In a previous post about what to wear while you're doing field work in Palau, there are sort of three core concepts:
1) Protect your feet from thorns/sharp rocks/stonefish, etc.
2) Protect your body from bugs and the sun
3) Don't overheat
An important point the blog post didn't cover that pertains directly to point 2 is sunscreen!
If your ancestors came from a place further away from the Equator than Palau, you might have a tough time with the levels of sunlight here. Even Palauans who work inside have told me that they get sunburned if they spend all day out on a boat. For those of you with fair skin, the only way you're going to be able to come away from this course without injuring yourself is to wear sunscreen when we're outside.
However, a growing body of research has begun to show that many of the most common active ingredients in sunscreen can be toxic to invertebrates and potentially contribute to coral bleaching. Ingredients that have been linked to detrimental effects on aquatic life include:
Octyl methoxycinnamate (EHMC)
4-methyl-benzylidene camphor (4MBC)
Some research has also shown that the very small particles of metal oxides (zinc and titanium) used in some sunscreens/sunblocks can also be detrimental to invertebrate health.
Since this research is relatively new, it seems that many companies that manufacture sunscreens haven't quite gotten the memo yet, so there are still lots of options on the shelves in the US and Palau that include these active ingredients. I checked two of the local dive shops here, and one of them carries a brand optimistically called "reef safe," but it has Avobenzone as one of the active ingredients. The other dive shop had a less deceptively-named sunblock that included Ocinoxate. The only sunscreen I was able to find that didn't include any of ingredients that are suspected to be harmful was this one:
Which has zinc oxide as the physical sunscreen barrier. If you have to buy sunblock in Palau, this might be the lesser of several evils, but as I mentioned earlier, the zinc nanoparticles are still potentially problematic for marine and freshwater invertebrates.
Anuschka, our guest instructor from Hawaii, has asked around, and says that Stream2Sea
is a favorite among some of the graduate students. There are others that could work as well, potentially including
Beauty by Earth: https://www.amazon.com/dp/B00KFNDWSY/
The Honest Company: https://smile.amazon.com/Honest-Company-Mineral-Based-Sunscreen/dp/B01E2327PG/
We'll bring some sunscreen to share, but it would be really great if you could get some environmentally responsible sunscreen, and perhaps even try it out before the course! This is a conservation biology course, so we want to make sure we minimize our potentially negative impacts on Palau, while minimizing the sun's potential negative impacts on our bodies.
I haven't ever assigned a reading from "Vogue" before, but this is a pretty good, to-the-point article about sunscreen ecotoxicology:
Jellyfish Lake in Palau, because it is small, somewhat hydrologically isolated, and potentially visited by up to 100,000 tourists a year, is a particularly sensitive area. As it's one of the primary draws bringing tourists to Palau in the first place, this is really where the interests of conservation biologist and ecotourism have the potential to conflict. Our friends at the CRRF and some of their collaborators conducted this study a few years ago:
Other, more technical sources include:
There's a turnoff in Ngardmau (or, depending on who you ask, Ngeremlengui) where you can see Ngarchelong and Ngeruktabel, Etiruir and Ngerulmud. On a really clear day, I'm pretty sure you might be able to see Kayangel. There are some really cool terrestrial habitats within walking distance, so we'll go there together once all y'all get here. This is looking northeast at the sunrise about an hour and a half after I arrived in Palau on Friday, April 27 (the evening of April 26 for you). See you in a few weeks!
As we get closer to the departure date, you might be thinking about what to pack. Well, here is a start:
To some extent, it makes sense to have separate clothing and gear for different habitats, so we'll break up this blog post a little bit. But also keep in mind that many days we'll be fairly amphibious: we probably won't do sampling in all three major habitats in one day, but most days we'll be either terrestrial/marine or terrestrial/freshwater.
In town / front country: There will be a day or two you'll be in nice-ish front-country (as opposed to backcountry) settings: you'll be interacting with Palauan elementary school students and their teachers, or the staff of a variety of NGO's and governmental agencies, so it would be good if you had an outfit or two that would not be offensive to moderately conservative mid-western Americans. Palau has a lot of foreign tourists, so the in-town dress code is fairly relaxed: you can pretty much wear things you'd wear on campus during the summer. Some of our front-country time will be spent in air-conditioned rooms, though, and they're sometimes quite chilly, so it would be good to bring at least one or two outfits that you'd be comfortable sitting around and using a microscope for a few hours when it's in the mid-60s. I usually just bring some long pants and a polypropylene long-underwear top or two. The long underwear top can also double as a rash-guard (discussed in the marine habitat section).
