Wave of Marine Species Extinctions Feared

[Guest guest]

http://www.truthout.org/issues_05/082505EA.shtml

 

 

(Life in the oceans is not just a pleasant curiousity for us to watch.

It is integral to life on this planet. Tear the web of ecology far

enough and, life as we know it, on this planet will disappear altogether.)

 

 

 

 

 

Wave of Marine Species Extinctions Feared

By Juliet Eilperin

The Washington Post

 

Wednesday 24 August 2005

 

 

 

 

Marine biologist Ellen K. Pikitch holds a baby lemon shark on the

island of Bimini, where the species' habitat is shrinking because of

development.

(Photo: Grant Johnson Photo)

Bimini, Bahamas - The bulldozers moved slowly at first. Picking up

speed, they pressed forward into a patch of dense mangrove trees that

buckled and splintered like twigs. As the machines moved on, the

pieces drifted out to sea.

 

Sitting in a small motorboat a few hundred yards offshore on a

mid-July afternoon, Samuel H. Gruber - a University of Miami professor

who has devoted more than two decades to studying the lemon sharks

that breed here - plunged into despondency. The mangroves being ripped

up to build a new resort provide food and protection that the sharks

can't get in the open ocean, and Gruber fears the worst.

 

" At the end of my career, I get to document the destruction of the

species I've been documenting for 20 years, " he lamented as he watched

the bulldozers. " Wonderful. "

 

Gruber's sentiments have become increasingly common in recent

years among a growing number of marine biologists, who find themselves

studying species in danger of disappearing. For years, many scientists

and regulators believed the oceans were so vast there was little risk

of marine species dying out. Now, some suspect the world is on the

cusp of what Ellen K. Pikitch, executive director of the Pew Institute

for Ocean Science, calls " a gathering wave of ocean extinctions. "

Dozens of biologists believe the seas have reached a tipping point,

with scores of species of ocean-dwelling fish, birds and mammals

edging toward extinction. In the past 300 years, researchers have

documented the global extinction of just 21 marine species - and 16

have occurred since 1972.

 

Since the 1700s, another 112 species have died out in particular

regions, and that trend, too, has accelerated since the mid-1960s:

Nearly two dozen shark species are close to disappearing, according to

the World Conservation Union, an international coalition of government

and advocacy groups.

 

" It's been a slow-motion disaster, " said Boris Worm, a professor

at Canada's Dalhousie University, whose 2003 study that found that 90

percent of the top predator fish have vanished from the oceans. " It's

silent and invisible. People don't imagine this. It hasn't captured

our imagination, like the rain forest. "

 

Many activists have focused on the plight of creatures such as the

ivory-billed woodpecker and the grizzly bear, but relatively few have

taken up the cause of marine species. Ocean dwellers are harder to

track, and some produce so many offspring they can seem invulnerable.

And, in the words of Ocean Conservancy shark fisheries expert Sonja

Fordham, often " they're not very fuzzy. "

 

Although a number of previous extinctions involved birds and

marine mammals, it is the fate of many fish that worries experts. The

large-scale industrialization of the fishing industry after World War

II, a global boom in oceanfront development and a rise in global

temperatures are all causing fish populations to plummet.

 

" Extinctions happen in the ocean; the fossil record shows that

marine species have disappeared since life began in the sea, " said

Elliott A. Norse, who heads the Marine Conservation Biology Institute

in Redmond, Wash. " The question is, are humans a major new force

causing marine extinctions? The evidence, and projections scientists

are making, suggest that the answer is yes. "

 

Large-scale fishing accounts for more than half of the documented

fish extinctions in recent years, Nicholas K. Dulvy, a scientist at

Lowestoft Laboratory in England, wrote in 2003. Destruction of

habitats in which fish spawn or feed is responsible for another third.

Warmer ocean temperatures are another threat, as some fish struggle to

adapt to hotter and saltier water that can attract new competitors.

