Clinking Glasses: Not Just for Toasts

Jaclyn Caruso, Salem State University

Me Aquarium

The Approach: How can sea urchins tell us whether preservatives used in cosmetics are harmful to the environment? Our approach involves the rhythmic clinking of glasses—but we’ll get to that.

As detailed in my previous post, concerns about the use of parabens as preservatives led to the introduction of new, “safer” alternatives, like phenoxyethanol and chlorphenesin. We are testing the effects of these preservatives on the early development of the purple sea urchin, Arbacia punctulata. Sea urchins are useful for laboratory studies because they are easy to rear and they have free-swimming larvae with distinct morphologies, allowing us to test for both lethal and subtle effects of these chemicals.

Because this is a first test with sea urchins and concentrations that induce a response have varied among studies, the concentrations of chemicals in seawater we are using span a large range—1000 to 0.1 parts per million (ppm). Including controls with no chemicals creates 34 jars per trial. Over the summer we will be able to complete several independent trials using different male-female pairs.

To collect sperm and eggs from male and female sea urchins, we apply a mild voltage with electrodes to the top of the sea urchin close to the gonopores, the small openings where gametes come out. Once we gather the sperm and eggs, we dilute them to specific concentrations, combine them, and let nature take its course! After an hour, we add fertilized eggs to each of the jars, which are stirred by glass paddles. The stirring allows larvae to get plenty of oxygen and to avoid settling at the bottom of the jar. The paddles have to be glass because plastics can potentially alter the results (ASTM, 2015). The whole apparatus has a pleasant clinking sound once running!

After two days, we collect the developing stages, preserve them with methanol, and keep them at ‑20°C until they are measured. Finally, the analysis begins! We load a counting chamber with the larvae and use a microscope to count the number of individuals that are in each stage of development. By this point, a larva should have 4 arms—known as the pluteus stage.

Pluteus

A preserved 4-arm pluteus larva. Scale bar = 0.1 mm. Jaclyn Caruso, 2018.

If larvae in the chemical jars are at earlier life stages compared to the controls, it suggests that the chemicals delay or stop development.

To look at more subtle effects, we are also measuring 20–25 individuals that have reached the larva stage per jar using 10 specific landmarks on the body. The microscope uses a camera lucida to project an image of the larva onto a digitizing pad that can record the location of landmarks in three dimensions. We use these data points to generate 3D models of each of the larvae to measure the size of the skeleton. This technique will allow us to test for sublethal effects of the chemicals that might not be obvious at first glance.

Workspace

The camera lucida arm of the microscope sits over the digitizing pad. Jaclyn Caruso, 2018.


Acknowledgements

Thank you to Dr. Bob Podolsky (CofC) for his mentorship, Dr. Cheryl Woodley (NOAA) for providing her procedures and resources, and Pete Meier (CofC) for teaching me the ropes of setting up aquaria. This project is supported by the Fort Johnson REU Program, NSF DBI-1757899.


References

ASTM (2015) ‘Standard Guide for Conducting Static Acute Toxicity Tests with Echninoid Embryos’, Astm, 131, pp. 1–2. doi: 10.1520/D7385-13.2.

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Is “Paraben-Free” the Way to Be?

Jaclyn Caruso, Salem State University

Me-WetLab Edit

In the wet lab, we wear a lei to remember to shut off the tank valve. Photo: Jaclyn Caruso, 2018.

The problem: Have you brushed your teeth today? Washed your hair? Put on deodorant, perfume, makeup, or lotion? If you (hopefully) have, you’ve used a cosmetic. According to the FDA, anything that is applied to your body with the intention of cleansing or beautifying it is a cosmetic (FDA, 2018). Because this category covers such a wide variety of products, it’s easy to imagine just how many are used worldwide on a daily basis.

Like anything people use, cosmetics are eventually washed off, and often end up in the ocean from sewage drains and wastewater treatment plants. The problem with this pollution is that cosmetics contain preservatives. Although these components prevent the growth of bacteria and mold, their actions when introduced to natural systems are not tested at great lengths when considering their frequent use. Until a few years ago, the most common preservatives were a group of chemicals called parabens.

But, you’ve probably heard of at least one product that claims to be “paraben-free.” This aversion to parabens followed a landmark study in 2004 which showed that parabens have the potential to accumulate in human breast tumors (Darbre et al., 2004). The authors explicitly stated that the source of the parabens (methylparaben, mainly) was unknown, but many people were shaken by the findings. Cosmetics manufacturers began changing their formulations by using newer, “safer” preservatives like 2-phenoxyethanol and chlorphenesin (Bressy et al., 2016). However, these alternative preservatives have not been extensively tested for their effects on marine animals, which may be at risk when these chemicals enter the ocean.

Me with Urchin

Collecting sea urchins at Breach Inlet! Photo: Dr. Podolsky, 2018.

My research this summer aims to explore the effects that these alternative preservatives have on marine animal development. We will use the local sea urchin Arbacia punctulata as a model, because it is easily collected in the wild and reared in the lab. Like many marine animals, A. punctulata is a broadcast spawner—males and females release their sperm and eggs into the water column. After fertilization, the embryos develop into free-floating larvae, which are highly sensitive to pollutants.

