Tag Archives: green algae

Day 14: Revisiting back reef and lionfish

This morning we spent an hour on the back reef on the northeast side of Middle Caye. We had visited the area on May 28th, but this time we went to collect all of the biodiversity of the zone that we could. Most of what we were able to collect was algae because it is usually stationary and safe to touch. We also collected some mollusks and crustaceans. A lot of the hermit crabs that we found in the water were occupying old conch shells, which shows how large they were. It was interesting to compare how the live conchs and hermit crabs in conch shells looked when they were retracted. Our jellyfish expert, Sam, found dead box jellyfish floating near the shoreline and collected them even though their tentacles are very dangerous to touch.

We collected a lot of the species of algae that I had already seen last time we visited the back reef, but it was good to consolidate the data. Overall we collected samples of Halimeda incrassata, H. opuntia, Dictyosphaeria cavernosa, Penicillus capitatus, Rhipocephalus phoenix, Udotea conglutinata, U. flabellum, Caulerpa cuppressoides, C. racemosa, and possibly Chaetomorpha linum. It was difficult to tell the difference between the Penicillus species because some seemed to have a slightly flat top or a slightly bigger top than the descriptions of P. capitatus that I was able to find in the literature. I am not sure that the filamentous algae that we collected were C. linum. They seemed similar to the description, but I couldn’t completely rule out other species.

Halimeda spp.
Halimeda spp.
Dictyosphaeria cavernosa
First five: Penicillus spp.; last two: Rhipocephalus phoenix
Caulerpa cuppressoides (top) and C. racemosa (bottom)

In the afternoon we dissected lionfish to record their dimensions and what they were eating. We had caught 4 lionfish, and the individual that my group dissected had puncture wounds in its face from the spear. The most difficult part of the dissection was attempting to sex the fish. Ultimately my group was not able to determine where the gonads were, so we couldn’t tell whether it was a female or a male. We opened up the lionfish’s stomach and found a much smaller fish that was barely digested. The lionfish was 19cm from mouth to the tip of the tail, and the ingested fish was 2cm long. Lionfish stomachs can expand to 30 times their empty size, which made the stomach of our individual comparatively empty.

Dissecting the lionfish
Adrienne cutting the poisonous fins off of a lionfish

By this time tomorrow we will all be back in the United States. Tomorrow promises to be a crazy day, and I’m looking forward to end the trip with the same spirit that we have had throughout our time here.

Day 13: Marine debris and mangroves

Sunrise on Middle Caye

The project of the morning consisted of quantifying the marine debris that was washed up on the windward side of Middle Caye. At four sites we measured the amount of trash that the 14 of us could collect in 15 minutes. By weight, 50% of the debris that we gathered was plastic and another 21% was Styrofoam. 14% was rope and 15% was glass, rubber, or other materials. Overall we collected 41.22 kg of debris in one hour, which is especially significant because the shore gets cleaned every week. The amount of debris that we collected on a small portion of this small island far away from the shore was staggering.

In the afternoon we ventured through a stand of mangroves to the leeward side of the island to the back reef. We were there to collect data on coral colonies that the EBIO 319 students measured last year, but we were also able to explore the area. The large quantity of sand on the back reef made it a good place to find green algae. Most of the Caulerpa that I saw were either Caulerpa cupressoides (cactus tree algae) or C. urvilleana. The Caulerpa were often found near Penicillus capitatus and Udotea flabellum. I also saw a few examples of Dictyosphaeria cavernosa (green bubble algae) on corals and in sea grass.

While we were collecting debris I noticed a fair amount of filamentous algae on the rocks along the shore. I’m not sure whether they were from the Cladophoraceae or Derbesiaceae family. Some of them might have been Rhizoclonium riparium.

I forgot to mention yesterday that I found Caulerpa racemosa (green grape algae) on the windward back reef that we visited. The algae were in very shallow water right behind the reef crest. I also have seen examples of Acetabularia calyculus (mermaid’s wine glass) in the shallow water off of the dock.

Caulerpa racemosa on the back reef at Middle Caye
Caulerpa racemosa (green grape algae), turf algae, Halimeda, and brown algae on the back reef at Middle Caye
Acetabularia calyculus (mermaid’s wine glass)

Day 12: Fore reef, back reef

Fore reef diversity with Orbicella annularis

To start off this morning we ventured outside of the atoll’s lagoon to the fore reef. The fore reef is the outer edge of the reef and has the highest diversity of any reef zone. However, the fore reef also has the highest wave energy and is much deeper than the lagoon or back reef. The boat ride to the drop zones was pretty choppy, which was a bit of a challenge for some people, but most people were able to enjoy the reef once they got off the boat, and we didn’t have any vomiting.

