Tag: Marine Mammals

My name is Solène Derville and I am a master’s student in the Department of Biology at the Ecole Normale Supérieure of Lyon, France. As part of my master’s, I am spending a few months in Newport, where I am working under Dr Leigh Torres’s supervision in the GEMM Lab. Hopefully, this will be the starting point for a longer term collaboration, for a PhD project about the spatial ecology of humpback whales in New-Caledonia (South Western Pacific Ocean) which I am currently preparing.

On an early morning of February 2015, I am waiting at the airport for my flight to PORTLAND/PDX. I’ve had only one day to pack but I feel confident that I’ve made the right choices as my 23kg luggage contains mainly jumpers, sweatshirts, thick socks, and a brand new umbrella. I’ve got everything I need to face my four months internship in rainy Newport, Oregon.

A few disillusionments await me when I finally land: 1) my “saucisson” (fancy sausage) can’t pass customs and ends up in a bin despite my attempts to negotiate with the customs official, and 2) as soon as I am out of the airport, it starts raining. At first sight this looks like the harmless kind of drizzle I’ve experienced in England, until I realize it’s raining sideways! So much for buying a new umbrella…

Luckily, these small inconveniences don’t affect my spirits for long as I get to discover the richnesses Oregon has to offer.

My mouth drops open the first time someone tells me that I can see elk around Newport and that gray whales are commonly observed next to the jetty at this time of year. It’s difficult to describe to someone who’s always been living in this environment how exciting it is to me. I am not used to all this wilderness and certainly not to living so close to it. It’s a thrill to think that I only need to ride my bike for a few miles to meet the amazing local fauna.

Of course, the beauty of Oregon’s landscapes and the richness of its wildlife is not the only thing that catches my attention. I am immediately touched by the kindness of people, the sense of sharing and the deeply rooted sense of community. I feel welcomed at HMSC, and by my colleagues in the GEMM lab and I am eager to start my internship.

So what is my work here exactly?

Well, believe it or not, I’ve crossed the Atlantic Ocean and came to the US to actually work on a species of dolphins endemic to New-Zealand! Dr Leigh Torres, and I are investigating the fine-scale distribution and habitat selection patterns of Maui’s dolphin (Cephalorhyncus hectori maui). This subspecies of the more common Hector’s dolphin (Cephalorhyncus hectori, also endemic to New-Zealand) is the smallest dolphin in the world and unfortunately among the most endangered (listed as “critically endangered” by the IUCN). The Maui’s dolphin population is thought to have decreased to under 100 individuals in the past decades.

In practice, this means I am doing data analysis so I spend my days in front of my computer. This may sound a bit dull, but computer work is actually a great part of research in ecology (apart from awesome field work stage, but this is only the tip of the iceberg). Speaking for myself, I’ve always found it very exciting to put together all this hard-won data to answer important questions, especially when the conservation of species as emblematic as the Maui’s dolphin is at stake. To tell the truth, the nerdy code writing work is also a lot of fun!

My data set consists of boat-based observations of Maui dolphin groups made during the 2010, 2011, 2013 and 2015 summer surveys. Overall about a hundred groups were observed. Based on these observations we would like to know: WHERE are the Maui dolphins (distribution pattern)? And WHY (habitat preferences)?

My job is first to describe the spatial distribution patterns of these observations given the year, composition of groups, or group behaviour (whether animals were feeding, resting etc.). This can be done using kernel density estimates: a very good method for “smoothing” a distribution in 2 dimensions and highlighting its main characteristics (extent, core areas etc.). This allows us to answer (or try to answer) the “WHERE” question.

The second stage of my analysis is to describe the environmental conditions at each of the dolphin group locations and compare them with the environmental conditions in surveyed areas where Maui dolphins where not observed. This allows us to better understand the environmental cues that Maui dolphins might be following to find “suitable” places for their every-day activities and therefore try answer the “WHY” question. In statistical jargon, we are exploring the relationship between probability of presence of Maui dolphins and environmental predictors such as: sea surface temperature, turbidity of the water, distance to closest river mouths, distance to the coast and depth.

The resulting models will be used to predict seasonal variations in Maui’s dolphin distribution, notably in winter when direct surveying is difficult because of weather conditions. Based on the resulting dynamic distribution models, we finally aim to predict how Maui’s dolphins might interact with anthropogenic activities or react to changes in their environment.

So far, preliminary results are very promising and I am hoping to share these soon!