Terrestrial habitats: If you're from the northeast, chances are you've had the experience of being in the woods when it's hot and humid. Chances are you've walked through a thorn patch or two, and chances are you've run into some high densities of biting insects. For our terrestrial field work, it would be a good idea to be prepared for all of these things. That means it's a good idea to have long pants and close-toed shoes that let you walk through a thorn patch and avoid mosquitos a little bit. Synthetic pants sold at outdoor supply stores are a pretty good option:
Thick cotton pants (e.g., jeans) will tend to be uncomfortable in the humidity. They're pretty good for places like Arizona, but in the humidity of Palau they pretty much won't dry out... ever. They're find for front-country wear, though.
Usually on our terrestrial/freshwater days we'll be under a decent canopy of trees, so sun protection won't be quite as much of an issue, but it can still be nice to wear a light long-sleeved shirt, again, for biting insects and thorns. My favorite field shirt is a cotton men's seersucker dress shirt I got at a Ross Dress-for-Less in Guam. Hopefully I'll be able to find it for this trip so you can all revel in how awesome it is :)
Footwear for terrestrial habitats is also kind of a tricky situation. Most of the terrestrial work we'll be doing could involve a short jaunt through the water, so leather hiking boots probably aren't a great idea (like jeans, they won't dry out, and will sometimes start to rot). It's hard to find shoes that will both let you get wet and fend off thorns a bit. The neoprene booties scuba divers use are actually pretty good, but don't provide any ankle support:
Same goes for these Japanese gardening shoes (tavi's) that some people wear. They're canvas and rubber, so they breath better than neoprene booties, but they're not great for long hikes over hard-packed trails, where you would want more insole cushioning and more ankle support.
Many people who do terrestrial field biology in the tropics wear some kind of rubber rain boot, similar to this:
I personally find this general style of boot uncomfortable (they're pretty hot, and they abrade my calves when I walk, etc.), but lots of people I've worked with in, e.g., Panama, think they're great. In Borneo, I've done tropical field work in something like this,
These were honestly great, but I don't know if you can get them in the US. If you had some old, beat-up sports cleats, those would probably work pretty well, too.
A good compromise might be some old running shoes you don't mind getting wet. There are some close-toed shoes specifically made for use in the water, but it might not really be worth getting them for a 2-week course.
For walking around in the woods, you'll probably want a backpack like the one you might use for school. It's useful to have at least some part of your backpack that is waterproof. Some heavy-duty garbage bags and zip-lock bags are good for this, or, for a more long-term solution, something like the small version (4L) of this might be nice:
(Beyond this course, if you're thinking about doing marine or freshwater work (or super-rainy days on land), it can be nice to have a solid dry bag with backpack straps, like this:
But keep in mind that if your water bottle leaks while it's in this bag, the water will stay in the bag. So, having one or more waterproof/water resistant containers within your bag can be nice.)
Freshwater habitats: The freshwater habitats we'll be working in will mostly require between 15 minutes and 2 hours of walking through the forest, so you'll more or less have wear clothes you'll be comfortable in both places with. For freshwater sites we can access directly from the road, it would probably be most comfortable to wear shorts and some kind of Teva- or Chaco- like sport sandal. But I've had bad luck walking through thorns and then walking through the mud (had to miss a few field days because of a staph infection in some thorn scratches), so it's probably wisest to stick with your terrestrial outfits: old running shoes or neoprene booties, and long pants. The parts of the rivers we'll be visiting will mostly be a bit too shallow for snorkeling, so expect to get wet up to your knees or waist, but you don't need to be prepared for fully swimming in the water with mask, fins, and snorkel. The deeper parts of the rivers tend to be closer to the estuaries where there are lots of mangroves, which is where crocodiles tend to hang out, so we won't be swimming there.
