Canned salmon may seem like a mundane pantry item, but it turns out that these cans hold a treasure trove of information about Alaskan marine ecology. When Natalie Mastick and Chelsea Wood from the University of Washington were approached by Seattle’s Seafood Products Association with boxes of old and expired cans of salmon dating back to the 1970s, they saw an opportunity to uncover the secrets of parasites in marine ecosystems.
Parasites often go unnoticed in ecosystems, despite playing crucial roles in the interactions between different species. Anisakids, the 0.4-inch long marine parasites found in the canned salmon, are harmless to humans but can provide valuable insights into the health of marine ecosystems. These parasites enter the food web through krill and eventually end up in the intestines of marine mammals, completing their life cycle through reproduction.
The collection of 178 tin cans of salmon from the Gulf of Alaska and Bristol Bay served as a unique archive of preserved specimens, allowing researchers to study the changes in parasite populations over a 42-year period. Despite the challenges of identifying specific species of anisakids due to the canning process, Mastick and Wood were able to analyze the number of worms per gram of salmon in different species.
Through their analysis, the researchers found that the number of worms had increased over time in chum and pink salmon, indicating a stable or recovering ecosystem with sufficient hosts for anisakids. However, the levels of worms in coho and sockeye remained stable, posing a mystery for the researchers. The inability to identify the specific species of anisakids highlights the complexity of parasite interactions in marine ecosystems.
Mastick and her colleagues believe that the innovative use of old cans of salmon as an ecological archive could lead to further scientific discoveries in the field of parasite ecology. By repurposing these cans as a window into the past, researchers have unearthed a wealth of information that could help unravel the complexities of marine ecosystems. In essence, this study has truly opened a can of worms, paving the way for future exploration and understanding of the delicate balance of nature.