lower granite fish count

Lower Granite Fish Count Report: Tracking the Population of Fish in the Columbia River Basin

Why Monitoring the Lower Granite Fish Count is Critical for Fisheries Management

Lower Granite Fish Count

The Lower Granite fish count is a crucial indicator of the health of the Snake River salmon and Steelhead populations. Every year, wildlife agencies and fisheries managers use a federal dam to count these fish as they make their way upstream to their spawning grounds. The Lower Granite Dam is the last of the four major hydroelectric dams in the Snake River that the salmon and Steelhead must pass. By monitoring fish counts at this critical point, biologists can estimate the size and composition of fish populations, which is essential for ensuring the long-term health of these precious species.

Why does it matter? Fisheries are a critical source of protein and income for millions of people worldwide. Many fish species are also an essential part of the ocean food chain, providing nourishment to larger predators like whales, sharks, and sea birds. If fish populations are not managed sustainably, they can quickly become depleted or even extinct, causing a ripple effect throughout the ecosystem and impacting human livelihoods.

For instance, declining salmon and Steelhead populations on the Snake River can put recreation and commercial fisheries at risk, impacting local economies and communities. These fish also provide food for indigenous peoples, and their cultural, spiritual, and ceremonial significance cannot be overstated. Furthermore, as salmon and Steelhead migrate upstream, they play a vital role in transporting nutrients from the ocean to inland ecosystems, contributing to the health and productivity of riverine environments. Therefore, understanding and managing these populations is critical for the well-being of not only the fish but also the ecosystems and communities that depend on them.

By monitoring the Lower Granite Fish Count, scientists and fishery managers can track changes in population trends over time and take steps to mitigate negative impacts on these important species. This information helps them set management goals, such as setting sustainable harvest levels, protecting spawning habitat, and enhancing fish passage around dams. It also enables them to evaluate the effectiveness of different management strategies, such as restoring degraded habitats or implementing fishing regulations.

In conclusion, monitoring the Lower Granite fish count is an essential tool for effective fisheries management. By tracking changes in population trends over time, biologists can identify the causes of declines, implement measures to mitigate negative impacts, and ensure that salmon and Steelhead populations remain healthy and productive for generations to come.

The Results of Lower Granite Fish Count

Lower Granite Dam Fish Count

The Lower Granite Dam is an important location that enables fish from the Pacific Ocean to reach their spawning grounds in the Snake River Basin. The fish count at this particular location has been conducted annually since the 1930s, and the most recent count has revealed some interesting results.

According to the data collected during the 2020 Lower Granite fish count, a total of 174,000 adult salmon and steelhead were counted crossing the dam. This was a significant decrease from the previous year, during which 272,000 fish were counted. The 2020 results are also below the 10-year average count of 259,000 fish, which is concerning for the survival of these fish populations.

Of the fish counted during the 2020 season, over 80% were fall Chinook salmon, with steelhead making up the remainder of the count. The majority of these fish were headed to the Clearwater River Basin, while smaller numbers were destined for the Snake and Salmon River Basins.

One potential reason for the lower count could be the unusually warm water temperatures during the spawning season. High water temperatures can harm fish populations, and they were recorded up to 71 degrees Fahrenheit at Lower Granite Dam. Additionally, reduced feed availability in the ocean may have contributed to a lower number of fish making their way up to the river to spawn.

The Lower Granite fish count is essential for monitoring the health and abundance of these important fish populations, and it can act as an early warning system for any issues that may need to be addressed. While the 2020 results are concerning, they do not necessarily indicate a long-term trend, and it will be important to continue monitoring the fish count in subsequent years to better understand the fate of these populations.

Water Temperature

Water Temperature

Water temperature is one of the most important factors affecting fish counts at Lower Granite Dam. Various fish species have different temperature requirements for their growth, reproduction, and migration. For example, Chinook salmon prefer water temperatures in the range of 50 to 55 degrees Fahrenheit for spawning, while steelhead prefer temperatures between 40 and 45 degrees Fahrenheit. If the water temperature at the dam is outside the species’ preferred range, it can have a negative impact on their behavior and survival.

In addition, changes in water temperature can affect the timing of fish runs. Warmer water temperatures can cause fish to run earlier in the season and arrive at the dam earlier than usual. Conversely, cooler water temperatures can cause fish to run later in the season and arrive at the dam later than usual. This timing difference can lead to fluctuations in fish counts at Lower Granite Dam.

