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Introduction

Many marine habitats can be classed as extreme, based on for example, salinity, temperature, increased pressure or nutrient deficiencies. The Bowhead Whale, Balaena mysticetus (Linnaeus,1758) spends its entire life in the coldest temperature extreme. There are two cold extreme habitats, known as the Polar regions, located at the highest latitudes (North and South poles). The Bowhead whale, also known as the Arctic Right Whale, Greenland Right Whale, Great Polar Whale or Ahvik (Braham et al., 1980), lives its entire life in the Arctic Ocean. There are three cetaceans that live exclusively in the icy extreme of Arctic Ocean, with Bowheads being the largest and the only Arctic endemic  baleen cetacean (Braham, 1984). Thus Bowheads are an apex predator to zooplankton, controlling the lower food chain abundances; therefore the Bowhead whale is an important part of the Arctic Ocean ecosystem (Blix, 2005). In order to survive in this cold extreme it has become highly adapted to ice covered seas and can navigate easily through solid ice (Moore and Laidre, 2006). This blog examines some of the Bowhead’s unique adaptations that allow it to survive in the coldest extreme all year round.

As the ocean and seas are energetically challenging due to 25 times more heat being conducted away from the Bowhead body by water then in air.  Bowhead have adaptation mechanisms to regulate the body temperature (core temperature 33.8°C) (George, 2009, Heyning, 2001).  Therefore they have evolved very efficient thermoregulatory (maintain a constant core temperature in freezing cold waters) mechanisms and modified their reproductive strategy (slowing growth, delayed maturity), feeding strategies and other morphological and behavioural adaptations, increasing their reproductive success in this harsh environment (George et al., 1999).

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