DNA in the water shows South African scientists where to find a rare pipefish
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Loading... - Charlotte OLOGE
- 31 Jan 2023
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Keeping track of the world's wildlife populations is fundamental to conservation efforts in the face of the continued deterioration of global biodiversity.
But some species are harder to study than others. Some aquatic species, for instance, elude detection because they are extremely rare and sparsely distributed.
One especially elusive example is the estuarine pipefish (Syngnathus watermeyeri). It is the only critically endangered syngnathid (the family of fishes that includes seahorses, pipefishes and seadragons) in the world. It is only found on the African continent and is endemic to just a few estuaries on the Eastern Cape of South Africa.
It has long been apparent that the estuarine pipefish is threatened. The species was classified as extinct in 1994 before being rediscovered in 1996. There are an estimated 100–250 remaining globally, but not much more is known.
The biggest challenge is keeping count. Population survey methods that work for other species—such as netting, counting and tagging—are simply not as effective for the elusive S. watermeyeri. They are just too small: adults reach between 10cm and 15cm and they are experts at camouflaging amid seagrass to avoid detection.
New technologies may solve the problem. One is environmental DNA (or eDNA). This refers to genetic material derived from organisms—skin cells, blood, feces and so on—that can be extracted from environmental samples such as water, soil, ice or air. Since it degrades within days or weeks in aquatic environments, eDNA can provide an up-to-date snapshot of the biodiversity within a region. Analyzing this material can reveal the presence of rare species that may have otherwise remained hidden.
Our recent study set out to determine whether eDNA is a good tool for monitoring estuarine pipefish. The answer is a resounding "yes." It is far more successful at detection than the conventional method of seine netting. Read More…
