Reef news

Our reefs are in trouble. Many people of the world depend on coral reefs, but they are in critical danger. Here's the latest news release.

The Blue Hole

Katheryn Patterson and I joined divers from Blackbird Caye Resort yesterday and dove the Blue Hole and a couple of sites outside of the Blue Hole. The Blue Hole is Belize's most famous dive. Actually, our island manager and boat driver, Mr. Kent (that's a common way of referring to people down here -- I'd be Mr. Jerred), was part of Jacques Cousteau's first visit to the Blue Hole. I preferred the dives that we did outside of the Blue Hole to the dive inside of it. The Blue Hole is a limestone sinkhole. One of the draws to the dive is that there are huge stalactites deep in the hole and there are a lot of sharks that hang out in the area. We did see a number of large reef sharks and huge grouper. Because of its depth, I didn't bring my camera, so I don't have any pictures, sorry. It's depth also makes the dive very short. (Biology majors and A&P students should be able to calculate about how many atmospheres of pressure is at 130 feet. Taking that information, I'm sure that they could calculate the partial pressure of Nitrogen and understand why the dive is so short.)
After the dive in the Blue Hole, we dove a site called Half Moon Caye Wall and another site called Aquarium. Here are a few pictures from those dives.

Underwater scenery from "The Aquarium"

A Hawksbill Turtle

A spotted moray eel

A Ruffled Feather Duster Worm

A neon goby on Whitestar Sheet Coral (Agaricia lamarcki)

Grooved Brain Coral (Diploria labyrinthiformis) polyps

Blue Bell Tunicates

Sponge Brittle Stars on Pink Vase Sponges

Final Croc Additions

Apparently, other folks did capture photos of one of the crocs that we caught hissing. The first image is Leslee Parr's and the second one is Kat Patterson's. These look pretty dramatic, so I thought that they'd be good to include.

Terror has a red eye

Since my last post, we surveyed a beach for crocodile nests, and found several, performed night shoreline surveys for croc eyes, caught a couple of crocs and had a lot of nice meals anchored in the boat waiting for dark. In case you haven't caught a crocodile from a boat before, I'll outline how it works.

Croc Capture Instruction (boat method):
1. Someone sits on the bow shining his spotlight on the mangroves looking for croc eye-shine. In this case, that someone was Thomas Rainwater. The eye-shine should be red. Thomas likes to say "Terror has a red eye." which helps distinguish between croc eyes and those of many other animals (e.g., wolf spiders). Thomas can't actually see the red, due to his color-blindness, but trust me, it works. When discussing your crocodile captures, you may want to employ Thomas' "Rambo Scale." Catching crocs rates higher on the Rambo scale than, say, analyzing satellite images of coral reefs or crocheting. Although we caught some nice crocs over the last few days, they didn't put up enough fight to be high on the Rambo scale. They fell somewhere in the mid-to-low range. We actually wonder if some of the crocs that we caught, which were recaptures from previous croc surveys, maybe enjoy being sexed (determining if they're male or female -- in case you were confused) a bit too much and thus didn't put up a fight. There is a bit of cloaca manipulation that has to take place to sex a croc. I digress.
2. Once you spot a croc, keep the light on its eye to "blind" it so that it can't see your approach.

3. Sneak up to it on the boat and and slip a snare over its head. After the croc is snared, it will likely start spinning. Don't worry this is normal. It may also start hissing. Again this is normal. (We got great photo opportunities when one pissed-off croc was hissing at us, but the Leslee's lens cap was in the way.) Eventually the croc will tire.
4. At this point, it can be brought over to the side of the boat.
5. Next, place a separate noose around the croc's mouth, so that it doesn't bite you. OK?
6. You can pull the croc into the boat.
7. Secure its head, hind legs and tail. Sit on it, if necessary.
8. Duct tape its mouth closed.
9. Cover its eyes. This may calm it down some.
10. Now look at how beautiful a croc is up close.


Now what are you going to do?
Collect data. Sometime during this process, collect information about the location of the croc, or eye-shine if you don't get a capture. Here's Kat and Thomas collecting location information. Take measurements of the crocodile (length, snout width, etc.) and mark it, so that if you catch it again, you can see how it has changed or if it has moved. Take a break and look at the funky crocodile features. Check this out. This croc's lower teeth go THROUGH its upper jaw! That's most of it.




















Just remember, "Terror has a red eye." I think that both Thomas Rainwater and the crocs would agree with this.

Possible Answers

Here are my answers to the questions that I posted about croc scaling. The 16 foot saltwater croc that lives in saltwater would be about 640 lbs (twice as long, but eight-times heavier), where the 16 foot saltwater croc that lives in freshwater would be about 1200 lb. In fact, Thomas caught a 16 footer in a freshwater lagoon in Costa Rica that was about 1200 lbs. I think that the osmotic stress imposed by being in saltwater may have a significant enough cost that american saltwater crocs that live in saltwater don't have as much energy available to grow as the individuals that live mostly in freshwater.

Scaling

We got a croc last night! Here is its mug-shot.
I don't have time to do a full post yet. Plus, we may get another one tonight. The croc was about 8 feet long. Thomas and I think that it was about 80 lbs. Here's a scaling question for my biology majors: Assuming that these crocodiles scale isometrically and all 8-footers are about 80 lbs, about how much should a 16 foot crocodile weigh? (Interesting aside: snails make up much of the diet of many big Morelet's crocodiles caught on the mainland.) The saltwater crocs that live mostly in fresh water in Central America tend to be larger than the saltwater crocs that spend much of their time in salt water. All of the crocs tend to take advantage of hanging out in fresh water when they can. An 8-foot salty that lives in fresh water would weight more, approximately 150lbs. How much, assuming isometry, would a 16-footer living in fresh water weigh? Why might the american crocodiles that live in fresh water be larger than those that live in saltwater?

H2S

Hey former biology students! There's a new hydrogen sulfide news release. You should have found it on your own, but in case you didn't here it is. This whole hydrogen sulfide things is just crazy!
http://www.sciencedaily.com/releases/2008/07/080701145926.htm

We're going out to look for crocs again tonight. We didn't have much luck catching the big one behind our place last night.

Surf Birds

Just a quick note. If you like blogs by science geeks, then here's a great one by my good friend Hugh -- http://aphriza.wordpress.com/