Wanted: another planet Earth by 2030

Key terms used in the 2010 Living Planet Report (by wordle) © WWF / Wordle

The latest Living Planet Report was released today by WWF and the Global Footprint Network, which finds we are now using resources and producing carbon dioxide at a rate 50 percent faster than the Earth can sustain.

It comes in perfect timing with the upcoming COP10 meeting on the Convention on Biological Diversity (CBD) in Nagoya, Japan from 18 – 29 October, where the Parties to the Convention will decide upon what actions to take to stem the loss of biodiversity over the next ten years. 2010 is the International Year of Biodiversity, and also the year which the Parties to the CBD had agreed to achieve a significant reduction of the rate of loss of biodiversity. Despite some wins from the conservation movement, overall it is clear that attempts to slow the destruction of nature have failed miserably.

Some of the key findings from the Living Planet Report are:

  • Since 1961, humanity’s Ecological Footprint has more than doubled
  • We’ll need 2 planets to support humanity’s demand by 2030, and 2.8 by 2050
  • The top 10 countries with the biggest Ecological Footprint per person are the United Arab Emirates, Qatar, Denmark, Belgium, United States, Estonia, Canada, Australia, Kuwait and Ireland
  • 31 OECD countries account for 37% of humanity’s Ecological Footprint
  • Brazil, Russia, India and China have the fastest growing Footprints, and are on a trajectory to overtake the OECD bloc if they follow the same development path
  • Countries such as Afghanistan & Bangladesh have Footprints that are too small to provide for basic needs

Amidst all of this doom and gloom, this year’s report has made a point of emphasising the intimate connection between the preservation of biodiversity and human well-being, and a message that the path to sustainability is possible – but we need to make changes to how we live, and how we measure progress, in order to fit within the limits of a finite planet.

“The challenge posed by the Living Planet Report is clear,” said Jim Leape, Director General of WWF International. “Somehow we need to find a way to meet the needs of a growing and increasingly prosperous population within the resources of this one planet. All of us have to find a way to make better choices in what we consume and how we produce and use energy.”

Part of this transition to sustainability, I would argue, is to develop an economic system which recognises these limits, and which doesn’t require continuous growth in the consumption of natural resources and production of wastes in order stay affloat.

You can download the full report here, and also check out the many fantastic educational resources that WWF have developed alongside the report – including interactive graphs and maps, plus this cute video.

Grazer composition an important factor in controlling macroalgae

The redband parrotfish was one of the species studied as part of research into the importance of fish diversity for the health of coral reefs.

The redband parrotfish was one of the species studied as part of research into the importance of fish diversity for the health of coral reefs.

We know the biomass of macroalgae on coral reefs is largely controlled by herbivory and that one of the most important groups of grazers are parrotfish.  A new study published in PNAS (Berkepile and Hay 2008) indicates that the richness and composition of grazer species is also important.  In a nutshell, different fish consume different seaweeds because of their differing chemical defenses.  Similar work in other benthic marine systems has found that consumer species richness can be an important determinant of ecosystem functioning, yet this is the first such study on a coral reef.

Our study shows that in addition to having enough herbivores, coral ecosystems also need the right mix of species to overcome the different defensive tactics of the seaweeds.  explained Mark Hay, the Harry and Linda Teasley Professor of Biology at the Georgia Institute of Technology.

Despite different species of parrotfish in the Caribbean having different feeding behaviors, bioerosion rates, and preferred diets, parrotfishes are often considered as a unified functional group when inferring their effects on community structure. However, we found that redband and princess parrotfish had considerably different effects on communities, suggesting that grouping all parrotfishes may blur important distinctions among species.

Despite their different feeding morphologies, ocean surgeonfish and princess parrotfish generated similar macroalgal communities dominated by upright brown macroalgae (e.g., L. variegata and Sargassum spp.). In contrast, despite their more similar jaw morphology, the communities generated by redband and princess parrotfish differed considerably in the abundance of upright macroalgae. Similar to the work of Bellwood et al., these results show that fishes with different feeding morphologies can have similar effects on community structure, suggesting that relying primarily on jaw functional morphology to construct functional groups or infer a species’ impact may be unreliable.

Working out of the underwater Aquarius laboratory off Key Largo Florida, Hay and co-author Deron Burkpile – who is now at Florida International University in North Miami – constructed 32 cages on the reef. Each cage was about two meters square and one meter tall and was sealed so that larger fish could neither enter nor leave.

The number and type of fish placed into each four-square-meter cage varied. Some cages had two fish that were able to eat hard, calcified plants; some had two fish able to eat soft, but chemically-defended plants; some had one of both types, and some had no fish at all

For the cages in which we mixed the two species of herbivores, the fish were able to remove much more of the upright seaweeds, and the corals in those areas increased in cover by more than 20 percent during ten months, Hay said.

The data we are seeing in Fiji [from similar experiments] suggests that diversity may be even more important there than it was in the Caribbean.  There are a lot of different species doing a lot of very different things. These consumers are very important, and in areas where they are over-fished, the reefs are crashing.


Berkepile, D.E. and M.E. Hay. 2008. Herbivore species richness and feeding complementarity affect community structure and function on a coral reef. PNAS 105: 16201–16206

Diver Todd Barsby secures a cage to the coral reef during a study of the role of diversity among herbivorous fishes.

Diver Todd Barsby secures a cage to the coral reef during a study of the role of diversity among herbivorous fishes.