Blues Clues

Although blue whales are big, the South Taranaki Bight is bigger. So finding them is not straight forward. In fact, with little prior research in this area, the main focus of our project is to gain a better understanding of blue whale distribution patterns in the region. So, while bouncing around on the sea, we are collecting habitat data that we relate to whale occurrence data to learn what makes preferred whale habitat.

We conduct CTD casts. CTD stands for Conductivity, Temperature and Depth. This is an instrument we lower down to the bottom of the ocean on a line and along the w ay it records temperature and salinity (conductivity) data at all depths. This data describes the water structure at that location, such as the depth of the thermocline. The ocean is often layered with warm, low-salt water on top, and cooler and salty water at the bottom. This thermocline can act as a boundary above which prey aggregate.

Todd and Andrew deploy the CTD off the R/V Ikatere.
Todd and Andrew deploy the CTD off the R/V Ikatere. (Photo by Callum Lilley)
CTD cast
Example data retrieved from a CTD cast showing how temperature (green line) decreases and salinity (red line) increases as it descends through the water column (depth on y-axis).

We also have a transducer on board that we use to record the presence of biological material in the ocean, like krill (blue whale prey). This transducer emits pings of sound through the water column and the echoes bounce back, either off the seafloor, krill or fish. This glorified echosounder records where blue whale prey is, and is not.

Example display image from our echosounder (EK60) showing patches of prey (likely krill) in the upper surface layer.
Example display image from our echosounder (EK60) showing patches of prey (likely krill) in the upper surface layer.

Additionally, the research vessel is always recording surface temperature (SST). I monitor this SST readout somewhat obsessively while at-sea as well as study the latest SST satellite images. Using these two bits of data as my “blues clues”, we search for blue whales.

After a bumpy ride across the Cook Strait we had a good spell of weather last week. We covered a lot of ground, deploying our 5 hydrophones across the Bight and keeping our eyes peeled for blows. Our first day out we found three whales. Fantastic sightings. But, as we continued to survey through warm, low productivity water we found no signs of blue whales. The third day out was a beauty – the type of day I wish for: low swell and low winds – perfect for whale finding. We covered 220 nautical miles this day (deploying 2 hydrophones) and we searched and searched. But no whales. I could see from the SST satellite image that the whole Bight was really warm: about 20 ⁰C. I could also see a strip of cold water down south, toward Farewell Spit. I said “Let’s go there”.

Sea surface temperature (SST) satellite image of the South Taranaki Bight region in New Zealand that shows mostly warm water with a plume of colder water down south.
Sea surface temperature (SST) satellite image of the South Taranaki Bight region in New Zealand that shows mostly warm water with a plume of colder water down south.

After twelve and a half hours of survey effort through clear, blue, warm water, we finally saw the water temperature drop (to about 18 ⁰C) and the water color turn green. We started to see gannets, petrels, shearwaters, and common dolphins feeding. Then I heard the magic words come from Todd’s mouth: “Blow!” So began our sunset sighting. From 7:30 to 10 pm we worked with four blue whales capturing photographs and biopsy samples, and echosounder prey data.

Diving blue whale in the South Taranaki Bight, NZ (photo by Leigh Torres)
Diving blue whale in the South Taranaki Bight, NZ (photo by Leigh Torres)

This is an example of a species-habitat relationship that marine ecologists like me seek to document. We observe and record patterns like this so that we can better understand and predict the distribution of blue whales. Such information is critical for environmental managers to have in order to effectively regulate where and when human activities that may impact blue whales can occur. Over the next two weeks we will continue to document blue whale habitat in the South Taranaki Bight region of New Zealand.

Blown out.

By Dr. Leigh Torres, Assistant Professor, Oregon State University, Marine Mammal Institute, Geospatial Ecology of Marine Megafauna Lab

Hurry up and wait. Can’t control the weather. All set and nowhere to go.

However you want to say it, despite our best efforts to be ready to sail today, the weather has not agreed with our best-laid plans. It’s blowing 20-30 knots in the South Taranaki Bight, which makes it very difficult to spot a whale from our small (but sturdy) research vessel (NIWA’s R/V Ikatere), and practically impossible to take good photos of the whales or to deploy our hydrophones. So, we wait.

