Tsunamis make you think.

Came back from the mainland yesterday afternoon. Our outboard is broken, so we have to use one of USCs boats. No problem. It’s 5 in the afternoon, time to psyche myself up for our evening dive. It takes me 45 min to get my gear on. It takes John and Dan only 15.

But tonight we don’t even start that. I get a phone call from the dive officer, Gerry Smith. There is a TSUNAMI warning for Catalina Island! We all remember the Indonesian tsunami in 2004. But this warning was for Catalina Island. And that’s where we are! Of course the predictions were for tiny 1-2 foot waves, but even a 2 foot rise in sea level over 15 min can create a nasty current. 

So we ditched our dive and started playing with our data. We weren’t sure what to do with it. We threw out our early dives, in which we used bright lights and glow sticks that clearly inhibited initial pounce behavior. Then we just placed the dives on our Google map of the different zones. Each red dot represents a clean night dive presenting sea hares to lobsters. The white zone is preserve, the red zone non-preserve (this is just a rough draft). 

Then we measured the distance of the dive from the nearest boundary (negative distance for outside, positive distance for inside the preserves), and plotted the proportion attacking as a function of that distance. This created the scattergram you see here. 

What’s cool about this graph is that it shows that location matters.  If you are clearly outside the preserve you see NO attacks.  If you are way inside the preserve you see 30-35% of presentations eliciting attacks.  If you are a little way inside the preserve you see just a few attacks.

So we three sat around the lab and talked about what might be going on.  We wondered why don’t all reserve lobsters attack?  Perhaps it is because only 30-35% are residents.  The rest are transients from outside the preserve.  They are not yet hungry enough to eat  sea hares.  Give them two months and they might.  But more likely they will wander on out of the preserve.

 Next we wondered why don’t we see attacking lobsters outside the preserve.  We surmised that hungry lobsters might be wandering out of the preserve, but they will soon find food and immediately give up their sea-hare-eating ways.

 All speculation, but it did lead us to wonder what will happen

a.)       when the lobster season starts on Friday night?  (We think we will get a huge influx of non-attackers)

b.)       two months from now when there is very little immigration from outside the preserve (divers have either taken the lobsters or driven them out), and all the arrivals from October start getting hungry (We predict that in December a much higher proportion of remaining lobsters will attack).

All this BSing is EXACTLY what scientists are supposed to do.  Without it, our measurements get us nowhere. 

We also realized that we only have 2 reliable points from outside the preserve.  Aargh, we’ve got to get a few more before the lobster hunters ruin things.  I’m going with a CSU Fullerton student tomorrow night.  Then Friday before the midnight opening, Dan and John and I and three new volunteers will dive two or three more times on non-preserve lobsters.  That should do it.  

Whew.