This post is one of a series on projects supported by the Anderson Cabot Center’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists, and grassroots organizations all around the world as they work to address the most challenging problems facing the oceans.
For over 35 years, the New England Aquarium has studied, catalogued and helped to protect the endangered North Atlantic right whale. The Aquarium has also supported the research and conservation of the North Atlantic right whale’s relatives, the southern right whale through small grants from the Anderson Cabot Center for Ocean Life’s MCAF program.
Since it was founded in 1999, MCAF has funded southern right whale projects in countries such as Australia, New Zealand, and Chile. Most recently, with support from MCAF, scientist Florencia Vilches was trained in the management of a long-standing catalog of southern right whales in Argentina, which like Aquarium’s North Atlantic right whale catalog, helps document the health of the population over time. In the post below, Vilches explains how working with whale watch operators in the region greatly increased the number of sightings in this 46-year-old catalog.
I traveled from Argentina to the US in June 2016 to spend three months learning how to identify individual right whales from the patterns of raised patches of roughened skin (callosities) on their heads and the shape and position of white or grey blazes on their back (Fig. 1A and B). When there, I worked with Vicky Rowntree, who manages Ocean Alliance’s (OA) 46-year study of the southern right whales that use Peninsula Valdes (PV), Argentina, as a calving ground. I am a member of OA’s sister group in Argentina, the Instituto de Conservacion de Ballenas (ICB). With support from the Marine Conservation Action Fund (MCAF), Vicky and I spent the summer working on a new project to incorporate photographs of individual whales taken by whale-watch boat operators at PV into our aerial survey database which includes sighting histories of over 3,000 individuals that have been photo-identified at PV since 1971.
With support from MCAF, Florencia Vilches (left) traveled from Argentina to Colorado where she learned from Vicky Rowntree (right) how to identify individual right whales from the patterns of raised patches of roughened skin (callosities) on their heads and the white or grey blazes on their backs.
The project began in 2015 during our annual meeting with the six whale-watch companies at PV where we discuss new findings and current problems such as the recent high mortality of calves and the constant harassment of calves by Kelp gulls that feed on skin they tear from the backs of calves. At the end of the 2015 meeting, the operators asked if we could identify individual whales in photographs they have taken during whale-watch trips. They want to learn individual life histories to improve the stories they share with the 300,000 tourists and students that travel to PV each year to see the whales. The operators really enjoy it when a whale known from a previous year returns with yet another calf and they want to enhance the tourists’ experience by introducing them to the whales as individuals, each with its own life story. The whale-watch operators play an extremely important role in creating broad grass roots support for protecting PV population and its habitat.
We replied, “Yes, absolutely!͟” And they gave us copies of 460,000 boat-based photos they took between 2004 and 2016. The sightings from whale-watch boats will provide valuable new information that cannot be gathered during annual aerial surveys. The aerial surveys are expensive and are conducted once a year at the time of peak whale abundance. During the surveys we try to photo-identify all whales sighted close to shore along the 500 km perimeter of PV. The whale-watch boats, on the other hand, photograph whales along a much smaller segment of the coast (25 km) but do it multiple times a day, almost daily over the seven-month period of the whale-watch season. The whale-watch sightings will add many new whales to the catalog, increase the number of whales of known age (because the close-up photographs taken from boats will allow us to document details in the callosity patterns on the small heads of calves), document the length of time different age and sex classes stay in the whale-watch area, and provide information on social bonds by documenting whales that are repeatedly seen together throughout the calving season.
Different computer programs are used to assist in identifying individual right whales depending on the photographic platform. Identifying individuals in lateral photographs taken from boats (Pirzl and Watson, 2001), often requires examining multiple photographs taken at different angles to score the presence or absence of specific characteristics such as the number of callosity islands on the left and right sides of the head (Fig. 2, left: 4 islands on left and 3 on right) and the presence or absence of lip patches (present on both sides in Fig 2 left). Once the pattern is scored the program is asked to show all photographs of whales with similar scoring and the researcher either finds a match or determines it is not in the catalog and should be considered new whale. Aerial survey photographs, on the other hand, are taken from directly overhead and thus often show the callosity pattern on both sides of a whale’s head in a single frame. This allows us to use a program similar to those used for matching fingerprints (Hiby and Lovell, 2001). The program compares a silhouette of the pattern of callosities on a whale’s head (Fig 2, right) to silhouettes of all the whales in the catalog and rearranges the photos of whales in the catalog in order of best to worst match which we then examine and usually finding a match in the top 70 whales or call it a new whale.