I found it harder to see details on the fore reef because it was deeper and I couldn’t dive far enough down, but I was still able to see interesting aspects of the fore reef. There were bigger fish than in the lagoon, and I believe that the diversity of fish species may have been greater as well. The coral on the fore reef was also amazing because it had more space to grow, so the colonies were much larger. We even saw some Acropora palmata colonies, which is a species of coral that used to be a dominant reef builder but recently saw enough colony death to make it endangered. I also enjoyed seeing Acropora cervicornis because it has distinct white tips with an apical polyp that is much larger than the rest of the coral’s polyps. I learned about A. cervicornis in a class that I took last semester, so it was cool to be able to see it in person.

While we were on the fore reef we also saw a huge ray swimming across a sandy area and a nurse shark that followed our group for a while as we snorkeled alongside the reef crest.

The huge ray we saw
A huge ray swimming along the ocean floor (Photo creds: Anna)

In the afternoon we were able to go out on the back reef by Middle Caye. The water was around three feet deep, making it difficult to navigate, but we were able to get closer to the sea floor than we had been able to before. This was especially beneficial for viewing green algae, as they flourish in areas with high sun and sand. I saw a number of species of Udotea, Caulerpa, and Penicillus all in close proximity. These three species were all found on the sea floor in sandy areas or on dead corals that had accumulated a large amount of sediments. Some species of Halimeda were also found in sandy areas on the sea floor, but some were growing in crevices found on corals. The Halimeda on the floor were taller and had smaller segments, whereas the species on corals were more clumped and had larger segments

Caulerpa and Penicillus on back reef

The back reef had the first lionfish that we were able to spear. While on Middle Caye, we aren’t permitted to eat any fish that we catch other than lionfish, because they are invasive. Tomorrow we will be taking measurements of the four lionfish that we caught and then we’ve been promised lionfish ceviche, which sounds delicious!

Day 11: Counting corals and urchins

The projects of the day consisted of comparing live stony coral cover and numbers of urchins between the Marine Protected Area (MPA) and a zone outside of the MPA at Glovers Reef. To measure coral cover, we laid down 7 transects that were each 100 ft long. Every 25 ft along the transect we measured two quadrats that were 2 ft by 2 ft. Each quadrat is fitted with twine to make 81 squares, or 64 intersection points. We looked at what was underneath each intersection and classified it as live stony coral, recently dead stony coral, macroalgae, other living organisms, or other dead/abiotic objects. Tomorrow we will analyze the data that we gathered, but we predicted that there would be a higher percent of live coral cover inside the MPA.

To count urchins, we timed how many urchins 18 people could collect in 25 minutes. Tomorrow we will compile all of the data and determine which urchin species were most common and quantify the difference between the MPA and the area outside the MPA.

Collected urchins (Photo credit: Scott)
Collected urchins (Photo credit: Scott)

We didn’t have very much time to explore the reef, but during data collection I was able to observe several species of parrotfish, including what I believe was a stoplight parrotfish. I also noted a large number of flamingo tongue snails, which are an interesting species of mollusk that is mostly an off-white shade with yellow spots that have a black outline. The snails are mostly found on sea fans.

As for green algae, I saw pinecone algae in the MPA. The pinecone algae are concentrated in sandy areas where they are able to attach their holdfast to the sand. The pinecone algae were smaller than I was expecting and were narrower, so they could be a slightly different species than I researched. There was also calcareous green algae that was growing on dead coral both in the MPA and outside of it. While the algae consisted of multiple species, I believe that most of them were species of Halimeda. Most of the green algae that I saw today was covered in sediment so it was difficult to identify the exact species.

Day 10: Quadrats and Transects

We started off this morning with a refreshing snorkel session at 8:30am. This time we brought out more gear, specifically a clipboard with waterproof paper to take notes of what we saw. There was a general feeling among all of us that the waterproof paper had to be some sort of black magic, but it worked so we stopped questioning it. Holding the clipboard and trying to take photos and write notes while avoiding being pushed into the coral by the currents took a long time to get used to, and I definitely haven’t mastered it.