To manage water temperatures, the U.S. Army Corps of Engineers (USACE) releases water from Dworshak Dam upstream from Lower Granite Dam to control the temperature of the water as it passes through the Snake River. However, the effectiveness of this method can be limited by weather conditions and the amount of water available for release.

Water Quality

Water Quality

Water quality is another critical factor that affects fish counts at Lower Granite Dam. This can include factors such as pH, dissolved oxygen levels, and pollutants. Changes in water quality can affect the behavior and physiology of fish, which can ultimately affect their survival and migration patterns. For example, low dissolved oxygen levels can cause fish to become stressed or suffocate, while high levels of pollutants can lead to disease and other health problems.

The USACE and other agencies regularly monitor the water quality at Lower Granite Dam and work to maintain suitable conditions for fish. This can involve managing water releases, reducing the use of harmful chemicals in nearby agricultural operations, and preventing spills and other incidents that can cause water pollution.



Predation is the third factor that can significantly impact fish counts at Lower Granite Dam. Predators can include both natural predators, such as birds and mammals, and non-native species, such as walleye and bass, that have been introduced into the ecosystem. The presence of predators can affect the behavior of fish and make them more difficult to catch and count.

The USACE and other organizations use various tactics to control predators at the dam, including removing non-native species, using nets to protect spawning areas, and implementing deterrents such as acoustic devices.

Despite these efforts, predation continues to be a significant cause for concern at Lower Granite Dam. In 2019, adult Chinook salmon and steelhead counts were lower than expected due to predation from sea lions and other natural predators. These trends underscore the importance of continued monitoring and management efforts to ensure the long-term survival of fish populations in the Snake River.

How Lower Granite Dam Affects Salmon Populations

Lower Granite Dam and Salmon

Lower Granite Dam is a concrete structure that spans the Snake River in southeastern Washington state. It is part of the Columbia River basin and is an essential link in the migration of salmon between their spawning grounds in the upper reaches of the Snake River and the ocean. However, the construction of the Lower Granite Dam in 1975 has affected the salmon population in both positive and negative ways.

On the one hand, Lower Granite Dam provides a stable pool of water behind the dam, which keeps water levels high and prevents salmon from getting stranded in shallow areas. This allows salmon to migrate upstream to their spawning grounds more easily, which is essential for their reproduction.

However, on the other hand, the Lower Granite Dam also poses significant threats to salmon populations. The Dam has created a series of reservoirs that are still water; this stagnant water can reach temperatures that are too warm for salmon, especially during summertime. This can be fatal for salmon, as they require certain water temperatures to survive.

The dam can also disorient salmon with the ship traffic and noise generated, as it makes the salmon think that they have reached their spawning grounds, which can cause confusion among the salmon as to where and when to swim correctly. The dams on the river also cause significant changes to the flow rates which can disrupt the migration of the salmon.

The construction of the dam has also led to a significant reduction in salmon populations. Historically, the Snake River has seen an impressive Chinook salmon population in the spring and fall. However, studies show that since the dam’s construction, there has been a 98% reduction in the number of Chinook salmon that come up the river. Other salmon populations that migrate through the Snake River, including steelhead, sockeye, and coho have also seen similar population declines.

To mitigate the negative impact of the dam on salmon populations, numerous strategies have been implemented, including building fish ladders, modifying the dam’s water discharge to mimic natural flows, and transporting young salmon past the dam. These initiatives have been implemented to help the salmon migrate, but their success is still yet to bring the salmon populations back to their original levels.

In conclusion, the Lower Granite Dam’s role in fish count is both positive and negative. While it provides stability for migratory fish in some regards, the dam also causes significant problems that have adversely affected the salmon population in the Snake River. Understanding how this dam affects fish populations is crucial in creating balanced management strategies that can help ensure the survival of these essential fish species for future generations.

Habitat Restoration

Habitat Restoration

Habitat restoration is a critical factor in the effort to increase fish abundance in Lower Granite. The main objective of the program is to restore the habitat that is important for the survival and growth of fish populations. The restoration process involves restoring the streambed, banks, and the surrounding area of the river. This is done by planting vegetation and trees, removing debris, controlling invasive species, and improving water quality. When the habitat is restored, fish populations are likely to increase since they have suitable spawning areas and feeding grounds.