In our marine surveys, it'll be important to be comfortable in the water, but it's also important to be comfortable taking short walks across potentially sharp corals and stones, so the combination of "open-heel" style fins and rubber-soled neoprene booties is pretty nice to have:
or something like these:
fins (recommend "open-heel" design to accommodate booties):
For the booties and the fins, it's OK to go pretty low-budget, but when it comes to masks you probably want to spend more than $40, and make sure you try your mask on. You should be able to put your mask on your face, breath in a little bit, and hold the mask on your face with no hands and no strap: that's how you tell it's air-tight. Having a mask that really fits your face really makes a huge difference in how much you can see while you're snorkeling. Here's a quick youtube video that talks about fitting a mask to your face in case what I just said doesn't make sense: https://www.youtube.com/watch?v=Yv7o8EeAIYY
Another really useful item of marine clothing is a long-sleeve rash guard:
The water is warm enough (generally around 82 degrees F) in Palau that people don't usually snorkel with a neoprene wetsuit, but the rash guard is nice because it provides some warmth, and also protects you from the sun. If you're coming more or less straight from Syracuse to Palau, your body might not be great with dealing with being in the tropical sun all day. Similarly, for women, it can be nice to wear knee-length shorts while you're snorkeling, since it's basically extra sun protection (and can give your legs a bit of extra protection while you're doing terrestrial field work on combined terrestrial/marine days). If you get cold easily (and/or want some extra sun protection and/or modesty), it might be worth looking into one of the longer swim-suit designs, like this:
In addition to warmth and protection from the sun, longer swimsuits also provide some protection from stinging cnidarians, like jellyfish and firecorals.
For getting your salt-water-y gear from the boat to the car, it can be nice to have a mesh bag like this:
If it's raining on the boat ride home, it can get pretty chilly, so it's nice to have a light rain jacket. In the forest, I personally think it's a little too hot for raincoats, and it often feels more comfortable to use an umbrella. Umbrellas can make activities like eating and writing in the rain much easier and more pleasant.
Finally, for both freshwater and marine surveying from out of the water, it can be very nice to have a decent pair of polarized sunglasses. Polarized lenses genuinely do cut down on glare from the sun reflecting off water (it's not just a gimmick), so they can help you see below the surface. You don't need to spend thousands of dollars on sunglasses, but you might want to spend more than $10. When you try on the sunglasses, look at the sky (if it's daylight and you're not too far into a store), and tilt your head from one side to the other. The sky should change color perceptibly as you tilt your head. Here are some somewhat reasonably-priced sunglasses with polarized lenses that float:
For doing work at night, it would be great if you had a headlamp. If you can, bring a waterproof flashlight as well, in case we get the chance to go snorkeling at night. There could be some pretty cool stuff going on in the ocean with the full moon on May 29th.
So, in summary, the tl;dr version of what kinds of clothing/field gear to bring:
Front country pants (1 - 2; synthetic or cotton: for wearing in overly air-conditioned buildings)
Front country longsleeve shirts (1 - 2; consider a medium-weight polypro long underwear top or flannel)
Front country footwear (doesn't have to be fancy: just something relatively dry and mud-free; I usually wear flip-flops aka slippahs aka zories)
One or two semi-respectable front country tops (for wearing when we're presenting things to school kids or meeting important people)
Backcountry pants (2 - 3 pairs; synthetic, to protect against mosquitos and thorns)
Backcountry longsleeve shirts (2 - 3; cotton or synthetic; see notes about pants above)
swimsuit (1 - 2; a good idea to rinse off with freshwater after use)
shorts: good for mixed backcountry / front-country (5 - 7 pairs, e.g., "board shorts")
tshirts for back-country / front country (5 - 8)
Rash guard / longer swimsuit options
underwear and socks for 7 - 8 days (we'll be able to do laundry at least once during the course)
Light raincoat / poncho (ponchos are super-cheap and can also cover your backpack)
1 - 2L water bottle(s)
Mesh bag (optional, but can be nice)
Neoprene booties / water socks
Mask & snorkel (make sure it's a good mask that fits your face! see discussion above!)
Waterproof watch (an inexpensive waterproof watch can be really handy; it would be good if at least half of you had one)
writing implements (especially pencils)
Laptop (if you have one)
camera (if you have one)
OK, thanks for reading! Definitely feel free to ask Jesse or Dr. Rundell questions, or add comments below!
