[Coral-List] Use and misuse of sediment traps on coral reefs

[Mike Field]

  Colleagues,

  We have recently published a paper in Coral Reefs on the use and  
misuse of sediment traps in coral reef environments. We’re providing  
this information here because not all listers may have access to the  
journal, and because many monitoring protocols and research studies  
depend—sometimes inappropriately or erroneously-- on the use of traps  
to estimate or monitor sedimentation on coral reefs.

The paper is:

Storlazzi , C.D., Field  M. E., H. Bothner, M. H., 2011 The use (and  
misuse) of sediment traps in coral reef environments: theory,  
observations, and suggested protocols. Coral Reefs, v. 30, p 23-38

  The abstract for the paper is below. If you would like a pdf copy of  
the paper, please send a request to Curt Storlazzi  
(cstorlazzi at usgs.gov) or to me (mfield at usgs.gov).

Mike



ABSTRACT

Sediment traps are commonly used as standard tools for monitoring  
‘‘sedimentation’’ in coral reef environments. In much of the  
literature where sediment traps were used to measure the effects of  
‘‘sedimentation’’ on corals, it is clear from deployment descriptions  
and interpretations of the resulting data that information derived  
from sediment traps has frequently been misinterpreted or misapplied.  
Despite their widespread use in this setting, sediment traps do not  
provide quantitative information about ‘‘sedimentation’’ on coral  
surfaces. Traps can provide useful information about the relative  
magnitude of sediment dynamics if trap deployment standards are used.  
This conclusion is based first on a brief review of the state of  
knowledge of sediment trap dynamics, which has primarily focused on  
traps deployed high above the seabed in relatively deep water,  
followed by our understanding of near-bed sediment dynamics in shallow- 
water environments that characterize coral reefs. This overview is  
followed by the first synthesis of near-bed sediment trap data  
collected with concurrent hydrodynamic information in coral reef  
environments. This collective information is utilized to develop nine  
protocols for using sediment traps in coral reef environments, which  
focus on trap parameters that researchers can control such as trap  
height (H), trap mouth diameter (D), the height of the trap mouth  
above the substrate (zo), and the spacing between traps. The  
hydrodynamic behavior of sediment traps and the limitations of data  
derived from these traps should be forefront when interpreting  
sediment trap data to infer sediment transport.


************************************************
Michael E. Field
US Geological Survey
Pacific Science Center
400 Natural Bridges Drive
Santa Cruz, CA 95060
(831) 427-4737;   FAX: (831) 427-4748

http://coralreefs.wr.usgs.gov