Fish Passage

Fish Passage

Fish passage is a significant initiative that aims to increase the survival of fish as they travel through the dam system. The dam blocking the river hinders fish migration, and therefore, fish passage facilities are constructed to provide upstream and downstream passage for various fish species. This passage is achieved through the use of fish ladders, elevators, and fish screens. A fish ladder is a series of steps built on the side of a dam, which allows fish to swim up and over the barrier. The success of fish passage initiatives is crucial in preventing the decline of endangered fish species and boosting fish numbers.

Water Temperature Management

Water Temperature Management

The temperature of the water within Lower Granite is monitored and regulated to suit the needs of fish species. Most fish species tend to thrive in waters that have a specific temperature range. When the temperature exceeds or falls below this range, it can have a significant impact on the fish’s growth and reproduction rate. Therefore, temperature management initiatives are crucial in ensuring the survival of the fish population. The water temperature management programs ensure that the water temperature is conducive for fish survival. This may involve releasing cold water during warmer seasons to cool the water temperature and vice versa.

Fish Stocking Programs

Fish Stocking Programs

Fish stocking programs are implemented to increase the abundance of fish species in the lower granite area. The program involves introducing fish species into the water system to establish a new population or supplement existing ones. The fish species introduced into the area are those that are native to the habitat and can thrive well in the ecosystem. The success of fish stocking programs depends on several factors, such as water quality, food availability, and habitat suitability. Such programs are likely to increase fish abundance in the area.

Research and Monitoring

Research and Monitoring

The success of the initiatives to increase fish populations at Lower Granite depends on accurate data collection and monitoring. Research and monitoring programs are crucial in providing relevant information, such as the number of fish species, survival rate, and migration progress. The data collected from the research and monitoring programs is used to adjust fish management strategies to achieve the desired results. These programs also provide insight into the effectiveness of the different initiatives aimed at increasing fish populations in Lower Granite.

Climate Change

Climate Change Lower Granite Fish Count

Climate change is one of the biggest challenges facing fish populations at Lower Granite Dam. The rapid increase in global temperatures has caused a range of environmental pressures, including droughts and flooding, which affect the behavior and survival rates of fish species.

Droughts and warmer water temperatures can reduce the amount of oxygen in the water, making it difficult for fish to breathe. This can lead to increased mortality rates, particularly for young and vulnerable fish. Warmer water temperatures can also trigger premature migrations, which can cause fish to miss out on important feeding opportunities and reduce their overall fitness and growth rates.

Flooding can also have a negative impact on fish populations. It can disrupt fish spawning cycles, displace fish from their habitats, and increase the level of pollutants and sediment in the water, making it less suitable for fish to live in.

Water Pollution

Water Pollution Lower Granite Fish Count

Water pollution is another major challenge facing fish populations at Lower Granite Dam. The release of pollutants, such as agricultural runoff and chemical contaminants, can cause significant harm to fish, reducing their lifespan, growth rates, and reproductive success.

Chemical contaminants can enter the food chain, affecting not just fish, but also the animals that prey upon them. This can have a knock-on effect on the entire ecosystem, reducing the number of fish available for both commercial and recreational fishing.

Reducing water pollution is a complex problem that requires changes in agricultural practices, industrial processes, and government policies. The implementation of best management practices on farms, the use of sustainable production methods in industry, and the enforcement of regulations on polluters are some of the ways in which water pollution can be addressed.


Predation Lower Granite Fish Count

Predation is a natural process that has been occurring for millions of years. However, the introduction of non-native species, such as pikeminnow and walleye, has had a significant impact on the native fish populations in the Columbia River basin.

Predatory fish can cause a decline in the number of juvenile fish, reducing the reproductive capacity of the population. This can have a cascading effect on the entire ecosystem, as fish play a crucial role in nutrient cycling and food webs.

Efforts to control predation include the use of selective fishing techniques, such as electrofishing and seining, the construction of predator exclusion screens at dam intakes, and the removal of non-native predators from the ecosystem.

Dam Operations

Lower Granite Dam Operations

The operation of Lower Granite Dam can have significant impacts on fish populations. The construction of the dam has altered the natural flow of the river, creating new obstacles and hazards for migrating fish.

The installation of fish passage systems, such as fish ladders and juvenile bypass systems, has improved the number of fish that can pass through the dam. However, these systems can also cause delay, injury, and mortality for fish, particularly when they become clogged with debris or suffer from technical malfunctions.