Jellyfish Lake, Palau: Early diagenesis of organic matter in sediments of an anoxic marine lake (summary by Ming)
Orem, W. H., Burnett, W. C., Landing, W. M., Lyons, W. B., & Showers, W. (1991). Jellyfish Lake, Palau: Early diagenesis of organic matter in sediments of an anoxic marine lake. Limnology and oceanography, 36(3), 526-543.
Jellyfish Lake on Eil Malk Island in the Western Pacific country of Palau is an isolated marine lake. Restricted circulation in the lake leads to formation of anoxic bottom water layer which helps preserve organic matter in sediments. The authors sought to measure the elementary contents and stable isotopes in sediments from Jellyfish Lake and studied the process of diagenesis.
Wet sediment samples were collected from Jellyfish Lake for dissolved organic carbon analysis. Then the concentrations of elemental contents in organic matter obtained were measured. Carbonate shells of bivalves and gastropods from Jellyfish Lake sediments were collects for stable isotopes measurements.
The result of measurement shown that organic matter is abundant in sediments of Jellyfish Lake. Around 91% of organic matters in sediments are derived from vascular plant remains and 9% are from algal. Elementary content results and stable isotopic data of shells from the sediments suggest the differences between Jellyfish Lake and other marine lakes can caused by long-term geological changes, close climatic and ecological changes, vegetation around the lake.
Significance for Palau:
This research is relevant to conservation of jellyfish and other species in Palau because it studied the formation and composition of organic matters in Jellyfish Lake, a marine lake which sufficiently isolated. Permanently stratified marine lake like Jellyfish Lake is not usual. The stratification caused by restricted water circulation separate lake water into oxygenated top layer and highly sulfidic anoxic bottom layer. Special conditions of this lake affects speciation and migration of the golden jellyfish, Mastigias cf. papua etpisoni and other species. Findings about the elementary content composition an organic matters in Jellyfish Lake helps maintain and protect the habitat for living species in Jellyfish Lake.
Sampling across space and time to validate natural experiments: an example with ant invasions in Hawaii (summary by Jani)
Krushelnycky, P.D. & Gillespie, R.G. (2010) Sampling across space and time to validate natural experiments: an example with ant invasions in Hawaii. Biological invasions, 12, 643–655.
Studying the ecological impacts of invasive species on an ecosystem can be difficult because experimental approaches involving introduction or removal of an invasive species cannot be used. Instead, such studies are often done by comparing communities of invaded habitats to communities of similar, uninvaded habitats. Krushelnycky and Gillespie test a comparative method of sampling inside and outside of invasion boundaries as well as across time with invasive ant species in two sites on Hawaii Island.
Invaded plots, uninvaded plots, and plots that were expected to become invaded were sampled at each site, examining arthopod species richness and the presence of indicator species associated with invaded and uninvaded conditions. The plots were sampled a second time two years later and community composition was compared between plots and between the two sampling events.
In one site, the community composition in plots before invasion was significantly different from that of invaded plots and not significantly different from uninvaded plots and became significantly different from uninvaded plots and not significantly different from invaded plots after invasion. In the other site, changes in community composition were found in plots before and after invasion. In both sites, several arthropod species that were found to be indicator species shifted in abundance before and after invasion. The results suggested that at least partial transition of community composition had occurred after two years in response to ant invasion.
Significance for Palau:
The two species of ants studied, Phelidole megacephala and Linepithema humile, are reported to be among the most dominant invasive ants in the world. Introduction of these or similar ant species may be a possible threat to Palauan biodiversity, based on their invasion of sites in Hawaii. The small size of some habitats in Palau and the exclusive range of many invertebrate species may further increase the impact of invading species on local communities. The sampling method used in this study may be useful for long term studies in Palau; the authors were able to use this method on another small tropical Pacific island. The study also suggested that more than two years would be needed for significant changes in response to invasion to be observed. Even if differences exist between the conditions described in the paper and Palau, conservation studies in Palau would likely involve similar procedures and comparisons of arthropod and invertebrate communities.
Woesik, R., Houk, P., Isechal, A.L., Idechong, J.W., Victor, S., & Golbuu, Y. (2012) Climate-change refugia in the sheltered bays of Palau: analogs of future reefs. Ecology and evolution, 2, 2474–2484.
