Micronesia: Day 3

Wednesday, June 25, 2013

Started: ~10:30 P.M.

Hey folks. I’m pretty tired right now, so I’m going to do the day 3 post on day 4, which will be more mellow. Today was a research and adventure day out in the field. We went up the Sapwalap estuary to collect salinity samples and take counts of mangrove trees. As we went further up the estuary, the salinity dropped to near 1 psu. For comparison, Puget Sound is around 28 psu and the ocean off our coast is 33 psu.

The specific mangrove genuses we saw were Bruguiera, Sonnertaria, Rhizophora, Lumnitzer, Barringtonia,  Xylocarpus, Heritiera, and Nypa. I will post pictures of these bad boys tomorrow, but hiking through the mangrove swamps was more treacherous than I imagined. Due to my epilepsy and the risk that I have an unprotected fall in the swamp, I did not go into some of the mangrove regions that the rest of the group went into, and for good reason. Even the ones that I did go into had to be treated with caution by everybody. I ended up getting pretty muddy on the first stop I was able to go in (we had five stops; I went in 1, 3, and 5 if I recall correctly) and it wasn’t long before I stepped in an especially weak point in the mud that covered these swamps, especially close to the water, and sunk down to my knees. I was definitely the dirtiest of the group, but that’s just how I roll.

We took a salinity sample at a place in the morning on the outgoing tide, and the salinity was around 31 psu (practical salinity units). When we came back ~5 hours later, the tide was coming in, and due to the influx of saltier, marine water coming into the estuary, the water had higher salinity

We also went snorkeling. Due to my epilepsy, I was not permitted to wear a snorkel, but I sould still swim with fins and a mask. I saw some beautiful coral, man tropical reef fish, sea stars, and even a manta ray near the bottom 30 feet down. Remember Gill from Finding Nemo, the angelfish with the scar who lived in the aquarium tank and helped Nemo escape from the ocean? I saw one of those and was amazed. They are incredibly beautiful.

Just driving around the mountain in a boat was beautiful. We saw a dredged channel with two houooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooonnnnnnnnnnnnnnnnnkkkkkkkkkkkkkkkkkkkkkkkmmmmmmmmmmmmmmmmmmmmmmmmmn                                        mgs……………………………………………………………………………………………………………………………………………………………………………………………….g……………………………………………………………….s…sm
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If my word choice and sentence fluency is good right now, that’s very impressive because Io am doing a miz of resting in my bed while tyuping c with my head.
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Started 3:59 P.M. (6/26/13)

Wow, I really was tired. I did not know that I had my hand on the keyboard for those letters. I’m just going to keep that stuff up there because it’s hilarious. Not only do I get tired easily, but yesterday was an absolutely exhausting day. We took a lot of interesting data, and we are currently analyzing it right now. I’ll make another post about the data when we are done analyzing it and its significance for the Sapvalap estuary, other places on Pohnpei, and the mangrove habitat in general, both on Pohnpei and worldwide.

When I first came into the program, I just thought that mangroves were these shrubby things that grow along the coast in saline environments. I didn’t know how they did it, but I didn’t really care. I didn’t see any flowers on them (it turns out that some of them have spectacular flowers), and although this is subjective, I didn’t think they were particularly spectacular. They were more impressive than than the invasive Himalayan Blackerry that seems to pop up everywhere, but they could not hold a candle to the massive Sitka Spruce I’ve seen in Olympic National park. And even if they were prettier than blackberries, as was previously stated, they didn’t bear delicious fruit (there actually is one genus that has some pretty amazing fruit, the Xylocarpus, but I did not know this at the time.

In this post, I want to go through the eight different types of mangroves we saw and some distinguishing characteristics of all of them. I’ll also present some beautiful pictures from the boat ride to and near the mangroves.

We left the dock at around 9, but I forget the particular time. We originally had three boats, but one of them had engine trouble, so we crammed all 13 of us in two small skiffs. The boat ride was an hour long, but it was absolutely beautiful. The first couple days were really rainy, but yesterday was dry and mainly clear, with only a few orographically-enhanced showers over the mountainous inland regions of Pohnpei. Today is even drier and clearer… the last time I checked the temperature (which was probably 2 P.M. or so, it was 95 in Kolonia (the most developed and most populous hotel on the island, and our hotel is on the outer fringe of it).

