Scientific Photography

by Jackson Chu

We all have indispensible tools we use in science. A sturdy bucket for sampling intertidal critters and seaweeds. Our trusty calipers for measuring morphometrics. Our favorite R-package for numerical ecology. All these are important for doing science. My favorite tool for scientific communication and outreach are pretty photos! A good photo can captivate and create interest in your work and, more importantly, let you communicate science to a much greater audience.

Three classes of sponges. Left: a calcareous sponge (Sycon sp.). Middle: a carnivorous demosponge (Asbestopluma occidentalis). Right: a juvenile hexactinellid (glass) sponge (Aphrocallistes vastus). All scale bars  = 1 cm.  © Jackson Chu. All rights reserved.

How did I take those photos?

There are a few key ingredients: (1) a digital slr, (2) a  50mm lens or 28mm lens, (3) a reversing ring, and (4) a flash that can be used off camera. (e.g. with an off-camera sync cord)

My science photography kit.

My science photography kit.

As a graduate student living on mac and cheese, I cobbled together my used camera equipment from various online sources (e.g. eBay). The camera brand really makes no difference. I would estimate I spent ~$300 for everything:  $200 for the camera, $50 for the lens, $2 for the reversing ring, and $50 for the flash. Because I am always working with small (but not microscopic) invertebrates, one trick to close-up (macro) photography is to mount the lens backwards onto the camera using the reversing ring.  A 50mm lens mounted backwards onto a camera will give you a 1:1 magnification ratio (1 cm object will be 1 cm on the camera sensor).  A backwards mounted 28 mm lens will give you a higher magnification ratio of 3:1. There are also other alternatives that yield similar results: macro-focusing teleconverters, extension tubes, or dedicated macro lenses.  In order to get proper lighting, a flash will have to be oriented close to the object. You can do this in one of two ways. Modern day flashes can be wirelessly triggered from the camera. Otherwise, an off-camera flash cord can be used.

Most of the time I’m trying to take photos of my live study organisms.  What’s worked for me is to use a shallow, flat-bottomed glass tray filled with filtered seawater. Petri dishes work great for tiny 1-cm critters like carnivorous sponges. Glass baking dishes are great for >5 cm sized critters like nudibranchs and seapigs. I usually slip my neoprene laptop sleeve underneath the tray of seawater to create a black background in my photos.

Here are some examples!

Some nudibranchs from Scott’s Bay, Bamfield. Left to right: orange peel nudibranch (Tochuina tetraquetra), white lined dirona (Dirona albolineata), opalescent nudibranch (Hermissenda crassicornis), and clown nudibranch (Triopha catalinae). © Jackson Chu. All rights reserved.

Sea piglets. Juvenile sea pigs (Scotoplanes globosa) sampled from 1500 m in the northeast Pacific Ocean. Each sea pig was ~5 cm in length. © Jackson Chu. All rights reserved.

Bamfield featured tonight on CBC’s Still Standing

by Amanda Kahn

Jonny Harris showcased Bamfield, B.C. in an episode of Still Standing, airing tonight at 9:30 PM PST. Image linked from the website of Still Standing.

In 30 minutes, the town of Bamfield will be featured on CBC’s comedy show Still Standing.  Jonny Harris visited Bamfield and met its wonderful residents, plus got a tour of the marine station.  You can watch the show online here.

Dr. Louis Druehl is one of many Bamfielders featured in Still Standing. Image from the Still Standing Facebook page.

Long carapace spines help larval crabs swim

by Anna Smith and Amanda Kahn

We are used to seeing crabs scuttling across the seafloor or scrambling under rocks in the intertidal zone, but before they settle on the seabed they have larval stages that live in the water column as plankton.  Zoeae (pronounced zoe-EE-uh) and megalopae (MEG-uh-lope-ee) drift through the water, eating food and eventually metamorphosing into bottom-dwelling crabs.

Life cycle stages of a crab: an egg hatches into swimming zoea stages, then to a megalopa, then metamorphoses into a benthic juvenile and adult crab. Image credit: A Snail’s Odyssey

For her class project in Crustacean Biology (a summer course taught in 2012), Anna Smith worked with instructor Greg Jensen to study how swimming is accomplished by the zoeae of a porcelain crab, Petrolisthes cinctipes. Most crab larvae swim vertically in the water column and are fairly poor swimmers. These zoeae are swept along with the currents and are often taken out to sea with no hope of returning to the shore to settle. Check out the video below to see how zoeae of most crab species move in the water.

