Whales

Do whale watchers bother whales? A number of studies on tourism's impact on whales, which were based on behavioural observations, have concluded that tourism caused only minor disruptions to the mammals. 

For example, in 2015, a study led by Marianne H. Rasmussen, director of the University of Iceland Húsavík Research Centre, found that whale watching as currently practised does not seem to be having any long-term negative effects on the life expectancy of minke whales.

Pygmy blue whales are the smallest members of the blue whale family, but that's the only small thing about them: they can reach up to 24 meters long.

Despite their enormous size, blue whales have been difficult to observe in the Southern Hemisphere as they live offshore and don't jump around like the humpback whales; thus, for some regions, their population structure, distribution and migration routes remain poorly understood. In particular, little is known about the blue whales in the northern Indian Ocean.

Narwhals, notwithstanding their unicorn-like tusks, are a mysterious species. They live in distant Arctic regions and hunt as deep as 1,000 meters down. 

They orient themselves using echolocation, making clicking sounds to explore their surroundings. When they hunt, the clicking sounds turn into buzzing sounds as the interval times shorten.

A new population of pygmy blue whales has been discovered in the Indian Ocean, thanks to underwater nuclear bomb detectors that recorded their whale songs.

The research team, led by the University of New South Wales (UNSW), had been studying data from the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) which monitors international nuclear bomb testing, when an unusually strong signal caught their attention.

In late January 2021, the World Cetacean Alliance (WCA) named Dana Point, California as a Whale Heritage Site, the first such site in the Americas.

The reasons were obvious: As one of the world's top whale-watching destinations, it hosts a variety of whales all year round, including the blue whale. It has more dolphins per square mile than anywhere in the world. Dana Point also has a small non-commercial harbor, community support, and undertaken public outreach and education, advocacy and research efforts. 

Focusing on nine of the most commonly found dolphin, whale and porpoise species in UK waters, the strategy has been developed by the Scottish Government, in collaboration with the UK Government, the Welsh Government and the Northern Ireland Executive.

Its objective is to ensure the effective management to achieve and maintain the current favourable status of the nine species. It highlights certain pressures where further research or extra management measures may help to improve the conservation of marine mammals.

Equipped with an autonomous hydrophone, the buoy's function is to conduct for the first time real-time acoustic monitoring of the water's cetaceans to assess how oceanic noise pollution affects them. 

Deployed as part of the Smart Whale Sounds project, it will also track the distribution and behaviour of whale species in real-time and be used to train machine learning models to identify different species' calls. 

Cetaceans were not limited by gravity in the buoyant marine environment and evolved multiple giant forms, exemplified today by the largest animal that has ever lived: the blue whale (Balaenoptera musculus).

There are tradeoffs, however, associated with large body size, including a higher lifetime risk of cancer due to a greater number of somatic cell divisions over time.  The largest whales can have ∼1,000 times more cells than a human, with long lifespans, leaving them theoretically susceptible to cancer. 

Using mercury and stable isotopes of carbon and nitrogen to obtain such information, the team were able to also analyse how the ice cover and the impact of potential toxic compounds have evolved over time.

Their findings were published in the Current Biology journal.

The tusks of the ten narwhals involved in the research were 150 to 248 cm long, and contained data from the time period 1962 to 2010.