TY - JOUR
T1 - Life-histories explain the conservation status of two estuary-associated pipefishes
AU - Whitfield, Alan K.
AU - Mkare, Thomas K.
AU - Teske, Peter R.
AU - James, Nicola C.
AU - Cowley, Paul D.
N1 - Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017/8
Y1 - 2017/8
N2 - Two endemic southern African pipefish species (Teleostei: Syngnathidae) co-occur in estuaries on the southeast coast of South Africa. The larger longsnout pipefish, Syngnathus temminckii, is abundant and has a wide range that comprises coastal and estuarine habitats in all three of the region's marine biogeographic provinces. In contrast, the smaller estuarine pipefish S. watermeyeri is critically endangered, and confined to a few warm-temperate estuaries. Here, we explore reasons for these considerable differences in conservation status. Fecundity is related to fish size, with large live-bearing S. temminckii males carrying up to 486 developing eggs/embryos, compared to a maximum of only 44 recorded for S. watermeyeri. Loss of submerged seagrass habitats due to episodic river flooding appears to be correlated with the temporary absence of both species from such systems. Prolonged cessation in river flow to estuaries can cause a collapse in estuarine zooplankton stocks, a food resource that is important to pipefish species. The greater success of S. temminckii when compared to S. watermeyeri can be attributed to the former species’ wider geographic distribution, fecundity, habitat selection and ability to use both estuaries and the marine environment as nursery areas. Genetic data indicate that this has resulted in a much smaller long-term effective population size of S. watermeyeri, a situation that has persisted since the beginning of the present interglacial period. Syngnathus watermeyeri is thus naturally more susceptible to anthropogenic disturbances, which have resulted in an alarming reduction in its contemporary population size. Possible measures to promote the conservation of S. watermeyeri are presented.
AB - Two endemic southern African pipefish species (Teleostei: Syngnathidae) co-occur in estuaries on the southeast coast of South Africa. The larger longsnout pipefish, Syngnathus temminckii, is abundant and has a wide range that comprises coastal and estuarine habitats in all three of the region's marine biogeographic provinces. In contrast, the smaller estuarine pipefish S. watermeyeri is critically endangered, and confined to a few warm-temperate estuaries. Here, we explore reasons for these considerable differences in conservation status. Fecundity is related to fish size, with large live-bearing S. temminckii males carrying up to 486 developing eggs/embryos, compared to a maximum of only 44 recorded for S. watermeyeri. Loss of submerged seagrass habitats due to episodic river flooding appears to be correlated with the temporary absence of both species from such systems. Prolonged cessation in river flow to estuaries can cause a collapse in estuarine zooplankton stocks, a food resource that is important to pipefish species. The greater success of S. temminckii when compared to S. watermeyeri can be attributed to the former species’ wider geographic distribution, fecundity, habitat selection and ability to use both estuaries and the marine environment as nursery areas. Genetic data indicate that this has resulted in a much smaller long-term effective population size of S. watermeyeri, a situation that has persisted since the beginning of the present interglacial period. Syngnathus watermeyeri is thus naturally more susceptible to anthropogenic disturbances, which have resulted in an alarming reduction in its contemporary population size. Possible measures to promote the conservation of S. watermeyeri are presented.
UR - http://www.scopus.com/inward/record.url?scp=85030648831&partnerID=8YFLogxK
U2 - 10.1016/j.biocon.2017.06.024
DO - 10.1016/j.biocon.2017.06.024
M3 - Article
AN - SCOPUS:85030648831
SN - 0006-3207
VL - 212
SP - 256
EP - 264
JO - Biological Conservation
JF - Biological Conservation
ER -