Tag Archives: sea urchins

2022

urchins upon urchins upon sea eggs

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Today, in contrast with yesterday, did start out with urchins! Bright and early in the morning we headed out to a patch reef in the MPA to collect data for our research question. Afterwards, we collected urchins for the urchin hunt, and gathered a whopping 52 urchins at the first patch reef, plus one West Indian Sea Egg that I named Harry. We had three slate pencil urchins and 49 E. virdis urchins. We went to another MPA and collected more data, and more urchins. This time around, we got 57! All of them were E. virdis. I also found another sea egg, which I named Sally. I have faith that the two of them will cross the atoll and find each other eventually 🙂 Overall, it was a great morning for echinoderms (the species including urchins, sea stars, sea cucumbers, etc), as we also came across multiple brittle stars and two sea cucumbers!

Harry the west indian sea egg
Sally the west indian sea egg, covered in sea grass

In both MPA patch reefs, I was on the lookout for brown algae. I saw a lot of the saucer leaf algae (turbinaria tricostata) and white scroll algae (padina jamaicensis). I also saw some really cool y-branching algae that had some vibrant blue branches, which I believe to be dictyota menstrualis. Also, I finally figured out what the brown algae clumps were that I couldn’t identify! I believe it to be padina gymnospora, a species related to the white scroll algae. This variety had been covering the reef patch in the MPA that we saw yesterday, so it was nice to figure that out.

dictyota menstrualis (the brown y-branches and the blue y-branches toward the center)

In the afternoon, we went on a “for fun” snorkel in the reef flats. We came across a reef that was mostly algae, but had some sparse coral and lots of fish varieties! We came across three lionfish, but none of them were caught, unfortunately. We did spear one earlier, bringing the current lionfish count to two. Also, fun fact lion fish catching is the only kind of fishing allowed in the conservation zone, since it is an invasive species!

There were also several giant lobsters, yellow jacks, damsel fish, parrot fish, and angel fish! One of the areas was like a fish highway, which was cool to see, in spite of the reef not really being a true coral reef anymore. As I mentioned, the reef area was mostly algal-dominated, and there was rotting sargassum covering a lot of the reef floor. As the sea weed rots, it releases nutrients in the water, which actually promotes more algal growth, rather than coral growth. The fact that there was healthy coral there at all was quite impressive.

But that was about it for today! Tomorrow, we will most likely be either going to the forereef or a non-MPA to do more research, and then we will be doing some sort of land activity. I will let you know tomorrow!

-Elena

a whole lotta brown algae
Sophia taking data from the quadrat
2022

i thought the urchin was my friend…but it was anemone

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Unfortunately, the day did not begin with urchins, but they will enter the scene soon, don’t worry!

We started off the morning by planning out another experiment. We knew we were going to be visiting preserved reef patches and non-preserved reef patches and collecting some sort of data with the quadrats, and that we would be doing urchin scavenger hunts. From there, we developed a research question that we could answer by gathering this data. We decided to investigate the correlation between live coral coverage and urchin prevalence, and how the amount of each changed between protected areas and non protected areas. We did not finish collecting data, so stay tuned!

Before we went out to the reefs, we waded in the sea grass bed and collected specimens to look at more closely in the outdoor lab. Some notable finds include a Caribbean spiny lobster, mantis shrimp, damsel fish, several varieties of crabs, lime urchin, anemone, corallimorph, conchs, and our favorite-brown algae! We found some sargassum natans, and some of the saucer leaf algae!

Afterwards, we went to the reef patches. We went to the non-protected area first to collect our data. It was difficult conditions, since the waves were strong and it was hard to stay in place. The urchin hunt was also difficult, since they like to hide in little burrows, so one could not easily get them out without harming them. We then went to the protected reef to snorkel for fun.  Entering the protected area, I felt like I had died and gone to brown algae heaven (although maybe that wasn’t a great sign for the corals). There was saucer leaf algae, white scroll algae, and sargassum everywhere! They were intermixed with another type of algae, although I couldn’t identify it. The algae was growing all over the old, dead corals so densely I couldn’t even see the sand. Exciting stuff!

We also found a damsel fish garden, which was super cool. The damsel fish have little gardens where they cultivate their favorite algae, and protect it from other fish. And finally, the group spotted a lionfish, which was promptly speared (lionfish are invasive, and their capture is actually encouraged!) and brought aboard so we can use it for activities later this week.

When we got back, we counted, IDed, and measured the diameter of the urchins we collected, and then settled in for the night! Tomorrow, we are going to be collecting more data for our research, and maybe we’ll even have an answer. See you all then!

-Elena

some of the algal friends we collected
a slate pencil urchin
the damsel fish garden ft. the gardener itself
saucer-leaf algae and the unknown algae
free the homie
…but like don’t cuz they’re invasive 🙁
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Collecting Specimens: Lionfish Spearing

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Today we spent our morning collecting specimens in the shallows near the island and identifying them in our wet lab before releasing them! We were able to collect a surprising amount of organisms, including lots of green algae, a few crabs, a spiny lobster, and some mantis shrimp!