We will expose the sea urchin larvae to various concentrations of each chemical to test whether larval development is affected negatively by the chemicals. Such negative effects could inhibit the ability of sea urchins to develop properly, leading to death or inability to mature to adulthood. If we see effects in sea urchins, there is a possibility of similar effects in other species that may be more directly important to humans, like fish and crustaceans.

Our ultimate goal is to explore whether products that are safer for people are safer for the marine environment. If they are—great! If not, we need to think critically about the products we use that end up in the ocean, because human and ocean health are inextricably linked. Healthy oceans, for example, provide us with food, medications, recreation, and more (NOAA, 2018).

Blog 1 Photo

Left: A beautiful specimen of Arbacia punctulata. Scale bar = 1 cm. Right: Dr. Podolsky demonstrating how to induce spawning in sea urchins using a low voltage across the gonopores. Photos: Jaclyn Caruso, 2018.

 


Acknowledgements

Thank you to Dr. Bob Podolsky (CofC) for his mentorship and endless patience, Dr. Cheryl Woodley (NOAA) for graciously offering her procedures and resources, and Pete Meier (CofC) for teaching me the ropes of setting up aquaria. This project is supported by the Fort Johnson REU Program, NSF DBI-1757899.


References

Bressy, A. et al. (2016) ‘Cosmet’eau—Changes in the personal care product consumptionpractices: from whistle-blowers to impacts on aquatic environments’, Environmental Science and Pollution Research. Environmental Science and Pollution Research, 23(13), pp. 13581–13584. doi: 10.1007/s11356-016-6794-y.

Darbre, P. D. et al. (2004) ‘Concentrations of Parabens in human breast tumours’, Journal of Applied Toxicology, 24(1), pp. 5–13. doi: 10.1002/jat.958.

FDA (U.S. Food & Drug Administration) (2018) ‘Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?)’ https://www.fda.gov/Cosmetics/GuidanceRegulation/LawsRegulations/ucm074201.htm (accessed Jul. 2, 2018).

NOAA (National Oceanic and Atmospheric Administration) (2018) ‘What does the ocean have to do with human health?’ https://oceanservice.noaa.gov/facts/ocean-human-health.html (accessed Jul. 2, 2018).

Are New Englanders more tolerant than Southerners? A test of latitudinal variation in Atlantic sea urchins

Kaelyn* Lemon, Macalester College/ Dr. Bob Podolsky and Grice Marine Lab

If you’re not a climate change denier, you know that global climate change, mainly driven by the increasing amounts of carbon dioxide that humans release into the atmosphere, has been raising the Earth’s average temperature and will continue to do so for the near future. If you are particularly well-versed in your environmental science, you know that these increasing amounts of carbon dioxide are also causing the oceans of the world to become more acidic (see: coral bleaching) (1). Unless you are a marine or climate scientist, though, you probably don’t know why climate change is causing ocean acidification or how this will affect ocean animals besides probably not being the best thing ever for them.

Our oceans actually absorb around 30% of the carbon dioxide we release into the air (2). This CO2 hangs around as a gas mixed into the water and goes through a series of chemical reactions that both release hydrogen ions (the H in pH), therefore lowering the pH of the water and making it more acidic, and reducing the amount of carbonate available in the water for ocean animals and other organisms to use (2). Animals like sea urchins that build shells or skeletons out of calcium carbonate (the main ingredient in limestone) find this task more difficult when there is less carbonate around.

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Ocean acidification due to greater amounts of carbon dioxide in the atmosphere leads to less carbonate in the water (from http://www.i-fink.com/ocean-acidification/)

While the thought of sea urchins will bring to mind their hard, spiny exterior, these animals (yes, there are body tissues inside those aquatic pincushions) are actually most affected by ocean acidification during their larval stage of life, when they build a skeleton that allows them to swim around and eat (3) (urchin larvae are like insect larvae in that they behave and look very different from the full-grown animals they will eventually become). When oceans become more acidic and less carbonate is available, urchin larvae are smaller, which makes it harder for them to eat at the same time as they are more at risk of being eaten themselves (3). Unfortunately, a world with a lot fewer urchins would be a world where seaweed would easily overgrow ocean habitats and predators of urchins (like the adorable fuzzy otters that lay on their backs in the ocean and hold hands- google it) might have more difficulty finding food.

IMG-20150603-03088

One of the sea urchins from South Carolina with some of the seaweed they like to eat (photo credit: Kaelyn  Lemon)

I’m looking into whether sea urchins (specifically the species Arbacia puntulata, which is found in the Atlantic ocean) from Massachusetts and South Carolina will react differently in higher acidity. If one group of urchins can produce larvae that maintain a larger body size under more acidic conditions than the other group, then we will know that there is some degree of variability within the species. This would be a positive result for the sea urchins (and therefore for oceans in general) because it would mean that these urchins may be able to adapt to acidified waters more easily than we can currently expect.

Sources:

1. IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.

2. Clark D, Lamare M, Barker M. 2009. Response of sea urchin pluteus larvae (Echinodermata: Echinoidea) to reduced seawater pH: a comparison among a tropical, temperate, and a polar species. Marine Biology. 156: 1125-1137.

3. Sheppard Brennand H, Soars N, Dworjanyn SA, Davis AR, Byrne M. 2010. Impact of ocean warming and ocean acidification on larval development and calcification in the sea urchin Tripneustes gratilla. PloS One. 5:1-7.

Funding from the NSF and support from the College of Charleston

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