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Hudson Canyon Shelf Hudson Canyon Shelf Tilefish Habitat AreasTilefish Habitat Areas
Vincent G. Guida US Dept. of Commerce NOAA, NMFS, NEFSC
J.J. Howard Lab 74 Magruder Rd.
Highlands, NJ 07732
Hudson Hudson CanyonCanyon
SW Tilefish SW Tilefish HabitatHabitat
Hudson Canyon Hudson Canyon Habitat Area of Habitat Area of Particular Particular Concern (HAPC) Concern (HAPC) in relation to in relation to Tilefish Habitat Tilefish Habitat areasareas SW SW
Tilefish Tilefish HabitatHabitat
Outer Shelf
Slope
NE Tilefish NE Tilefish HabitatHabitat
Modified after: EFH Omnibus Amendment Draft Environmental Impact Statement (DEIS), Phase I Maps of Habitat Areas of Particular Concern (HAPC) Alternatives, NEFMC, 2007.
39.2
39.3
39.4
39.5
39.6
39.7
39.8
-72.9 -72.8 -72.7 -72.6 -72.5 -72.4 -72.3 -72.2 -72.1 -72.0
Station locations
Approx limits of USGS multi-beam coverage
LEGEND
Possible gravel areas from USGS multibeam chart
Station where tilefish burrows were seen
80
80
100
120
140
500
1000
160200
100
120 140160
200
500
1000
UV3
BD4
BD3
BD2BD1
IJ4
IJ3
IJ2
IJ1
HG1
HG2
HG3HG4
BD8
S
IJ5
BD5
PR2
PR1
ST3
ST2
ST1
ST4
IJ0
KL4KL3
KL2
KL0
KL1
MN4MN3
MN2
MN1
BD0
BD00
S*UV1
Hudson Canyon
Y4
Y5
Y6
PR4PR5
PR31
OUTER SHELF
CONTINENTAL SLOPE
INNER SHELF
N
6 nmi = 11.1 km
UV00
WX3
UV0UV2
UV4
UV5
UV6
WX1
WX2
WX4
WX5
WX6
WX7
KL5
Known gravel areas
SW Tilefish SW Tilefish HabitatHabitat
NE Tilefish NE Tilefish HabitatHabitat
2001-2004 Sites where tilefish burrows were seen in Seaboss transects
12
34
56
6
5
4
3
2
1
0
100,000
200,000
300,000
Tilefish Catch by 10' Squares
80 m
200 m
500 m
HUDSON HUDSON CANYON: CANYON: depth contours depth contours in yellowin yellow
2001 Commercial Catch Data: NMFS Northeast Regional Office
N
Annual tilefish catch from 10’ Square block #397244
SW Tilefish SW Tilefish HabitatHabitat
Annual Catch (lbs.)
10 min. Longitude block
10
min
. Lat
itu
de
blo
ck
39º N
40º N
72º W
73º W
The SW Tilefish Habitat includes the 10’ Square block from which the The SW Tilefish Habitat includes the 10’ Square block from which the largest commercial catches have been made.largest commercial catches have been made.
Subadult tilefish (Lopholatilus chamaeleonticeps): 40 cm TL, 0.68 kg: caught in 36’ otter trawl, Station BD4 (39º 17.67’N, 72º 21.78’W), 191m depth: Cruise DE05-14, 11/02/05, 20:36 UTC
IMAGES OF TILEFISH BURROWS FROM THE SW TILEFISH HABITAT AREA taken by USGS
Seaboss aboard NEFSC Benthic Habitat Cruises in 2001, 2002, and 2004.
