Now you see it, now you don’t: the troubled tale of the estuarine pipefish

The estuarine pipefish, has been playing a frightening game of hide-and-seek for decades.  Not only was this pipefish thought to be extinct once, it was feared to have disappeared from the world a second time… only to be discovered yet again by scientists. You may wonder, just as we did, why this species has been lost and found so many times. What is it about this fish that makes it so vulnerable to extinction and why is it struggling to stay alive? Perhaps it is because this pipefish is very vulnerable to environmental changes or maybe because it is so rare?

It is interesting that, in many cases, it is the tiny animals that fall through the conservation crack. The estuarine pipefish is possibly one of the best examples of this phenomenon.

The story begins in the early 1960s when Douglas Galpin first discovered and captured this small (<13 cm), rarely seen pipefish, that lives only in the Eastern Cape Province of South Africa. When the new pipefish was officially described in 1963 by Professor J.L.B Smith, it was only known from a few coastal estuaries, namely the Bushmans, Kariega and Kasouga. Ironically, the very same year this pipefish was described was also the last time it was seen in the wild for more than 30 years. The IUCN Red List of Threatened Species declared the estuarine pipefish extinct in 1994.  But wait… there was a second discovery.

In 1996, Professors Paul Cowley and Alan Whitfield (from the South African Institute for Aquatic Biodiversity) recorded a viable breeding population during a fish survey in the same region of South Africa, this time in the East Kleinmonde Estuary. Unfortunately, the species did not thrive in this estuary for long and by 2003 it was thought to be locally extinct – seven years after it was rediscovered! Once again, the species was feared lost…

In 2006, new hope emerged when 20 juvenile estuarine pipefish were discovered yet again within the species’ historic range – the first record of this species in the Kariega Estuary for over 40 years. Dr. Paul Vorwerk and other researchers serendipitously found the elusive pipefish during a survey on the 18 km long Kariega Estuary.

Changes in water flow, at least partly through current management practices, may explain much of the plight of the estuarine pipefish. The construction of dams and impoundments greatly affect river flow, as do changing land use practices. A large flood event in 2003 coincided with apparent local extinction of this pipefish in the East Kleinmonde Estuary.  Another flood in the Kariega Estuary, in 2012, removed almost all of the eelgrass beds where this species lives. Along with habitat loss, local water flow (prolonged droughts or floods, whether real or from regulation) affects the supply of zooplankton for the pipefish, particularly early juveniles. Loss of river flow can therefore result in a breakdown in the life cycle of this species.

The current pipefish population now appears to be restricted to a single estuary, that of the Bushmans River. Given its very small numbers, limited distribution and small geographic range, it is not surprising that the estuarine pipefish is listed as Critically Endangered on the IUCN Red List of Threatened Species.

 The odds are stacked against this little known pipefish and remedial action is urgently needed. The largest challenge is to understand the most serious threats to the species and act to mitigate them.  As management of water flow seems central to the problem steps must be taken to regulate land use practices and water control practices in favour of these fish.  This will require extensive dialogue with government agencies and regional stakeholders.

Biologists in South Africa are eager to play a role through extensive field surveys, genetic studies, and a captive breeding program. The Estuarine Pipefish Interest Group, a collaboration among various South African researchers established in 2016, aims to begin extensive field surveys in 2018, the first since 2013.  These evaluations will help determine the status and distribution of this pipefish, guide population monitoring and management planning. They also plan to establish a captive breeding programme, also a first for this species, to allow possible reintroduction into the estuaries. Reintroduction of any species into the wild is a tricky and complex process, but is a vital safeguard for species as imperiled as this one.

Long teetering on the brink of extinction, the estuarine pipefish remains in grave and imminent danger.  It needs focused attention and immediate precautionary conservation action, even while research gets underway. In order to buy us time, we hope that the new surveys reveal a few more of these pipefish, in another chapter of this worrying game of hide-and-seek.

 

 

Lily Stanton is the Syngnathid Research Biologist with Project Seahorse, a collaboration of the University of British Columbia (Canada) and the Zoological Society of London (UK). A biologist with a passion for conservation and biodiversity, she is a member of the IUCN SSC Seahorse, Pipefish and Stickleback Specialist Group.

 

 

 

Dr. Louw Claassens is Director of the Knysna Basin Project, an environmental NGO based in Knysna, South Africa,  and is a member of the IUCN SSC Seahorse, Pipefish and Stickleback Specialist Group. She recently completed her PhD at Rhodes University on the population ecology and behavior of the endangered Knysna seahorse, Hippocampus capensis.

 

References

Pollom, R. 2017. Syngnathus watermeyeri. The IUCN Red List of Threatened Species 2017: e.T41030A67621860. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T41030A67621860.en.

Vorwerk PD, Froneman PW, Paterson AW. 2007. Recovery of the critically endangered river pipefish, Syngnathus watermeyeri, in the Kariega Estuary, Eastern Cape Province. South Africa Journal of Science 103: 199-201.

Whitfield AK, Mkare TK, Teske PR, James NC, Cowley PD. 2017. Life histories explain the conservation status of two estuary associated pipefish. Biological Conservation, 212: 256-264.

 

 

 

 

 

 

 

 

 

 

Lily Stanton is the Syngnathid Research Biologist with Project Seahorse, a collaboration of the University of British Columbia (Canada) and the Zoological Society of London (UK). A biologist with a passion for conservation and biodiversity, she is a member of the IUCN SSC Seahorse, Pipefish and Stickleback Specialist Group.

 

 

Dr. Louw Claassens is Director of the Knysna Basin Project, an environmental non-governmental organization based in Knysna, South Africa, (www.knysnabasinrpoject.co.za) and is a member of the IUCN SSC Seahorse, Pipefish and Stickleback Specialist Group. She recently completed her PhD at Rhodes University on the population ecology, habitat use and behavior of the endangered Knysna seahorse, Hippocampus capensis.