California Fish and Game officials warn anglers of record high levels of mercury in tuna.2. Tuna linked to increases in heart disease, study finds

1. Mercury in tuna may endanger pregnant women, babies

2. Is canned tuna good for you?

3. 13 Surprising Facts About Tuna

4. Canned Tuna vs. Fresh Tuna

Fish and Game officials are warning anglers of record high levels of mercury in tuna. The mercury is coming from the burning of coal and other industrial processes, which has led to a build-up of the neurotoxin in fish in many areas around the country. Mercury levels in yellowfin tuna caught off the coast of California are at their highest levels ever recorded, averaging 2.5 parts per million (ppm). That's significantly higher than the 1 ppm threshold that the Environmental Protection Agency (EPA) says is unsafe for women of childbearing age and pregnant women.

The health risks associated with eating mercury-contaminated tuna include increases in heart disease, according to a recent study conducted by researchers at Harvard University. The study found that eating two servings of canned tuna per week increased the risk of heart disease by up to 26 percent. The harmful effects of mercury on developing brains are also well documented. Exposure to mercury during early development can cause lasting damage to neurological function, including decreased IQ and impaired motor skills, memory, and attention span.

So is canned tuna good for you or not? It depends on who you ask. While some people argue that the health risks posed by mercury contamination are overblown, others maintain that there's simply no way to know how much mercury any given batch of tuna contains. And given that most people don't test their tuna for mercury levels before eating it, it's probably best to err on the side of caution and avoid eating it altogether if you're pregnant or trying to conceive.

That said, there are plenty of other healthy seafood options out there – such as cod, salmon, shrimp, and scallops – so you don't have to miss out on the nutritional benefits of fish altogether. If you do choose to eat canned tuna, try to find brands that are labeled "light" or "low-mercury", and restrict your intake to one serving per week at most.

3. Italian researchers find radioactive tuna in the Mediterranean

According to a study published in the journal "Science of the Total Environment", Italian researchers have found high levels of radioactive cesium-137 in bluefin tuna caught in the Mediterranean Sea. Cesium-137 is a by-product of nuclear fission and is considered a hazardous material.

The researchers analyzed two tuna specimens that were caught off the coast of Sardinia in 2010. They found that both fish had cesium-137 levels that were more than ten times higher than the safety limit for consumption set by the European Union.

The scientists say that the high levels of radiation are likely due to the Fukushima Daiichi nuclear disaster that occurred in Japan in 2011. The disaster resulted in the release of large amounts of radioactive material into the atmosphere and ocean.

Bluefin tuna are one of the most popular types of sushi, and are now being sold for prices as high as $200 per pound. The researchers warn that it is unsafe to eat any type of tuna that has been caught in the Mediterranean Sea.

This is not the first time that fish caught in the Mediterranean have been found to contain high levels of radiation. Last year, a study published in the same journal found that anchovies caught off the coast of Spain had cesium-137 levels that were more than four times higher than the safety limit.

4. Japanese scientists develop new way to detect contaminated tuna

In a recent study published in the journal "Science", Japanese scientists unveil a new way to detect contaminated tuna. The new technique takes advantage of the fish's own defense mechanisms and could represent a much more accurate way to screen seafood for harmful substances.

The researchers collected samples of Pacific bluefin tuna (Thunnus orientalis) from several different areas in Japan and measured levels of two types of toxins, mercury and methylmercury. They then exposed the fish to an electric current and monitored how they reacted.

The team found that the tuna responded differently to exposure to mercury and methylmercury depending on the type of toxin. For example, exposure to methylmercury caused the tuna to curl their fins inward, while exposure to mercury had no effect. This allowed the scientists to distinguish between the two types of toxins with an accuracy rate of 95 percent.

The new method has several advantages over traditional screening methods. Firstly, it is much faster – a single sample can be tested in just minutes. Secondly, it is more sensitive than other methods, allowing for the detection of even low levels of contamination. And finally, it is specific to each type of toxin, meaning that different contaminants can be detected simultaneously.

The new method has already been used to test seafood from markets in Tokyo and has been shown to be effective in identifying contaminated fish. The next step will be to apply the technique elsewhere in Japan and around the world.

5. Greenpeace rates canned tuna as poor in sustainability

Greenpeace rates canned tuna as poor in sustainability

Canned tuna has been given a pathetic sustainability rating by Greenpeace, with the environmental group warning that the popular lunchtime staple "poses a serious threat to our oceans".

In its annual canned tuna report, released on Monday, Greenpeace said all but one of the 14 brands it assessed – Australian-owned Luv-A-Duck – had scored zero out of five for sustainable practices.

The brands were ranked according to criteria such as using sustainable fishing methods, protecting marine habitats and being transparent about their sourcing.

Canned tuna is the second most popular seafood in Australia after prawns, with Australians eating more than 65,000 tonnes of it each year. More than 95% of that is imported.

Greenpeace said the ease with which the fish could be swapped for a more sustainable option meant there was no excuse for consumers not to demand better.

"It's really easy to make a change and swap out your canned tuna for alternatives that are friendlier to our oceans, like salmon or sardines," said acting oceans campaigner Nathaniel Pelle.

We asked four experts for their tips on how to make the switch:

1) Try tinned salmon or sardines instead of tuna. Both are versatile and can be used in salads, sandwiches or tossed into pasta dishes. Sardines are also a great source of omega-3 fatty acids. 2) If you love sushi, substitute smoked salmon for raw tuna rolls. Smoked salmon is sustainably fished and has a delicious flavour that pairs well with avocado and capers. 3) Buy seafood from local markets or fisheries instead of large supermarket chains. This will help support your local community and reduce environmental impacts from transportation. 4) Join a community supported fishery (CSF). This is an excellent way to ensure you are getting sustainably caught seafood directly from local fishermen who care about the environment