Oceans getting packed with sardines, not tuna

First I found this in the Daily Mail:

How the demise of the shark has led to our oceans becoming packed with sardines



OK, but big sharks don't eat little fish (but little sharks do). It's more to do with the loss of the big predator fish, like the incredible built-to-eat bluefin tuna. What got me was that the increase in the sardines and other small schooling fish could lead to algae overblooms, because the little fish eat the zooplankton that normally graze on the phytoplankton.

(Thus for the Chesapeake Bay the decline in menhaden, which should help increase zooplankton numbers, probably doesn't have much of an effect, because all the algae in the eutrophied bay overwhelms the Bay's zooplankters).

Now I figured there'd be more of a scientifically oriented write-up on this, and of course there is, especially since this was presented at the American Association for the Advancement of Science (AAAS) meeting taking place right now just up the road in Washington, DC.

First, there's the University of British Columbia (UBC) press release:

Fishing down food web leaves fewer big fish, more small fish in past century: UBC research

“Currently, forage fish are turned into fishmeal and fish oil and used as feeds for the aquaculture industry, which is in turn becoming increasingly reliant on this feed source,” said [study author Villy] Christensen. “If the fishing-down-the-food-web trend continues, our oceans may one day become a ‘farm’ to produce feeds for the aquaculture industry. Goodbye, wild ocean!”

Christensen’s presentation was part of an experts’ panel to answer the question “2050: Will there be fish in the ocean?” The panel predicted that while there would be fish in 2050, it would consist mostly of the smaller variety.

Here's the real take-home headline:

Predatory fish in sharp decline, UBC researchers say

The UBC team found that 54 per cent of the decline in predatory fish population took place in the last 40 years.

(Rapidly increasing human population does have a few downsides, doesn't it?)

And there's this culinary suggestion:

Save the seas: eat small fry like sardines instead of tuna

PLEASE tell this to the Japanese!