Report card on Australia’s oceans

I love being a scientist. It can be the most self-indulgent of careers and I feel lucky to live in a society that allows me the freedom to pursue ideas and information. I have the opportunity to explore ideas about how humans interact with our oceans, how we do bad things to them, and most importantly to me, try to figure out how to help them recover. The first step is gathering this information so that people can access it.

While scientists often disagree on things (a very important part of the job), getting a group of scientists together on a problem can truly help to pull together a massive amount of information very rapidly. In this spirit, the “Marine Climate Change Impacts and Adaptation Report Card (Australia)” was released last week. I am lucky enough to have been involved with two of the chapters, observed impacts of Ocean Acidification and observed impacts on marine Macroalgae. Unfortunately, I’d have to say that things aren’t looking good. We are only at the leading edge of some of the changes we are going to see over the next 100 years and some of the observed changes are already bad.

An example that most people wouldn’t know about (because you can’t see it from the surface) is the shift in the distribution of some algae. Algae, aren’t they just the “seaweeds” that we see washed up on the beach? Well, yes, but before they get to the beach they are the foundation of many food webs of the ocean; if they are lost then so are the ecosystems that they support. I must be honest here, when we started this project I didn’t actually expect to find anything to have happened yet, but it has. We have documented substantial southward shifts of entire assemblages of these algae on both the east and west coasts of Australia.Why? The waters of both coasts have warmed rapidly over the past 50 years. In fact, the Leeuwin Current was so strong this year with warming and El Nino that it pushed well into South Australia (see here for a Sea Surface Temperature image from IMOS). Not unheard of, but becoming stronger and more common.

Are we in danger of losing our iconic kelp forests? If so, what will happen to the ecosystems that they support (including 100’s of millions of dollars worth of fisheries)? Only time will tell, but I sincerely hope we can figure out a way to help them…..

The present…..

 

 

 

 

 

 

 

 

 

The future?

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Climate change real, says self proclaimed sceptic

At the end of July, the Berkeley Earth project team released the analysis of the most comprehensive land temperature data set ever collected. And do you know what they found? That climate change is real.

This is a stunning result because the leader of the team, Professor Richard Muller, has been a self-confessed “climate sceptic” for many years. In all fairness, Prof. Muller has always stated that his scepticism is based on what he perceives to be problems with the methods by which previous “climate” datasets have been analysed. So, after his team have analysed over 1.5 billion data points he is now (in his own words) a “converted sceptic”. What is more important, though, is that in his interviews he expresses the belief that not only were past analyses correct but that they have underestimated the rate of global warming. This is bad news.

But, to some of us this is no real surprise. In a recent paper, my collaborators and I used historical data to document a shift in entire assemblages of seaweeds due to warming ocean waters on both the west and east coasts of Australia. Not a good thing because thousands of species rely on these seaweeds for habitat and food.