Research in Australia 2018 Field Report

Our research team has finished up data collection from the 2018 field season, and what a season it was! Pacific Whale Foundation has been studying humpback whales in Hervey Bay for over 30 years, providing us with long-term sightings data in the form of our South Pacific Humpback Whale Catalogue. In 2018, we took over 10,000 research photos onboard Ocean Defender, including flukes, dorsal fins, injuries or skin lesions, and photos of the genital area to determine sex. We are still processing the data, but several of the whales from the early part of the season have been new to our catalog. Since subadults comprise the majority of pods in the beginning of the season, and the population is estimated to be steadily increasing, this result is somewhat expected, and we look forward to finding out how many additional new animals we may have as well as how many repeat visitors we have seen this season.

Along with our ongoing photo-identification work, this year was the first in our Swim-With-Whales Impact Study. We completed 19 trips towards this research study with 134 total swimmers who helped to make this study possible. This study allows our researchers to assess whether commercial swim-with-whales operations in Queensland are affecting the behavior of humpback whales. Using detailed behavioral observations before, during, and after swimmers are in the water with whales, we can look for patterns and changes in the whales’ behaviors; any such patterns can help determine best practices for this new, immersive form of tourism.

Another highlight of the season was the number of different species seen on our trips. Along with our familiar humpback whales, we saw southern right whales, bottlenose dolphins, Australian humpback dolphins, dwarf minke whales, dugongs, green sea turtles, loggerhead sea turtles, a hammerhead shark, a tiger shark, dingoes, and several species of seabirds. Although we don’t specifically study these species, it is always exciting to see the other inhabitants of this very special ecosystem.

Whales divided: how adults and calves use Hervey Bay differently

If you go whalewatching in Hervey Bay after mid-September, you may notice that there is a calf in nearly every pod you see. Mothers with calves are typically the last to arrive in the bay, and they may be the group that benefits most from the shallow, protected waters near Fraser Island.

Our research on the East Australia population of humpback whales allows us to ask questions about long-term trends in behavior and habitat use within the area. Using sighting data collected by our research team from 2004 – 2016, we looked at whether pods with a calf preferred different areas of the bay compared to pods without a calf. As it turns out, mothers with calves do show a preference for an place just inside the U-shaped coastline of Fraser Island, known colloquially by whalewatch operators as “the pocket”. Pods without a calf show an opposite preference for waters a bit farther offshore.

Although depth and distance to shore do not vary much throughout the bay due to the overall shallow waters and the U-shape of the coastline, mothers may prefer that area because it might be the most protected from rougher weather conditions. They may also use it as a place to avoid pursuing males and competition pods. Pods that do not have a calf may prefer the area slightly farther out of the pocket if they are seeking mating or socializing opportunities from other adults or subadults.

The study provides a baseline to compare future observations of whale distribution within the Hervey Bay area, particularly as this population continues to coexist with human activities in the bay including recreational boating, commercial whalewatching, and swim-with-whales tourism.

How can you tell a male and female humpback whale apart?

In many animals, different sexes have different appearances, with males often being larger, showier, or both: think of brightly colored male songbirds or male lions with their luscious manes. For humpback whales, however, this is not the case. Apart from females being slightly larger than males on average, humpback whale males and females look very similar to each other, making it very difficult to visually determine sex. Adding to this, all reproductive organs in both females and males are neatly tucked away behind a genital slit to help them be more hydrodynamic and sleek in the water.

Luckily for us researchers, though, we have a few tricks up our sleeves to tell the difference between the sexes, allowing us to collect additional data for our photo-identification catalog.

The easiest way to determine a female humpback whale is a close association with a calf. Mothers and calves maintain a strong bond throughout the first year of the calf’s life, so when we see an adult whale closely accompanied by a calf, we can safely assume that she is the mother of that calf.

In the absence of a calf, though, things become trickier. If the whales roll over onto their backs, often we can see the genital slit on their abdomen. The relative location of the genital slit offers some clues: For males, the genital slit is located closer to the whale’s belly, while the females’ genital slit is closer to their tail flukes. Immediately towards the tail from the genital slit, females have a grapefruit-sized lump known as a hemispherical lobe. No one knows what exactly this structure does, but we do know that it is only present on females. Females also have two mammary slits, one on either side of the genital slit, which they will use when nursing their calves.

