A team led by the Hong Kong University of Science and Technology (HKUST) has developed a technique to study how different species of fish interact with each other in a coastal region, a breakthrough which helps to explain the complex relationships of marine species and how global warming effects. fish population.
By analyzing tiny traces of fish DNA from seawater samples, the team combined the use of environmental DNA—known as eDNA—and advanced statistical analysis to not only detect the presence of species in fish, but also reveals how species interact with each other.
The use of eDNA to monitor biodiversity has surged in popularity in recent years, especially for the identification of aquatic organisms such as fish. As animals move around their environment, they shed bits of genetic material, such as skin cells, waste products, and other body fluids. By extracting these traces of DNA from samples of water, soil, or air, scientists can determine the presence and diversity of species with high precision.
But previous eDNA studies were mostly limited to identifying the presence or absence of certain species. To better understand and monitor ecosystems, it is necessary to estimate the number of fish species and detect interspecific interactions, or interactions between species.
The team, led by Prof. Masayuki Ushio, Assistant Professor in the Department of Ocean Science at HKUST and Dr. Masaki Miya of the Natural History Museum and Institute, Chiba, Japan, developed a new technique to achieve the aforementioned goal by analyzing high-frequency time-series data from fish eDNA, which makes possible comprehensive monitoring in species interactions.
Interspecific interactions, such as prey-predator, competitive, and mutualistic relationships, have a significant impact on ecosystem dynamics. The research paves the way for scientists to contribute to a more accurate assessment of the state of the ecosystem and future predictions of its dynamics.
The researchers set up 11 study sites along the coast of the Boso Peninsula in Chiba Prefecture, Japan, where they conducted biweekly water sampling for two years. They extracted eDNA from collected samples and analyzed fish communities using a method that generated eDNA-based high-frequency time series of fish communities in coastal ecosystems. Then, they detected and quantified the strength of fish-fish interspecific interspecific communities by analyzing high-frequency eDNA time-series data using cutting-edge time-series analysis methods.
Among their important findings is that water temperature can have both positive and negative effects on how different fish species interact with each other. They also found that different fish species may react differently to changes in temperature, shedding light on how global warming affects the complex relationships between fish species in areas. on the beach. The findings were recently published in the journal eLife.
“By combining state-of-the-art techniques from different scientific fields, we show that eDNA analysis can estimate not only ‘what’ and ‘how many’ species exist, but also ‘who with whom'”, Prof. Ushio says.
The framework can be used to study interactions between different types of organisms, not just fish. This includes microbes, crustaceans, and other invertebrates. For example, scientists can use the technique to study how different organisms interact in aquaculture systems. It also helps to identify potential harmful pathogens that may affect commercially important fish species.
In the long run, he said the research will help scientists and policymakers better understand how climate change is affecting fish populations, including commercially important and rare species.
“This information can be used to develop better conservation strategies to protect these species and ensure the long-term sustainability of the ocean. For example, to preserve a rare species, it may be important to also protect the a species of fish that has a significant impact on rare species,” he said.
The team will soon explore new technologies, such as automated water sampling systems and seawater sampling using underwater drones, to make eDNA analysis more efficient and effective, to increase our understanding of how the organisms interact with each other in nature, such as the effect of pathogens on fish. population.
They also plan to use advanced DNA sequencing technology to investigate eDNA sequences in more detail, such as long-read sequencing.
“By using these new technologies and collaborating with experts from different fields, we can continue to improve our understanding of how climate change affects marine ecosystems, and create better way to protect it,” he said.
Masayuki Ushio et al, Temperature sensitivity of interspecific interaction strength in coastal marine fish communities, eLife (2023). DOI: 10.7554/eLife.85795.2
Awarded by the Hong Kong University of Science and Technology
Citation: Deciphering fish species interactions for climate change insights (2023, July 13) retrieved on July 14, 2023 from https://phys.org/news/2023-07-deciphering-fish- species-interactions-climate.html
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