Trying again.

Last night, John and I dove on the cage that Dan and I had deployed the day before.  Fear and loathing in my heart.  I noticed the gaps in the cage doors the day before, and figured those busy-body sea hares would just march right through them.  When John arrived from the mainland, I bitched and moaned about the gaps as we started making the second cage.  Different people around the Marine Lab had different suggestions.  A student in the CSU zoology class out here suggested we just make it so the meshes overlap when the door is closed.  The doors don’t really close like that.  They are on loose zip-tie hinges, not solid ones.  I got the idea of sewing a drawstring to the hatch and having a little Santa bag entrance to the cage to put rocks and lobsters in and out.  The driver for the supply boat said cut some hose lengthwise and put them on the PVC to make a tighter fit.

We tried the last idea.  It worked great in our as yet undeployed cage 2.  Now, there are no gaps bigger than a finger.  So we decided to take the idea down to the already deployed cage. 

So how do you plan a dive, when you have no idea what will greet you when you drop down there? 

Will the cage be ripped to shreds like the last time?  If so, let’s pull it up and bring it back to dry land and get drunk. 

What if it only has one hole?  Ok, we mend it underwater. 

What if all 5 sea hares escape? We put on the hoses and come back to the dock and get more sea hares.

What if 2 sea hares escape?  We put on the hoses and go find an attacking lobster.

What if zero sea hares escape?  We put on the hoses and go find an attacking lobster.

What if we can’t get the hoses on underwater?  We take off the doors and ascend to the whaler and work on them there.  Then go find an attacking lobster.

We take the whaler over to Siwash, jump in the water with our gear on, and descend down to the cage.

Guess what?  All 5 sea hares are there.  3 of them were on the walls of the cage, 2 of them on the rocks, feeding on the algae. 

Hurray!

John and I flash reciprocal “OK” signs (understatement) and get busy.  Wrassle stubborn half-split hose onto the four sides of the PVC.  Wrassle little zip ties through the fine Pet Screen mesh to secure the hose to the PVC.  John and I each working on one gate, furiously.  Knowing if we delay too much, we won’t have enough air to find an attacking lobster.  Within 20 min the job is done.  Check on the sea hares again, and now, let’s go find an attacker!

Why is it that when you really need a taxi quick, they are never around?  Lots of little guys running around, but none of the tanks we’ve regularly seen.  We try a few.  Some half-hearted pounces, but none of the committed attacks we have grown so familiar with.  We start by heading out toward the point, but then I change my mind.  I’m thinking we have to get back into the core of the preserve.  We don’t know, maybe people are poaching out here, even.  So, I turn and head back.  We go for a long time seeing very few lobsters.  Getting nervous.  When you aren’t in the middle of doing something, but just swimming, you start to think about monsters.  Goddamnit, where are the lobsters??

Then I see a tank.  Finally.  Wiggle my light at John.  He comes over, red light on the lobster.  I take a sea hare out of my game bag and offer it up to the lobster.  Full-blown attack.  Ink flying everywhere.  Lobster marching with his prey to another den.  Signal John to “get him”.  John has really learned how to catch a lobster with high probability out in the open.  The key is to avoid the antennae.  If the bug has his antennae laid back, you just have to wait.  This one was trucking along with his inking sea hare under his mouth.   Finally he slows down.  John moves in.  Lots of kelp in the way.  Not a great shot.  He lunges, pins the puppy to the bottom.  5 million bubbles come up from my sigh of relief. 

He has the lobster clutched to his chest.  It is MY job to now figure out where the cage is.  I’ve gotten better at keeping track of my location.  And there are a couple of landmarks at this spot.  So there it is right there.  We swim over.  John carefully pulls the lobsters legs off his chest without breaking them.  Puts the bug into the cage.  Then he fastens the hatch, we signal ok, then thumbs up means we head to the surface.

I don’t think I’ve ever felt so good after a dive.  We congratulate each other, put our gear away, eat a big omelet, and go to bed.  

If at first you don't succeed...

So, my hypothesis is that first, the lobster ate one of the sea hares enclosed with him in the cage. 