We were also able to generate a new research question and go farther out from shore to see some more patch reefs within the atoll and collect data to answer our question. We are interested in how sea urchin abundance correlates with the percentage of coral cover that is dead, and how this relationship might be different in areas of the reef that are protected and other unregulated areas. Data collection today was very challenging due to strong current and some equipment malfunctions, but we made it work! We should be working on this project for a few days so hopefully we will have better luck tomorrow!

We also visited patch reef that is a marine protected area (MPA) which was much deeper and more complex than we have seen so far! Although I didn’t spot any more jellyfish today, I saw so many magnificent coral structures and colorful fish. I saw an entire school of what might be blue tangs pass by, and some truly massive Orbicella corals. We even spotted a lionfish, which is a very venomous, very invasive species which Dr. Solomon was able to spear and catch for us to eat tomorrow! It was so exciting to watch!

2022

Day 4: Patch Reef Health + Sea Urchins

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Our class traveled on boat to perform some examinations of the patch reefs on Glover’s Atoll today! Using our transect tapes and quadrates again, our class decided toe analyze the relationship between the density of sea urchins and percentage of live and dead coral on both marine protected reefs as well as unprotected reefs. We discovered that although our methodology seemed sound that with the shallow waters, strong ocean currents, and the presence of millepora alcicornis or Branching Fire Coral that was present on both reefs. Jasmine got stung by this hydrozoan unfortunately :(, but the stings will go away with hydrocortisone! We did discover that the marine protected reefs were deeper and had healthier and more abundant corals and fish!

In the marine protected area I saw many solitary Christmas Tree worms of all colors!Right next to it is some Magnificent Feather Duster worms!

I also got to see my first split crown feather duster! You can tell by the how the radiole splits perfectly in half mirroring itself.

I believe I also got to see my first Christmas Tree Hydroid which was very exciting!

I even saw three lobsters with Faith all lined up in a row! Incredible!Right after I saw my biology professor, Dr. Solomon, spear a lionfish which is an invasive and harmful, yet delicious, species to the Caribbean. Lillian was very excited! 😀

Earlier in the day we collected all sorts of sea creatures for examination in the wet lab room. There was: green algae species, brown algae species, glass shrimp, conch species, anemones, mantis shrimp, several crab species, sea urchin (Caio picked it up with a net), and even a lobster!

I can’t wait to go to see more on the outer reefs tomorrow! Peace out!

~ Maegan

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Passenger Fish

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May 26, 2019

Today we started and completed a whole new experiment. To look at sea urchin community structure (and the indications it may have for herbivory and reef health), we went out and collected sea urchins in a bucket and recorded the species and diameter of each urchin.

During the search, I noticed several new hydroids! I saw what I believe to be a lot of Box Fire Coral (Millipore squarrosa), which is the third and last species of fire coral that I found to be common in the Caribbean.

I also spotted some Kirchenpaueria halecioides, a small hydroid that gets up to about one inch tall (see photo below) in addition to a possible Feather Bush Hydroid (Dentitheca dendritica).

Much later in the day, we got back in the water for a night snorkel. It was fun, but my dive light went out, and we were all way too close to each other – I think we were all paranoid about losing the group. When I got back, I found a tiny little fish inside my swimsuit. It must have somehow made its way into my skintight dive skin and swimsuit, but nothing can surprise me at this point.

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ANGUS crab

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Day 3 of Beach Days

Today’s activity definitely took a toll on us — but our Dermit Rab made it all better.

Me and Aungus prior to the start of the race, 3rd and 4th from the right.

We woke up, ate, and swam to the edge of the thousand-feet-drop in the benthos (sea floor). On the way, the supposedly calm waters rocked us to differing degrees of sea sickness. In the water we went in all different directions with regards to the waves, on which we bobbed up and down while we looked in the deeper ocean for interesting life forms. One of the forereefs we explored was geographically filled with canyons of corals. Centuries of wave engergy shaped the current-day grooves filled with hard and soft corals, among other life forms. We observed an especially problematic species of fish, called the lion fish, camouflouging in the corals today. Their presence in this region, which is far from their native rainge, has caused up to 70% decline in native fish populations. Obviously, we speared them and brought them back to dissect, fry, and eat. Which is a prospect even the “vegetarians” are supporting.

In the afternoon, we quanitified the degree of biodiversity of Echinoderms (particularly sea urchins) in a protected and an unprotected marine area. Which means we spent an hour spotting and picking off the spiny sea urchins from dead corals and algae on which they are grazing. While searching for sea urchins, I saw two types of brown algae, specifically, they were two types of white-scrolled algae. One has a darker base and the other a lighter color, but both have a characteristic curly shape that resembles a scroll. In addition, we came into contact with Sargassm seadweed again, which is more or less impossible not to come into contact with due to their prevalence and distribution on the ocean surface. In addition we observed many blister saucer algae, both attached to corals and floating on the surface. Interesting, they too, like the Sargassum, are able to keep some air within their chambered body so that when squished air bubbles are released. Although they do not have a characteristic air bladder like the sea weed, these saucer algae had triangular bulbous organs to hold air.

