When you hear about Greenpeace taking action against shady fishing vessels, you may not think that fishing in Taiwan really impacts you. Well, it’s not true. Our planet is covered in ocean- 70% of the Earth is covered in water. That’s one big ocean with different names- the fish and other marine life within them don’t carry passports, don’t know about borders and fisheries regulations. And global demand for fish like tuna means that fishing fleets are travelling farther, catching more and more and forever changing the makeup of the oceans. Our lack of knowledge of what lies behind our tuna sandwiches is only helping to wipe out fish populations, putting people out of work and taking food from the mouths of coastal peoples.

Earlier today, Greenpeace confronted a dodgy fish carrier ship that helps transfer tuna at sea, helping overfishing continue and preventing well-meaning officials from keeping track of who is taking fish from the oceans and where they end up. What we know about this vessel? Well, it was docked in Taiwan, registered in Vanuatu, previously flagged to Panama, arrested in Japan and provides tuna to operations that send canned tuna to the United States. This global chain of custody is not rare: chances are that your tuna sandwich has crossed more time zones than most airplanes. More than half the world’s tuna is caught in the Pacific and that’s where the change is needed most and where Greenpeace is campaigning right now.

Because tuna travels far means that we need people to take action and make the right choices every step of the way. The only way that we can leave behind living oceans for our kids and their kids is if we do the right thing ourselves and demand that everyone else do the same. If you eat tuna, make sure that it’s caught responsibly and from a fair fishery. Buy tuna that isn’t caught by operations that engage in overfishing, transported on shady vessels with human rights records. Tell your supermarket, tell your favorite tuna brand that you want sustainable fish. Tell your elected leaders to support sensible oceans conservation. After all, our oceans provide millions of people with jobs and every single one of us with the oxygen we breathe. We simply can’t live without them- and your tuna purchasing decision can have a direct impact on our oceans and our future. If you sell tuna, make sure you’re selling tuna that won’t destroy island communities and leave our oceans empty. Make the switch to better tuna: caught using methods like pole-and-line, which can help maintain jobs and balance in the world’s waters.

Greenpeace is working to defend our oceans every step of the way. We’re working with nations to develop robust and sound sustainable tuna fishing industries. We are educating consumers about the plight of the oceans and urging them to buy the right tuna for the planet. We’re demanding that tuna brands do the right thing and stop canning ocean destruction. We’re getting supermarkets behind our vision of a future with plentiful tuna and healthy oceans. We’re pushing the people meant to “manage” our fisheries to manage our oceans for all of us, not just the narrow tuna interests. And, we’re working with governments to create a global network of marine reserves. All of these are important parts of our campaign to save the oceans and our vision for a green and peaceful future.

This peaceful protest in Taiwan is a huge step for us - Greenpeace is a relative newcomer to Taiwan, home to one of the world’s largest tuna fleets. Our brave activists took a risk to call attention to the role one ship plays in a huge problem that impacts us all. Just a few weeks ago, our UK office ramped up the pressure on tuna giant Princes. Taipei and London are far from each other, but very much connected in the tuna trade. Change needs to happen in both places – and many other in between – to keep our oceans alive. So, think twice about what your tuna decisions and start getting active and join us in defending our oceans. After all, nothing tastes as good as a healthy future will feel to those who come after us.

Steve works in the communications department at Greenpeace International's Amsterdam headquarters. He is a Scorpio.

Top image: A schoolgirl from Pohnpei, Micronesia - displays tin's of Skipjack Tuna in front of the 'Commission Headquarters For The Conservation And Management In The Western And Central Pacific Of Highly Migratory Fish Stocks'. © Greenpeace / Alex Hofford