This study sets out to describe the effects of location on the degree of coral bleaching from thermal stress. They add the factor of taxonomy to determine which clades of coral are the most affected by this change. The scientists use this information to recommend where we should focus conservation efforts spatially in the face of climate change.
Scientists used still pictures from video footage taken before and after a thermal stress event in 2010 to determine the degree of coral bleaching in Palauan reefs caused by the change in temperature. They recorded patterns in 35 genera of coral and three types of reef areas: bays, patch reefs, and outer reefs, and used a satellite to compare their respective geographical temperature.
Populations of the coral genus Pocillopora were the most affected by thermal stress, followed by Psammocora and Seriatopora. The warmest reefs experienced the least amount of temperature-derived damage. Therefore, the bay reefs were described as a possible refuge for coral during the event of thermal stress.
Significance for Palau:
Although the Palauan thermal stress event of 2010 serves as a microcosm of global climate change, the results apply directly to the health of Palauan coral reefs. This study tells us that the bay reefs of Palau should be the healthiest compared to any other type of Palauan reef. Therefore, Palauan bay reefs could be useful for the salvation of coral clades such as Pocillopora, which suffer greater consequences of thermal stress in out in patch and outer reefs. Additionally, it is possible that more diversity can be observed in these regions, which is helpful to understand for further research in Palau and even ecotourism.
Green, Peter T., Dennis J. O’Dowd, Kirsti L. Abbott, Mick Jeffery, Kent Retallick, and Ralph Mac Nally. Invasional meltdown: Invader-invader mutualism facilitates a secondary invasion. Ecology, vol. 92, no. 9, 2011, pp. 1758-1768.
Green et al. discuss the increasing prevalence of species invasion in all ecosystems due to human invasion and note the unexplored idea that interactions between invasive species in the same environment could have notable consequences, such as impacting invasion success and propagule pressure. The focus is brought to the invader-invader mutualism between the yellow crazy ant and honeydew-secreting scale insects, two bioinvaders of Christmas Island that together create yellow crazy ant supercolonies. Their interactions facilitate a secondary invader, the giant African land snail, by suppressing the native red land crab. The authors observe the relationship between the mutualistic invaders and the giant African land snail over the course of 7 years to gain insight on the poorly-understood effects of interactions between invasive species.
The authors used Bayesian hierarchical models to determine if the effect of the ant-scale insect invasion influences the spread of giant African land snails, which they tracked over the course of 7 years. Potential reversal effects of suppressing the ant-scale insect supercolonies were explored, as well as the effect of suppressing the red land crab on giant African land snail populations through site comparisons and experiments.
The probability of giant African land snails invading sites with abundant red land crabs is 14 times lower than that for sites with no crabs or supercolonies, and 253 times lower than that for sites with supercolonies and a suppressed crab population. Managing these supercolonies at certain sites reverses the probability of snail invasion and recovers the crab population for those sites. At sites with supercolonies, almost all snail mortality is due to starvation, and ants only feed on dead snails.
Significance for Palau:
Palau is an isolated archipelago with a plethora of unique endemic species inhabiting its many islands; as a similarly isolated land mass, Christmas Island has evolved into a unique environment, housing many endemic species of its own. This study demonstrates how just two small exotic organisms, introduced to the environment through human interference, can become a massive threat to biodiversity in a given area. Furthermore, it demonstrates the importance of studying the interactions between invaders, as well as the success of suppressing the invasive populations to recover native populations. As a republic with an economy heavily based on tourism, Palau continues to be subjected to more and more invasive species that disrupt the delicate native ecosystems. This study is especially relevant to conservation in such a place, as it lays some of the groundwork required for remediating the natural environments of isolated land masses such as Palau.
Pollinator dependency, pollen limitation and pollinator visitation rates to six vegetable crops in southern India (summary by Alexandria)
Carr, S. A., & Davidar, P. (2015). Pollinator dependency, pollen limitation and pollinator visitation rates to six vegetable crops in southern India. Journal Of Pollination Ecology, 16 51-57.
