PRACTICE PAGE: research methods
Whale Wise aims to promote evidence-based conservation through research and engagement. At present, we are using a variety of research methods to assess the impact of whale watching encounters and vessel traffic on whale populations in north Iceland. We have two major goals for this research:
- Deduce vessel impacts, in order to guide future management plans.
- Develop targeted and powerful research techniques, in order to assess other human activities.
We want to be clear on our intentions: we do not want to shut down whale watching activities- we love to watch whales and other people are entitled to that same privilege. Whale watching also supports coastal economies and encourages marine conservation. We have no right to threaten these benefits. Rather, we aim to promote practices which minimise any observed negative impact, whilst allowing high quality and profitable encounters.
Perhaps the most exciting part involves blow sampling, whereby we collect samples of a whale’s exhaled breath (the blow). Like our own breath, whale blow is an incredible source of biological information, containing substances such as DNA, bacteria and whale proteins. We are currently interested in whale hormones, particularly cortisol (a stress-related hormone found in most mammals). Generally, cortisol levels increase during times of high stress. Our idea is to collect blow samples in areas and times of high and low vessel activity in order to measure the physiological stress actually caused. We could simply rely on behavioural indications of stress but these may be misleading. For example, a starving whale which has just migrated from its tropical breeding grounds may not sacrifice feeding in the presence of vessels, but this does not eliminate the potential for stress.
How do you collect whale blow?
Early attempts at blow sampling relied on a long pole holding a collection device (such as Petri dishes or nylon mesh) extending from a research vessel. Since the vessel must travel in close proximity to the target whale, this may both confound our results and conflict with our goals, of reducing the impact of human activity.
So, how can you collect samples of whale blow without disturbing them?
The potential answer: drones.
As with other areas of whale research, drones have revolutionised blow sampling and represent a cheap, simple and unobtrusive alternative. Now, we can attach Petri dishes to an affordable drone using a simple frame (which in our first season was improvised from some coat hangers) and fly the dishes through whale blow. We first attempted this in June 2018 in Iceland- the first study of its kind in Iceland and the most northerly attempt to date- and collected 16 samples. Our current drones of choice is a DJI Phantom 4- not too expensive, safe to launch from a vessel and manoeuvrable at sea.
Although we see drones as a less disruptive alternative to research vessels, they still have the potential to disturb whale behaviour and cause stress. When blow sampling, make all attempts to minimise the time spent flying in proximity to whales. We constantly monitor surface behaviour when conducting drone research.
Following the collection of whale blow, we take our samples to the lab, back in the University of Edinburgh, where we can measure the levels of specific hormones. Our method of choice is liquid chromatography-mass spectrometry, a selective and sensitive analytical technique. By working with the university’s clinical research facility, we can make use of advances in medical research for the purposes of whale conservation.
We want to be clear that this is part of our research is very exploratory- blow sampling has yet to be used to demonstrate the impact of human activity. As such, we are cautious with our expectations- simply, it may not work. However, with a solid theoretical basis, careful planning and help from other researchers, we are quietly optimistic.
All previous assessments of whale watching impact have focused on behavioural responses. How do vessels alter the feeding, resting, travelling and social behaviour of different whale species? Such studies have indicated that whales may perceive vessels as a predatory threat and then behave in order to minimise this perceived threat. As a result, whale watching can reduce feeding and resting, whilst increasing travelling. Recent studies have built on this by translating behavioural responses into changes in energy acquisition and expenditure. This allows consideration of the impact of whale watching on entire populations.
In our current project, Whale Wise aims to follow previous research by observing whale behaviour in the presence and absence of whale watching vessels. However, we also hope to take this further by assessing the relative impact of different types of encounter. For example, is the behavioural response of whales dependent on vessel size or the number of vessels? Are whales sensitive to the minimum approach distance of a vessel? Does engine noise play a role in whale watching impact?
This is key to our overall principle. Instead of halting whale watching, we aim to promote practices which minimise any observed negative impact, whilst allowing high quality and profitable encounters. Therefore, we must consider how different practices impact whales in different ways.
From our behavioural observations, we can estimate the impact of whale watching encounters on the energy acquisition and expenditure of individuals. However, how does this influence their welfare, health and survival?
To answer this question, we first need some crucial baseline data, specifically concerning their body condition at the time of an encounter. Naturally, we would expect this to determine the severity of any impacts. A fat, healthy whale might be relatively unaffected by whale watching disturbance, with their reserves of blubber allowing them to skip a meal with little consequence. However, the story may be different for a starving whale with little fat to spare. For these whales, we would expect every meal to count.
Therefore, we are also using drones to capture aerial images of whales. From these photographs, we can measure the length and width of individuals (known as photogrammetry), and thus assess their body condition. Generally, whales which are relatively wider have more blubber, are in better body condition and should be more resistant to whale watching disturbance.
Climate response modelling
From the results of our whale watching impact assessment, we hope to design a conservation plan aimed at balancing the needs of whales and humans. Crucially, we need a plan that works not only now, but far into the future. With dramatic climate change forecast in the coming decades, with associated shifts in ocean habitats, this presents a challenge. Will the whales of north Iceland still be around in the future? To what extent can future whale watchers rely on seeing whales on a daily basis? Will north Iceland still represent an important feeding ground in years to come?
To answer these questions, we will work with iAtlantic, a collaborative, EU-funded project aimed at monitoring the response of marine life to oceanographic changes in the Atlantic Ocean. Using long-term time-series data for humpback and blue whales in Icelandic waters, we will perform habitat modelling, mapping their distribution against various oceanographic variables such as depth, temperature, plankton and fish distribution. Following this, we will apply climate forecasts to predict how these variables will change in the future. Therefore, we can estimate how the distribution and numbers of humpback and blue whales will change around Icelandic waters in coming years.
To summarise, we aim to assess the impact of whale watching on whale populations, in order to design a conservation plan that will minimise its negative impacts whilst simultaneously allowing amazing encounters for its passengers. By modelling future changes in whale distribution, we hope to design a plan that remains relevant and effective for many years to come.