In the evening, we had one of the best meals we’ve had yet — consisting of flan, spiced chicken, banana bread, lemon cookies, homemade bread, and mashed potato. After our lectures, we collected blue crabs and hermit crabs to race in the sand. Among 5+ competitors, one travelled in the opposite direction, 1 paused, and 2 finished close to each other. It seems like the large hermit crabs are the best for Dermit Rab. Also obvious that blue land crabs are not the best as they walk side ways and are prone to going to dark places to hide. Angus, me and Claire’s contestant, although big, did just that. :/

The communal nap I have been predicting and advocating for — also happened today! Our tiredness has come to an all time high, but with proper rest, i.e. communal naps, we seem to be a very resilient group.

2017

DAY 4 – 2 URCHAINZZZ

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Hi friends,

Today was similar to the previous day in terms of the diving activities, as we redid the patch reef data collection and sea urchin collection on an area outside of the marine protection zone. We then compared the two data sets, analyzed them based on our project hypothesis and came up with a final poster to showcase our results.

My first takeaway of the day was how adorable sea urchins are. After seeing how they move about using their spines, my perception of them changed completely. And having to handle and measure them also made me like them so much more. Just see the picture below to see how close we’ve gotten.

Black sea urchin (Diadema antillarum) on my back!

It was also fun surveying another patch reef area, and after the experience from the previous day, I was much more confident with collecting data and also identifying organisms in general. Below are some of the creatures I managed to capture (with my camera)!

It’s a Christmas Tree Worm (Spirobranchus giganteus)!

There were Christmas tree worms everywhere!!! And I saw a new mollusk species which I have never seen personally, the Cyphoma gibbosum (flamingo tongue shell):

Flamingo tongue (Cyphoma gibbosum) right in the middle

Exciting times. I’m looking forward to the next few days because we will get to check out other reef types such as the backreefs and forereefs, and I’m eager to see how different they will be from path reefs.

After snorkeling, we spent the afternoon analyzing our data and creating our poster to present to Adrienne and Scott. And then right before dinner we had a friendly pickup game with some of the island staff. Got to sweat it all out! I have to say, Alessi is pretty tenacious when it comes to fighting for the ball, and Therese and Isaac are great technical players. Meanwhile, Deepu is definitely the star striker like Cristiano Ronaldo, scoring 2 of the goals for us. This is my brief analysis of EBIO 319’s soccer team.

All in all, today went by really quickly and I thoroughly enjoyed both the snorkeling experience and the free time to mingle with the other people in Middle Caye. Looking forward to more tomorrow!

Till then,

Damien

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Day 11: Counting corals and urchins

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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.

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Urchin Day + Snorkel Fun

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Hi everyone! I saw so many urchins today!! Before I get into those, I’ll give a quick rundown of the day’s activities. Today consisted mainly of two projects: determining the percent coverage of live coral on the reef and collecting sea urchins. This morning we took a boat out to a patch reef in the lagoon and used transects and quadrats to count the number of live coral, recently dead coral, and macroalgae among other things to determine the health of the coral reef. Since sea urchins both help the coral by consuming the algae that live on them and harm the coral by boring into them, we also did a timed sea urchin collection to see how many urchins we could all catch and returned to the island to identify and measure them. In the afternoon, we repeated the morning’s activities outside of the lagoon.

Slate pencil urchins (Eucidaris tribuloides)
Slate pencil urchins (Eucidaris tribuloides)

Now on to the sea urchins!! In the lagoon alone, we collected over a hundred Echinometra viridis (a small brown/red urchin with spines that have a pale ring close to the body). We also found quite a few Eucidaris tribuloides (commonly known as slate pencil urchins, reddish brown body with blunt spines) and some Tripneustes ventricosus (an urchin with a black/dark purple body and short white spines) hiding in the coral crevices in the lagoon.

A long-spined sea urchin (Diadema antillarum)
A long-spined sea urchin (Diadema antillarum)

In the afternnon, we also collected some Diadema antillarum (a long-spined sea urchin whose spines easily penetrate skin) among the coral and a few Meoma ventricosa, both the live and dead versions (a flattened globe urchin with a reddish body and a five petal design on its back) buried in the sand along with the other species. It was interesting to me that we found the long-spined urchins and red heart urchins mainly outside of the lagoon, while inside we mainly were able to find the viridis species.

Several reef urchins (Echinometra viridis)
Several reef urchins (Echinometra viridis)

In other words, it was a very exciting day for me! I absolutely loved getting to find, hold, and work with the urchins more today. 🙂 I can’t wait to see what tomorrow brings and what echinoderms I’ll spot tomorrow. Thanks for reading everybody!