Anyway, here are some pictures of the boat drive over. All pictures are taken on my Nikon COOLPIX S6300 digital camera unless otherwise specified

Leaving Kolonia for the long boat ride to Sapwalap
Leaving the Kamar estuary with mountains in the background
More mountains
Looking seaward
Waves crashing against the barrier reef that surrounds the island
More beautiful mountains on a beautiful day.
A shallow coral reef we had to carefully navigate through
A cool house on an island away from Kolonia.
Some Pohnpeians on the island
Super shallow coral that has grown in the supposedly dredged channel adjacent to the island previously shown
People taking notes on the boats
A mountain that looks like a canine tooth. Probably the best looking tooth on the island (that’s for another blog). Note the change in water clarity
Heading into the Sapwalap estuary

Finished ~5:20 (I told you this internet was slow!)

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Started 7:03 P.M. (6/27/13)Ugh. Here I am again, and I still haven’t started the main section of my post. Well, let’s get to it. I have a huge day exploring some ruins at Nan Madol. I thought the Micronesia trip for have more time for us to meditate and reflect on our feelings. Boy was I ever wrong.

I mentioned that I saw Bruguiera, Sonnertaria, Rhizophora, Lumnitzer, Barringtonia,  Xylocarpus, Heritiera, and Nypa in the swamps. I have a bunch of data for these guys, but I figured I’d first stick to simple species identification and notable characteristics.

DISCLAIMER: I DIDN’T TAKE PICTURES OF EVERY SINGLE ASPECT OF A GIVEN GENUS. I DID NOT TAKE PICTURES OF SOME GENUSES AT ALL BECAUSE I DIDN’T SEE THEM OR WASN’T SMART ENOUGH TO DISTINGUISH THEM AS A SEPARATE GENUS (PROBABLY THE LATTER).

Alright, let’s start with Bruguiera.

The Bruguiera‘s most distinctive feature (in my cocky opinion) is its “knee roots. These roots come out of the sludge/water at an angle and, after extending around 6 inches above the ground, make a  ~60 degree angle back to the ground to never be seen again. I guess it is possible for the same root to come up twice, but I’m just going to assume it generally doesn’t because ‘never to be seen again’ is a winning phrase.

A good mnemonic device to remember the genus is that most people often bruise their knees (I can’t remember the last time I specifically bruised my knee, though). I also think of Bulgaria. I’m kind of like Dory from Finding Nemo when it comes to memory, so some mnemonic devices help me, especially if I make them up myself. They don’t have to make any sense, but if I pick a word to associate with a genus, it sticks in my head better.

“Knee Roots”

Let’s talk about leaves. The picture below is kind of blurry, but it gives a good idea of the typical characteristics of the Bruguiera leaves. The leaves are pretty large (10-20 cm) and occur in these radiating clumps at the ends of branches. They are skinnier and shinier than some of the other mangrove leaves, and I personally think they are the easiest leaf to identify.

The Bruguiera are big trees… they can grow to 25 meters, and like many other mangroves, they are spectacular once you can stop focusing on sinking into the super slimy sludge that they inhabit. They have rough bark that is darker than that of many other mangroves, and they often grow in tandem with Rhizophera, which is another species I will get to later on.

Bruguiera leaves. Photo Credit: James Kohn (another awesome student on the trip)

Many mangroves have these viviparous seedings called propagules. As such, the seeds and fruit germinate and start to grow before they drop from the tree. Propagules come in all kinds of shapes and sizes, but the ones that fall from Bruguiera are, as my field guide says, “cigar-shaped” and 10-20 cm long. I don’t like the whole cigar analogy… I’ve never smoked one, but I have seen them. I think these propagules look more like a miniature, very skinny cucumber. However, this might be hard for some people to visualize as cucumbers this skinny do not exist, so I guess the cigar analogy will do.

One very interesting, ingenious strategy that propagules use to effectively propagate is their use of the natural buoyancy of water. When these propagules fall from the tree onto the muck they reside in, they will generally stand vertically, and they will start growing. If they fall into the water, they rest horizontally at first. But as Father Time continuous to turn babies into toddlers, historical structures into condos, and trans fat into heart disease, these propagules absorb water through the root tip, and due to the now increased density of the root tip, the propagule lies vertically in the water.

Below is a picture of a propagule with the red flower from the tree still partially attached, and below that is a propagule that has turned vertically in water.