Over the last few days we have been busy tracking down gear, assembling the hydrophones, discussing project logistics, preparing equipment (Fig. 1), provisioning the vessel, getting the crew in place, and practicing vessel operations. We have flown to the other side of the world. We have prepared. We are ready. And we wait. Such is field work. I know this. I’ve been through this many times. But it is always hard to take when you feel the clock ticking on your timeline, the funds flowing from your budget, and your people waiting for action. Fortunately, I have built in contingency time so we will still accomplish our goals. We just have to wait a bit longer. As the Kiwis say, ‘Bugger!’

kristin and hydrophones small
Figure 1. Kristin Brooke Hodge of The Bioacoustics Research Program at Cornell University performs a global sound check on the hydrophones (loud bang of hammer to pipe) so that times can all be synced and any clock drift accounted for.

Below is a wind and rain forecast for New Zealand (provide by the MetService). The box in red is our study region of the South Taranaki Bight. We are currently in Wellington where the green star is, but we want to be in Pohara where the yellow star is – this will be our base during the field project, if we can just get there.

NZ wind

Wind strength and direction in these types of maps is depicted by the wind indicator lines: the wind is coming from the tail toward the flag end of the symbol, and the strength is symbolized by the number and size of the barbs on the flag end.

wind barbs

Notice how inside the red box there are lots of barbs on the indicator lines (most saying about 20 knots), but just to the west and north there are few barbs – about 5 to 10 knots. These are great survey conditions, but not where we want to be! A bit heartbreaking. But that’s how it goes, and I know we will get our weather window soon. Until then, we sit tight and watch the wind blow through the pohutukawas and cabbage trees in beautiful Wellington.

An update from the Antarctic Peninsula

By: Erin Pickett

Yesterday someone said to me, “I don’t know if it was sunrise or sunset, but it was beautiful”. So it goes on the R/V Lawrence M. Gould (LMG), the surrounding scenery is incredible but the work schedule on this research ship makes it difficult to remember what time of day it is.

Here on the Antarctic Peninsula, the sun never really sets and our daily schedules are dependent on things like the diel vertical migration of krill, the current wind speed and the amount of sea ice in between us and our study species, the humpback whale. For these reasons, we sometimes find ourselves starting our workday at odd hours, like 11:45 pm (or 4:00 am). As a reminder, I am currently working on research vessel on a project called the Palmer long term ecological research (LTER) project.  You can read my first blog post about that here. We are about one week into our journey and so far, so good!

Our journey began in Punta Arenas, Chile, where we spent two days loading our research supplies onto the LMG and getting outfitted with cold weather gear. From Punta Arenas we headed south through the straights of Magellan and then across the Drake Passage. Along the way we spotted a variety of cetaceans including minke, fin, sei and humpback whales, and Commerson’s and Peale’s dolphins. I spent as much of our time in transit as I could looking for seabirds, the most numerous being white-chinned and cape petrels, southern giant petrels, and black-browed albatrosses. Spotting either a royal or a wandering albatross was always exciting. An eleven foot wingspan allows these albatross to glide effortlessly above the water and this makes for a beautiful sight!

We have spent the last four days transiting between various sampling stations around Palmer deep, which is an underwater canyon just south of our home base at Palmer station. When conditions allowed, we loaded up our tagging and biopsy gear into a small boat and went to look for humpback whales. We’ve been incredibly successful with the limited amount of time we’ve had on the water and this morning we finished deploying our sixth tag.

We brought a few different types of satellite tags with us to deploy on humpback whales. One type is an implantable satellite tag that transmits location data over a long period of time. These data allow us to gain a better understanding of the large-scale movement and distribution patterns of these animals. The other tag we deploy is a suction cup tag, so called because four small suction cups attach the tag to the whale. These suction cup tags are multi-sensor tags that measure location as well as fine scale underwater movement (e.g. pitch, roll, and heading). They are also equipped with forward and backward facing cameras and most importantly, radio transmitters! This allows us to recover the tags once they fall off the animal and float to the surface (after about 24 hours). The data we get from these tags will allow us to quantify fine-scale foraging behavior in terms of underwater maneuverability, prey type and the frequency, depth and time of day that feeding occurs.

When we deployed each of these tags we also obtained a biopsy sample and fluke photos. Fluke photos and biopsy samples allow us to distinguish between individual animals, and the biopsy samples will also be used to study the demographics of this population through genetic analysis.

Now that we’ve deployed all of our satellite tags and have recovered the suction cup tag just in the nick of time (!), we are starting our first major transect line toward the continental shelf. We will be continuing south along these grid lines for the next week.

