Seafood dilemma

I'm having a dilemma over seafood at the moment. I really love good, fresh seafood, although I don't tend to eat a lot of it. But it seems lately that the more I read, the less I feel I ought to eat. This despite the fact I'm constantly hearing on the news that seafood and fish oils are so good for my health and that most people don't eat enough of them.

In a typical week, the only seafood I am likely to eat is some canned tuna or a fresh piece of salmon, maybe a different fresh fish if something else looks good at the markets. If I lived at the coast that might be different though. I'm very careful to avoid species that I know are being unsustainably harvested, such as orange roughy. I know that salmon and tuna aren't perfectly managed either, but I've generally considered them to be better fish to eat from a conservation perspective. But this week I've read several things that have made me think I may be wrong. Perhaps I should give up on fish altogether? Here are some things to think about:

1) On Southern Fried Science, a really interesting post about why "Dolphin friendly" tuna might not be very friendly to anything else apart from dolphins - so maybe I should cut back on the tuna after all?

2) But maybe there is some hope? Tuna fisheries are also notoriously unkind to albatross populations, especially long-line fisheries. The birds try to eat the bait, get caught in the hooks and drown. I have always felt some guilt for these unseen deaths when eating my tuna mayonnaise. Then today I read on The Great Beyond that albatrosses may be saved after all. Changing practices have lead to an 85% decrease in the number of albatrosses killed by the fisheries. This can only be good news, surely?

3) I've also found another reason to worry about eating salmon. BBC Wildlife Magazine has an article in the February 2009 issue (page 39) describing a decline in salmon numbers in British Columbia. Fewer salmon means less food for grizzly bears for starters. So why are the salmon declining? The article points the finger at overfishing and the effects of fish farms on wild fish: sea lice breed in the farms then move out to infect wild fish. The salmon I get all comes from Aussie waters, mostly Tasmanian, but even though there are no bears to go hungry I'm sure the farms have the same problems. Perhaps I shall rethink salmon too?

I think I might just have to fork out a few dollars and get myself a copy of the Australian Marine Conservation Society's Sustainable Seafood Guide. At least then I'll have a better idea where I stand.

Finally, to end this post on marine life, I loved reading about this  in the Telegraph: a biologist on a tagging trip caught a huge stingray, 7 foot by 7 foot!!!

In the news today

Some sciencey stories that have caught my eye this week:

A paper in Genome Research describes the sequencing of the entire mitochodrial genome of the extinct thylacine or Tasmanian tiger. This probably deserves it's own post: it uses new methods and the results are surprisingly different from the sequences previously available. I'll try to review it in more depth later...

Scientific American reports on the discovery of two species of fly in Namibia which are members of a genus previously only known from the fossil record. This is pretty cool, especially given my personal soft spot for Namibia. Maybe I have unknowingly inhaled one of these flies! I am however a little disappointed that the good folk at Scientific American have described the flies as "living fossils". The term is not helpful. If a fly is alive it isn't a fossil. And where should the line be drawn? Many extant species have close relatives known from the fossil record. Are they all "living fossils"? How much divergence is required before they are no longer classed as "living fossils"? I think terms like this can really confuse people.

ABC news reports on the births of ten Tasmanian Devil pups on an island sanctuary. The pups are the offspring of devils chosen for captive breeding because of their good genetics. They have similar genetic profiles to the famous Cedric, a devil who raised, then dashed, the hopes of researchers by first showing immunity to the devastating Devil Facial Tumour Disease, only to later contract the cancer. Maybe these pups will show greater resilience to the disease?

And finally I can't resist posting a link to this: BBC footage of bears catching dead fish with their feet! Apparently they don't like to get their ears wet :-)