for survival when

they are reintroduced into nature. Despite these short-

comings, seed banks are increasingly viewed as important

because they safeguard seeds for future generations.

1. What is conservation biology? When is in situ
   conservation used? ex situ conservation?


2. What are the goals of restoration ecology?

change and general neglect. There have even been some
instances of using seeds from seed banks to reintroduce
to nature a plant species that had become extinct.
Seed banks have some disadvantages. Seeds of many
types of plants, such as avocados and coconuts, cannot
be stored because they do not tolerate being dried out, a
necessary step in freezing the seeds. Seeds do not remain
alive indefinitely and must be germinated periodically so
that new seeds can be collected. Also, growing, harvest-
ing, and returning seeds to storage is expensive. Perhaps
the most important disadvantage of seed banks is that

Conservation Policies and Laws

LEARNING OBJECTIVES

1. Describe the benefits and shortcomings of the
   U.S. Endangered Species Act.


2. Relate the purpose of the World Conservation
   Strategy.

I

n 1973 the Endangered Species Act (ESA)
was passed in the United States, authorizing
the FWS to protect endangered and threat-
ened species in the United States and
abroad. Many other countries now have similar legisla-
tion. International laws and policies also seek to conserve
Earth’s biological resources.

The Endangered Species Act

Currently, almost 1400 species in the United States
are listed as endangered or threatened (Table 15.2,
ˆ}ÕÀiÊ£x°£Î). The ESA provides legal protection to
listed species to reduce their danger of extinction. The
ESA requires the FWS to select critical habitats and
design a detailed recovery plan for each species listed.
The recovery plan includes an estimate of the current
population size, an analysis of the factors contributing
to its endangerment, and a list of activities to help the
population recover.
The ESA was updated in 1982, 1985, and 1988. It is
considered one of the strongest pieces of U.S. environ-
mental legislation, in part because species are designated
as endangered or threatened entirely on biological

53ORGANISMSLISTEDASENDANGEREDORTHREATENED

*ULY s4ABLE

 .UMBEROF .UMBEROF

4YPEOF ENDANGERED THREATENED

organism species species

Mammals 70 15

Birds 77 15

Reptiles 13 22

Amphibians 15 10

Fishes 80 69

Snails 28 12

Clams 68 8

Crustaceans 19 3

Corals 0 2

Insects 52 10

Spiders 12 0

Flowering plants 613 147

Conifers 2 1

Ferns and other plants 27 2

Lichens 2 0

TOTAL 1078 316

Source: U.S. Fish and Wildlife Service (2012).