Click through the photos in this gallery and our researchers will explain how we were able to identify the sex of these humpback whales

When we are able to determine the sex of a whale, this information is included along with the animal’s fluke photo when it is added to the catalog. Knowing the sex of different individuals enables us to more accurately determine calving rate and sex ratios of different habitat areas.

Southern right whales in Hervey Bay

This season, humpback whales haven’t been the only large baleen whale sighted in Hervey Bay. We have also had several sightings of mother-calf pairs of southern right whales, a rare species for this area. The first pair was seen in July, and there have been many additional sightings over the past several weeks, much to the surprise and delight of passengers and staff onboard Ocean Defender.

All right whales have white patches of rough skin on their heads called callosities. The pattern of callosities is unique to each individual whale, and researchers use these patterns to identify right whales much in the same way that we use fluke patterns to identify humpback whales. Using the patterns of callosities, we have been able to recognize at least three different mothers that have been sighted this season.

These mothers belong to the southeast Australia population, which is more commonly seen farther south in Victoria and New South Wales. Similar to humpback whales, southern right whales prefer relatively warmer, calmer waters for their calves, but they do not typically travel all the way to tropical areas. In fact, Hervey Bay is considered the extreme northern extent of their range. Southern right whales were hunted extensively since their slow swimming speeds and thick blubber made them the “right” whale to kill, particularly before the industrial era of whaling. The populations are recovering, though, and it is encouraging to see these mothers and calves along the east coast of Australia.

Looking back through the past several years of data from Hervey Bay, Pacific Whale Foundation researchers have only seen right whales in the area in 2006, 2007, 2009, and 2012 prior to this year. In those years, there were also fewer sightings: 2009 and 2012 each had sightings on two days, but our team only saw right whales a single time in 2007 and 2009. Although we can’t say for sure why these mothers and calves decided to visit Hervey Bay for such an extended time this season, it will certainly be interesting to see what future years bring for sightings of this amazing species.

Although Pacific Whale Foundation does not currently study southern right whales, our research team is collecting data and submitting all sightings and identification photos to the Australian Marine Mammal Centre which maintains a catalog of this population.

 

Reuse or Refuse Drinking Straws

Plastic straws are one of the top 10 marine debris items collected during beach clean-ups worldwide. They are polluting the oceans and injuring, even killing, marine wildlife. Many plastic products we use only once, and then throw away. These single-use plastics and causing a massive pollution problem around the world, and we are advocating for people to refuse all single-use plastics, starting with drinking straws.

In the United States alone, we use and throw away 500 million plastic straws each day. That is enough straws to fill over 120 school buses or to circle the Earth two and a half times! Since plastic straws are so lightweight and tend to blow away easily, they rarely make it to landfills or recycling facilities. Other single-use plastics include beverage containers, food wrappers, and packaging, which currently comprise nearly a quarter of all waste in the United States. Since plastics are such a durable material, they never truly ‘go away’ – meaning all plastics that have ever been produced, including items that are only used once, are still around today in some form or another.

Of the single-use plastics out there, plastic straws are a relatively easy item to eliminate by refusing them at bars and restaurants. Additionally, for those who still prefer or require a straw, there are several reusable options, and Pacific Whale Foundation has some options for purchase at our Ocean Stores. Although our efforts are aimed toward plastic straws, we hope that making one small change will inspire people to refuse other single-use plastic items.

We all contribute to the problem, but we can all take action to turn the tide on plastic pollution. Did you know that Pacific Whale Foundation stopped serving straws on our PacWhale ecotour vessels in 2015? Join us in this movement! You can join us in our campaign to #ReuseorRefuse your straw by signing our pledge and telling your favorite bar/restaurant to go straw free!

Seeing Some Familiar Fins

The PWF research team recently had a great encounter with a pod of bottlenose dolphins that were hunting fish. Back in the office, we used the bottlenose dolphin photo-identification catalog to reveal some interesting information about the group. As it turns out, this pod contained an adoption animal (#095, “Pa‘ani”), our oldest cataloged animal (#005), a dolphin newly confirmed as a male (#114), and a female who had a calf last summer (#006).

Dolphin #005 was sighted in the very first pod added to the PWF bottlenose dolphin catalog in 1996, and dolphin #006 was first seen in 1997, making them at least 21 and 20 years old, respectively. Our adoptable female, #095 (“Pa‘ani”), was first seen in 2010, meaning she is potentially a bit younger than #005 and #006. Since she had already reached her adult size when she was first seen, it is difficult to determine her actual age, but we know she is at least 7 years old.

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