Ocean health suffers from overfishing, index finds

18.10.2013 15:34

The health of the world's oceans are
inextricably linked to human health and
well-being; more than one-third of people
worldwide depend on seafood for 20
percent of their animal protein, according
to the United Nations.
To gauge how well the oceans are doing,
a large team of researchers created a
wide-ranging measure of the oceans'
health. On Tuesday, the second annual
edition of the Ocean Health Index was
released, which shows that unsustainable
fishing has taken a toll on fish populations
around the world, putting many people's
food security at risk, said Ben Halpern, a
marine biologist at the University of
California, Santa Barbara, and the
project's lead scientist.
The index ranks the health of the oceans
in 10 different categories, including
subjects such as purity of water and levels
of tourism, on a country-by-country
basis. This year the world's oceans scored
a 65 out of 100 possible points,
unchanged from when it was first
released last year, Halpern told
LiveScience. While it could be worse, the
score suggests there's "definite room for
improvement," he said.
The index's category of "natural
products" — a measure of how well
humans sustainably use non-food ocean
products such as fish oil, sponges,
ornamental fish and coral products —
received the lowest score this year, with a
31 out of 100, according to the index's
website . The low score is an indicator of
overfishing, which takes fish and other
ocean resources out of the ocean faster
than they can be replenished, a statement
from the index said. For this same reason,
the category of food production also
scored low, a 33. [Video: Humans Hit the
Oceans Hard]
The index also found that many countries
have less natural protection from storms
and hurricanes than they did several
decades ago, with a number of these are
in the annual path of tropical cyclones,
according to the index.
Halpern said the index has helped him
visualize and integrate many disparate
aspects of the world's oceans into a single
whole. "It was really transformative in
how it helped me understand the oceans
(and) gives me far deeper insight into
what is doing well and what isn't when it
comes to improving the oceans' health,"
Halpern said.
Halpern and colleagues have worked on
the index for more than six years, and at
different times up to 20 scientists have
been employed full time. The plan is to
update the index every year, to see how
patterns change over time. For instance,
in the span of one year certain changes
have popped up; for example, increased
pollution in Eastern European countries
has reduced several countries' scores,
Halpern said.
Some debate
Not all ocean scientists are finding the
index useful, though.
Jake Rice, chief scientist with Fisheries and
Oceans Canada, told LiveScience he was
"cautiously positive about it" when the
index first came out last year. Since then,
however, he thinks that the index has
gotten too complicated, in part due to
criticisms that it was oversimplifying.
"Now it's harder to interpret what the
values mean," he said.
Rice also said that the index appears to be
unduly affected by countries' economies
and relative isolation, and that values
aren't likely to change much from year-to-
year. For that reason, the index may say
more about static or slowly changing
aspects of each country — such as the
geography and economy — than about
the relative health of the ocean in each
area. And because of this, a yearly update
provides little value for a lot of effort, he
That said, over longer time scales, it could
help show trends in ocean health in
different countries, Rice said.
Becky Goldburg, director of ocean
science for the PEW Charitable Trusts, an
environmental and public policy group,
said the index helps to combine disparate
information about the world's oceans and
how conditions change over time. The
focus on overfishing is apt, she said, since
"it's certainly one of the major problems
in ocean management."