Author Archives: rebekaryvola

Harbour Seal Feeding Behavior: Uncovered and Explained

Posted on April 10, 2011 | 3 comments

“One of the predators missing from the documented literature is the harbour seal”, says Austen Thomas, a PhD candidate at the University of British Columbia.

In 2008, Austen led an exciting research project examining the feeding behaviour of harbour seals in the Strait of Juan de Fuca, off the coast of Washington state. Austen was interested in finding out whether harbour seals have different feeding patterns during the winter spawning season of Pacific herring — a species which comes into close proximity with the seals when they move inshore to lay their eggs. Austen wanted to know whether the seals made use of the increased herring numbers when they occurred conveniently nearby. Surprisingly, he found that the seals did not catch more spawning herring during winter spawning season in general, choosing instead to catch young, small fish. This behaviour allows for the successful laying and hatching of a new generation of herring.

We set out to find out more about how Austen carried out his research; how he used equipment and analysis to track seals and uncover their feeding habits and diet; and what the “bigger picture” implications of his work are. The below video tells the story of Austen’s research.

https://www.youtube.com/watch?v=zpX8-FlfFvU


Austen and his team use glue to attach the TDR-GPS combo to a seal. Austen Thomas photo.

As mentioned in the video, Austen used Global Positioning Systems (GPS) and time depth recorders (TDR) to understand where and when harbour seals most frequently feed. Both the GPS and TDR use satellites to pinpoint the seals location and monitor their diving behaviour at their feeding grounds. While the GPS revealed movement of the seals around their home, Protection Island, the TDR showed the diving depth patterns of seals. The tracking devices showed Austen how the seals movements matched up with the movement of the Pacific herring population.

A seal makes a break for home after getting outfitted with the tracking devices. The devices are designed to come off when the seal molts. Whether they floated as planned is another story. Austen Thomas photo.

seal scat. Austen Thomas photo.

In addition to tracking seal movement through space and time, Austen also collected and analyzed harbour seal feces, or scats. This portion of his research allowed him to identify the species and age of fish consumed.

 

Collecting seal scat for diet analysis. Austen Thomas photo.

Scat analysis was done by examining the bone remains under a microscope. Specifically, looking at the otoliths (the inner ear bone of the fish) that remained in seal fecal samples enabled Austen to identify age, size, and species of the fish consumed. This research revealed how much of different-aged Pacific herring was being eaten during different times of the year.

Besides learning about Austen’s research, we wanted to find out about the broader impacts of his work. For example, his work has potential implications for both local fisheries and the Species at Risk Act (SARA), which is used to guide resource management efforts. In the following podcast, we discuss the “bigger picture” context that Austen’s research fits into.

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Austen’s research sheds light on unexpected feeding behaviour of the seals residing on Washington’s Protection Island. These findings are not only interesting; we will likely see that Austen’s discovery of surprising seal feeding patterns contributes to shaking up common understanding of this marine ecosystem.

-This multimedia project was a Group A production.

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Posted in Biological Sciences, Final Project, Interview Project, Issues in Science

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BC killer whales can’t hear each other!

Posted on April 6, 2011 | 3 comments

I spent much of 2010/2011 working on a research project so thought that I would use this ultimate SCIE300 blog post to tell you all about it.

Last September, myself and four others in UBC Environmental Science were put on team and instructed to research whatever environmental science topic we wanted. We were all broadly interested in researching some sort of ecological impact of the Gateway Program, BC’s massive plan for highway and port expansions. We spent first semester narrowing in on a more specific area. Eventually, we landed our focus on the impacts of increasing commercial shipping traffic on the Southern Resident killer whales (SRKW). This population is designated as endangered by the Species at Risk Act and has been in decline over the past several decades.

Photo: Minette Layne on Flickr

This semester, we went into a research paper-reading frenzy on everything and anything to do with killer whales, ships, and killer whales and ships in order to find a manageable gap in the understanding of commercial ship impacts on the SRKW we could work to fill. We soon found that the influence of commercial shipping sound in the SRKW critical habitat — area identified as especially important for the well-being of this species — is little understood.

Also at around this time, a lawsuit led by several environmental groups against the Department of Fisheries and Oceans (DFO) was in the midst of unfolding. Team Enviro had taken DFO to court for failing to protect the SRKW critical habitat (which DFO is legally obliged to protect), and in December 2010, the court ruled against DFO. Noise pollution — along with food availability and toxic pollution — were among the key areas DFO was found to be failing to address. So, knowing that DFO might be considering doing a better job of safe-gaurding the critical habitat, we wanted to conduct research that could inform recommendations to lessen noise impacts on the SRKW.

We got to work using GIS analysis to map out areas of sound influence in the SRKW habitat, identifying spots where the killer whales’ ability to communicate was compromised. In addition, we mapped out noise pollution scenarios under different ship speed limits to see whether the noise level decreased significantly.

In the end, we found that noise pollution is omnipresent in the SRKW critical habitat; the whales are almost never freed from some sort of interference in their communication calls. Additionally, we found that no realistic speed limit reduces noise significantly. What does this mean for the SRKW? Mostly, our research reiterates that DFO has done a poor job in protecting the home of this endangered species. However, we believe that future research into alternate shipping routes and identification of specific months or times of day for shipping that avoid critical killer whale feeding and breeding times and areas could lead to successful SRKW protection.

