Tag: Cetaceans

 

By: Kelli Iddings, MSc Student, Duke University, Nicholas School of the Environment

The excitement is palpable as I wait in anticipation. But finally, “Blow!” I shout as I notice the lingering spray of seawater expelled from a gray whale as it surfaces to breathe. The team and I scurry about the field site taking our places and getting ready to track the whale’s movements. “Gray whale- Traveling- Group 1- Mark!” I exclaim mustering enough self-control to ignore the urge to drop everything and stand in complete awe of what in my mind is nothing short of a miracle. I’ve spotted a gray whale searching and foraging for food! As a student of the Master of Environmental Management program at Duke University, I am collaborating on a project in Port Orford, Oregon where my team and I are working to gain a better understanding of the interactions between the Pacific Coast Feeding Group (PCFG) gray whales and their prey. Check out this blog post written earlier by my teammate Florence to learn more about the methods of the project and what motivated us to take a closer look at the foraging behavior of this species.

Understanding the dynamics of gray whale foraging within ecosystems where they are feeding is essential to paint a more comprehensive picture of gray whale health and ecology—often with the intent to protect and conserve them. A lot of our recent effort has been focused on developing and testing methods that will allow us to answer the questions that we are asking. For example, what species of prey are the PCFG whales feeding on in Port Orford? Based on the results of a previous study (Newell and Cowles 2006) that was conducted in Depoe Bay, Oregon, and a lot of great knowledge from the local fisheries and the Port Orford community, we hypothesized that the whales were feeding on a small, shrimp-like crustacean in the order Mysida. Given the results of our videos, and the abundance of mysid, it looks like we are right (Fig. 1)!

Mysids are not typically the primary food source of gray whales. In their feeding grounds in the Bering and Chukchi Seas near Alaska, the whales feed on benthic amphipods on the ocean floor by sucking up sediment and water and pushing it through baleen plates that trap the food as the water and sediment is filtered out. However, gray whales demonstrate flexible feeding strategies and are considered opportunistic feeders, meaning they are not obligate feeders on one prey item like krill-dependent blue whales. In Oregon, mysid congregate in dense swarms by the billions, which we hypothesize, makes it energetically worthwhile for the massive 13-15m gray whales to hang around and feed! Figure 2 illustrates a mysid swarm of this kind in Tichenor Cove.

Once we know what the gray whales are eating, and why, we ask follow up questions like how is the distribution of mysid changing across space and time, if at all? Are there patterns? If so, are the patterns influencing the feeding behavior and movement of the whales? For the most part, we are having success characterizing the relative abundances of mysid. No conclusions can be made yet, but there are a few trends that we are noticing. For instance, it seems that the mysid are, as we hypothesized, very dense and abundant around the rocky shoreline where there are kelp beds. Could these characteristics be predictors of critical habitat that whales seek as foraging grounds? Is it the presence of kelp that mysid prefer? Or maybe it’s the rocky substrate itself? Distance to shore? Time and data analysis will tell. We have also noticed that mysid seem to prefer to hang out closer to the bottom of the water column. Last, but certainly not least, we are already noticing differences in the sizes and life stages of the mysid over the short span of one week at our research site! We are excited to explore these patterns further.

The biggest thing we’re learning out here, however, is the absolute necessity for patience, ingenuity, adaptability, and perseverance in science. You heard that right, as with most things, I am learning more from our failures, than I am from our successes.  For starters, understanding mysid abundance and distribution is great in and of itself, but we cannot draw any conclusions about how those factors are affecting whales if the whales don’t come! We were very fortunate to see whales while training on our instruments in Newport, north of our current study site. We saw whales foraging, whales searching, mother/calf pairs, and even whales breaching! Since we’ve been in Port Orford, we have seen only three whales, thrown in among the long hours of womanpower (#WomenInScience) we have been putting in! We are now learning the realities of ecological science that >gasp< fieldwork can be boring! Nevertheless, we trust that the whales will hear our calls (Yes, our literal whale calls. Like I said, it can get boring up on the cliff) and head on over to give the cliff team in Port Orford some great data—and excitement!

Then, there is the technology. Oh, the joys of technology. You see I’ve never considered myself a “techie.” Honestly, I didn’t even know what a hard drive was until some embarrassing time in the not-so-distant past. And now, here I am working on a project that is using novel, technology rich approaches to study what I am most passionate about. Oh, the irony. Alas, I have been putting on my big girl britches, saddling up, and taking the whale by the fluke. Days are spent syncing a GoPro, Time-Depth Recorder (TDR), GPS, associated software, and our trusty rugged laptop, all the while navigating across multiple hard drives, transferring and organizing massive amounts of data, reviewing and editing video footage, and trouble shooting all of it when something, inevitably, crashes, gets lost, or some other form of small tragedy associated with data management. Sounds fun, right? Nonetheless, within the chaos and despair, I realize that technology is my friend, not my foe. Technology allows us to collect more data than ever before, giving us the ability to see trends that we could not have seen otherwise, and expending much less physical effort doing so. Additionally, technology offers many alternatives to other invasive and potentially destructive methods of data collection. The truth is if you’re not technologically savvy in science these days, you can expect to fall behind. I am grateful to have an incredible team of support and such an exciting project to soften the blow. Below (Fig. 3) is a picture of myself embracing my new friend technology.

Last but not least, there are those moments that can best be explained by the Norwegian sentiment “Uff da!” I was introduced to the expression while dining at The Crazy Norwegian, known famously for having the best fish and chips along the entire west coast and located dangerously close to the field station. The expression dates back to the 19^th century, and is used readily to concisely convey feelings of surprise, astonishment, exhaustion, and sometimes dismay. This past week, the team was witness to all of these feelings at once as our GoPro, TDR, and data fell swiftly to the bottom of the 42-degree waters of Tichenor cove after the line snapped during deployment. Uff da!!! With our dive contact out of town, red tape limiting our options, the holiday weekend looming ahead, and the dreadful thought of losing our equipment on a very tight budget, the team banded together to draft a plan. And what a beautiful plan it was! The communities of Port Orford, Oregon State University, and the University of Oregon’s Institute of Marine Biology came together in a successful attempt to retrieve the equipment. We offer much gratitude to Greg Ryder, our retrieval boat operator, OSU dive safety operator Kevin Buch, and our divers, Aaron Galloway and Taylor Eaton! After lying on the bottom of the cove for almost three days, the divers retrieved our equipment within 20 minutes of the dive – thanks to the quick and mindful action of our kayak team to mark a waypoint on the GPS at the time of the equipment loss. Please enjoy this shot (Fig. 4) of Aaron and Taylor surfacing with the gear as much as we do!

The moral of the story is that science isn’t easy, but it’s worth it. It takes hard work, long hours, frustration, commitment, collaboration, and preparedness. But moments come along when your team sits around a dining room table, exhausted from waking and paddling at 5 am that morning, and continues to drive forward. You creatively brainstorm, running on the fumes of the passion and love for the ocean and creatures within it that brought everyone together in the first place; each person growing in his or her own right. Questions are answered, conclusions are drawn, and you go to bed at the end of it all with a smile on your face, anxiously anticipating the little miracles that the next day’s light will bring.

References

Newell, C. and T.J. Cowles. (2006). Unusual gray whale Eschrichtius robustus feeding in the summer of 2005 off the central Oregon Coast. Geophysical Research Letters, 33:10.1029/2006GL027189