Do landlocked Pacific salmon die after spawning?

Yes. This phase of their life history is the same as their seagoing relatives.

How large do salmon get?

Chinook Weights of 100 pounds and slightly over have been reported from European countries for the Atlantic salmon; the record for the largest of the Pacific species, chinook, is 126 pounds for a fish caught on commercial gear in Alaskan waters.

What is the oldest known age of salmon and steelhead (in completed years)?

Atlantic salmon: 8
Steelhead trout: 8
Pacific salmon: 7
chinook: 7
sockeye 7
chum 6
silver 4
pink 2

The steelhead is a rainbow trout that migrates to sea as a juvenile and returns to fresh water as an adult to spawn. Unlike the Pacific salmon, the steelhead trout does not always die following spawning and may spawn more than once and return to the sea after each spawning.

How old are salmon when they migrate from fresh water to the ocean?

That depends on species:

Fall Chinook: 3-4 months after hatch
Spring Chinook: 12-16 months;
Coho: 12-24 months;
Chum: a week to a month;
Sockeye: 12 months to 36 months;
Pink: a week to a month.

Sockeye

How many eggs do salmon have?

Generally from 2,500 to 7,000 depending on species and size of fish. The chinook salmon generally produces the most and largest eggs.

Chinook

What are salmon fed in a hatchery?

Vitamin-rich, high-protein diets made up of dried meals from coarse fish, animal meat excess, plant meal and bone meal, or meal from calcium-rich shells.

How many of the young salmon released from hatcheries come back as adults?

Releases of large fingerlings usually result in returns of one to five percent.

Why are fishladders constructed?

A fishladder, or fishway, often used in salmon country, is constructed to provide for up-stream passage of fish over a dam or a natural barrier that might prevent or impede progress to spawning grounds.

Fish Ladder