The research team uses two different computer programs to identify right whales We first completed scoring the callosity patterns of the 3,000 whales in the aerial survey catalog so they could be used to identify whales in boat-based photographs.
Luckily, much of this work had been completed before I arrived and by the beginning of August the job was done and we began entering, scoring and searching for the whales photographed by the whale-watch photographers.
I returned to Argentina in September for the right whale field season and presented the results from my first searches using the callosity scoring system. The room for our 2016 annual meeting was filled with whale-watch operators and other people from the community (population 600). When it came time for me to speak, I described how the callosity scoring system works, and showed how the callosity features are scored using one of the whale-watch photographers’ picture as an example. I then asked the program to show us photographs of the whales in the catalog that had the same or similar features to the one we were looking for. They all looked intently at the first possible match (Fig 3), and I pointed out the places where the callosity patterns differed, then I showed the second possible match, but when I came to the third possible match, someone in the audience suddenly said ͞UUUPPAAAA!͟ and everyone began clapping (Fig 4) when they too could see the match. It was magical to have so many in one room feel the same joy that we get when making a match!
Using photos contributed by these whale-watch operators, MCAF grantee Florencia Vilches explains how the callosity scoring system used to identify individual right whales.
Someone in the audience suddenly said ͞UUUPPAAAA!͟ and everyone began clapping when they too could see the match in the callosities.
I then presented the results of the searches for the first seven whales photographed by whale-watch photographers. They included: 20 new whales and resightings of 35 whales seen during aerial surveys. The examples below show how individual biographies were enriched:
Whales 0272-93 and 1149-93 were both born in 1993 as indicated by the ͞-93͟ at the end of their names (the first four digits are their mothers’ names). Both whales were photographed next to their mothers during the 1993 aerial survey. Whale 0272-93 was resighted the following year, shortly after being separated from its mother; the other calf, 1149-93, was next seen in 1997, as a four-year-old juvenile (Fig. 5). More than a decade passed with no further sightings of either whale until 2008 and 2010, respectively, when each returned to PV! Whale-watch photographs filled in missing information from 2004 when these two beautiful females were photographed next to calves of their own! These matches increased the number of sightings of known individuals, provided the first evidence that the whales were females and added information about calving frequency and calving patterns of known aged whales.
Sightings of whale 1149-93
Whales 1911 and 2262 are distinctive because they are both partial albinos (whales that are primarily white at birth with dorso-laterial splattering of black pigmentation) (Fig. 1, right). They were each seen only once during aerial surveys in 2006 and 2008 (respectively) when they were photographed as juveniles in socializing groups. Both sighting histories were enriched after analyzing whale-watch operators’ pictures which showed them as calves next to their mothers, one in 2004 and the other in 2005! These matches illustrate another important contribution to the PV whale database: we now know that whales 1911 and 2262 currently are 11 and 12 years old and we know which families they belong to because their mothers were also photographed next to them when they were calves.
The whale-watch operators have become the de facto front-line spokespersons for the PV whales and their conservation needs. Becoming directly involved in our research has helped them become more deeply a part of the families of whales that return to PV each year, increased their sense of ownership and improved the quality of information they share with tourists who take their experiences home with them, and thereby increase concern for southern right whales throughout Argentina and the other Southern Cone countries. The preliminary results of this ongoing project underscore the valuable contribution that MCAF funding made by funding the initiation of this project. The first trickle of information presented here will grow with time and greatly improve the world’s understanding of the PV right whale population and its needs.
Tags: right whales