Estuaries are where ocean water pushed in by the tides mixes with freshwater flowing out of the watershed into the sea. This creates a high energy and high productivity environment that juvenile salmon rely on for bulking up and getting ready to migrate to the open ocean.

Estuaries are also historically and presently major centers for humans who build homes, farm, and recreate in them. The infrastructure supporting these human uses sometimes interferes with the needs of salmon as dikes, tide gates, and culverts can impede access and flow into historical tidal wetlands.

These issues can be addressed through fish friendly tide gates, land management, and other strategies. Additionally, restoring tidal wetlands can benefit human communities by absorbing floodwaters and reducing the flood risk elsewhere in the estuary.

Like all animals, Coho require a place to hunt, to rest, to hide from predators, and to mate. Similar to how humans eat in a dining room and sleep in a bed, Coho use different types of habitat for different activities.

This means that more diverse habitat can meet more of their needs than a simplified habitat. They need pools to rear in, logs and undercuts to hide under, gravels to spawn in, and riffles that grow their favorite bugs to eat. All these different habitat types are created by logs and boulders in the stream. These logs and boulders interrupt the stream flow causing water to slow down, gravels to deposit, digging out pools, and more. They also can also slow water down causing it to flow over streambanks, exchanging nutrients with the floodplain, and recharging groundwater.

Without logs and boulders in a stream it becomes more uniform as gravels get carried away, bedrock is exposed, and flood flows are faster and higher.

Even the best habitat isn’t useful to a salmon if they can’t reach it to use it. Roads are an essential part of human infrastructure, getting us to work and home again, out to hiking trails, and allowing for businesses to transport goods around the region.

However, as many of our roads were built before we understood the needs of salmon, the culverts that keep the roads from flooding were built simply to move water and not fish.

High water velocity in too-small culverts can prevent salmon from migrating to spawning or rearing habitat. Culverts that are too high above a stream are like a wall to a salmon. Replacing those too small culverts with properly-sized culverts or a bridge allows humans and fish to both get where they need to go.