Gathering data in sea grass beds

To make everything more confusing, we added more gear after lunch. We performed a short experiment to practice using transect tapes and quadrats. The question that we were trying to answer was whether Halimeda or Penicillus species had a higher abundance and density in the sea grass off of the pier at Middle Caye. We worked in 6 groups to run transects across the beds of sea grass and counted the number of individuals of each species in quadrats along the transects.

In the end, we found 153 Halimeda individuals and only 1 Penicillus individual in the 216 square feet that we measured. We noticed that even slight differences in the composition of the sea grass bed, such as the density or length of the grass, changed the likelihood of algae being found in the plot. To quantify these differences we would have to run another experiment that focused on the different zones in the sea grass bed. Our experiment was limited because of the small area that we covered and difficulty that we had counting the individuals. Even though we were in water that was 8 feet deep at most, it might have been easier to run the experiment using SCUBA so we wouldn’t have to keep surfacing, which made counting confusing when we had to see under blades of grass.

Halimeda and Penicillus are interesting green algae because they are calcareous. Halimeda incorporates calcium carbonate into its thallus in flat chips, whereas Penicillus has calcium carbonate in the brush-like filaments at the top of the algae. The different forms of calcium carbonate lead to different types of sand. Halimeda creates large, flat grains of sand. The sand from Penicillus is finer and muddier.

Day 9: The Reef!

View of Glovers Reef from observation tower on Middle Caye
Patch reef in Glovers Reef

Today we traveled from the zoo to Glovers Reef. Glovers Reef is one of three atolls in Belize. It consists of four islands – Southwest Caye, Middle Caye, Long Caye, and Northeast Caye. We got to the island around 3:45pm and were able to snorkel for an hour before we had dinner. To our surprise, the water was like bathwater, especially right by the pier. It almost wasn’t refreshing, but being in the water was amazing.

Most of the sea floor that we saw was covered in sea grass. There weren’t any trees in the sea, but someone found a Penicillus capitatus, which is a species of green algae that looks like a paint brush. A little farther out, the sea grass gave way to a few patch reefs. The reefs had more sediment than I was expecting, but the diversity on the reefs was still greater than almost all reefs I have visited. The first species that I noticed were Gregonian sea fans, that were purple and rose gracefully from the mounds of coral.

Halimeda sp.

The sedimentation on the patch reefs made them a good habitat for green algae. The highest concentrations of green algae that I found were along the edge of the patch reef. There were multiple species of Halimeda, but I wasn’t able to identify the exact species. There was a lot of Caulerpa cupressoides, which was smaller than I was expecting but still very recognizable. I also saw a species that could be Anadyomene stellata, but I need to look at the morphology of the algae more closely.

Tomorrow I’m looking forward to having more time in the water and learning about more reef species.

Day 8: Belize Zoo Tropical Education Center

Today we left Las Cuevas Research Center and traveled to the Belize Zoo. After a long morning, we arrived at the Zoo’s Tropical Education Center. The center was really interesting because it consisted of a large property with multiple ecosystems, such as pine forests. The director of TEC warned us to watch out for wild snakes and other wildlife around the cabins, but the only wildlife that I saw were birds.

After dinner at TEC, we went for a night tour of the zoo. We only visited nocturnal animals because the guides didn’t want to disturb the diurnal animals. We got to visit two jaguars out of the 18 that the zoo has. The zoo has so many jaguars because they rescue animals that are in danger of being shot by farmers. One of the jaguars that we saw was a black jaguar named Lucky Boy who was rescued from a Belizean resort that had been abandoned. Black jaguars are extremely rare. They are the equivalent of the opposite of albino animals; they have too much melanin.

Lucky Boy (Photo creds: Lucrecia)
Lucky Boy (Photo creds: Lucrecia)

We also got to feed a tapir and saw an ocelot. The ocelot was entertaining because it wouldn’t stop growling, even when the zoo keeper fed it. The only difference was the change from a growl to a growling “nom nom nom” sound.

Because of all of the travel time, I didn’t get a chance to observe specific tree species. We passed through multiple ecosystems, and I saw many of the same species that I observed over the past week.

Day 7: Collecting Camera Traps

Today we spent the day collecting the 12 camera traps that we placed on day 3. We got a much earlier start than we got when we were putting the traps up, which meant that we were able to collect them all before it got dark. We were done at 3:30pm and made it back before dark, unlike last time.

