My niece always talks about becoming a marine biologist when she grows up. I think it' really cool that a kid would want to do something good for animals and the environment instead of trying to be a teen pop idol like so many girls seem obsessed with doing these days.
Marine ecology affects everybody in the world, whether we'll admit to it or not. If the ocean gets polluted enough, not only will seafood end up filled with dangerous toxins, but the ocean could also get so imbalanced that whole species of plant and animal marine life could die off.
If that happens, not only will we be contributing to extinctions and losing biodiversity, but seafood may become something for the history books.
Last but not least, even if you live inland, if the ocean ecology gets out of whack than you'll feel it. The ocean is the biggest body of water on the planet, and it soaks into every continent -- it won't be long before pollution starts seeping into our soil and our crops on land.
Anyway, I think it's a great thing to encourage our kids to get into a job with substance, like marine ecology or marine biology, instead of a shallow materialistic lifestyle aiming to be the next pop star.