1) How has the fish biomass in the oceans changed in recent years? What has caused the changes?
We have lost around 80% of the larger fish in the world oceans over the last hundred years. The decline was rather slow up to 1970, faster since then. We have estimated that 60% of this decline has been just in the last 40 years.
The one and dominant reason for the decline is overfishing. Up to the 1970s, industrial fisheries were concentrated in the northern developed countries, but since then it has spread across the globe.
You can think of the fish biomass as our "capital in the bank" (fishing bank if you will). We can draw an interest from that capital every year. That's what we call "sustainable fisheries". But we have been eroding the capital year after year, and we are now left with so small fish stocks that the world catches are smaller now than they were in the 1980.
This is not because we have become more responsible and have eased the fishing pressure, on the contrary. Fishing pressure keeps building at the global level.
The implication of this is that there is less food to feed more people. And seafood is not a luxury product you find in restaurants. In many developing countries seafood is the most important form for animal protein.
The decrease in fish biomass is only for the larger fish. The ones we tend to eat, we call them "table fish". The smaller fish, the anchovies and others, often called "forage fish" have not shown a decrease. We find they have been steady, perhaps even increased slightly. We do fish quite a bit of the smaller fish, but a large fraction of that is used for fishmeal and fish oil, not to feed humans directly. (but that is what aquaculture to a large extent relies on.
What we are finding is thus in support of "fishing down the food web", that this is a global phenomena.
2) Nereus is the first international initiative dealing with the studying the global outlook for marine biodiversity. Can you describe the sort of projects that you'll be working on in Nereus?
The current predictions for how food supply from the oceans will be in the future range from "all fish populations will be collapsed by 2048" to "we have turned the tide, things are improving". All of these studies are however built on very incomplete information. (The study we present at AAAS this year is actually the first to build on truly global information about how much life there is in the oceans)
We need to do better than this.
The "Nereus – Predicting the Future Ocean" program is a partnership between the Nippon Foundation and the University of British Columbia and a network that also involves Princeton University, Duke University, UNEPs World Conservation Monitoring Centre at Cambridge, and the Stockholm Resilience Centre. Jointly we will build models of the global ocean spanning from climate over fish and fisheries to economic and social aspects. Will there be seafood and a healthy ocean for our children and grand children to enjoy? That is the crucial question we are addressing.
We have been inspired by IPCC, they rely on a suite of global models to predict the implications of climate change. We must build the same capacity for dealing with life in the oceans, not just for the temperature and currents.
3) Why did you begin studying marine science?
Come from a family of fishermen. First to go to high school (not to talk about university). But always been fond of the sea. I just had an opportunity the previous generations didn't have.
4) What's up next for your research?
Developing global models for how life in the oceans has developed and will develop in the future.
We have to be concerned about climate change. Our study indicates that 1 ˚C warmer water means 5% less fish!