Our poster we presented to the EOSC faculty. You should be able to read it by clicking on it.

See our blog for more info on our project:-)

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Posted in Biological Sciences, Environment, Issues in Science, Science in the News

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Searching for disease-unlocking keys

Posted on March 13, 2011 | 1 comment

Ryan Centko, molecular connoisseur

Have you ever heard of a molecular connoisseur? Like wine connoisseurs, they are able to pick up on minute details and identify differences that an untrained person cannot. Only they are identifying molecular structure-scale details and differences, not fruity legs and woody undertones. My friend Ryan Centko is a self-described molecular connoisseur in training. And as part of research that was just published in Organic Letters, he recently helped discover 4 previously unknown molecular compounds in a fungus called Penicillium purpurogenum. While the 4 compounds found are structurally very similar, they may differ from one another in one or two very subtle ways. The structures that Ryan helped to uncover could prove to be the keys that unlock, or cure, diseases that do not yet have effective cures.

Ryan is part of a group of scientists working in a lab at UBC scouring previously unidentified or unexamined organisms for new compounds. He recently spoke with me about his work on Penicillium purpurogenum, the purplish fungus found on Averrhoa Bilimbi, or what can be better described as cucumber trees, in Sri Lanka.

Averrhoa Bilimbi, the cucumber fruit tree. de Silva photo.

Penicillium purpurogenum in a petri dish. de Silva photo.

I found out that the fungus was brought over to UBC researcher Raymond J. Anderson’s lab by a Sri Lankan scientist named Dilip de Silva. Ryan, a PhD candidate working under Anderson, got to take part in the analysis of this exciting organism. To begin the search for unique molecular compounds, the fungus was first prepared for examination. This involved growing it in petri dishes in the lab. Once the fungus grew into a large enough amount, it was mixed with a solvent such as ethanol. Finally, the whole mixture was dried into a sort of paste – the optimal substance for the identification of new compounds.

The four new compounds found within the Sri Lankan Penicillium purpurogenum have been named Dhilirolides A, B, C, and D. Ryan and the rest of the team have sent out the Dhilirolides A – D compounds to researchers around the world who are going to be taking these “keys” and seeing whether they have antibiotic potential (seeing whether they can find the appropriate disease “locks”). In the meanwhile, Ryan and the rest of the team are looking for more unique compounds within Penicillium purpurogenun – Dhilirolides E – Z, perhaps? As Ryan says, the more unique structures they find, the better chance they have of finding something that could work as an antibiotic.

Read Ryan’s Organic Letters paper here!

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Posted in Biological Sciences, New and innovative science

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The amazing and curious world in the treetops

Posted on January 19, 2011 | 4 comments

Photo: thaths on flickr

Is there anything more incredible than the rainforest canopy? Not very likely. The rainforest canopy – the dense area containing the majority of trees branches – is home to some of the greatest biodiversity, or biotic variety, on earth. And where else can you find a complete ecosystem with soil, megafauna, and what is estimated to be half of the world’s plant species – all off the ground?! However, what we know about these incredible “biodiversity hotspots” is very little, as rainforest canopies are among the world’s least understood ecosystems.

So unparalleled is the rainforest canopy in mystery and intrigue that naturalist William Beebe pronounced that, “another continent of life remains to be discovered, not upon the Earth, but one to two hundred feet above it, extending over thousands of square miles.” That was back in the early 1900s, and despite much research being done since then, this quote still holds true.

Among what has been discovered, The EarthWatch Institute details some stand-out research findings including the discovery of the first herbivorous spider; work suggesting that perhaps 6 million insect species exist on earth; and the uncovering of thousands and thousands of species previously unknown to us, many of them endemic – meaning they are found nowhere else in the world – to their respective rainforest canopy.

Where else can you find animals as curious as the pink-eyed katydid newly discovered in Papua New Guinea:

Photo: Naskrecki/iLCP

or the Malagasy Red-bellied Lemur?

photo: BBC

Unfortunately, the well-being of much of the world’s fascinating and mysterious rainforest canopy ecosystems is threatened by human activities. Work by William F. Laurence, published in a 1991 issue of Nature, warned that human activities causing forest fragmentation are compromising the health of these unique ecosystems. A study by Erika Styger and fellow scientists published in a 2007 issue of Agriculture, Ecosystems & Environment looked at the large-scale degradation caused by slash-and-burn farming techniques. Additional research keeps pointing at humans as the cause of increasingly unhealthy rainforest canopy ecosystems.

Scientists are currently working to understand the biological and chemical processes at work within the canopy in order to gain a better idea of how we can protect these ecosystems. Some are working to document canopy species composition and interactions while others are expressing concerns over the ability of the rainforest canopy to continue supporting its species in the face of climate change – an area that is beginning to get a lot of research attention. Thus, work is being done to better understand what is happening in the mysterious and marvelous rainforest canopy. Whether we can protect the very-worthy-of-protection rainforest canopy ecosystems before their health is globally compromised remains to be seen.

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Posted in Biological Sciences, Environment, Issues in Science

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