The aim of the study is to observe and gather information on the levels of pollinator dependence, pollen limitation and identifying major pollinating insects that visit flowers and six vegetable crops in Southern India. The six different type of crops consist of brinjal, tomato, chili pepper, okra and bitter and snake gourds. Pollinators are crucial to the reproduction of plants and studying what affects the our produce/agriculture could further studies on that topic.
The study was done in Tamil Nadu where six family farms were selected during December 2011 to June 2012, from November to December 2012, and from January to March 3013 which were main growing seasons for vegetables. In order to gather information of the plants, level of autogamy and pollinator dependancy Carr and Davidar used hand pollination experiments. Plants were randomly selected and stemens of the six plants would be collected in order to gather how much pollen there is. In order to collect pollinators they captured them after treatment of flowers using cotton mosquito mesh cloth bags. How much fruit each plants had was also looked at. There are two different treatments they did on the flowers: self, cross, and open pollination treatment. They observed the breeding system using the index of self-incompatibility; pollination dependacy was estimated by subtracting the percent fruit by autogamous pollination from percent fruit set bt open pollination and pollen limitation was found as the ratio of percent fruit set from hand cross pollination to open. Lastly pollinators were observed and categorized as well as doing a non parametric statistical analysis to test the differences between fruit set from the pollination treatments between crops, and visitation rates of different pollinator taxa.
The fruit set during the cross pollination treatment was lower than open which could damage floral parts during emasculation or poor quality pollen. Fruit set for the open pollination treatment was from 40-72% and didn’t differ in crop type. Pollinator dependacy average was 26+/- 21 where tomato was 0; it also ranged from 8-76% within crop variety except for tomato. There was no evidence of pollen limitation except for from brinjal at one site.The found that there five main pollinators: social bees, stingless bees, solitary bees, Lepidoptera (butterflies and moths), and wasps. Honeybees and butterflies visited all flowers but had the highest visitation rates for tomato, chili, and gourds. Solitary bees and butterflies to brinjal. Honeybees went to the okra.
Significance for Palau:
I will specifically be observing pollinators in Palau since it hasn’t been studied in depth there. I think this study can help me relate to what I would be looking for when I get the chance to do my own study. While reading the study it gives me a lot more depth and explain what certain things mean which can help me understand what I am looking at while observing the invertebrates that pollinate certain flowers in Palau. Even though this study was done looking at the agricultural background it would have the same effect as if I do it with any other flower.
Fortunato, H. (2015) Mollusks: Tools in Environmental and Climate Research. American malacological bulletin, 33, 310-324.
The purpose of this paper is provide “an overview of the use of mollusks in environmental and impact studies,” ranging from paleo-environmental conditions to potential changes due to global warming. This paper looks at how the wide variety of mollusks provide insight into the environmental factors that influence ecosystem health and composition and why mollusks are key indicators of ecosystems around the world.
This paper analyzes the use of mollusks as indicators for environmental conditions both in the past and for future changes in climate based on the composition of their shells. This meta-analysis bases its claims from a number of different studies regarding the use of magnesium calcite and aragonite compounds in mollusk shell composition as proxy data to evaluate paleo environmental conditions.
Due to the wide variety of mollusks habitats and the even wider variety of mollusk species globally, the various, yet specific chemical composition of their shells provides details in changes in environmental factors such as ocean warming, ocean acidification, and increased surface temperatures. The deposits of mollusk shells on the sea floor also gives indication of what past ocean conditions were like, acting as a proxy for ocean and climate data. Additionally, some species adapted better to changes in ocean temperature and pH, showing significant differences between the various species that show the versatility of the taxa for future studies as environmental indicators for climate change.
Significance to Palau:
As the paper examined, mollusks provide a way to gage ecosystem health and changes in climate and weather in the present and the past. Palau is home to hundreds of species of mollusks, both aquatic and terrestrial, that can provide insight into how each respective ecosystem will respond to climate change. Due to the rapid changes in climate in areas such as Palau, mollusk populations are more important than ever as a tool to study these effects. However, without considerable efforts made to conserve these populations, we are at risk of losing a vital part of the ecosystems of Palau and the regions around it. Conservation of mollusk populations in Palau will not only help an individual species, but all ecosystems on the islands as well as hundreds of other ecosystems worldwide through the knowledge studying mollusk populations can provide.