Our oceans in peril

Are we facing global ecological apocalypse? Experts report accelerated melting of the Greenland and Antarctic ice sheets; decrease in Arctic Sea Ice; sea level rise and release of trapped methane from the seabed. How have these changes and human activities affected our oceans – the largest ecosystem on Earth that maintains our world in a habitable condition?

A June 2011 summary report of the “International Earth system expert workshop on ocean stresses and impacts” held in April 2011 found that that the whole of marine degradation is now happening at a faster rate than predicted.  Human actions have resulted in warming and acidification of the oceans and are now causing increased hypoxia, i.e. low oxygen in the water.

The workshop in University of Oxford attended by 27 participants from 18 organisations in six countries enabled leading experts to take a global view on how all the different effects we are having on the ocean are compromising its ability to support us.  This examination of synergistic threats led to the conclusion that we have underestimated the overall risks.

According to the experts there have been changes in the distribution and abundance of marine species, harmful algal blooms and increases in health hazards in the oceans e.g. pathogens.  The loss of large, long-lived and small fish species is causing widespread impacts on marine ecosystems, including direct impacts on predator and prey species. As a result, food webs have been destabilized and simplified.

We are experiencing severe declines in many species to the point of commercial extinction in some cases.  A survey by the Fisheries Research Institute showed that the fish biomass in the waters off East Coast and West Coast of Peninsular Malaysia has been dwindling between 1981 and 1991. Fish biomass in the Straits of Malacca showed a decline of 90% from 1971 to 1997, whilst in the South China Sea it dropped to 88% from 1986 to 1998. The situation has definitely worsened.

There is also an unparalleled rate of regional extinctions of habitat types (e.g. mangroves and sea-grass meadows).  In Malaysia, data indicate that 27% of mangrove forests gazetted as permanent reserved forests have been destroyed from 1980 to 2000 and converted for aquaculture, agriculture and other development, whilst 85% of our coral reefs are threatened by human activities.

What is of concern is that we now face losing marine species and entire marine ecosystems, such as coral reefs, within a single generation. The changes in the ocean that are coming about as a result of Carbon dioxide emissions are perhaps the most significant to the Earth system particularly as they involve many feedbacks that will  accelerate climate change.

The experts recommend that to maintain the goods and services oceans provide us, human interactions with the ocean must change with the rapid adoption of a holistic approach to sustainable management of all activities that impinge marine ecosystems. This has to be part of a wider re-evaluation of the core values of human society and its relationship to the natural world and the resources on which we all rely.

The report underscored the need for more effective management of fisheries and pollution and for strengthening protection of the 64% of the ocean that lies beyond the zones of national jurisdiction.

Our oceans are in peril due to the combined effects of climate change, overexploitation, pollution and habitat loss. The scale of the stresses on the ocean means that deferring action will be costly in the future, leading to even greater losses of benefits.

The experts state that unless action is taken now, the consequences of human activities are at a high risk of causing the next globally significant extinction event in the ocean.  Hence, we urge the Malaysian government and all other country governments and citizens to work together to protect our oceans and natural ecosystems.

Letter to the Editor, 16 August 2011