Fish Carcass disposal, tips?

Maybe if you have rude and inconsiderate throw it in their garbage can when they are not looking. Better yet throw on their roof top!

I meant neighbor.

I, for one, like the whole circle-of-life idea. I either freeze them and use them as ice in my cooler on the next trip and dump them into the water they came from. I also toss them out back of my house and the buzzards take care of them no time. It's amazing how quickly those birds find carrion! The only downside is that the buzzards roost in the trees around my house and I get to be the final rung of the circle-of-life! They are absolute crapping machines, turning my black truck white.
I also try to bring home only fillets.

At the request of Bluekayak, here are some fish head/carcass tips and recipes from my mother.  I will also post the same under the recipe section as this clearly applies to both.  A short disclaimer, I have no idea about the basis for her comment about Salmon heads but she does know how to cook.

FISH HEAD USES, for bluekayak and others:
I use them as I would use bones to make broth, by adding onions, celery, carrots, sometimes fennel too, and even turnips. Turnips may not be our favorite veggie, but it adds great flavor. You need water, to cover generously salt and pepper too, in moderation.
Simmer for 40 m. let cool in pan.

BUT--and this is important:
The broth is going to be a dirty color. Way to get rid of the sludge and opacity:
Let the broth rest overnight in the fridge, and then, filter it, being careful to leave all the bits from the bottom of pan OUT, including veggies.

(I hear fish head sludge makes great fertilizer) Use either a double layer of cheese cloth in a strainer, or use a a metal coffee filter.
(bought mine at Peet's)
Takes time, but it's worth it.

After filtering, taste. You may add either:
flat beer-- no need to open your best-
or left-over white wine,
a very small amount of sherry, port wine, or, if you're in a great mood, a little orange brandy: not enough to taste it as orange, but to intensity the other flavors.
Herbs like thyme, chives, lemon grass,
rosemary,(that one, sparingly)
Simmer again.
If the flavor is still too weak, add a bottle or two of clam juice.

For a CANADIAN CHOWDER for 2-4 people
Use half full milk and half broth
Cut a large potato in small cubes, 1 cup diced celery, Simmer, covered by the mixed liquids, Add diced smoked bacon or ham 1-2 slices per person, simmer again and add:
Pieces of fresh fish, shrimps if you have some and simmer before serving,a couple of m Adjust liquid and seasoning.
Serve hot with chopped fresh parley on top.

For a luxury touch: add fresh cream, 1 TBS per person, before serving.

Served along crusty bread and good cheese, it makes a great lunch.

If you really want to go overboard-- ( Mmmm, bad pun,that!) Omit bacon, add strands of SAFFRON,
2-3  peeled tomatoes, cut up
1 Tbsp powdered CUMIN
1 tbs orange peel cut in very thin strips Simmer, taste, adjust seasoning.
If you want a richer soup, add rice and simmer till tender.

Note: However delicious ocean salmon is, and however clever salmon is, their heads give a tasteLESS broth. Other heads are better.
The saying goes that many heads are better than one. It's true of fish broth.

Note #2: Left over broth can be boiled down to half its volume and frozen for a couple of weeks.

To serve with cold fish:
I've used unflavored gelatin with good thawed fish broth, let it set in the fridge, cut it up into fine dice, and surrounded a whole fish with it.
 If the broth is too pale, add a little sherry and a little soy sauce.
Top the fish with whole tarragon leaves, or parley leaves in diagonal stripes. Yummy.

ahhhhhhhhhhhhhhhhhh, the old coffee filter trick.  Great set of recipes.  Thanks Etienne.