WX-6 #10 DE04-12 8/27/04 20:05:13 UTC 39º 28.6431’ N 72º 21.6855’ W 136.7 m
Chain Dogfish over Tilefish Burrow Complex in Clay with Galatheid Crabs
20 cm
Photo: USGS
IJ1 #34 DE01-11 10/31/01 01:08:22 UTC 39º 26.772’ N 72º 25.674’ W ~125 m
10/30/01 20:08:22 local Tilefish burrow in muddy sand
Photo: USGS
IJ4 #24 DE01-11 10/31/01 04:24:52 utc 39º 22.926’ N 72º 18.155’ W ~170 m
10/30/01 23:24:52 local Yellowfin bass Anthias nicholsi nestling in tilefish burrow
Photo: USGS
BD4 #16 DE01-11 11/02/01 00:31:50 UTC 39° 18.076’N 72° 21.314’W ~197 m
11/01/01 19:31:50 local Unidentified fish nestling in old tilefish burrow complex
Photo: USGS
BD8 #8 DE01-11 11/02/01 03:48:42 UTC 39° 20.864’N 72° 28.111’W ~136 m
11/01/01 22:48:42 local Partially collapsed tilefish burrow complex with Cancer sp. crab
Photo: USGS
KL4 #4 OC02-12 10/28/02 ~193 m
Tilefish burrow complex in clay with sunken Sargassum thallus
Photo: USGS
20 cm
KL4 #20 OC02-12 10/28/02 ~193 m
Tilefish burrow complex in clay
Photo: USGS
IJ0 #12 OC02-12 10/29/02 ~116 m
Unidentified fish and galatheid crabs in tilefish burrow complex in muddy sand
Photo: USGS
IJ0 #25 OC02-12 10/29/02 ~115 m
Tilefish burrow complex in muddy sand with Astropecten americanus
Photo: USGS
WX7 #24 DE04-12 8/27/04 20:12:25 UTC 39º 28.6447’ N, 72 º 21.7587’ W 134.3 m
Tilefish burrow complex in clay
Photo: USGS20 cm
Tilefish burrow complex in clay with galatheid crab
Photo: USGS
20 cm
WX7 #30 DE04-12 8/27/04 20:16:59 UTC 39º 28.6521’ N, 72 º 21.8165’ W 134.4 m
Some Observartions & Questions:
• Net avoidance has made accurate fisheries-independent stock assessment of tilefish via Survey Trawls virtually impossible. Can their numbers be assessed by means of visualizing their burrows or via ultra high-resolution acoustic methods? Can active/inactive burrows be distinguished?
• How are burrows distributed on a small scale within a habitat, e.g. spacing and clustering patterns, patch density, etc. Very limited side scan sonar data suggests that there are distinct non-random patterns.
• Observations (preceding photos) suggest that tilefish can excavate burrows in a variety of sediment types. How are burrows distributed with respect to substrate type.
• Observations also suggest that the importance of habitat engineering by tilefish may depend on the nature of the substrate; burrow complexes surrounding tilefish burrows in firm clay appear to be larger and supporting more secondary excavations than those in muddy sand. Is this true, and how does this influence the roles of tilefish in differing habitats?
Tilefish stock management, habitat conservation, and the their role in ecosystem fisheries management will require better stock assessment techniques and a clear understanding of the role of tilefish as habitat engineers.
Objectives:
1. Utilize Habcam high resolution side scan sonar in concert with synoptic visual imagery to test acoustic methods for assessing tilefish burrow density, including distinguishing active and inactive burrows, and distribution patterns on scales of meters and on scales of km (i.e. stock assessment improvement).
2. Utilize Habcam high resolution side scan sonar in concert with synoptic visual imagery to assess the degree of secondary burrowing and the identity of secondary burrow inhabitants and other predators associated with tilefish excavations (i.e. community support issues).
3. Utilize Habcam high resolution side scan sonar in concert with synoptic visual imagery and sediment characterization to determine the role of sediment characteristics in the distribution and intensity of both primary and secondary burrows (ecosystem level issues).
NEBO Hudson Canyon Tilefish Habitat NEBO Hudson Canyon Tilefish Habitat Investigation ObjectivesInvestigation Objectives
Rationale for use of HabcamRationale for use of Habcam1. The characteristics of tilefish burrows are best assessed visually, but burrows are spaced sufficiently far apart that few can be seen in a typical video/photo transect (e.g. 20 min. Seaboss deployment)
2. Tilefish have never been observed in their burrows with Seaboss because the fish are photophobic and easily escape a vehicle that typically moves at about 0.5 kt. Judgments with regard to what burrows are active or inactive have therefore been made based on wall condition and the presence of a cloud of sediment in the central burrow, presumably resulting from the rapid egress of the resident tilefish.
3. Due to wider swath width, many more burrows can be seen with side scan sonar than visually, but geolocation with typical side scan equipment in not accurate enough to make comparison of acoustic and visual images of the same burrow. Such comparison is necessary to develop an acoustic assessment method.
4. Habcam’s side scan capability, its more rapid speed for towing Habcam (2+ kt.) and longer deployment, its ability to simultaneously obtain overlapping photo and sonar images allow for the possibilities of acoustic imaging of enough burrows to see local distributional patterns, actually seeing tilefish in their burrows, and obtaining simultaneous acoustic and visual images of the same burrows to determine how to use acoustic imagery to distinguish such features as active/inactive status and the intensity and extent of secondary burrowing.