Alright, enough of that. It is now 8:12 P.M., which means I am making serious progress. Well, at least I don’t have any more pictures to upload at this time, so I can just tell ya’lls some basic information about the different genuses of mangroves and hope that I am somewhat accurate. I’ve memorized every single species and can tell the difference just by hearing the ever so slight sounds they make as they grow, but I don’t have time for that as a blogger. Besides, you wouldn’t understand anyway… it’s beyond your cognitive abilities.

Alrighty. Next up is Sonneratia. This particular mangrove is pretty darn dangerous. I’ll show you a picture of its roots. It should speak for itself.

pencil roots (my photo)
more pencil roots – Photo Credit: James Kohn

These roots are known as “pencil roots,” but I think they should be called “torture roots.” Why do I say that? Well, I just thought that if one really, really evil person was trying to get answers from a prisoner, they could tie them up to a mangrove tree, take out some of these roots, and stab parts of their body and nail them to the tree until they finally gave in. I used to not associate roots with instruments of torture. After seeing these roots, however, I can’t associate them with anything else.

These trees can grow to 15 meters tall and have leaves that are smaller and proportionally wider than the Bruguiera. These leaves average 7 cm on a mature tree and are rounded and opposite of each other on the branches. This mangrove is colloquially known as the “Mangrove Apple,” and is called such because the fruit (propagules) look like small apples. An interesting tidbit on Sonneratia is that the flowers only last for 24 hours. Enjoy them while you can, but if you miss them, there will be a brand new set of flowers a few hours later.

The bark on these buddies is greyish-brownish, and it is slightly cracked. Sometimes its hard to find which torture devices are associated with which specific tree, but if you see those spikes, you can be sure that there is an least one Sonneratia around.

A singular Rhyzophera

Our next serving of our eight-course meal is the mangrove we all know and love: the Rhyzophera. I say that this is the mangrove that we all know and love because it loves to inhabit the shoreline and is the most common in general. When you see mangroves from a boat, you are probably seeing Rhyzophera.

Rhyzophera on the coast off the Sapwalap estuary

These mangroves also have extremely distinctive roots. Instead of going underground and popping up as tripping hazards or a torture device straight out of Saw, these roots are helpful, kind, and inviting. Prop roots extend downward into the soil from the trunk of the tree, with the most roots congregated at the lowest part of the trunk.

The leaves are fairly long… about 10cm to be exact. They are easily distinguished by brown speckles on their lighter green underside, and just like the Brugueira, they tend to form in clumps on the end of branches.They also have some white flowers which are pretty boring but a nice addition nonetheless.

Rhyzophera leaves and flowers
Professor and trip leader Julian Sachs pointing out some characteristics of Rhyzophera.

Keeping with the cucumber analogy, these propagules are like those of the Brugueira, but even longer and skinner, and therefore, less like a cucumber. I think the best analogy for these propagules would be to compare them to those super long Laffy Taffy candies. I doubt they are as delicious though.

Rhyzophera propagule

Some of the propagules of Rhyzophera mucronata can get extremely large. Check out my baseball skills below.

Using an extremely large propagule as a baseball bat. This picture was taken two days after our Sapwalap mangrove expedition (today) in Nan Madol, which is another adventure that will require extensive blogging

Rhyzophera mangroves generally occur in the intertidal zone, where the roots are exposed during low tides and submerged during high tides. I saved the picture below because Julian told me that those huge strands hanging down from the tree are actually prop roots. He said they weren’t standard prop roots, but they still got nutrients from the water and delivered them to the plant. That’s pretty impressive.

More Rhizophera trees by the shoreline of the Sapwalap estuary

Next up is Lumnitzera. I don’t have any photos of this genus, which is probably a good think because it is now 9:46 P.M. In any event, these mangroves don’t grow to extraordinary heights, as the tallest of the two species in the genus only reaches a maximum height of 6 meters. The other I have discussed have very identifiable root systems, but the roots of the Lumnitzera are primarily underground, with the occasional knee root popping up here or there. The leaves are small (7 cm) and light green, and they have a little indentation at the end that distinguishes them from other mangroves.

The tree has red or white flowers depending on the species, and some of the Lumnitzera are hybrids and have pink flowers. The bark is grey-ish and rutty. These were not a common sight on out expedition… perhaps because they prefer water the inland sections of mangrove swamps. We only went 50 to 100 meters in.

Barringtonia also do not have any recognizable above-ground root systems, but they are still identifiable (especially at close range) because of their beautiful flowers. These flowers hang down like beautiful necklaces (that have been unchained, of course). These guys can grow to 20 meters, and they have very large leaves… up to 40 cm long and 15 cm wide. The bark is grey and smooth. It’s probably just because I’m learning about mangroves for the first time, but all this bark stuff makes me confused.