 

But nothing has pushed marine life to the edge of extinction more

than aggressive fishing. Aided by technology - industrial trawlers and

factory ships deploy radar and sonar to scour the seas with precision

and drag nets the size of jumbo jets along the sea floor - ocean fish

catches tripled between 1950 and 1992.

 

In some cases, fishermen have intentionally exploited species

until they died out, such as the New Zealand grayling fish and the

Caribbean monk seal; other species have been accidental victims of

long lines or nets intended for other catches. Over the past two

decades, accidental bycatch alone accounted for an 89 percent decline

in hammerhead sharks in the Northeast Atlantic.

 

Today, sharks, along with sturgeon and sciaenids (known as

croakers or drums for the sounds they make undersea), are among the

most imperiled of the species that spend most of their lives in the ocean.

 

Populations of sharks, skates and rays - creatures known as

elasmobranchs that evolved 400 million years ago and have skeletons of

cartilage, not bone - have difficulty rebounding because they mature

slowly and produce few offspring. Shark-fin soup, an Asian delicacy

that sells for more than $100 a bowl, has spurred intensified shark

hunting in recent years.

 

Despite the sturgeon's fecundity, overfishing and habitat

destruction have caused that population to dive as well. Beluga

sturgeon, the source of black caviar, release 360,000 to 7 million

eggs in a year, Pikitch noted, but they have declined 90 percent in

the past 20 years. Just this month, scientists in Kazakhstan reported

that they failed to find a single wild, reproducing beluga female,

leaving them with no eggs for hatcheries.

 

Croakers' large swim bladders - air-holding sacs that help them

maintain buoyancy - account for their imminent demise. Traditional

Chinese medicine prizes the bladders, and the sound they make when

pressed against vibrating muscles can reveal croakers' location to

fishermen through sonar.

 

" They've been survivors on an evolutionary scale, but they've met

their match, and it is us, " said Pikitch, who writes about sharks and

sturgeon in an upcoming book, " State of the Wild 2006. "

 

Despite scientists' warnings, American and international

authorities have been slow to protect marine species. The only U.S.

saltwater fish to make the protected list is a ray, the smalltooth

sawfish, which was added in 2003.

 

The National Oceanic and Atmospheric Administration's Fisheries

Service is charged with protecting 61 threatened or endangered marine

species. Director Bill Hogarth said his agency focuses on protecting

vulnerable populations so they will not have to be listed.

 

" That's our job - to make sure species don't wind up on the

endangered species list, " he said.

 

But conservationists said NOAA officials are reluctant to classify

fish as endangered because doing so conflicts with the agency's

mission of promoting commercial fishing.

 

Michael Hirshfield, chief scientist at the advocacy group Oceana,

said he has repeatedly seen government officials provide shifting

estimates of how many threatened or endangered sea turtles can

acceptably die each year in eastern scallop fisheries.

 

" You never get an answer to the question how many turtles would

have to be killed before you would say, 'That's not okay,' " he said.

 

On Bimini, 50 miles from the Florida coast, Gruber is trying

unsuccessfully to stave off the golf resort that could bring 5,000

tourists a day. The island has just 1,600 residents but supports more

than a dozen shark species.

 

Based on an 11-year survey starting in the mid-1990s, Gruber

documented that between 2000 and 2001, during the heaviest dredging of

the ocean floor for the resort's construction, the survival rate for

lemon sharks fell 30 percent, and sharks in the dredging area had

higher toxin levels. He has yet to assess the impact of the mangrove

destruction, which began on a large scale this year.

 

The president of the Bimini Bay Resort and Casino, Rafael Reyes,

said he understands the concern but questions Gruber's statistics and

the idea that " sharks and development don't mix. "

 

" We have a vested interest in making sure things remain as they

are, " Reyes said, adding that he is demolishing mangroves in a place

that is " basically not a sensitive area... . I have to make sure the

environment's pristine because my clients are fishermen. "

 

But Gruber remains unconvinced.

 

" I believed when I started the ocean was so vast there was no way

you could ever kill off the sharks or anything, " he said. When it

comes to being a fish, he said, " Now you can run, but you can't hide. "

 

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