DNA analysis in seawater samples can tell which fish are present in a particular part of the sea.
The ability to track the diversity of deep-sea fish is essential in order to control biodiversity, monitor how slavery affects populations and monitor the effect of climate on fish abundance. However, existing methods such as baited camera traps or acoustic monitoring are limited and difficult to use in much of the ocean.
A new technique, called eDNA metabarcoding, can identify which fish are present in a given habitat by analyzing the DNA of the surrounding stratum (eDNA). This is the DNA that is released by organisms into the environment when they go about their normal activities.
To assess the effectiveness of eDNA metabarcoding for detecting deep-sea fish, a team of scientists collected seawater from the Labrador Sea at depths of up to 2,500 meters. In the sample, 11 fish families, 11 genera and 8 species were identified.
The researchers compared their results for metabarcoding eDNA with those obtained with conventional methods and found that their algorithm was more efficient.
The researchers note that this method can already be used to monitor fish diversity in the deep ocean. Despite this, the group plans to improve this procedure.