There is, however, one bark that I instantly recognize from a distance. This is the bark that belongs to Julian’s favorite mangrove: the Xylocarpus.

buttress roots

There are a lot of things to like about these trees. First off, they can get extend to 25 meters above the ground. This may not sound like a lot, but when you take a look at how intricate  these mangroves are and how there is not much of a singular trunk, these beasts are very impressive.

Anyway, back to the bark. It’s easy to recognize because it is not brown or grey. It is tan, and sometimes, it even looks pink. If you are close, you’ll notice that the bark flakes off if you rub your hand against the tree. Don’t worry, the tree won’t disintegrate and fall to the ground if you rub too hard for too long. The leaves are small and oval-shaped compared to the other mangrove leaves that I know of.

The above picture shows the “buttress”  roots that are unique to the Xylocarpus, although they occur to a much lesser extent in Heritiera. These roots provide wonderful habitat for trekking humans to get a solid hold on without falling into the mud. And they are absolutely beautiful. They look like a maze of strong, wavy walls that spread out in a million directions. Julian told me that these roots were cool, which I had trouble believing because I honestly didn’t see how roots would be cool. These roots where spectacular. Still, they come up second place to the roots of the Sonneratia.

A chunk of fruit from the Xylocarpus

These mangroves are also interesting because they form these huge fruits that are arranged in amazing patterns. The fruits can get to the size of bowling balls before they finally call it quits and drop from the tree. Even more amazing is how they are structured. There are a whole bunch of “puzzle pieces” to the fruit which, in my opinion, are shaped like small 3D rhombuses. They are about 1.5 cm long if I remember correctly, but that could be off. Anyway, the number of seeds packed into one of these fruits is around 12-18. They are truly amazing to see. Even though the roots come in second to the Sonneratia, this is my favorite mangrove because of its bark and its amazing fruit. I’ve never eaten the fruit, and I don’t know anybody who has. It is something I would like to try at some point, though.

Time update: 10:28 P.M. Two more genuses to go through. I can do this.

Our next guest is Heritiera, and I hope you will all give him a warm welcome. Heritiera is, in some ways, the chief of the mangrove jungle. I say this because it can grow to astonishing heights – up to 30 meters. I’ve never seen one this high, but can you imagine a mangrove extending to 100 feet above the ground? I know I can’t.

Keeping in line with my mnemonic devices, I’ve labeled the Heritiera as a tree that has a heritage and has been around a long time. Most of the Heritiera we saw were small, but the tree’s leaves looked like they belonged in a retirement home. Not all of the leaves looked like this, but a disproportionately large number of them did.

This leaf has seen the wonders and horrors of its life, and as such, it’s a great psychological resource for those who would like some solid advice from a counselor that can help them navigate through life’s many difficulties.

It has buttress roots, but they are not as defined as those of Xylocarpus. In any event, the leaves are easy to identify. Not all the leaves look like they are celebrating their 50th birthday, so here are some general characteristics: the leaves grow up to 30 cm long, a dark green base, and have a silvery-white undersurface. The bark is nothing to get excited about… it is grey-ish and relatively rough just like everything else on the island. It does not have a hint of brown though, so that helps.


WOW. It’s 10:45 P.M. and I am absolutely exhausted. This blogging stuff is harder than it looks.

Our last genus is Nypa. These dudes were pretty rare where we did our research… even though they are very distinctive, I only found two on the entire trip. To make things simple and save time, they look like a palm tree that explodes out of the ground. There is no bark because there is no trunk. The fruit it produces is actually pretty groovy… it has a spiky surface and can grow to the size of a soccer ball. This is another fruit I’d love to eat.

On a side note, it’s really, really great to see coconut palms here. I’ve seen lots of palms in California that honestly annoy the dickens out of me. They don’t have coconuts, they don’t have dates… nothing. But these palms… these palms are useful. I’ve had some coconut juice (it isn’t milk… there are no breasts involved).

I apologize if my writing isn’t very fluent or if I have typos that I didn’t catch. This post took a ton of effort and I don’t want to spend all of my time in Micronesia on a computer. I am proud that I finished this though… in addition to helping others learn about mangroves, it is a great review and learning experience for me.

One more picture looking into the depths of the mangrove jungle. It is 11:17 P.M. Over and out

Charlie

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