Most crab zoeae have sharply pointed spines projecting from their carapace, as pictured below. Previous studies have found these spines to be connected with predator avoidance by making the larvae harder to swallow. The zoeae of porcelain crabs, however, have unusually long spines sticking out the front and back of the carapace. They are also much stronger swimmers than zoeae of many crab species, enabling them to stay close to shore and avoid being swept away from settling grounds. These zoeae swim horizontally through the water column and exhibit much more directional control than most crab zoeae. Anna studied whether the elongated spines of porcelain crabs were connected to their unique swimming by studying their swimming ability with both spines intact, then removed the front, back, or all spines to see how their swimming changed.

Zoea of a porcelain crab. Image credit: Greg Jensen 2015. This image is from his new book, Crabs and Shrimps of the Pacific Northwest.

The spines were in fact very important to the swimming ability of the zoeae.  Zoeae who had their front (anterior) spine removed could not maintain constant depth in the water.  Zoeae who had their posterior spines removed could not swim backwards or change directions easily and with both front and back spines removed the zoeae could not swim at all. This led Anna and Greg to conclude that the spines contribute to the superior swimming ability of porcelain crab zoeae.

Why is this important? This suggests that the carapace spines are not only used as physical protection from predators, as previously suggested, but also contribute to their survival in other ways. Anna and Greg also hypothesize that the ability to better control direction and water column depth helps the zoeae navigate currents and stay close to shore and may explain their limited dispersal offshore.

Citation:

Smith, AE, and GC Jensen (2015). The role of carapace spines in the swimming behavior of porcelain crab zoeae (Crustacea: Decapoda: Porcellanidae).  Journal of Experimental Marine Biology and Ecology, 471:175-179.

If you want to learn more about the crabs and shrimps along our coast, check out Greg Jensen’s new crustacean guide Crabs and Shrimps of the Pacific Northwest.

To learn more about this course and others offered at BMSC, check out the University Programs website.

Flat foram

By  Nicole Webster

I had a thin section made of one of my shells, and it came back with a serendipitous hitchhiker. A foraminiferan, you know, those single celled protists that make a gorgeous test (shell) usually out of calcium carbonate? Well it was at just the right place to be beautifully sectioned itself. The section is 30um thick of a 5cm shell, and the foram itself is only 0.5mm wide.

Foram thin section in plane polarized light.  The darker spots inside the test are probably dried up tissue, and the little balls underneath the test are probably the glue used to attach the foram to the shell. Credit N. Webster

Foram thin section in cross polarized light. Credit N. Webster

Thin sections are typically used in geology to identify different crystals, and thus the rocks that they are made up of. I recommend a quick Google image search, some are really quite pretty. Here I was using it to see how many layers and in what orientation the crystals are layed down in my snails.
A chunk of rock (or shell) is ground down as smoothly as possible to 30um (0.03mm) so that it is transparent. Once under the microscope, a polarizing filter is used to see crystal features better. A cross polarizing filter is used to see interference colours, allowing greater characterization of the mineral. That is why the second image looks a little like something from the 60s. Although the CaCO3 is relatively clear, the glass of the slide refracts the light quite a bit, making a psychodelic pick rainbow. This is a very simplistic view of thin sectioning, please correct me if I’ve misunderstood something.

PS I learned a new word making this post. Arenaceous. It means sandy, or likes sand (for plants), and specifies a geologic grain size ranging from 2 to 0.625mm. In this context it means those foraminifera that don’t grow their own shell, but rather glue bits (read:sediments particles) together to make a shell.

References
1. Rock-Forming Minerals in Thin Section. Steve Dutch, Natural and Applied Sciences, University of Wisconsin. https://www.uwgb.edu/dutchs/Petrology/thinsect.htm
2. Corliss, B. H. 1985. Microhabitats of benthic foraminifera within deep-sea sediments. Nature 314:435-438.

Jack O’ Lanterns Made with R

Figure 1. Jack O’ Lanterns carved with the statistics application R, by students in the Bamfield Marine Sciences Centre Fall Program.

Maybe you already know that the computer programming language R can be used for statistics, and data visualization. You can also use it to draw pictures. The easiest way to do this is by using the ‘locator’ and ‘polygon’ functions. You can make your own Jack O’ Lantern with R using the script provided in the previous post “Pumpkin Carving with R”.

Link

By Amanda Kahn

This summer’s Marine Protected Areas class stumbled upon a rare sight: while using the BMSC remotely operated vehicle they encountered a massive aggregation of box crabs. Also seen in the video is a flatfish and several crinoids.

