Seems all the fashion on food blogs across the blogosphere to recommend sardines from Bittman to Grist to now Culinate but even Sardines can be overfished to catastrophic results..

As quoted from a PBS show, National Geographic's Strange Days on Planet Earth:

_ Namibia is home to one of the most productive ocean systems in the world. Fueled by nearly constant winds that help draw up deep-water nutrients, these plankton-rich waters attract billions of hungry sardines. The sea is transformed into muscular silver. At least, that’s what used to happen. After foreign fishing fleets over-harvested these waters in the 1970s, the sardine populations never fully recovered despite Namibia’s best efforts. Working together, Currie, Weeks and Bakun revealed how the sardines may have been key to keeping those oceanic stench events in check. Here’s how their theory works.

Without sardines devouring plankton, mountains of the stuff sink to the bottom and decay producing a ticking time bomb of hydrogen sulfide and volatile methane on the seafloor. Under the right conditions, say when a rainy low-pressure weather system reduces pressure on the coastal ocean, the whole thing can blow. And the results can be explosive—like popping the tops off millions of rather stinky bottles of champagne. Once that hydrogen sulfide reacts with oxygen, the resulting elemental sulfur turns the ocean water white. Toxic gas suffocates nearby fish and an unmistakable rotten egg odor permeates the air. Along with the hydrogen sulfide comes methane, lots of it. Methane packs a punch since this gas is 26 times more effective at trapping heat than carbon dioxide. And according to Andrew Bakun, global warming can lead to more winds, which can in turn lead to more nutrients, more plankton growth, more decay and more releasing of smelly gas. Bakun suggests that that this system could be creating a rather unfortunate positive feedback loop. Who would have thought loosing sardines could be linked to methane production or changes in Earth’s atmosphere?_

The goal should not be eating more of anything but choosing well which includes lower on the food chain stopping not just at sardines but going for the foods which give them their omega 3 profiles such as algae.