The WA keyword tool gives 81 pages of results out of 479,000 results. Since I know that Google lies and adds to their results all similar terms, I need to determine is what the real results are.

81 Pages have 10 results per page so I can be pretty confident that there are actually 810 results not 479,000.

I'd like to see a search volume of greater than 100 and a competition of less than 400.

810 results is still more than I like to compete with. I'll look a bit deeper by adding the word Rare to the front. So now my search term is [Rare Blue Lobster]

This is not an ideal keyword, but it is close enough for my purposes.
All I was interested in was writing an article to break out of my funk and as a recreational exercise.

I did a bit more research and found 2 more good keywords, the last entry [rare blue lobster caught] and [Maine Lobster Harvest]. As these are not my main keywords, I can get by with less searches than 100. Maine Lobster Harvest seems to be a very good one.

I'll leave it to you to check these out.

Update: as of June 2018 the results of a Jaaxy Search are these: