I like the overall direction of the paper, but there are some things you need to change.
I come from a world where memories are simply just memories until I take the time to reminisce and make them once again the reality that laid the foundation of who I am today.
Your first sentence does need to be worded differently. It did make sense to me once i read it over, but take into account that the people reading these letters are going to have the time to read things over. It's good little intro, it just needs to be fashioned into something a little bit more easy to comprehend.
Also, you need to add to the ending of your essay. Talk about how the ocean has inspired you to protect what can't speak, or how you want to become a marine biologist and help save marine life from extinction. This is something you NEED to add, because without it you are definitely lacking an answer to the question.
Other than that there are a couple things that you will catch that need fixing once you proofread thoroughly EX:
As I flipped through one photograph after another, I begin to retain information about the memories that lay before me.
When you write " I begin" it just sounds a little odd.
Another technique you should try at the end of your essay once you add your dreams and aspirations part is trying to tie everything back to the beginning. Meaning you should somehow mention the photographs in the end, this is something I've seen many good essays do.
Good Luck