Impact of Global Fisheries and Global Warming on Marine Ecosystems and Food Security Daniel Pauly Sea Around Us Project Fisheries Centre, UBC A Future for Fisheries? Toward Effective Strategies for Sustainability KU Leuven, February 5, 2008

This graph, illustrating a Canadian tragedy, leads to several questions. One of them is: how typical is the story of the Northern cod fishery? Can we generalize? And it goes on!

We can define… Now let’s apply these definitions to the global FAO catch statistics… Fully exploited Developing Underdeveloped… Over-exploited Crashed

Stocks (%) Our first generalization is bleak indeed. Developing Fully exploited Over-exploited Crashed Underdeveloped

Also, it is tempting to project these trends… Stocks (%) 2048 ?

Our next generalization relies on maps. We don’t really know where most fisheries operate, but when we have global FAO catch statistics, we can infer the distribution of fisheries (and of catches) by using a filtering approach…

Taxon (what) FAO Area (where)Country (who) Taxon Distribution Database Spatial Reference Database Fishing Access Database Common Spatial Cells? Assign catch rates to cells YES Over 99.9% of the global marine catch can be assigned to ½ degree spatial cells, and we are steadily improving the underlying databases … No; improve underlying databases

This is the first map we got. It was not very exciting, except for the anomalies (red)…. 0 We had no problem with Peruvian and Chilean waters being extremely productive. But China?

Thus, global fisheries landings, despite (or because of ) increasing effort, have been declining since the late 1980s, a fact long hidden by over-reporting from China: Watson and Pauly (Nature), 2001.

In fact, the decline is even stronger if one considers discarded fish. This was generally overlooked when FAO’s last estimate of discards (dot E; 7-8 million t) was released. Zeller and Pauly (Fish & Fisheries, 2005) Peruvian anchoveta Other landed fishes and invertebrates Discarded fishes and invertebrates

Back to basics: ecosystem fluxes move up ‘trophic pyramids’… Trophic level Phytoplankton Top predators Prey fish Zooplankton * *.*. *.*  10% * and each species tends to have its own trophic level…

Another generalization emerges when we compute the mean trophic level of world catches. This shows a global decline… Pauly et al. (Science, 1998)

In fact, ‘fishing down’ is so widespread that the Convention on Biological Diversity (CBD) now uses mean trophic levels as an index of biodiversity, the “Marine Trophic Index”. Trophic level change ( ) >1 0.5 to 1.0 no change /no data

And this means that ‘fishing down’ is everywhere

We can see from space how trawlers stir up sediment… Photo courtesy of Dr. Kyle van Houten (Duke University) Here: shrimp trawlers off the Texas Coast, Gulf of Mexico

The Benguela Current may be the first system where jellyfish became dominant, but it won’t be the last…

Consumers in the ‘North’ have not noticed this, nor similar trends: while most seafood is traded between the EU, the USA and Northeast Asia, the ‘South’ has so far met the shortfall in the ‘North’….

We’ll need to get out of the vicious circle of contemporary fisheries management.

We can do things right, as illustrated by Georges Bank haddock 200-Mile Limit Emergency Closure

Now turning to subsidies MEY MSY Bionomic equilibrium (BE) Total cost of fishing effort (TC) Total Revenue (TR) Fishing effort (E) TR & TC ( $) E1E1 E2E2 E3E3 Max. rent TC 1 TC 2 BE 2 BE 1 TR & TC ($) E3E3 E4E4 Fishing effort (E) Cost-reducing subsidies Let’s assume a Gordon-Schaefer bioeconomic model How subsidies induce overfishing

Global subsidy comparisons Sumaila and Pauly (2006)

Subsidies come in different flavors… Sumaila and Pauly (2006)

Marine Protected Areas are part of the solution. There are many, but most of them are tiny… 1% of world ocean area (growth rate ~ 5% year -1 ) Wood et al. (in press)

As a result, the growth of the global MPA network is so slow that we will miss all the targets… Wood et al. (in press)

China However, all the optimistic projections forget that aquaculture is mainly a Chinese enterprise (2/3 of production), devoted mainly to freshwater fishes… Aquaculture has grown to a production of 40 millions t in the last decades, and some believe it is solution to our fish supply problem… Freshw. fishes

But a major trend in aquaculture is what may be called ‘farming up the food web’, which occurs in major producing countries … Note absence of an increasing trend for the USA, due to a high production of (low trophic level) catfishes (Pauly et al Conservation Biology in Practice 2(4): 25). The farms’ impacts on coastal ecosystems are, besides pollution, that they tend to increase the ‘fishing down’ effects…

Jacquet, J. and D. Pauly The rise of consumer awareness campaigns in an era of collapsing fisheries. Mar. Pol. 31: One approach much talked about are market-based mechanisms, see e.g., Another approach is illustrated here… Photo (?) by Jennifer Jacquet

Source: Watson, Alder & Pauly, 2006 However, over 1/3 of the world’s fish catch is currently wasted, i.e., turned into animal feeds… 36%

…which is a tremendous waste of good food

Meanwhile, thing are heating up… Al Gore & IPCC: Nobel Prize 2007 ………..

Probability of occurrence by water temperature Temperature-abundance profile Small yellow croaker (Larimichthys polyactis) Low High Relative abundance

Small yellow croaker Year 0

Year 30 Small yellow croaker

Year 0 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 2 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 4 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 6 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 8 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 10 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 12 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 14 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 16 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 18 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 20 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 22 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 24 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 26 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 28 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 30 Barndoor skate (Dipturus laevis) Low High Relative abundance

Year 0 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 2 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 4 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 6 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 8 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 10 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 12 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 14 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 16 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 18 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 20 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 22 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 24 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 26 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 28 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Year 28 Low High Relative abundance Greenland shark (Somniosus microcephalus)

Original (static) distribution Low High Relative abundance Distribution after 30 years Antarctic toothfish (Dissostichus mawsoni) …as an example of a species predicted to go extinct

Acknowledgements… Thanks to the Pew Charitable Trusts, Philadelphia; Fisheries Centre, University of British Columbia; Members of the Sea Around Us project, and many others... visit us at