July 15, 2024
Salmon

New Study Finds Human-Made Cooling Stations Could Aid Spawning Salmon

As global warming continues to raise river temperatures, the survival of spawning salmon is increasingly threatened. However, a recent study conducted by hydrology PhD candidate Kathryn Smith and her colleagues at Dalhousie University in Canada has discovered a potential solution. The researchers explored the concept of utilizing human-made cooling stations in rivers to provide relief for the stressed fish during their journey.

Typically, salmon find respite in what are known as thermal refuges, areas where cool water from underground springs or tributaries flows into the main river, reducing the temperature. While these natural refuges do offer some relief, the impact they have is diminishing due to the effects of climate change.

To address this issue, Smith and her team developed and tested two types of human-made thermal refuges in Nova Scotia. The first was an active refuge that employed a pump to deliver cool groundwater from a municipal well into a warm section of the river. This created a plume of cooler water that extended at least 60 meters downstream. The second was a passive refuge that utilized a covered trench to divert water from a meander back into the main river. By shielding the redirected water from direct sunlight, its temperature decreased.

The researchers employed various methods, including thermal probes, drone thermal mapping, and time-lapse underwater cameras, to observe the behavior of spawning Atlantic salmon. The results showed that even a reduction of a few degrees in water temperature attracted a significant number of salmon to the refuges. Furthermore, during a heat wave, a greater number of fish congregated at the stations, indicating the effectiveness of the refuges in mitigating the impact of rising temperatures.

Smith plans to scale up the technology for further testing and implementation. She will present her research this week at the Geological Society of America’s GSA Connects 2023 meeting in Pittsburgh.

The introduction of human-made cooling stations in rivers could have significant implications for the survival and conservation of salmon populations. By providing these thermal refuges, scientists hope to offer a solution to the increasing threat posed by global warming. Further research and implementation of these innovative techniques will be crucial in supporting the continued migration and spawning of salmon in warming river environments.

Salmon, known for their preference for cold-water habitats, face considerable stress as they swim upstream in rivers with rising temperatures. However, a recent study conducted by hydrology PhD candidate Kathryn Smith and her colleagues at Dalhousie University in Canada has found a potential solution. The researchers investigated the use of human-made cooling stations in rivers to provide relief to the fish during their journey to spawning grounds.

Salmon often find respite in what are known as thermal refuges, areas where cool water from underground springs or tributaries flows into the main river. These refuges can help reduce water temperatures and provide some relief to the fish. However, due to the effects of climate change, natural thermal refuges are becoming less common and less effective. This inspired Smith and her team to explore the concept of creating artificial thermal refuges.

The study involved the testing of two types of human-made cooling stations in rivers in Nova Scotia. The first was an active refuge that utilized a pump to deliver cool groundwater from a municipal well into a warm stretch of the river. This created a plume of cooler water that extended at least 60 meters downstream. The second was a passive refuge that redirected water from a meander back into the main river using a covered trench. By shielding the redirected water from direct sunlight, its temperature decreased.

To assess the effectiveness of these refuges, the researchers used thermal probes, drone thermal mapping, and time-lapse underwater cameras. The data collected revealed that even a small reduction in water temperature attracted a significant number of salmon to the refuges. Additionally, during a heat wave, more fish were observed gathering at the stations, indicating the importance of these refuges in alleviating the impact of rising temperatures.

Based on the promising results, Smith plans to further develop and test the technology on a larger scale. The implementation of human-made cooling stations could play a crucial role in supporting the migration and spawning of salmon populations in warming river environments. The research findings will be presented this week at the Geological Society of America’s GSA Connects 2023 meeting in Pittsburgh.

The introduction of human-made cooling stations has the potential to significantly contribute to the conservation efforts of salmon populations. As global warming continues to pose a threat to these cold-water fish, innovative solutions like thermal refuges can help mitigate the impact and protect their survival. Continued research and implementation of these groundbreaking techniques will be essential in safeguarding the future of salmon in increasingly warm river ecosystems.

*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it