Then, the monster from Iron Bound Bay wreaked havoc on the cage, and ate the other sea hares with one gulp.  Let’s see 19 Oct.  That’s one day past the new moon.  A fully moonless night.  Plenty of time for the monster to make his way up from Iron Bound Bay, to flit along the ridge down to the isthmus, and over to Big Fisherman’s Cove.  I think he has a lover in the blow-hole on the point at Fishermans.  Then, the two of them ransacked the bay, ripping up lobster dens, pulling out kelp plants.  Trashing cages. 

So, I spent ALL DAY on the mainland trying to find chain mail to wrap our cage with.  My wife and I found some mobile screen-making outfits in LA, but I needed to go to Orange and give letters of recommendation to the PreMed advisor there.  Calling and driving, leaving messages, getting half-yesses.  Nobody seems to have 25 feet by 60 inches of chain mail.  I ask our department assistant, Cheryl, to find me some chain mail while I write these letters.  She gets on the internet and calls all the Home Depots and Pet Smarts around Orange, and all they have are small pieces.  48”.  That won’t do.  So I’m now in the office googling “screen and windows Orange” getting nowhere, when Brad, the other assistant shows me an advertisement from his “Yellow Pages”

Whazzat?  Yellow Pages is how people used to find things like monster-proof netting for lobster cages, before the internet.  There it was.  Mobile Screen and Windows.  I called.  Talked to Chris.  He checked.  He had it.  25 feet of 60” reinforced “pet-proof” screen.  I screemed yay! And took off in a flurry.  Found the place in the bowels of Orange County freeways, and got the fucking chain mail. 

Back out to Catailina.   Dan and I put in the chain-mail on the frame day before yesterday afternoon, and redeployed the cage with sea hares, one more time, last night. 

Now we have a waxing moon.  Hopefully Mr. Monster, Sir, stays on the south side of the island.

This film is of us deploying the improved cage.  I think you can see the cage eater, if you look very closely.  Note the daring absence of wet suits (a short dive on a sunny day).

The monster from Iron Bound Bay

My dad was a scary man.  He could scare the daylights out of you.  As kids, one of the highlights of coming over to Howland’s Cove on Catalina for the weekend was after dinner.  My two brothers and I would beg and beg, and finally the old man would relent, and tell us a scary story.  Actually my big brother Howard really wanted to hear the scary stories, but Ricky and I were not so sure we wanted one, but we went along with Howard anyway.  I don’t know if Dad was tapping oral traditions, or just making shit up.  He once told us about a star-crossed couple, just married, who were found embraced, dead as door nails on the point at Lion’s Head (this same point marks the boundary between the Invertebrate No Take zone to the west and the recreational lobster fishery on the Isthmus side; see earlier maps).  The lovers were both buried there on Lion’s Head, side-by-side by their next of kin, as a warning to other lovers to “watch out”.

Watch out for what, Daddy?

The monster from Iron Bound Bay. 

What’s that, Daddy?

It is a large, dark, wet, slimey creature that emerges on moonless nights from the murky waters of Iron Bound Bay. 

Where is Iron Bound Bay, Daddy?

Just the other side of that big ole hill right there.

The thing is, Dad’s story checks out. There IS (or at least was) a pair of tombstones on Lion’s Head.   Also, I have often perused charts of Catalina.  There actually IS an Iron Bound Bay.  And it is on the opposite side of Catalina Island from Howland’s.  Just like my Daddy said.

A few years back, my wife and I nosed the Siwash in to Iron Bound Bay on a wonderful round-Catalina week.  There are blow-holes everywhere in Iron Bound Bay.  A blow hole is a concavity that traps air.  When a big wave comes in, the air is compressed and finds an outlet somewhere and blows.  There are lots of variant blow-holes (you’re probably thinking I’m one of those variants, called a blow-hard), but they ALL make deep, scary noises.  There we are on a sunny day with a pretty big south swell running, and there is this symphony of deep rumbles, and gurgles, and hisses.  We’re talking surround sound.  The cliffs go up so steep, you hurt your back trying see the top of them.  Just for the hell of it, we turned off the engine to listen more carefully. 

