Japan, Greece and the Philippines are among the countries that enjoy
lots of marine biodiversity but are at highest risk of damage from
human impacts like overfishing, marine pollution and climate change,
according to a new study.
There are varying estimates of how many species are in the world’s
oceans (2.2 million is a common estimate), but the vast majority of
them have never been seen or named by scientists. Decreases in marine
biodiversity can threaten coastal protection services and ecosystem
services like fisheries.
The new study used a database of where 12,500 marine species are
located and combined the data with maps of where human impacts are
having major negative effects on oceans. With limited resources to
protect the ocean, finding out which areas have the most marine species
and are at highest risk can help policymakers decide how to prioritize.
“Our results emphasize the importance of both developing policies that
promote sustainable fisheries management and that also reduce the human
activities responsible for climate change,” said Elizabeth Selig, the
study’s lead author.
For Japan, the risks to its coral reef species and cold-water species
include fishing, climate change and shipping pollution. For Greece,
risks include overfishing and runoff from land pollution. Marine
species in the Philippines are threatened by shipping traffic pollution
and damaging practices such as dynamite fishing.
Where protein supplies are at risk
The oceans that are most at risk include the southwest Indian Ocean,
the Mediterranean and Baltic seas, and the so-called Coral Triangle in
According to the Convention on Biological Diversity, fish and marine
invertebrates provide more than 2.6 billion people with at least a
fifth of their protein intake. A major loss of marine biodiversity
could threaten parts of that food source.
Selig, director of marine science at Conservation International, warned
that high temperatures can particularly affect coral reef systems in
the tropics where, when temperatures are high enough for an extended
period of time, it can cause coral bleaching and coral deaths.
“Because those corals are the foundation on which all the species in
those regions depend, coral deaths can lead to a major ecosystem
collapse,” she said in a telephone interview.
However, the news isn’t all bad, and there are opportunities to protect
marine biodiversity. Areas that have lots of marine biodiversity but
are relatively unaffected by human activities include southern Africa,
Australia and South America, according to Selig.
She acknowledged that there can be natural changes in species
composition but said “the levels of change now are really unprecedented
and a real cause for concern.”
The study was published this week in PLOS ONE.