Fishing in Drought Conditions: A Fisheries Management Perspective
by Debbie Kay
This winter was not kind to the skiers in the PNW. As we approached spring, snowpack was already at summer lows. For some, this means less time doing what they love in the winter. For anglers and regulatory agencies, this means drought preparation. Ever wonder what fish management agencies consider during a drought? Here is a look at some of the things they do, and why:
Why Drought Affects Fisheries
There are several things that affect the level of fish during drought conditions. Everyone knows about water. If it’s not in a stream, fish have nowhere to go. However, droughts cause a number of additional issues that affect fish health:
- Solarity: Years with little rain have less cloud cover. The more sun, the more heat on the water.
- Temperature: Warm water holds less oxygen than cold water. Fish need this to breathe. Fish like trout need very high oxygen levels to survive.
- Food: These same conditions don’t just stress fish, they stress their food- fewer insects mean fewer fish.
Short Term Solutions
When it comes to drought, there are a number of different things that can be done. Often, different watersheds in an area will have different kinds of solutions. This is because the water resources and level of development surrounding these areas during a drought are different, and certain measures may be more or less effective depending on those conditions. Here is a look at some of the short-term actions that can be taken:
- Reservoir Use: Areas with salmon are known for this–additional water can be released from a reservoir to protect salmon levels. This is especially true if the fish involved have Endangered Species Act protection.
- Hatchery Assistance: Water level can have hatcheries change release sites, hold fish longer, or change the number of stock they will release due to a fear that wild numbers for the season will drop. Manually stocked lakes may get a boost due to an expectation of fewer surviving existing fish.
- Catch Limit Changes: Areas which are highly regulated may see changes in catch limits due to strained conditions. In warmer water systems, there may be a warning about catch and release during high temperatures as well, due to the fact that the fish are already stressed in the warmer water.
Long Term Solutions
As climate change becomes a larger part of the conversation in fisheries management, the idea of more frequent drought seasons is becoming a major topic. California is reaching this point, and the PNW states and provinces are taking notice of how they handle the situation. Some of the discussions for longer term protection for fish during drought are habitat based. They include a combination of restoration and resource projects:
- Hatcheries: In areas where populations are becoming more of a risk, the idea of saving some of these genetics is very popular in some circles, but controversial in others. Many who support hatcheries do so because they do a lot to ensure there’s a fishable population each year.
- Adjacent Habitat: If the stream is too hot or too low, the presence of swamps, ponds, and wetlands that attach to the stream can save a fish population. Many of these areas were drained and built on, but there is a big push to bring them back.
- Shade Corridors: Even if water levels are low, cooler water temps can still make a difference for fish. Shady streams go a long way in keeping temperatures cool. Shady stream systems do even more.