Southe a st Ge org e s Ba nk Cornell University Cooperative - - PowerPoint PPT Presentation

E va lua tion of the L a rg e Me sh Be lly Pa ne l in Sma ll Me sh F ishe rie s a s a Me thod to Re duc e Ye llowta il F lounde r Byc a tc h on Southe a st Ge org e s Ba nk

Cornell University Cooperative Extension Marine Program - Riverhead, NY Emerson Hasbrouck John Scotti, Tara Froehlich Kristin Gerbino, Joseph Costanzo Cornell University

• Dept. of Natural Resources – Ithaca, NY

Patrick Sullivan Superior Trawl – Narragansett, RI Jonathan Knight F/V Karen Elizabeth – Point Judith, RI Captain Christopher Roebuck

F unde d by the Nor the ast Coope r ative Re se ar c h Pr

• gr

am

Project Purpose



The project addressed yellowtail and windowpane flounder bycatch concerns on Georges Bank by evaluating the effectiveness of a standard net modified with a large mesh belly panel to reduce bycatch of these species in deep water while targeting squid and whiting

• The project was proposed by GB small mesh fishermen as

means to pursue gear certification to be used for yellowtail and windowpane bycatch avoidance in GB small mesh fisheries when Accountability Measures are triggered.

• Based on similar inshore work conducted by CCE and funded

through CFRF

Project Summary



The vessel towed the control trawl (3-bridle 4-seam standard box trawl) and experimental trawl (box trawl modified with the large mesh belly panel) simultaneously. Comparisons were based on paired differences in catch by species.



Four species were analyzed including yellowtail flounder, windowpane flounder, squid and whiting

• F/V Karen Elizabeth

(Point Judith, RI), a twin- trawl vessel, was chartered to conduct all at-sea research.

Similar Gear Research Performed by CCE



Use of A 12” Drop Chain Sweep To Reduce Winter Flounder Bycatch in the Longfin Squid Fishery



Use of a Large Mesh Belly Panel to Reduce Winter Flounder Bycatch in the Longfin Squid Fishery



Gear Trials - Evaluation of the 12” Drop Chain Sweep and the Large Mesh Belly Panel to Reduce Winter Flounder Bycatch in the Whiting Fishery CCE tested and evaluated the gear concepts above as a means to reduce winter flounder bycatch in small mesh fisheries. Avoidance of winter flounder catch during the lucrative squid fishery is imperative to assist in the rebuilding of the winter flounder stock. Both gear adaptions significantly reduced winter flounder bycatch. Gear Modification Fishery Winter Flounder Bycatch Reduction Significant Reduction in Target Species 12” Drop Chain Sweep Longfin Squid 78% Reduction NO Large Mesh Belly Panel Longfin Squid 88% Reduction NO 12” Drop Chain Sweep Whiting 25% Reduction NO Large Mesh Belly Panel Whiting 44% Reduction NO

Sketch of Large Mesh Belly Panel Configuration

The large mesh panel was made of 80cm (32”) mesh 6mm poly webbing, 2 meshes deep X 16 meshes wide sewn into the standard 16cm (6”) mesh of the belly. With the ‘saw-toothing’ of the 16cm mesh, this yields an effective opening of 3 full meshes deep, a total of about 8’ of large mesh. The panel attaches five 16cm meshes (approximately 2.5’) behind the footrope and goes from gore to gore (22 meshes wide or approximately 30’).

Large Mesh Belly Panel

Project Locations

Phase 2 Phase 1

Phase 1 Summary

• Phase 1 of the project was conducted in January 2014 at the

Southern Flank of Georges Bank, near Munson Canyon

• 40 paired tows were completed in one 6-day trip
• Squid was the target species
• All tows were 30 minutes in length
• Tows occurred during both the day & night

Phase 1 Results – Yellowtail Flounder

Paired Tow Difference (Control-Experimental)

Distribution of Paired Tow Differences for Yellowtail Flounder

Frequency

The large mesh belly panel significantly reduced the quantity of yellowtail bycatch. Paired t-test results showed a significant difference in catch weight between the control and experimental net (p=<0.0001).

Phase 1 Results – Yellowtail Flounder

2000 4000 6000 8000 10000 12000 14000

LARGE MESH BELLY PANEL CONTROL Catch Weight (lbs)

Total Catch Weight of Yellowtail Flounder (lbs) in the Experimental and Control Net for All Tows Combined

The large mesh belly panel reduced yellowtail flounder bycatch by 72.3%.

Phase 1 Results – Windowpane Flounder

The large mesh belly panel significantly reduced the quantity of windowpane bycatch. Paired t-test results showed a significant difference in catch weight between the control and experimental net (p=<0.0001).

Distribution of Paired Tow Differences for Windowpane Flounder

Paired Tow Difference (Control - Experimental) Frequency

Phase 1 Results - Windowpane Flounder

The large mesh belly panel reduced windowpane flounder bycatch by 50.9%.

1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

LARGE MESH BELLY PANEL CONTROL Catch Weight (lbs)

Total Catch Weight of Windowpane Flounder (lbs) in the Experimental and Control Nets for All Tows Combined

Phase 1 Results - Whiting

Paired t-test results showed no significant difference in whiting catch between the control net and the net modified with the large mesh belly panel (p=0.8817).