Check out the video on Youtube here

And now for something completely different

By Nicole Webster

Perhaps we are a little focused on invertebrates here, or perhaps this gorgeous weather has gone to my head, but I have a ‘treat’ for you for an Image Fest Friday.

Fish bones dried on the docks. Not that interesting. Can anyone ID the parts?

Yeah, sorry, its poop. but whose?

That is clearly no bird poop. From the diameter I was thinking cat-sized.

It was all over the docks, to the dismay of Janice who washed it all off. She also solved my mini mystery. Its river otter poop! It is regularly appearing on the docks, and I saw a couple playing there earlier in the year, so there may be some living nearby.

Some Intertidal non-crustacean arthropods

By Nicole Webster

The intertidal is a transitional zone, from the water to the air, but also from salt to fresh water. A lot has been said about the ecological consequences of this transition, perhaps idealized by salmon’s migration and how they transfer nutrients from the marine to terrestrial/freshwater ecosystems (Cross-boundary subsidy). I’m not going to say anything in depth about this, and if you are interested, I recommend speaking to Caroline Fox (uvic website), who is in and out of Bamfield semi-regularly and is completing her PhD on this topic.

This post is nothing so ecological or philosophical. This summer I came across a couple arthropods (non-crustacean) that are not commonly mentioned and wanted to expand your view of the intertidal.

This is Diaulota densissma (I believe).

This is a rove beetle (Diaulota densissma) in a petri dish, with possibly a larva. They are not easy to photograph. I could have sedated one for better ID and imaging, but didn’t. Credit: N Webster

I encountered these beetles on the barnacle rocks that I heave to the lab to feed my greedy snails. Quite a few of them I found regularly swimming desperately on the water in my seatable and crawling around on the dry rocks. At first I thought they were unfortunates brought in from a true terrestrial habitat, but there were too many, and too consistent. It was suggested to me to check out Kozloff’s Seashore life of the Northern Pacific coast. It is not a field guide, nor is it like his Key to Marine Invertebrates. It is really a nice introductory book about the seashore, looking from high to low intertidal, from sandy to rocky shores, and describing the types of organisms found there.

This is the beetle on a barnacle rock. Credit: N Webster

Indeed my rove beetle is in the book. It is a small intertidal predator that eats mainly amphipods and other tasty arthropods at low tide. According to Ahn (1996) these beetles live even in the low intertidal, and can spend most of their day submerged. They don’t have gills, they just find an air pocket (barnacle test, under a rock) and wait. Watching them swim, they obviously have a highly hydrophobic coating, probably with lots of hairs to trap air bubbles.

 

This is Neomolgus littoralis. It is an intertidal mite, known as the red velvet mite.

Red velvet mite on some Ulva, in the high intertidal on Edward King. They are ~3mm in length. Credit: N Webster

These mites are found in the high intertidal and eat kelp flies (another intertidal insect). They are very easy to spot, as they are shockingly red.

 

References

• Kozloff, E.N. 1993. Seashore life of the Pacific Northwest: an illustrated guide to northern California, Oregon, Washington, and British Columbia. 370 p.
• Kozloff, E.N. 1974. Keys to the marine invertebrates of Puget Sound, the San Juan Archipelago, and adjacent regions. Seattle, Washington, University of Washington Press, 226 p.
• Kee-Jeong Ahn. 1996. A Review of Diaulota Casey (Coleoptera: Staphylinidae: Aleocharinae), with Description of a New Species and Known Larvae.The Coleopterists Bulletin Vol. 50:3, pp. 270-290

 

“Why Bamfield, British Columbia is unique, awesome and you should go there” part III

Bridgette just posted the last of her 3 part series on Why Bamfield, British Columbia is unique, awesome and you should go there. Part 3: Learning.

Do go check it out. I praised her and her blog last week, which you can check out here.

Bracket (shelf) fungus. Why? Because. Credit: N Webster

 

“Why Bamfield, BC is unique awesome and you should go there” – Bridgette Clarkson

A friend of mine has a wonderful blog. It is insightful, delightful and full of photos. Bridgette just completed a stint working as a public educator for BMSC, and described herself as a biologist and science education consultant.

Crashing Bull kelp (c) Bridgette Clarkson

In honour of World Oceans day (yesterday), she posted the 2nd part of her 3 part series about her time in Bamfield this year.

• Why Bamfield, British Columbia is unique, awesome and you should go there. Part 1: Adventures
• Why Bamfield, British Columbia is unique, awesome and you should go there. Part 2: Nature

I strongly encourage you to check them out, if only for the breathtaking imagery.

Do check out some of her other posts like how to check marine forecasts, or her flickr stream.