Extinction Of Fishes
Racing Extinction
Page 1
 Studies of the genetic structure of populations are an essential part of
fisheries management. Without them, local extinctions may go
completely unnoticed. It is important to understand the factors that
hinder the recovery of populations at both the individual and genetic
level, because there is strong evidence that local adaptation of fish is a
far more significant phenomenon.
 Some 1,200 more species are likely to disappear during the 21st
century."An equal number are so rare that they will need special protection
or likely will go extinct, too."
 "If biodiversitycontinuestodecline, the marine environment will not
be able to sustainour way of life. Indeed, it may not be able to sustain
our lives at all," Beaumont adds.
 Already, 29% of ediblefish and seafood specieshave declined by 90%
-- a drop that means the collapse of these fisheries.
 “Habitat destruction, selective hunting, invasive alien species and global
warming are all affecting natural populations of plants and animals
adversely”.
 Their bottom line: Everything that lives in the ocean is important.
The diversity of ocean life is the key to its survival. The areas of the
ocean with the most different kinds of life are the healthiest.
 In some cases, the loss of a complete bird species may be inevitable because
they are too sensitive to rapid changes that cannot be reversed in time to
recover, while in other cases simple changes and help from conservation
initiatives could lead to population recoveries.

Racing Extinction
2
Endangered species
 THE BLACKFIN CISCO: A
"salmonid" fish, and hence closely
related to salmon and trout, the
Blackfin Cisco was one plentiful in
the Great Lakes, but recently
succumbed to a combination of
overfishing and predation by not
one, but three, invasive species
(the Alewife, the Rainbow Smelt,
and a genus of sea lamprey).
 The Blackfin Cisco didn't
disappear from the Great Lakes all at once: the last attested Lake
Huron sighing was in 1960, the last Lake Michigan sighting in 1969,
and the last known sighting of all (near Thunder Bay, Ontario) in
2006.
 THE BLUE
WALLEYES: Also known as
the Blue Pike, the Blue
Walleye was fished out of the
Great Lakes by the bucket
load from the late 19th century
to the middle 20th--the last
known specimen being
sighted in the early 1980's.

Racing Extinction
3
 It wasn't only overfishing that led to the Blue Walleye's demise;
we can also blame the introduction of an invasive species, the
Rainbow Smelt, and industrial pollution from surrounding
factories.
THE GALAPAGOS
DAMSEL: The Galapagos
Islands are where Charles
Darwin laid much of the
groundwork for the theory
of evolution--and today,
this distant archipelago
harbors some of the
world's most endangered
species.
 The Galapagos Damsel didn't fall victim to human
interference: rather, this plankton-eating fish never
recovered from a temporary increase in local water
temperatures (caused by the El Nino currents of the early
1980's) that drastically reduced plankton populations.

Racing Extinction
4
 THE
GRAVENCHE: You might
think that Lake
Geneva, on the border
of Switzerland and
France, would enjoy
more ecological
protection than the
Great Lakes of the
capitalist-minded U.S.
 This is, in fact, largely the case, but these regulations came too
late for the Gravenche, a foot-long salmon relative that was
overfished in the late 19th century, had virtually disappeared by
the early 1920's, and was last seen in 1950.
 THE HARELIP
SUCKER: Considering how
colorful (not to mention
insulting) its name is,
surprisingly little is
known about the Harelip
Sucker, which was last
seen in the late 19th
century. The first specimen of this seven-inch-long fish, native
to the rushing freshwater streams of the southeastern U.S., was

Racing Extinction
5
caught in 1859, and only described nearly 20 years later. By
then, the Harelip Sucker was already nearly extinct, doomed by
the relentless infusion of silt into its otherwise pristine
ecosystem
 THE LAKE
TITICACA ORESTIAS: If fish
can go extinct in the vast
Great Lakes, it should
come as no surprise that
they can also disappear
from Lake Titicaca in
South America, which is
an order of magnitude smaller. Also known as the Amanto, the
Lake Titicaca Orestias was a small, unprepossessing fish with
an unusually large head and a distinctive underbite, doomed in
the mid-20th century by the introduction into Lake Titicaca of
various species of trout..
 THE SILVER
TROUT: Of all the fish on
this list, you might assume
the Silver Trout fell victim
to human

Racing Extinction
6
overconsumption; after all, who doesn't like trout for dinner? In
fact, this fish was extremely rare even when it was first
discovered; the only known specimens were native to three
small lakes in New Hampshire, and were likely the remnants of
a larger population that was dragged northward by
retreating glaciers thousands of years ago.
 THE
TECOPA PUPFISH:
Not only exotic bacteria
thrive in conditions that
humans would find
hostile to life: witness the
late, lamented Tacopa
Pupfish, which swam in
the hot springs of
California's Mojave Desert (average water temperature: about
110 degrees Fahrenheit). The Pupfish could survive harsh
environmental conditions, but it couldn't survive human
encroachment:
 a health fad in the 1950's and 1960'sled to the constructionof
bathhouses in the hot springs' vicinity, and the springs
themselves were artificially enlarged and diverted.

Racing Extinction
7
THE THICKTAIL
CHUB : Comparedto
the GreatLakes or
Lake Titicaca,the
ThicktailChub lived in
a relatively
unappealinghabitat:
the marshes,
lowlands,and weed-
choked backwaters of
California'sCentralValley.As recently as 1900,the small, minnow-
sized ThicktailChub was one of the mostcommon fish in the
Sacramento River and San FranciscoBay,and it helped to nourish
centralCalifornia's Native Americanpopulation.Sadly,this fish was
doomed both by overfishing(to service the burgeoning population of
San Francisco)and the conversionof its habitat for agriculture; the
last attested sighting was in the late 1950's.
YELLOWFIN
CUTTHROAT
TROUT: The Yellowfin
CutthroatTroutsounds like a
legend straightoutof the

Racing Extinction
8
American West: a 10-poundtrout,sporting brightyellow fins, that had
been spotted in the Twin Lakes of Coloradoduringthe late 19th
century.As it turns out, the Yellowfin wasn'tthe hallucinationof some
inebriatedcowboy,but an actualtroutsubspeciesthat was described
by a pair of academics in the 1891 Bulletin of the United States Fish
Commission.Unfortunately,the Yellowfin CutthroatTroutwas
doomed by the introductionof the more fecund Rainbow Troutin the
early 20th century;it's survived by its close relative,the smaller
Greenback CutthroatTrout.
Submitted by :
Siddharth Singh
Chandan Soni