Before you read the below you may want to read this article from Tropical Fish Magazine
https://www.tfhmagazine.com/articles/aquarium-basics/aeration-and-oxygenation
The Skeptical Fishkeeper: Aeration and Oxygenation
Author: Laura Muha from December 2007
My statement is not incorrect. Unfortunately, all I can see of the DeMoyera et. al. study is the Abstract unless I pay. However, the study is cited by a lot of other researchers. What is agreed upon regarding oxygenation via bubbling are several things. First, bubblers aerate in two ways- contact of bubbles with the water and then surface agitation as the bubbles reach the surface. Second, the size of the bubbles matters. The bigger the bubble the less gasses are transfered to the water. Third, depth is the most critical factor in determining the transfer for any bubble size and how many bubbles are being released. Fourth, the size of the device making the bubbles also determines the amount of gasses being transfered. Basically this means the bigger the airstone, the more bubbles it releases and that means more exchange and also more surface agitation. Another consideration is the power of the device blowing the air or even pure oxygen into the water. A more powerful air pump making more buvblles means more oxtgen can come into the water by diffusion and agitation
One study indicated:
Al-Ahmady, K.K. Analysis of Oxygen Transfer Performance on Sub-surface Aeration Systems.
Int. J. Environ. Res. Public Health 2006,
3, 301-308.
https://doi.org/10.3390/ijerph2006030037
Figure 5 indicated that, if the airflow rate is kept constant, oxygen transfer capacity (OC) is directly proportional to submergence. At 0.5 m submerges, the oxygenation capacity is ranging within a narrow limit between 18-34 grO2/m3water.hr depending on the (f/B) ratios. With increasing the depth, the oxygenation capacity is increased to about 160 grO2/m3water.hr at the 4.6 m submerges.
from
https://www.mdpi.com/1660-4601/3/3/301/pdf
It doesn't take a genius to understand the above. The shallow placement, .5 meters produced 18-34 grO2/m3water.hr. When the depth was 4.6 meters or 9+ times deeper, the same device and bubbles (size and rate) produced 160 grO2/m3water.hr or 4.7 times the oxygen.
How many folks here have a tank that is 1.6 ft. between an airstone and the water surface? If one allows for a couple of inches of subtrate and 3/4 of an inch below the top of the tank - this is about 3-4 inches and that would be about a 2 ft tall tank. How how many of you have a tank which is 15+ ft. deep?
Basically if you do not have a seriously deep tank, an airstone which makes extremely fine bubbles and is very large, it is creating more oxygen from surface agitation than diffusion from the bubbles to the water on their way to the surface. the operant term is "contact time." it matters a great deal how long a bubble is in contact with the water before it bursts at the surface.
Even the Abstract from the DeMoyera paper shows this (color added by me):
Abstract
The primary location of oxygen transfer in a diffused aeration system is examined by separately determining the surface air–water and bubble–water mass transfer coefficients. The mass transfer model developed to determine the mass transfer coefficients advances the McWhirter and Hutter (A.I.Ch.E. J. 35(9) (1989) 1527) model by tracking oxygen and nitrogen transfer into and out of the bubbles as they rise to the water surface. The resulting vertical profiles of the liquid-phase equilibrium concentration inside the bubble and the gas-phase oxygen composition give insight into how the bubble–water concentration gradient changes over depth. The surface mass transfer coefficient, kLsas, is 59–85% of the bubble mass transfer coefficient, kLab, and the driving concentration difference is smaller for surface transfer. Surface transfer and bubble transfer both contribute significantly to oxygen transfer; however, bubble transfer is the primary mode of oxygen transfer for this system at the air flow rates used. Further experiments demonstrate that most of the surface transfer occurs above the bubble plume.
The problem with the above when it states that the bubble transfer is the primary mode of transfer is that this is for a specific system which is described in the full paper. If somebody has access to the full study, please post the relevant info or links. Next, looking at the pictures in the article (not the study) it diagrams a small column of bubbles. The area for bubble creation affects the amount of surface agitation. Put another way, at the same depth, producing the same bubble size over the entire area of the device, the bigger the airstone, the more surface agitation that will result. Also, the more bubbles it will produce.
So for most of us in the hobby and the tanks we keep, surface agitation is the Prime method of gas exchange. The exception for this is in heavily planted tanks with some fast growers. Plants make oxygen in very fine bubbles, when you get to see pearling. But a lot of the oxygen we cannot see is coming from the plants. When I ran my pressurized co2 added, high light planted tank, I kept the surface agitation to a minimum so as not to outgas co2. This was the most healthy tank I had. I lost almost no fish over a decade and had farlowellas spawn in it. This could not happen if DO levels were much lower than normal saturation levels.