SPOOOKEY.  Really spooky.  Deep deep sounds, pitched so low you almost feel them, not hear them.  No real rhythm to the sounds.  It doesn’t sound like periodic stuff, like what waves make.  It sounds more like….  Turn the engine back on, Bill, quick.

I do, we leave, and that’s that.

What does the monster do, Daddy? 

He smothers his victims in kelp and slime, and then bites off their fingers and breaks their necks.

Oh, jeez.  Are we ok over here at Howlands?

Well let’s see, is there a moon tonight? 

Yes.

Then we’re ok.  It’s only on moonless nights that the monster comes over the hill.

Three nights ago, Dan and John redeployed our lobster enclosure cage.  John and I had worked like dogs to get the new mesh on.  This cage story is long and arduous.  Dan brought out some insect screen used for regular windows.  Really?  Ok, fine, let’s try it.  But Dan miscalculated.  There wasn’t enough to even cover one of the cage frames.  Now what’ll we do?  Long story, we “borrowed” mesh from a Cal State biologist named Mark Steele.  I promised to replace it.  Looked pretty good, about 1/8” mesh.  John and I set about putting it on the PVC enclosure frame.  Smoked twine round and round, the sun goes up and over and down, and we’re winding and tying, tying and winding.  Finally we get the fucking thing finished. 

John and I deploy the cage.  First night is control night, no lobsters; we want to prove that enclosed sea hares can’t escape.  John and I get our SCUBA gear on and put the cage on the whaler, sink the enclosure at the right spot, pile up a nice rock bottom, put out 5 sea hares, close up the hatches, and go back and make dinner.  I go back to the mainland the next day.  The first night off island I get a call from John. Something happened. 

What?

There’s a hole in the cage. 

Really?  What made it?

I don’t know.

Ok, 2 of the 5 sea hares escaped.  So Dan and John repaired the hole, put the remaining three sea hares back inside the cage.  Caught a big attacking lobster.  Forced the lobster into the cage, closed the hatch and went back and ate dinner.

Next night I get another call. 

Bill, things are really getting out of hand out here.  What do you mean?  Well, when we dove on the cage tonight, the netting was all ripped up.  Did all the sea hares escape?  Well sort of.  What about the lobster?  It was still there.  Are you sure it was the same lobster?  Positive.   

But there’s something else.  

What?

We found the intestines and buccal mass of a sea hare on the bottom of the cage.

Holy shit.

Looks like we’re going to need a bigger boat.

The “bliss” of research diving.

The other night we set out to test one of those alternative hypotheses.  Klaus from Sweden wanted us to do this.  So we did (this guy is an awesome scientist.  Ignore his ideas at your own peril.  Actually, layperson, Jeff, had the same idea, and that brings up another point about alternative hypotheses.  If more than one person brings them up, you’d best listen. 

Anyway, these guys asked whether the same lobsters that refuse to eat sea hares are still interested in eating something tastier.  If they are just being subordinate, or spooked, maybe they won’t eat anything.  Let’s offer them a juicy shrimp after they say pass on the sea hare.

Although the dive was still in the black of night, it was nevertheless a very pleasant thing.  We went off the lab dock.  No getting the boat ready, with running lights, radio, float plan for Gerry, anchor problems, etc.  Just drag our gear down to the dock and jump in.  The three of us are only out here on the same day once per week.  We took advantage of this to do an operation that really is best done with three divers.

Dan carried the camera and red light.  John carried the bag of sea hares.  I carried the juicy shrimps in a water-tight bag (I guess I’ve got the least number of years to live if the shrimp-eating great white should appear).  Thus, John presented sea hares, I presented shrimps, Dan filmed the mayhem.

