|
CRD 02-01 APPENDIX F
Descriptions of some representative habitats as presented
by Dr. Page Valentine, USGS.
Note: This is not a complete listing of habitats of the Northeastern
United States |
A. GEORGES BANK - Northeastern
Edge |
| HABITAT CHARACTER |
DESCRIPTION |
|
A. Topography
|
Featureless gravel except for few large sand ridges
|
|
B. Sediment texture and hardness
|
Gravel pavement (hard bottom); small areas of
gravel with sand veneer; sand
|
| C. Substrate roughness and surface area (undisturbed) |
|
|
Gravel pavement: pebbles, scattered cobbles and
boulders; little rippled sand
Sand ridges with ripples
|
|
Gravel pavement: calcareous worm tubes, bryozoa/hydrozoa, sponges,
and anemones attached to gravel
Sand: |
|
D. Substrate dynamics
|
Strong tidal and storm currents winnow sand from
gravel pavement, move shells, and move surfaces of sand deposits;
|
|
E. Water column
|
Generally mixed; high productivity; shallow
|
|
F. Possible fishing impacts
|
Disturb gravel pavement, reduce hard bottom and
expose sand for movement; move cobbles and boulders; disturb epifauna;
alter biodiversity
|
B. GEORGES BANK - Central Part |
| HABITAT CHARACTER |
DESCRIPTION |
|
A. Topography
|
Sand bedforms ranging from small ripples to very
large sand ridges
|
|
B. Sediment texture and hardness
|
Sand; shell beds; small areas of gravel between
sand ridges
|
| C. Substrate roughness and surface area (undisturbed) |
|
|
Sand bedforms of varying sizes; associated shell beds
Gravel: pebbles, cobbles, boulders
|
|
Sand bedforms: amphipod tubes, sand dollar concentrations and
burrowing anemones
Gravel: minimal epifauna due to sand movement |
|
D. Substrate dynamics
|
Strong tidal and storm currents build bedforms
and shell beds; daily sand transport; large stable sand ridges are
oriented parallel to direction of current flow; bi-directional sand
movement
|
|
E. Water column
|
Mixed; high productivity; shallow
|
|
F. Possible fishing impacts
|
Disturb sand bedforms and shell beds; disturb
amphipod tubes and burrowing anemones and expose sand for movement
|
C. GEORGES BANK - Southern Part |
| HABITAT CHARACTER |
DESCRIPTION |
|
A. Topography
|
Featureless sand except for patches of ripples
from intermittent storms
|
|
B. Sediment texture and hardness
|
Sand
|
| C. Substrate roughness and surface area (undisturbed) |
|
|
Depressions in sand formed by benthic fauna; scattered shells
|
|
Erect yellow sponges attached to shell fragments; amphipod tubes |
|
D. Substrate dynamics
|
Weak tidal currents do not move sediment; intermittent
strong storm currents form sand ripples
|
|
E. Water column
|
Mixed or seasonally stratified; high productivity;
shallow
|
|
F. Possible fishing impacts
|
Disturb sand depressions, erect sponges, and
amphipod tubesl break shells
|
| D: GEORGES BANK - Large Submarine Canyons on
Southern Margin |
|
HABITAT CHARACTER
|
DESCRIPTION
|
| A. Topography |
Deep incision into continental shelf edge; gentle
to steeply sloping canyon walls; sand bedforms in canyon axis |
| B. Sediment texture and hardness |
Sand and gravel on canyon rims and in axis; gravel
pavement common on eastern rims; clay layer and rock outcrops on canyon
walls |
|
C. Substrate roughness (undisturbed)
|
|
|
On canyon rims: depressions in sand formed by benthic fauna;
scattered shells; sand bedforms; gravel pavement of pebbles and scattered
cobbles and boulders
In canyon: sand bedforms; scattered pebbles, cobbles, and boulders;
clay burrows (formed by crustaceans, fish, worms …); irregular rock
outcrops |
|
|
Sponges, bryozoa/hydrozoa, soft corals attached to gravel and
rock outcrops; burrowing anemones; … |
| D. Substrate dynamics |
Moderate currents move sand from shelf onto canyon
walls; strong tidal currents form sand bedforms in canyon axis |
| E. Water column |
Stratified; low productivity; shallow to deep |
| F. Possible fishing impacts |
Disturb gravel pavement, reduce hard bottom and expose
sand for movement; move cobbles and boulders; disturb hardbottom epifauna;
disturb clay burrows; disturb burrowing anemones |
| E. GULF OF MAINE - Central Deep Water Banks |
|
HABITAT CHARACTER
|
DESCRIPTION
|
| A. Topography |
Banks, ridges, hills, mounds |
| B. Sediment texture and hardness |
Gravel and bedrock with intermittent thin veneer of
mud; patches of mud; hard and soft bottom |
|
C. Substrate roughness and surface area (undisturbed)
|
|
|
Gravel: pebbles, cobbles, boulders, and bedrock outcrops; scour
depressions around cobbles and boulders
Mud: mud burrows (crustaceans, fish, worms, …) |
|
|
Gravel: sponges, brachiopods, and anemones attached to gravel
Mud: burrowing anemones, sea pens |
| D. Substrate dynamics
|
Very weak currents; little or no sediment transport |
| E. Water column |
Stratified; low productivity; deep |
| F. Possible fishing impacts |
