The world’s oceans face an unprecedented threat from overfishing. To satisfy the growing demand for seafood, scientists are suggesting an innovative approach: diversifying your plate by eating a mix of smaller, more biodiverse fish species. This solution not only provides better nutrition but also helps conserve our planet’s precious marine resources.

Researchers at Cornell University conducted an analysis that found combining certain species can provide up to 60% more nutrients than consuming the same quantity of a single highly nutritious species. Sebastian Heilpern, the study’s first author, emphasizes the importance of biodiversity in achieving better outcomes for fishery sustainability.

The researchers began by identifying a list of commonly consumed fish species and cross-checking it with existing nutrient content data. They then created a computer model that considered biogeographic and nutrient data to determine the optimal combinations of species for meeting dietary needs while minimizing fish biomass consumption.

The study revealed that biodiverse fisheries tend to have smaller, lower-trophic species that are more resilient to overexploitation and climate change. These species grow at faster rates than larger ones and can tolerate wider temperature ranges, making them more adaptable to changing ocean conditions.

Tropical coastal countries like those in the Coral Triangle, Australia, India, and the Amazon have the most biodiverse fisheries. In contrast, many countries, including the U.S., tend to consume a select few species, with only 10 species accounting for up to 90% of fish consumed by Americans.

The research was funded by various organizations, including the Schmidt Sciences programs, Cornell University, the National Science Foundation, and the David and Lucile Packard Foundation. This study highlights the potential for sustainable seafood options that benefit both human health and marine ecosystems.

By adopting a mix-and-match approach to fish consumption, we can help preserve our oceans’ biodiversity while still meeting the world’s growing demand for seafood.

Coastal wolves in Alaska have been found to contain high concentrations of mercury, according to recent research. The study, published in the journal Science of The Total Environment, shows that wolves that eat sea otters have significantly higher levels of mercury than those that feed on other prey such as deer and moose.

The research was conducted by a team of scientists led by Dr. Ben Barst, an expert in ecotoxicology from the University of Calgary. They found that the high concentrations of mercury were due to the wolves’ diet consisting mainly of sea otters, which are known to accumulate methyl mercury from aquatic environments.

“We spent quite a bit of time trying to figure out the cause of her death by doing a necropsy and different analyses of tissues,” said Gretchen Roffler, a wildlife research biologist with the Alaska Department of Fish and Game. “What finally came up was really unprecedented concentrations of mercury in this wolf’s liver and kidneys and other tissues.”

The study compared wolves from Pleasant Island, located in the Alaska Panhandle region, west of Juneau, with those from the mainland adjacent to the island, as well as wolves from interior Alaska. The results showed that the highest concentrations of mercury were found in the wolves from Pleasant Island.

“It’s an organic form of mercury that really moves quite efficiently through the food web, and so it can reach high concentrations in predators that are tapped into aquatic food webs,” said Dr. Barst. “So, we see higher concentrations in wolves that are tapped into a marine system.”

The researchers also found that there could be a number of factors driving the higher concentrations of mercury, but they are still researching several possibilities.

Mercury has been shown to have negative impacts on wolf health, and the study’s findings raise concerns about the potential link between climate change and mercury levels in coastal Alaska wolves. With glaciers retreating at rapid rates, there is a potential for increased release of mercury from bedrock, which could lead to higher concentrations in predators.

The research highlights the need for further investigation into the impact of mercury on wolf health and the potential link to climate change.

Hawaii’s coral reefs are struggling to survive due to a perfect storm of environmental pressures. As global warming continues to heat up ocean waters, combined with high levels of pollution and rising sea levels, the already fragile ecosystem is on the brink of collapse.

A new study has highlighted the devastating impact of exploding sea-urchin populations on these delicate coral reefs. The research, conducted in Hōnaunau Bay, Hawaii, used a combination of on-site field work and airborne imagery to track the health of the reef.

The main culprit behind the surge in sea-urchin numbers is overfishing, according to Kelly van Woesik, Ph.D. student at North Carolina State University’s Center for Geospatial Analytics and lead author of the study. “Fishing in these areas has greatly reduced the number of fishes that feed on these urchins, and so urchin populations have grown significantly,” she explained.

The result is a catastrophic impact on the reef itself. With sea-urchin populations reaching as high as 51 per square meter – one of the highest densities anywhere in the world – the coral is struggling to keep up with the pace of erosion. This is compounded by water pollution and overheated waters, making it an extremely poor environment for coral reproduction and growth.

To put this into perspective, prior research has shown that a healthy reef would produce around 15 kilograms of calcium carbonate per square meter over a year. However, in Hōnaunau Bay today, the average net carbonate production is a mere 0.5 kg per square meter – indicating that the reef is growing at an incredibly slow rate.

Van Woesik’s research revealed that to break even with the pace of urchin erosion, the reef would need to maintain an average coral cover of around 26%. However, areas in shallow depths with more erosion would still require nearly 40% cover to simply stay afloat. Currently, the average coral cover across all depths is 28%.

The importance of these coral reefs cannot be overstated. They provide vital coastal protection against erosion from waves, absorbing up to 97% of incoming wave energy. Additionally, they are essential to the economies of the surrounding islands, which rely on the reefs and the fishes that inhabit them.

Van Woesik emphasized the need for more robust fisheries management in the area to bolster the populations of carnivorous fishes that eat sea urchins. “The reefs cannot keep up with erosion without the help of those natural predators, and these reefs are essential to protecting the islands they surround,” she said. “Without action taken now, we risk allowing these reefs to erode past the point of no return.”