Down we go.  John spies a bug, moves down to the bottom, and presents a sea hare.  Lobster attacks, John floats up, Dan moves down for a close-up.  After 10 sec, Dan moves up, and I move down with the shrimp.  This operation is orchestrated without words, in three dimensions, completely improvised.  Spontaneous movement in three dimensions.  We were deep enough (30 feet), where you can control your buoyancy by breathing.  Take a somewhat deep breath, and you slowly rise off the bottom.  Take shallow breaths and you sink down.  The cool thing is, this is not just showing off.  John noticed a few weeks ago, and I’ve now seen it too, that lobsters often spy the bioluminescence when you kick your fins or make any other movements, and shy away.  So don’t kick down to get into place, let out a long breath, and empty your lungs instead.  This is tricky.  You can’t hold your breath (this risks getting an air embolism and a consequent underwater stroke), but instead only inflate your lungs a little bit, then let it way out.  Yoginis can do this easy, I guarantee you.  But it’s a bit tricky for the rest of us.   Anyway, presentation 1: lobster eats sea hare, lobster eats shrimp.  Not test there, but still nice to know.

Second presentation, lobster didn’t pounce, but then John scared it trying to “make sure”.  He pushed the sea hare onto the unwilling lobster a little too aggressively.  It tail-flipped out of the picture.  

Third presentation, no pounce.  Perfect presentation.  John backs out, I breathe out, and descend from above.  The only light is the red one Dan is using to film the action.  I watch the lobster’s antennae; they aren’t allowed to touch me (or the gig is up).  Drop my shrimp in front of it.  Lobster pounces, starts to eat.  All the lights go on.  We need to document the white shrimp in the red lobster’s mouth.  He eats it right up, oblivious to the light.  This is the same oblivion we see after lobsters start to attack and eat sea hares.

Needless to say, this was all pretty cool.  Lobster says no to sea hare, yes to shrimp.  After the first couple of presentations, I was so excited I somehow LET GO of my bag of shrimps.  Damn, where did it go?  Swimming around looking for it.  Dan and John start to figure out what I’m doing.  Not sure if the bag sank or rose, but it is gone.  I give the thumbs up signal, which means go up, not ‘isn’t life fine’?  We float on the surface while I swear and apologize, apologize and swear.  Why didn’t I bring two bags in case this might happen?  Now what do we do?  Allright, goddamnit, let’s swim back to the dock.  Fifteen minutes back to the dock.  The boys laze there, while I walk the half-mile uphill in my wet suit (I imagine what it must be like to be a navy seal or Sean Connery) to the apartment and bring back another zip-lock bag of shrimp.  Of course, I’m so flustered, that I just remember to bring one bag back. 

This scant hour delay seems to take many hours.  I’m really pissed at myself, and wondering if my incipient Alzheimer’s has really started to set in.  Ok, get our gear back on, and down we go. 

Start our three-dimensional dance. 

I’m really back to enjoying it again.  Being underwater with your trusty research mates.  Spy a beast, wiggle your light at your mates, over they come, all lights off, red light coming on means Dan is filming, starting the dance.  We present shrimps to several more sea-hare-spurning lobsters.  All of them eat the shrimp.  I’m pretty excited.  I’ve got the next shrimp in one hand, the bag of remaining shrimp in the other.  John presents the sea hare, no response, then he gets out of the way.  As I move in I notice that he left his sea hare behind.  I pick it up as I go to present the shrimp.  Lobster eats the shrimp.  Yay!  Another one.

But wait.  I’ve got the Aplysia in the same hand I used to carry the bag of shrimp, but now no bag of shrimp. 

Again!  Oh, no!!

Then I turn. John hands me the bag.  He had watched me drop it.  We both snort a laugh underwater.  

Come up in time to make dinner and get to bed by 1AM.

AbstractDeadline

Below is the view while I write this blog.  Not bad, eh?  Siwash is farthest to the left over in the calmest corner (you might want to click on the photo to see the big version).  Our enclosure cage is (finally, more later) just about in line with the mast on the other side of Siwash in 20 ft of water.

Here is the final “Abstract”, as written for the Western Society for Naturalists.  We finished the writing of it at 4:59 PM a couple of days ago, a little less than a minute before the deadline. 