Paired Tow Difference (Control – Experimental)

Distribution of Paired Tow Differences of Whiting

Frequency

Phase 1 Results - Whiting

50 100 150 200 250 300 350 400 450 500 550 600 650 700 750

LARGE MESH BELLY PANEL CONTROL Catch Weight (lbs)

Total Catch Weight of Whiting (lbs) in the Experimental and Control Nets for All Tows Combined

Retention of whiting was maintained using the large mesh belly panel net.

Phase 1 Results - Squid

Paired t-test results showed a significant difference in the catch weight between the control and experimental net (p = 0.0022). The experimental net retained significantly more squid than the control net. Distribution of Paired Tow Differences for Squid

Paired Tow Difference (Control-Experimental) Frequency

Phase 1 Results - Squid

The experimental net actually retained 20% more squid compared to the control net.

200 400 600 800 1000 1200 1400

LARGE MESH BELLY PANEL CONTROL

Catch Weight (lbs)

Total Catch Weight of Squid (lbs) in the Experimental and Control Nets for All Tows Combined

Phase 2 Summary

• Phase 2 of the project was conducted in August 2014 on the Northern

Area of Georges Back designated as Cultivator Shoals

• 42 paired tows were completed in one 5-day trip
• Whiting was the target species
• Tows were 15 minutes in length and occurred during both the day &

night

Phase 2 Results – Yellowtail Flounder

Distribution of Paired Tow Differences for Yellowtail Flounder

The large mesh belly panel significantly reduced the quantity of yellowtail bycatch. Paired t-test results showed a significant difference in catch weight between the control and experimental net (p=<0.0001).

Frequency 20 40 60 80 2 4 6 8 10 12

Paired Tow Difference (Control-Experimental)

Phase 2 Results – Yellowtail Flounder

Total Catch Weight of Yellowtail Flounder (lbs) in the Experimental and Control Net for All Tows Combined

The large mesh belly panel reduced yellowtail flounder bycatch by 80.7%.

200 400 600 800 1000 1200 LARGE MESH BELLY PANEL CONTROL Catch Weight (lbs)

The large mesh belly panel significantly reduced the quantity of windowpane bycatch. Paired t-test results showed a significant difference in catch weight between the control and experimental net (p=0.0023).

Distribution of Paired Tow Differences for Windowpane Flounder

Frequency 5 10 5 10 15

Phase 2 Results - Windowpane Flounder

Paired Tow Difference (Control-Experimental)

Phase 2 Results - Windowpane Flounder

The large mesh belly panel reduced windowpane flounder bycatch by 59.3%.

Total Catch Weight of Windowpane Flounder (lbs) in the Experimental and Control Nets for All Tows Combined

20 40 60 80 100 120 LARGE MESH BELLY PANEL CONTROL Catch Weight (lbs)

Phase 2 Results - Whiting

Distribution of Paired Tow Differences of Whiting

Frequency

• 3000
• 2000
• 1000

1000 2000 3000 400 5 10 15 20 25 30

Paired Tow Difference (Control-Experimental)

Paired t-test results showed no significant difference in the catch weight between the control and experimental net (p = 0.1787).

Phase 2 Results - Whiting

Total Catch Weight of Whiting (lbs) in the Experimental and Control Nets for All Tows Combined

Retention of whiting was maintained using the large mesh belly panel net.

5000 10000 15000 20000 25000 30000 35000 40000 45000 50000 LARGE MESH BELLY PANEL CONTROL Catch Weight (lbs)

Phase 2 Results - Squid

Paired t-test results showed no significant difference in the catch weight between the control and experimental net (p = 0.1339).

Distribution of Paired Tow Differences for Squid

Frequency

• 1.0
• 0.5

0.0 0.5 5 10 15 20 25

Paired Tow Difference (Control-Experimental)

Phase 2 Results - Squid

Retention of squid was maintained using the large mesh belly panel net.

Total Catch Weight of Squid (lbs) in the Experimental and Control Nets for All Tows Combined

2 4 6 8 10 12 LARGE MESH BELLY PANEL CONTROL Catch Weight (lbs)

Summary of Results

Species Phase 1 Phase 2 Yellowtail Flounder Significant reduction (72.3%) Significant reduction (80.7%) Windowpane Flounder Significant reduction (50.9%) Significant reduction (59.3%) Whiting No Statistical Difference in catch between control and experimental nets No Statistical Difference in catch between control and experimental nets Squid Significant increase (20%) No Statistical Difference in catch between control and experimental nets

Ba se d o n the se re sults, sho uld the la rg e me sh b e lly pa ne l g e a r te c hno lo g y b e a ppro ve d a s a n Ac c o unta b ility Me a sure in the sma ll me sh Ge o rg e s Ba nk fishe rie s?

Acknowledgements

 NMF

S No rthe a st Co o pe ra tive Re se a rc h Pro g ra m

 F

/ V K a re n E liza b e th – Ca pta in Chris Ro e b uc k a nd Cre w, Po int Judith, RI

 Supe rio r T

ra wl I nc . – Jo na tha n K nig ht, Pt. Judith, RI

 Sq uid T

ra wl Ne two rk Pro je c t Adviso ry Co mmitte e , Wo rking Gro up, Pla nning Gro up a nd me mb e rs