IMIS | Flanders Marine Institute
 

Flanders Marine Institute

Platform for marine research

IMIS

Publications | Institutes | Persons | Datasets | Projects | Maps
[ report an error in this record ]basket (0): add | show Printer-friendly version

Indirect effects of clam digging on the viability of soft-shell clams, Mya arenaria L.
Emerson, C.W.; Grant, J.; Rowell, T.W. (1990). Indirect effects of clam digging on the viability of soft-shell clams, Mya arenaria L. Neth. J. Sea Res. 27(1): 109-118
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579, more
Peer reviewed article  

Available in Authors 

Keyword
    Marine

Authors  Top 
  • Emerson, C.W.
  • Grant, J.
  • Rowell, T.W.

Abstract
    A series of laboratory experiments was conducted to determine whether non-lethal burial or exposure on the sediment surface could alter the normal living depth of Mya arenaria in sand and mud. After 2 weeks, clams (~ 3 to 7 cm shell length) which were buried under 1 to 15 cm of medium-fine sand were found deeper than the controls, whereas clams (~ 1 to 7 cm length) which were exposed on sand (and had subsequently reburrowed) were able to re-establish their normal living depth. In contrast, clams (~ 1 to 7 cm length) buried under 1 to 15 cm of mud attained their normal living depth within two weeks, but exposed clams (~ 1 to 7 cm length) reburrowed to abnormally shallow depths. An increased likelihood of predation at shallow sediment depths was compounded by the 60% slower reburrowing speed of exposed clams in mud than in sand. An additional experiment determined the approximate depth of burial under which at least 50% of a laboratory clam population could survive (LD50). For small (< 3 cm in shell length), mid-size (3 to 5 cm) and large ( > 5 cm) clams in sand, LD50 values were > 75 cm, > 75 cm and between 50 and 75 cm, respectively. In mud, the LD50 of clams < 5 cm in length was < 25 cm, and between 25 and 50 cm for clams >=5 cm in length. It was concluded that the indirect mortality level associated with commercial and recreational harvesting will be much greater on intertidal mudflats than on sandflats.

All data in IMIS is subject to the VLIZ privacy policy Top | Authors