But that is the custom among busy scientists.  When I was a postdoctoral fellow in Tom Carew’s lab at Yale, the grad students and post-docs ponied up a milk shake for the person who waited the very longest to collect a data point used in the abstract.  This used to drive Tom utterly crazy.  Sometimes, the results weren’t certain until a day before.  I think the record (attained by a crazy French Canadian grad student, who is now a very successful scientist) was a data point that got included in a statistic an hour before the deadline. 

So, this year, we had much more time for our Abstract.  Our data were collected at least a few days before the deadline.  All we had to do was just write the sucker.  Of course, I also talked John into presenting an additional poster with his very sexy limpet data from last summer, so he and I had to wrangle two abstracts.  But we did it just fine. 

The key thing with abstracts is brevity, and conciseness.  Perhaps I should rewrite that sentence.  Abstracts need to be concise.  That’s all.  No need to add brevity, for that’s part of the word concise.  Make sentences square.  Active verbs.  Say I and we all you want, especially if it makes your sentence more concise.

I hesitate to put our abstract out there in front of all of you.  I know there are many among you who could have written it clearer, sexier, and more concisely.  But I am discovering the value of humility, and shared discovery in the scientific process.  Every day I discover this.   Rediscover it.

Here’s the abstract.

Lobsters exhibit unprecedented attack behavior on sea hares inside marine life protected areas.

A growing body of evidence suggests that marine protected areas can significantly change the density of fished species. Such direct effects can be of paramount importance to community structure.  However indirect effects of management decisions can be equally profound.  The present field study examined the indirect effect of a preserve on the dietary breadth of the California spiny lobster, Panulirus interruptus, on Catalina Island, CA.  We monitored this keystone predator’s attack behavior inside two separate preserves, and compared it to behavior in neighboring non-protected areas.  In particular, we used SCUBA to present the relatively unpalatable sea hare, Aplysia californica to foraging lobsters in the field.  No observations of natural attacks by lobsters on Aplysia have been reported prior to this study, and our presentations outside the reserve confirmed this lack of attacking behavior  (no attacks, 7 dives, 89 presentations).  However, within the two preserves, lobsters attacked sea hares an average of 24.8% of the time (sem = 3.4, Number of Dives = 14; 287 presentations total).  In the most vigilantly protected part of the preserves, this attack frequency increased to 34.5% (sem = 2.0; Number of Dives = 7; 93 presentations).  We conclude that marine preserves cause lobsters to broaden their diet, thereby consuming less-preferred species.  We hypothesize that this effect is mediated through intraspecific competition:  The lack of human fishing on lobsters in the preserve results in greater biomass density (size and numbers) of lobsters, thereby reducing available food.  The fact that lobsters in the preserves attack and eat Aplysia may have important implications for other non-preferred food items (e.g., urchins) with stronger functional connections to the ecosystem.

Cookie-lobster LIKE sea hare

How can a sabbatical be so damn busy?

Right?

I am supposed to have TIME.  I’m supposed to contemplate natural truths.  I’m supposed to get wise. 

I should have known.  Abstract deadline.  Might be a garage band title.  Those two words strike horror into the hearts of many a scientist.  Not me.  Ha ha.  I’m tenured.  I’m on sabbatical.  I don’t need no stinking poster.

But here we are.  Sitting on this cool, brand-new, lobster-attack data set.  

The Western Society of Naturalists meeting is in Monterey this year, the COOLest setting possible for a marine biology meeting.  They have an “attitude adjustment hour” where the drinks are at a table next to a 40-foot deep glass aquarium!  A kelp forest.  Full of fish.  And lobsters!  Lots of people there from my marine biology past (very few or none from my neurobiology past.  That conference is happening right now, and I’m missing it).

Hmm… maybe we SHOULD write an abstract.  Twould be fun to see all those crazies again.  They will love this lobster story.  Plus John did a project on limpets last summer that sings.  He’s been to WSN before, so he knows the ropes.  He can wrangle two posters in one meeting, right?

Ok.  Let’s do it.  Lets summarize our results in 250 words. 

Actually writing the results into the abstract is easy.  The hard part is committing to what the data mean.  Dan asks me, “Can we just narrate how we got here?  A chronological abstract?” 