My lab mate Logan Pallin and I will be continuing to write about our trip over the next couple of months on another blog we created especially for this project. You can find it here: blogs.oregonstate.edu/LTERcetaceans

I’ll leave you with a few of my favorite photos of the trip so far!

“This is what I would do if I weren’t afraid” – New Zealand blue whale field season 2016

By Dr. Leigh Torres, Assistant Professor, Oregon State University, Geospatial Ecology of Marine Megafauna Lab

Two years ago I documented a blue whale foraging ground in an area of New Zealand called the South Taranaki Bight (STB) – the country’s most industrially active marine area with intense oil and gas exploration and extraction since the 1970’s, elevated vessel traffic, and potential seabed mining (Figure 1). Over just five days of survey effort we observed 50 blue whales and documented foraging behavior. But we still know next to nothing about where and when blue whales are in the STB, how many whales use this area, how important this area is as a feeding area, or to what population the whales belong. Without answers to these questions effective management of human activities in the region to protect the whales and their habitat is unfeasible.

I am now heading back to New Zealand to collect the data needed to answer these questions that will enable successful management. That’s my goal.

Figure 1. Illustration of a space-use conflict between industry activity and blue whales in the South Taranaki Bight, which lies between the north and south islands of New Zealand. Blue whale sightings and strandings recorded between 1970 and 2012.
Figure 1. Illustration of a space-use conflict between industry activity and blue whales in the South Taranaki Bight, which lies between the north and south islands of New Zealand. Blue whale sightings and strandings recorded between 1970 and 2012.

Such research costs money. In collaboration with the Bioacoustic Research Program at Cornell University (birds.cornell.edu/brp), we are deploying five hydrophones to listen for blue whales across the region for 2 years. We will conduct vessel surveys for 1 month in each year to find whales and collect data on their habitat, behavior, and individual occurrence patterns. As far as field research projects go, this work is not very expensive, but we still need to pay for vessel time, equipment, and personnel time to collect and analyze the data. This is an ugly truth of scientific research – it costs money and there is not a lot out there.

For two years I’ve had my fund raising hat on (Not my favorite hat. I much prefer my research hat). I believe that industry groups active in the STB should take an active role in supporting the necessary research. They exploit the natural resources in the region and should therefore take responsibility for ensuring the ecosystem’s sustainability and health. Right? They did not agree.

I emphasized to these groups that by supporting the project they would demonstrate their environmental responsibility and ultimately be engaged in discussions of management options based on project findings. Despite hundreds of emails, phone calls and discussions, all the oil and gas companies, the seabed mining group, and the maritime traffic organization declined to fund the project, claiming lack of funds or lack of relevance to their interests. Meanwhile, other groups who prioritize conservation management are supporting the project. I am grateful to The Aotearoa Foundation, The National Geographic Society Waitt Foundation, The New Zealand Department of Conservation, Greenpeace New Zealand, OceanCare, Kiwis Against Seabed Mining, and an anonymous donor.

Lately I have been reading Sheryl Sandberg’s poignant book, Lean In, which I feel is a call to women to take responsibility for our equality and leadership. Those familiar with this book will recognize the opening of my blog title from her valid push for women to take more risks and push ourselves beyond our comfort zones. In many ways I feel I am doing this now. It would be much easier for me to withdraw from this project, say I tried, and let things carry on until someone else takes the challenge. Funding is short, last minute contract issues abound, equipment logistics are running late, I fear political pushback, and I have a sore throat. But it’s time for this project to happen. It’s time to recognize biodiversity’s innate right to healthy habitat. It’s time for industry groups to acknowledge their potential impacts on blue whales through elevated ocean noise, vessel strikes, and habitat degradation and displacement. It’s time for management to have the tools to act.

Figure 2. A blue whale surfaces in front of an oil rig in the South Taranaki Bight, New Zealand. Photo by Deanna Elvines.
Figure 2. A blue whale surfaces in front of an oil rig in the South Taranaki Bight, New Zealand. Photo by Deanna Elvines.

I remain hopeful that industry groups will engage in this research effort. Through diplomacy, transparency and robust science I want to bring together industry, NGOs, and management groups to develop effective conservation strategies to protect blue whales and their habitat in the STB. Collaboratively we can balance industry activity and biodiversity protection.

