| CRD 02-01
Table 5. Impacts of Otter
Trawls on Benthic Habitat |
| TYPE OF IMPACT |
DEGREE OF IMPACT |
DURATION |
TYPE OF EVIDENCE |
COMMENTS |
| MUD |
| Removal of Major Physical Features |
XXX (H)
N/A ( L) |
Permanent |
PJ |
(H) in Mud referrs to clay (i.e., tilefish burrows) in all
cases |
| Impacts to Biological Structure |
Unknown (H)
XX* (L) |
Months - Yrs |
PJ |
(L) opinions ranged from X-XXX |
| Impacts to Physical Structure |
XXX* (H)
XX* (L) |
Months - Yrs |
PR, GL, PJ |
(L) opinions ranged from XX-XXX and unknown |
| Changes in Benthic Prey |
Unknown |
|
|
|
| SAND |
| Removal of Major Physical Features |
N/A |
N/A |
N/A |
|
| Impacts to Biological Structure |
XX* (H, L) |
Months - Years |
PR, GL, PJ |
(H) opinion ranged from X-XXX
(L) opinion ranged from XX-XXX |
| Impacts to Physical Structure |
X* (H)
XX* (L) |
Days - Months |
PR, GL, PJ |
(H, L) opinion ranged from X-XXX |
| Changes in Benthic Prey |
XX* (H, L)
|
Months - Years |
PR, PJ, GL |
(H) opinions were XX or unknown
(L) ranged from X-XXX and unknown |
| GRAVEL |
| Removal of Major Physical Features |
XXX (H, L)
|
Permanent |
PR, GL,PJ |
|
| Impacts to Biological Structure |
XXX (H, L) |
Months - Years |
PR, GL, PJ |
|
| Impacts to Physical Structure |
XXX (H, L) |
Months - Years |
PR, GL, PJ |
Rocks altered or relocated |
| Changes in Benthic Prey |
Unknown |
|
|
|
| KEY: X = Effect can be present, but is rarely
large; XX = Effect is present and moderate; XXX = Effect is often
present and can be large; N/A = Effect is not present or not
applicable; Unknown = effects are not currently known; (H) =
High energy environment; (L) = Low energy environment; PR = Peer
reviewed literature; GL = Grey literature; PJ = Professional
judgement. For definitions of Substrate Type and Type of Impact
see Appendix D.
NOTE: Ongoing Canadian experiments will be able to
provide additional information in the near future.
* This
does not represent a consensus among the panel |
|