Nope.  Can’t do that.  Busy scientists don’t want to hear how you got here.  They want to hear about your results, and what you think they mean.

So what DO our results mean, Dr. Wright? 

I say something defensive, like “Fuck if I know.” 

But then we talk.  I’ve learned that I can’t very well just go “poof, this is what it means.”  I have to talk about it.  With students, with fellow scientists, with my dive officer, with my wife, with my mom, with whomever wants to talk about it. 

With you all!  An amazing conversation we had. Your “alternative hypotheses” keep dribbling in.  I’ll get to them in a later blog. 

But my point is, most data have multiple ways of viewing them.  In my case, our original view was, oh, we need a natural traumatic stimulus that might cause sensitization in sea hares.  What might that be?  Oh, how bout predators?  Ok.  What might eat sea hares?  Oh, how bout lobsters?  Ok.  But we have to starve them 6 weeks in the lab before they attack.   Oh, well, maybe lobsters on a preserve are hungry enough to attack, cause there are so damn many of them? Ok. Look, lobsters on the preserve DO attack and eat sea hares.  Cool!  Let’s publish.  Ok, but first, what does it all mean, Mr. Natural?  It DOES mean shit!  But what shit does it mean?

So, do we talk about sensitization?  Hmm… our audience is not neurobiologists.  They are mainly marine ecologists.  Nah, sensitization isn’t going to work.  The chronological abstract never works.

But really, for an ecologist, this is a totally cool finding.  Lobsters have a pervasive influence on near-shore communities (A “community” is the assemblage of marine species in the area of interest.  Actually, they also have a strong influence on the human community here on Catalina.  But that is a different story).

So, because lobsters can really change communities, they have been called “keystone predators.”  If they are there, the community is one way.  If they are not, it’s another.  When Carlos Robles built exclusion cages out here twenty years ago, he excluded lobsters.  This resulted in a homogenous blanket of mussels.  Take away the cage, and the lobsters eat all the mussels in a few weeks, and you get a lush carpet of lots of different algae and small invertebrates.  Regardless of which community you think is “better”, there is no doubt lobsters are the key; the keystone.

 So what WE’VE found is that lobsters’ eating habits change, depending on whether or not they are being fished. 

 Lots of fisherman comment that, no matter how much you fish, lobsters are still around.  This is true.  Take a dive off Palos Verdes peninsula, and you can see lobsters. 

 “See, there they are, right there.  Doing their keystone thing.  So take your Marine Life Protected Areas and stuff them in a closet on some other planet.  These lobsters are still here, so don’t tell us they aren’t.”

They aren’t.

That’s what our new results are telling us. The lobsters in Palos Verdes are a completely different beast than those at Big Fisherman’s Cove, and very likely they are a completely different beast than what lived at PV before modern humans got so efficient at catching them.    

 Nowadays the lobster that lives at PV is a connoisseur.  He only eats the most delectable items.  A fat mussel here, a limpet there.  Don’t bother him with eating sea hares.  They give him indigestion.  Don’t offer up urchins; too many nasty, pointy spines.  But he doesn’t get that easy life-style for nothing.  His life-expectancy is very short.  The modern lobster will be on some human’s plate a year or two after he reaches legal length.  That’s why the lobster had so much food.  His parents and grandparents and great-great grandparents have all been eaten, so he doesn’t have to compete with them.

 But at Big Fisherman’s Cove, we have a different species.  These lobsters cruise around in broad daylight turning over every shell and algae clump for something to eat.  A sea hare, mmm…. Cookie lobsters like sea hare.  A baby sea urchin?  Mmmm…. spines no matter, cookie lobster like spines.  These are bold, big lobsters. Maybe 3-5 pounds.  Underwater tanks turning over the bottom.  Probing, smelling, searching, pouncing, attacking anything that they can get their legs on.  Totally different from PV lobsters. 

 Guess what? The lobsters that cruised the bottom, before humans started fishing them, were 20 lbs and more.  Huge monsters.  Lots of them.  Hungry monsters.  Eat other lobsters.  Eat everything.  Now we’re talking keystone.  These guys were REAL keystones.  You can’t have an “urchin barren” with these mothers wandering the benthos.  Drop them on an urchin barren, and they call it breakfast. 

