SAN CARLOS, Sonora, Mexico » Here in the marina where my sailboat, Honu, and I await friends' arrival, I invited a neighbor to join me snorkeling. “;Thanks,”; he said. “;I need to find some clams for bait. I hope you don't mind.”;

I did mind. I traveled to the Sea of Cortez to swim with, sail among and marvel at the extraordinary animals here. The last thing I wanted was someone swimming next to me killing them.

But I eat them. Fish tacos, shrimp tostadas and a dish called “;fajita mixta,”; which includes the above plus octopus, clams and squid, are on all the menus in this seaside town. They're delicious and good for me, and above all, someone else killed them out of my sight.

That's hypocrisy squared, I know, and I think about it a lot. As a biologist with a boat, the issue of killing the wild animals I so admire is in my face. Sometimes it's in my hands.

When I was here in March, at anchor, a neighbor drove over in his dinghy. “;Take these,”; he said, handing up a bag. “;I dug up more than I can eat.”; Inside were about a dozen live chocolate clams, huge creatures with heavy shells that, in my outstretched palm, covered most of my hand.

The guy hadn't asked whether Craig and I wanted these clams. We did not. We didn't need the food, couldn't bear to cook the animals alive and disliked the fact that the man took more than he could eat.

After he left, we immersed our clams in a net bag over the side of our dinghy and drove them to the far end of the anchorage. Then free-diving, we half-buried each one and snorkeled above, watching the creatures dig themselves deeper into the sand.

That rescue surely made little difference to the chocolate clam population in the Sea of Cortez, but it sure felt good to set them free.

I was feeling far from good about seafood, though, when last week on my way through the marina, I stopped at the fish scale where anglers hang their catches to measure and take pictures.

There by the tail hung a magnificent marlin, its torpedolike body glistening metallic blue in the morning sun. One of the fish's eyes was just a pulpy hole, apparently gaffed, and blood dripped from the mouth.

“;Usually we let them go,”; the dad told me as we stared at the fish, “;but this is the kid's first big one, so we brought it in.”; I made myself watch and listen as the teenage boy, his father and grandfather took turns posing with the fish while telling the story of how hard the animal fought for its life.

Then I started to cry. I didn't want to. I wanted to get real about the food I eat. But tears for that wild animal just popped out of my eyes, and I had to leave.

I get some relief from my love-kill-eat animal di- lemma by eating far less animal flesh than I used to. It also helps to remember that we evolved as predators and meat eaters, and human instinct to hunt is strong.

I'm grateful I don't have to hunt my own food anymore, and when I eat seafood in restaurants, I now take a moment to silently thank the professionals who caught, killed, cleaned, cooked and served it to me. I also thank the animals that died for helping keep me alive and healthy.

By the time my San Carlos neighbor and I went snorkeling last week, I'd told him some of my Sea of Cortez experiences.

He did not hunt for clams.

Susan Scott can be reached at www.susanscott.net.