Table 5.8. Effects of New
Bedford-style scallop dredges on sand substrate habitat: summary of published
studies. (S = statistically significant; citations in bold print are
peer-reviewed publications.)
| No. |
Reference |
Location |
Depth |
Sediment |
Effects |
Recovery |
Approach |
| 1 |
Auster et al. 1996 |
Stellwagen Bank, Gulf of Maine, USA |
20-55 m |
Coarse sand |
Smoothing
of sand ripples and low sand waves; dispersal of shell deposits in wave
troughs. |
|
Examined
gear tracks in sidescan sonar images. |
| 2 |
Langton and
Robinson 1990 |
Fippennies Ledge, Gulf of Maine, USA |
80-100 m |
Gravelly sand with some gravel, shell hash, and small
rocks |
Coarser
substrate; disruption of amphipod tube mats; piles of small rocks and scallop
shells dropped from surface; S reductions in densities of tube dwelling
polychaete and burrowing anemone. |
|
Submersible
observations made 1 yr apart, before and after commercial dredging of area. |
| 3 |
Watling et al. 2001 |
Damariscotta River, Maine, USA |
15 m |
Silty sand |
Loss
of fine surficial sediments; lowered food quality of sediment; reduced
abundance of some taxa; no changes in number of taxa; S reductions in total
number of individuals 4 mo after dredging. |
No
recovery of fine sediments, full recovery of benthic fauna and food value
within 6 mo. |
Experimental
study (23 tows in 1 day); effects on macrofauna (mostly infauna) evaluated 1
day and 4 and 6 mo after dredging in an unexploited area. |