 So, that is the perspective we are choosing for this year’s Western Society of Naturalists meeting.  And this generalizes to any keystone predator system.  Keystones are not stones, they are flexible, plastic entities that CAN be keystones, but you have to know about their behavior.  In particular, do they broaden their diet when they reach high densities and eat all the delectables to oblivion?

Next post, I’ll give you the 250 word version.

Jeez, I guess I do have a little time after all.

John on the 1" mesh

We’ve been building some enclosure cages to try to experimentally test some alternative hypotheses in the field.  Most importantly, maybe lobsters don’t really eat sea hares in nature, even in preserves.  Maybe our experiments simply show that they eat sea hares dropping out of the water column.  This is Rob’s alternative hypothesis.  It is part of a larger question:  Just how devastating ARE lobsters on the ecology of sea hares?  We rarely see sea hares bigger than a cm or so out at Catalina, and have never seen them yet in the preserve.  Is it possible that this rarity is driven by lobsters?  So we (actually, John and Dan) built a couple of cages in which we intend to enclose lobsters with sea hares.  We predict that when we put some sea hares in the cage for a day or so and then put in one or two lobsters that attacked the field-proffered sea hares, the lobsters will readily eat one or more sea hares in a very short time (a couple of days).

Cool idea, eh?  If they consume the sea hares, it strengthens our case.  If they don’t, the idea that we are studying an artifact is strengthened.  Remember, anytime you feel scared for your hypothesis you are doing the right research.

If the lobsters do end up eating all the sea hares in the enclosure, we would say, ok, then we’d put in lobsters that don’t attack in the field.  The effect of these wimpy lobsters on the sea hares should be weaker or delayed.  Let’s do it!

Three days ago we tested the cage.  We had tightly wrapped it on all sides with netting of 1-inch mesh.  It looked good.  I used some lashing tricks I learned from my Dad on Siwash to keep the netting tight on the frame.  Dan and I sank the puppy right next to Siwash (close to ample supplies of attacking lobsters), and covered its floor with rocks.  A fun underwater job, one of the few that we could do in the daylight.  We put three sea hares in to make sure they didn’t go anywhere in the absence of lobsters.  A trivial “pre-test”.  The next day, John and I dropped down on the cage to find out whether the sea hares were standing on their tails waving for food, or hunkered down inbetween the rocks.

What we found was NO sea hares.  Gone.  All three of them.  Damn. What the hell?  Where are they?  We took out every single rock and still no trace of a sea hare.  Could they have slithered out of 1-inch mesh?  The answer if YES.  RATS!  All that work, to build and wrap the cage. Arggh.  Why the hell didn’t we try to enclose them at home before we came?  Now we’ve got to pull out the cage and wrap it with a MUCH finer mesh. 

This is all way depressing.  Experiments deepen your science.  We want some results.  Failing to do an experiment deepens your depression.  Shit, we are missing a chance, and just cause we weren’t thinking.  We’ve only got 5 more weeks.  What if the experiment takes 6?

Dan is bringing out finer mesh today, and John and he will retie the cage, and deploy it again. Those slithery sea hares.

Yesterday, we were offering sea hares to our captured lobsters in 3 foot deep tanks up near the dive lockers.  We are finding that the lobsters that attacked in the field are much more prone to attacking sea hares in these tanks as well.  They do so within a half an hour to a couple of days (non-attackers need to be held a couple of weeks before they attack in these tanks).  That is a good finding.  It means the difference in field behavior depends on the sea hare, not its immediate context (cave nearby, big kelp bass).  In the process of doing these lab presentations we figured out we could fish out the sea hares with a hand net.  Actually the fish net had pretty fine mesh.  About 1 inch.

Once, after leaving the recovered sea-hare in the hand net for maybe ten minutes while we set up the next presentation, we noticed the sea hare with its head and half its body hanging outside the net.   Hmm… I guess 1 inch mesh isn’t even close!