Scientists have been observing dead zones, and have noticed they are expanding at an alarming rate, shrinking liveable habitats. NOAA Fisheries biologist, Eric Prince, Ph.D., and a team of eight scientists are combining oceanography and fishery biology to determine how climate change is expanding dead zones. Prince states that by using his knowledge of fishery biology, and the NOAA oceanography team they can create "...a clearer picture"
Blue marlin, like many other marine predatory species, are high dissolved-oxygen consumers because they utilize a lot of energy to move, feed and reproduce. The team has learned that blue marlin venture deep when dissolved-oxygen levels are high and remain shallow when dissolved-oxygen levels are low. This is a result of the water column with low dissolved-oxygen caging the marlin near the surface where it can obtain sufficient oxygen.
This is one of the most important discoveries in billfish conservation. Recently some population assessments reflected an increase in billfish populations, but this research gives evidence to simply why more billfish are being seen. If marlin are being pushed up near the surface then they are more likely to be caught, sighted or hungry for a fishing lure due to displaced food sources. Without taking dissolving oxygen levels into account one could seriously misinterpret blue marlin numbers and cause irreparable damage by over estimating fishing quotas.