November 7, 2024 — The following was released by NOAA Fisheries:
For decades, Alaska has been leading the way in gathering and using ecosystem information to inform fish and crab resource management decisions. Now, scientists at the Alaska Fisheries Science Center can rapidly provide managers with information about how changes in the marine environment affect the basis of the marine food web. Details about this new methodology were recently published in a paper describing this new Rapid Zooplankton Assessment (RZA).
The RZA can supply near real-time information about the abundance and species composition of zooplankton. Zooplankton are the floating animals that, along with phytoplankton, form the base of the marine food web. These data—coupled with long-term data sets—can provide a snapshot of ecosystem health and help forecast the productivity of our fisheries.
Zooplankton Abundance Informs Fisheries Productivity
Across the world, fisheries managers are turning more and more to ecosystem-based fisheries management. It’s a holistic approach that aims to maintain the resilience and sustainability of an ecosystem. Not only does it recognize physical and biological information, but economic and social factors as well. It seeks to optimize benefits among a diverse set of societal goals, especially in the face of climate change.
Collecting ecosystem data is a huge and multifaceted task. Looking at one piece of the puzzle, our scientists have focused on more efficiently surveying zooplankton. It’s vitally important prey for fish at many stages of their life. Most importantly, zooplankton is the primary food source when marine fish transition from egg stage to larval stage and first begin to feed. This is deemed the “critical period” during which many fish die without abundant food. This, in turn, impacts recruitment—meaning how many fish will survive to older life stages. Zooplankton abundance is a good indicator of how strong recruitment will be for a specific fishery.
Zooplankton are also important to seabirds and marine mammals like whales. And zooplankton respond more immediately to climate variability. They are a great indicator of the health of an ecosystem. They can also give us insight into future climate regimes based on how they have responded to marine heatwaves and other large-scale changes.