Flatten small gravel mounds; move cobbles and boulders;
re-suspend fine sediment and increase turbidity; disturb epifauna; disturb
mud burrows; disturb burrowing anemones and sea pens |
| F. GULF OF MAINE - Central Deep Water Basins |
|
HABITAT CHARACTER
|
DESCRIPTION
|
| A. Topography |
Featureless mud except for small mounds |
| B. Sediment texture and hardness |
Mud; soft bottom |
|
C. Substrate roughness and surface area (undisturbed)
|
|
|
Mud: mud burrows (crustaceans, fish, worms, …) |
|
|
Mud: burrowing anemones; sea pens, "amphipod" tubes |
| D. Substrate dynamics |
Very weak currents; little or no sediment transport |
| E. Water column |
Stratified; low productivity; deep |
| F. Possible fishing impacts |
Disturb burrows; re-suspend fine sediment and increase turbidity;
disturb burrowing anemones and sea pens |
| G: GREAT SOUTH CHANNEL REGION - Central Part |
|
HABITAT CHARACTER
|
DESCRIPTION
|
| A. Topography |
Featureless gravel; gravel mounds; bedforms ranging
from small ripples to very large sand ridges |
| B. Sediment texture and hardness |
Gravel pavement; gravel between large sand ridges;
gravel with thin veneer of sand; sand
|
|
C. Substrate roughness and surface area (undisturbed)
|
|
|
Gravel pavement and mounds: pebbles, scattered cobbles and boulders;
shell beds
Sand bedforms of varying sizes |
|
|
Gravel: bryozoa/hydrozoa, sponges, attached anemones
Sand: |
| D. Substrate dynamics |
Strong tidal and storm currents; daily sand transport;
sand ridges relatively stable and oriented normal to direction of current
flow;
bi-directional sand movement |
| E. Water column |
Mixed; high productivity; shallow |
| F. Possible fishing impacts |
Disturb gravel pavement, expose sand for movement;
flatten small gravel mounds; move cobbles and boulders; disturb gravel epifauna;
disturb small bedforms and shell beds |
| H. GREAT SOUTH CHANNEL REGION - Northern Part |
|
HABITAT CHARACTER
|
DESCRIPTION
|
| A. Topography |
Featureless gravel with veneer of rippled sand |
| B. Sediment texture and hardness |
Gravel with mobile patchy sand veneer |
|
C. Substrate roughness and surface area (undisturbed)
|
|
|
Gravel: Pebbles, cobbles, and boulders; current scours around
boulders
Sand: rippled sand patches; rippled sand deposits streaming downcurrent from
boulders |
|
|
Gravel: little attached epifauna due to sand movment
Sand: |
| D. Substrate dynamics |
Strong tidal and storm currents; sand moving through gravel |
| E. Water column |
Generally mixed; high productivity; shallow |
| F. Possible fishing impacts |
Move cobbles and boulders; disturb attached epifauna; disturb
sand ripples |
| I. GREAT SOUTH CHANNEL REGION - Northeastern
Part |
|
HABITAT CHARACTER
|
DESCRIPTION
|
| A. Topography |
Featureless except for storm sand ripples |
| B. Sediment texture and hardness |
Coarse sand and gravel |
|
C. Substrate roughness and surface area (undisturbed)
|
|
|
Sand: storm-generated ripples
Gravel: pebble gravel pavement in ripple troughs; scattered cobbles and boulders |
|
|
Gravel: sponges and bryozoa/hydrozoa attached to gravel
Sand: |
| D. Substrate dynamics |
Moderate tidal currents; strong storm currents transport sand
and form ripples |
| E. Water column |
Mixed or seasonally stratified; high productivity; shallow |
| F. Fishing impacts possible |
Disturb sand ripples and gravel pavement; move cobbles and boulders;
disturb gravel epifauna |
| J. GREAT SOUTH CHANNEL REGION - Southwestern
Part |
|
HABITAT CHARACTER
|
DESCRIPTION
|
| A. Topography |
Featureless gravelly sand except for widely spaced very
large sand ridges |
| B. Sediment texture and hardness |
Gravelly coarse sand between sand ridges; sand on
ridges |
|
C. Substrate roughness and surface area (undisturbed)
|
|
|
Gravelly coarse sand: depressions in sand formed by benthic fauna;
scattered shells
Sand ridges with ripples |
|
|
Gravelly coarse sand: erect yellow sponges, attached anemones,
amphipod tubes
Sand: |
| D. Substrate dynamics |
Moderate tidal currents; strong storm currents transport
surfaces of relatively stable sand ridges; bi-directional sand movement |
| E. Water column |
Generally mixed; high productivity; shallow |
| F. Fishing impacts possible |
Disturb depressions in gravelly coarse sand, erect
sponges, attached anemones, and amphipod tubes |
K. GREAT SOUTH CHANNEL REGION - Western Part |
|
HABITAT CHARACTER
|
DESCRIPTION
|
| A. Topography |
Featureless |
| B. Sediment texture and hardness |
Mussel bed; hard bottom |
|
C. Substrate roughness and surface area (undisturbed)
|
|
|
Mussel shells |
|
|
Mussel bed with attached epifauna |
| D. Substrate dynamics |
Strong tidal and storm currents |
| E. Water column |
Mixed; high productivity; shallow |
| F. Possible fishing impacts |
Disturb living mussels, shells, and attached epifauna;
expose underlying sediment to strong currents |