Effect of sea cucumber density on the health of reef-flat sediments. In: Fiji’s Sea Cucumber Fishery: Advances in Science for Improved Management

@inbook{Lee2017,
  Title = {Effect of sea cucumber density on the health of reef-flat sediments},
  Author = {Lee, S and Ferse, Sebastian C.A. and Ford, Amanda and Wild, C and Mangubhai, S},
  Editor = {Mangubhai, S. and Lalavanua, W. and Purcell, S.W.},
  Year = {2017},
  Pages = {54-61},
  Isbn = {978-0-9820263-0-4},
  Booktitle = {Fiji’s Sea Cucumber Fishery: Advances in Science for Improved Management},
  Abstract = {Sea cucumbers are thought to play an important role in the recycling and remineralization of 
organic matter in reef sands through feeding and bioturbation. However, growing demand and 
high prices from Asian markets are driving the overexploitation of sea cucumbers globally, 
with little understanding of the consequences of local-scale removal from inshore coral reef 
ecosystems. Densities of Holothuria scabra were manipulated in enclosures in situ on a reef 
flat adjacent to Natuvu village, on the island of Vanua Levu, Fiji, between August 2015 and 
February 2016 to simulate an unfished and an overfished stock density. Two treatments were 
used: (i) high sea cucumber stocking density (350 g m-2); and (ii) exclusion of sea cucumbers (0 
g m-2). Two controls accounted for cage effects: (i) cage controls (no cage walls); and (ii) natural 
density (60 g m-2). Sedimentary oxygen consumption (SOC), grain size distribution, sediment 
porosity, and O2 penetration depth were recorded. SOC rates were consistently lower in high-
density enclosures than when sea cucumbers were exclude, indicative of ‘healthy’ sediments. 
O2 penetration depth decreased significantly when sea cucumber removal coincided with 
elevated sea surface temperatures which are indicative of sediment health decline. Thus the 
removal of sea cucumbers reduces the efficiency of reef sediment to function as a filter system 
to buffer organic matter pulses, and negatively affects the function and productivity of inshore 
reef ecosystems},
}

TY  - CHAP
AU  - Lee, S
AU  - Ferse, Sebastian C.A.
AU  - Ford, Amanda
AU  - Wild, C
AU  - Mangubhai, S
ED  - Mangubhai, S
ED  - Lalavanua, W
ED  - Purcell, S.W
TI  - Effect of sea cucumber density on the health of reef-flat sediments
PY  - 2017
SP  - 54-61
SN  - 978-0-9820263-0-4
BT  - Fiji’s Sea Cucumber Fishery: Advances in Science for Improved Management
AB  - Sea cucumbers are thought to play an important role in the recycling and remineralization of 
organic matter in reef sands through feeding and bioturbation. However, growing demand and 
high prices from Asian markets are driving the overexploitation of sea cucumbers globally, 
with little understanding of the consequences of local-scale removal from inshore coral reef 
ecosystems. Densities of Holothuria scabra were manipulated in enclosures in situ on a reef 
flat adjacent to Natuvu village, on the island of Vanua Levu, Fiji, between August 2015 and 
February 2016 to simulate an unfished and an overfished stock density. Two treatments were 
used: (i) high sea cucumber stocking density (350 g m-2); and (ii) exclusion of sea cucumbers (0 
g m-2). Two controls accounted for cage effects: (i) cage controls (no cage walls); and (ii) natural 
density (60 g m-2). Sedimentary oxygen consumption (SOC), grain size distribution, sediment 
porosity, and O2 penetration depth were recorded. SOC rates were consistently lower in high-
density enclosures than when sea cucumbers were exclude, indicative of ‘healthy’ sediments. 
O2 penetration depth decreased significantly when sea cucumber removal coincided with 
elevated sea surface temperatures which are indicative of sediment health decline. Thus the 
removal of sea cucumbers reduces the efficiency of reef sediment to function as a filter system 
to buffer organic matter pulses, and negatively affects the function and productivity of inshore 
reef ecosystems
ER  -