The dam’s operations can also have an indirect impact on fish populations through changes in water temperature and water quality. The discharge of cold water from the bottom of the reservoir can cause a reduction in water temperatures downstream, affecting the health and survival of fish species that are adapted to warmer waters. The rapid changes in water flow caused by dam releases can also disrupt fish behavior and migration patterns.

Hatchery Programs

Hatchery Programs Lower Granite Fish Count

Hatchery programs have been established to help restore and maintain fish populations at Lower Granite Dam. These programs involve the breeding and release of fish into the river, either to supplement existing populations or to re-establish extinct species.

While hatchery programs can be effective, they can also have negative impacts on natural populations. The release of hatchery fish can reduce the genetic diversity of the wild population, making it more susceptible to disease and environmental stress. Hatchery fish can also have lower survival rates and fitness compared to wild fish, which can lead to a decline in the overall health of the population.

Hatchery programs need to be carefully managed to minimize their impact on wild populations. This can be achieved through the use of selective breeding techniques, the release of fish at appropriate times and locations, and the implementation of monitoring and evaluation programs to assess the success of the program and identify any unintended consequences.

Regulation and Management

Regulation and Management Lower Granite Fish Count

The regulation and management of fish populations at Lower Granite Dam is a complex task that requires coordination between multiple agencies and stakeholders. There are many competing interests to manage, such as commercial and recreational fishing, conservation of endangered species, and the generation of hydroelectric power.

Effective regulation and management require the development of comprehensive management plans, based on the best available science and stakeholder input. It also requires a commitment to adaptive management, whereby management actions are adjusted over time as new information becomes available.

Increased public awareness and participation in the regulation and management of fish populations can also help to build support for conservation efforts and promote responsible use of natural resources.

1. Introduction: Understanding the Importance of Lower Granite Fish Count

Lower Granite Dam Fish Count

Lower Granite Fish Count is an essential factor in determining the health and sustainability of fish populations in the Snake River Basin. The monitoring of fish populations provides crucial data for fisheries management decisions, including regulating harvest rates and determining conservation efforts. Hence, it is essential to assess the future of Lower Granite Fish Count to make informed decisions regarding fish conservation in the region.

2. The Current State of Lower Granite Fish Count

Lower Granite Dam Fish Count

The current state of Lower Granite Fish Count has been marked with concerns due to the declining number of fish populations. In recent years, the count has revealed a decline in salmon and steelhead populations in the Snake River Basin, with numbers reaching their lowest levels in five years. This decline is attributed to various factors, including habitat loss, climate change, overfishing, and human activities such as dam operations and development.

3. The Impact of Low Fish Counts

Impact of Low Fish Counts

Low fish counts can have far-reaching consequences beyond the fish themselves. For instance, fish populations are a critical part of the food web, and their decline can impact other species that rely on them directly or indirectly. Additionally, low fish counts can also have significant economic impacts on the fishing industry and the region’s economy that may depend on it.

4. Conservation Efforts

Snake River Conservation Efforts

A combination of conservation efforts is required to protect and restore fish populations in the Snake River Basin. Efforts include habitat restoration, enhancing fish passage, releasing hatchery-raised fish, improving water quality, and regulating fishing practices. Additionally, management decisions aimed at reducing the impact of human activities such as hydroelectric dam operations have become necessary.

5. Future Predictions

Lower Granite Dam Fish Count

The future of Lower Granite Fish Count remains uncertain, and predictions vary depending on the effectiveness of conservation efforts. The warming climate, habitat loss, and other factors can continue to threaten fish populations in the region. Predictions indicate that fish populations are unlikely to recover to sustainable levels unless significant measures such as the removal of dams are taken.

6. The Importance of Public Awareness and Engagement

Public Awareness and Engagement

Public awareness and engagement are critical to the success of conservation efforts. Educating the public on the importance of fish populations and their role in the ecosystem can foster support for conservation measures. Additionally, the involvement of the public in the decision-making process can ensure that the measures taken align with the community’s needs and expectations.

7. Conclusion


The future of Lower Granite Fish Count remains uncertain and will depend on the effectiveness of conservation efforts, public awareness, and engagement. The ongoing monitoring of fish populations remains crucial for informed decision-making and the success of conservation measures. The need for significant measures to protect and conserve fish populations in the Snake River Basin has become apparent, and swift action is necessary to secure their long-term viability.

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