Since reading Lean In, I’ve been wondering if the conservation movement suffers because of women’s reluctance to challenge, take risks, and ‘sit at the table’ as Sandberg says. The conservation field is heavily dominated by women. For progress to happen we must be willing to force issues, be perceived as aggressive, and not be nice all the time. Just like men are expected to be.

Over the next four weeks colleagues and I will conduct research in the STB on blue whales. Stay tuned to this blog for updates.

Entering in the world of Photogrammetry

By Leila Lemos, Ph.D. Student, Department of Fisheries and Wildlife, OSU.

 

Hello everybody with the first post of the year from the GEMM Lab!!

The year of 2016 has just begun and with that comes new projects and great expectations about my PhD project.

During this week I am going to learn how to measure gray whales (Eschrichtius robustus) using aerial images that were captured during last summer’s pilot field season along the Oregon Coast led by my advisor Dr. Leigh Torres.

Dr. Torres aimed to test the methodology for our project that will combine these whales’ measurements data with hormonal analysis to assess the overall health of gray whales.

The aerial videos and images were taken through an unmanned aerial system (UAS) that is composed of a flying unit and an on-board camera. An example of this system can be seen below, in Figure 1.

Lt%20recaptures%20drone

Figure 1: Dr. Leigh Torres re-captures the UAS (DJI Phantom 3) while at sea after an over flight of a gray whale.

Source: Leigh Torres, 2015.

 

The measurement of the whales through aerial images is known as “photogrammetry” and this method can give us important information about the whales through this unique overhead perspective, such as individual identification using natural markings, sex and reproductive condition based on size estimation, and individual-based changes in growth, health and body condition (nutritive condition) over time through replicate samples.

Perryman and Lynn (2002) used images captured from planes and adopted four different measurements for each photographed whale: the total length (Lt), the width of the whale at its widest point (Wm), the distance from the tip of the rostrum to the widest point (RWm), and the width of the flukes (Fw), as shown in the Figure 2. Using these methods, this study was able to identify pregnant females and found that southbound migrating gray whales were significantly wider than northbound whales.

Captura de Tela 2016-01-08 às 4.49.47 PM

Figure 2: Features measured on vertical photographs in gray whales

Source: Perryman and Lynn, 2002.

 

We plan to build upon this established method by measuring width at multiple points along the whale’s body, in addition to the total length.

Images taken of the same individuals during different temporal periods can reveal variations in their body condition.

We aim to collect images of the same individuals at the beginning and end of a foraging season and hypothesize that due to weight gain and increased blubber mass the width of animals will increase. Additionally, when images of indiviudals are compared between years we hypothesize that body condition changes due to major events such as pregnancy, entanglements, skin lesions, and predation events, will be linked to changes in body condition.

We will relate these photogrammetry data to hormonal data on stress and reproductive status in order to describe individual stress variation as it relates to size, health, location, year, reproductive status and ocean noise levels.

During the pilot field season, six gray whale fecal samples were collected and hormonal levels in these samples were analyzed showing positive results. Based on the success of the pilot field season, I believe my PhD project will produce exciting and informative data about gray whale ecology by linking physiology and morphometrics.

I am excited to begin my thesis research and, until my field season starts next summer, you can find me measuring gray whales!

To illustrate, below are a few aerial images taken of gray whales off Newport, Oregon, using a UAS, which we will use to conduct photogrammetry (all photos taken under NMFS permit 16111 issued to John Calambokidis).

Captura de Tela 2016-01-03 às 1.29.00 PM Captura de Tela 2016-01-03 às 1.28.43 PM Captura de Tela 2016-01-03 às 1.28.25 PM

And, just for fun, here is a UAS clip of a foraging gray whale in a kelp bed off the coast of Oregon to give a sense of the unique perspective we can get on animal behavior.

* Taken under NMFS permit 16111 issued to John Calambokidis.

This research is facilitated through the collaboration with OSU’s Aerial Imaging Systems Lab (http://ais.forestry.oregonstate.edu/), and Cascadia Research Collective (http://www.cascadiaresearch.org/).

Until next time and thanks for reading!

 

Bibliographic Reference:

Perryman WL, Lynn MS. 2002. Evaluation of nutritive condition and reproductive status of migrating gray whales (Eschrichtius robustus) based on analysis of photogrammetric data. J. Cetacean Res. Manage. 4(2):155-164.