Oxygen uptake with gills from water vs lungs from atmosphere
The assumption in the question was corroborated by this article here, and is correct. The downvote is unnecessary, it is a valid question, and was easily answered with strong scientific consensus.


  As a precondition for the coevolution of eurythermy and life with high energy turnover, oxygen availability had to be maximized and the
  capacity of oxygen supply mechanisms selected high (Fig. 2). Such
  preconditions were met with atmospheric oxygen levels always above a
  minimum of 13%–15% during animal evolution (Fig. 4). Moreover, such
  preconditions were most ideally met in terrestrial environments since
  breathing air rather than water implies a reduction by one order of
  magnitude in the energy cost of ventilation at 30–35 times higher
  levels of ambient oxygen and about 103 times lower viscosity of the
  respiratory medium. However, new and largely different ventilatory
  systems had to be developed in air (lungs instead of gills in
  vertebrates) in most cases (except for terrestrial crabs) to exploit
  the excess amount of oxygen. At the same time, thermal conductivity in
  air is more than 20 times less and specific heat about four times less
  than in water, reflecting that thermal buffering is much less in the
  968 H. O. Po¨rtner terrestrial than in the aquatic environment. As a
  consequence, temperature changes occur on shorter timescales and at
  larger amplitudes in terrestrial than in aquatic environments.
  Therefore, terrestrial organisms at the same latitude are likely to
  experience much larger temperature fluctuations than aquatic
  organisms. Opposite to the marine realm, where temperature
  oscillations are less in polar and tropical than in temperate areas,
  those in air increase at high, especially Northern, latitudes, as
  estimated for mainland locations in the Americas (Gaston and Chown
  1999). According to these considerations, extreme stenotherms
  comparable to Antarctic marine species are highly unlikely to exist in
  (cold) terrestrial environments. Eurytherms will predominate instead.


Pörtner, H. O. (2004). Climate Variability and the Energetic Pathways of Evolution: The Origin of Endothermy in Mammals and Birds. Physiological and Biochemical Zoology, 77(6), 959–981. https://doi.org/10.1086/423742