After we got back, we looked through all of the pictures that our cameras had gathered. Unfortunately one of our camera’s battery died soon after we placed it, and seven of our cameras didn’t get any pictures of wildlife (unless you count very tired and dirty humans). As we scrolled through picture after picture of leaves moving and humans crossing the camera, our hopes dwindled. Luckily we were able to catch some animals. Two of our cameras caught what seemed to be the same bird species, and maybe even the same individual. Another camera caught a curassow, which is a very large black bird. But by far our most exciting sights were a tapir, ocelot, and agouti. Knowing that these animals were so close to where we had walked and spent time is almost unreal. It is strange to think about how many animals are roaming the area right by where we are but always just out of sight.

Tree species that I noticed today were the bayleaf palm (Sabal mauritiiformis) and the bay cedar (Guazuma ulmifolia). I also noticed a branch and a seedpod on the ground that were covered in dense brown spines. Each spine was about half an inch long. Based on the resources that I have, my best guess is that the species was Bactris major, but I am not sure that my analysis of the species is correct.

Day 6: Insects Galore

Day 6 began by collecting pitfall traps that we set out yesterday. The traps consisted of either water or urine and we’re placed in trees and on the ground. Insects either are attracted to the traps or fall into them and then are stuck. I was pleasantly surprised to see how many of our traps had caught insects in the 16-ish hours that they had been set up. We spent the morning analyzing the number of insects we caught. We looked at where they were caught and what morphospecies they were in order to determine the species richness and abundance of the samples. We then spent some time going over our data. It was difficult to determine exactly how we should summarize the data. We ended up coming up with one conclusion but completely reversing it after we talked to Adrienne and Scott. In the end, we found that insects in the canopy had a greater need for nitrogen and were more attracted to the urine traps.

In the evening we went on our first official night hike. Near the beginning of the hike we found an Acacia tree right on the trail that had two stick insects hanging off of it. The green stick insect was around a foot long and was hanging upside down with its front two legs extended above its head. The other stick insect was smaller and brown. Soon after we began observing them, the brown insect started climbing pretty quickly up the tree and away from our light.

Can you find the green stick insect?
Can you find the green stick insect? What about the long brown spines of the Acacia?

Acacias are special because they have a mutualism with ants, like Cecropia. The ant species is different and more aggressive. The tree that we observed didn’t appear to have an active ant colony, but we didn’t look very hard for it.

We also saw a lot of spiders and roaches.  We saw two tarantulas on a huge tree, which was different because all of the other tarantulas that we’ve seen have been on the ground. There were a lot of other large spiders and roaches that we would be much less likely to see during the day. It was good to be able to experience the forest at night, when so many new creatures can be seen.

Day 5: Null Hypotheses and Spelunking Adventures

Today we started off by summarizing the results from our experiments yesterday about Cecropia and ant interactions. My group ended up with negative results. We didn’t find any evidence of young Cecropia mimicking other plants. We did notice some differences between juvenile and adult trees, such as red petioles (the stems of leaves) and slightly longer trichomes (the tiny hairs on plants). However, we weren’t able to conclusively determine that those differences had an adaptive role. One group tested the toughness of juvenile and adult leaves and found that juvenile leaves were tougher. This could be adaptive because it would make it more difficult for herbivores to eat the leaves. If the project was continued, it would be beneficial to see if herbivores preferred younger or older leaves.

We also were able to visit the cave at Las Cuevas. The cave was a part of Mayan ceremonies, and there is still evidence of their presence. There are pottery shards throughout the cave system and the cave is built up in some areas. Platforms were built near the entrance and some spaces between chambers were made to be narrower. The whole history behind the cave is extremely interesting. The caves also had some wildlife. We saw at least two species of bats, millipedes, and a species of scorpion with long legs and no tail. One of the best aspects about the cave was how undeveloped it was. I’m not used to visiting preserved caves that haven’t been commercialized. It was cool to feel like I was one of the first to visit the cave, even though many, many people have visited it before me.

Entering the cave
Entering (taking pictures of) the cave

My favorite trees today were the big trees that we commonly see around the Chiquibul. The cedar (Cedrela odorata) can be 20-30m tall. Right now it doesn’t have leaves, but it has some wooden seed pods that are still attached to the branches. The seed pods look like 5-petaled flowers – they’re very pretty. Another big tree is the ceiba (Ceiba pentandra). When it is mature, its bark is very smooth and it can reach 60-70m. It has been difficult for me to identify ceiba from their leaves because the trunks reach so high into the canopy.

Cedar seed pod

We only have two more full days at LCRS, so we’ll have to make them count!