Case Studies Using Fathoms Plus Traps

Hawaii case study

ABSTRACT

This is a discussion of the lobster fisheries in Hawaii, addressing harvest levels, biology, and research. The fishery is a limited entry trap fishery with 1991 landings of 200 metric tons.

Lobster concentrations in the NWHI were documented by research cruises in 1976, and commercial trapping began in 1977. Since 1983, the lobster fleet has ranged from 9 to 16 vessels (15-to 35-m-long), each averaging three trips per year. A typical vessel sets about 800 traps per day and remains at sea almost 2 months per trip. The NWHI lobster fishery is Hawaii's most valuable demersal fishery; in recent years, annual landings have averaged about 600 metric tons (1 million lobsters), valued at about U.S.$6 million ex-vessel. Since 1988, about 80% of the landings have been spiny lobster.

SUMMARY

A COMMERCIAL SHELLFISH TRAP MADE BY FATHOMS PLUS® IS USED BY ALL THE FISHERMAN. THIS IS A DOME-SHAPED, SINGLE-CHAMBERED TRAP MADE OF MOLDED BLACK POLYETHYLENE WHICH MEASURES 980 BY 770 BY 295 MM, WITH A MESH SIZE OF 45 BY 45 MM (INSIDE DIMENSIONS). EACH TRAP HAS TWO ENTRANCE CONES LOCATED ON OPPOSITE SIDES. EACH TRAP ALSO HAS TWO ESCAPE VENT PANELS EACH CONSISTING OF FOUR 67-MM-DIAMETER CIRCULAR VENTS LOCATED ON OPPOSITE SIDES TO FACILITATE THE ESCAPE OF SUB-LEGAL LOBSTERS (LOBSTERS UNDER MINIMUM LEGAL HARVEST SIZE). THE TRAPS ARE TYPICALLY BAITED WITH CHOPPED MACKERAL AND FISHED IN STRINGS OF SEVERAL HUNDRED TRAPS PER STRING MOST FREQUENTLY SET IN DEPTHS FROM 20 TO 70 M.

Lobster concentrations in the NWHI were documented by research cruises in 1976, and commercial trapping began in 1977. Since 1983, the lobster fleet has ranged from 9 to 16 vessels (15-to 35-m-long), each averaging three trips per year. A typical vessel sets about 800 traps per day and remains at sea almost 2 months per trip. The NWHI lobster fishery is Hawaii's most valuable demersal fishery; in recent years, annual landings have averaged about 600 metric tons (1 million lobsters), valued at about U.S.$6 million ex-vessel. Since 1988, about 80% of the landings have been spiny lobster.

RESEARCH

After initial research cruises documented lobster concentrations in the NWHI in 1976, research focused on the biology of the spiny lobster. Trapping surveys mapped the spatial distribution of the spiny lobster in the NWHI and indicated that the highest catch rates ranged from depths of 55-73 m in the southeast portion of the NWHI to 19-54 m in the northwest portion of the Hawaiian Archipelago. The settlement of post-larval lobster, puerulus, were monitored at Kure Atoll, French Frigate Shoals, and Oahu with surface collectors. Puerulus settlement appeared seasonal at the ends of the Hawaiian Archipelago; the greatest settlement occurred during the summer at Kure Atoll and during the winter at Oahu while at French Frigate Shoals, more centrally located, settlement appeared more uniformly throughout the year.
 

Research conducted during 1984-87 developed escape vents to reduce the catch and hence mortality of sub-legal spiny lobster (<50mm tail width) and sub-legal slipper lobster <56 mm Tail width) without reducing legal catches.

MANAGEMENT

The fishery has been managed under Federal jurisdiction with a fishery management plan (FMP) administered by the Western Pacific Regional Fishery Management Council (WPRFMC) since 1983. Currently the plan prohibits the harvest of slipper lobster with a tail width of <56 mm and spiny lobster with a tail width of <50 mm, prohibits the retention of egg-bearing females, requires that all traps have escape vents to reduce handling and release-induced mortality on sublegal lobsters, and mandates that vessels submit logbooks recording daily catch and trapping effort. A decline in CPUE from 1.25 lobster per trap-haul in 1988 to 0.6 in 1990, as well as concerns that vessels from other fisheries in worse condition were considering entering the lobster fishery, motivated the fishermen to work with the WPRFMC to develop a limited entry and harvest quota plan.

Further, to protect the spawning biomass of the stock while the plan was being developed, the WPRFMC passed emergency regulations to close the fishery for 6 months in 1991. In March 1992, the lobster FMP was amended to include provisions for a limited entry system for a maximum of 15 vessels, an annual fleet harvest quota, and a closed season from January through June to protect the spawning biomass before the summer spawning. The quota is set to achieve an average CPUE over the fishing season of 1.0 lobster per trap-haul. A preseason quota is set using an estimate of the population size at the end of the previous fishing season and estimates of natural mortality and recruitment. A final quota is set after the first month of fishing based on the CPUE during that month. Information from research surveys can also be used in the quota calculations. Currently, fishermen and managers are considering whether an individual quota would be an improvement over the current fleet quota.
 

The lobster fishery has sufficient management regulations, which if applied correctly, should make the fishery sustainable and economically profitable. However, environmental factors may result in both considerable annual as well as decadal-scale variation in the exploitable lobster population and, hence, landings. 

Link to NOAA study:PIFSC Scientists Monitor Lobster Populations in the Northwestern Hawaiian Islands Ecosystem .

CHILE

The University of Concepción, under the FONDEF Project D97I-1058, has built up know-how on 5 new fisheries resources not commercially exploited to date. Attention focuses on the scientific and technological results obtained in extraction, handling and processing catch on board, and the development of techniques to ensure the quality of fish from each resource, their potential buyers and target MARKET.

A marine fish inhabiting the Chilean coast, from Coquimbo to Puerto Montt, at depths of 5 to 600 metres, best results being obtained in shallow waters (10-100 metres) on rocky bottoms.
 

The project has led to finding fishing grounds in Area VIII, where biomass and fish yield averaged at 2.67 kg/tube in 1999 with tube-trap lines.
 

Sizes recorded ranged from 30 to 91 cm total length (with an average of 59.8 cm), and individual weights varying from 40 g to 1,750 g.
 

Hagfish is exported to South Korea whole, non-gutted, skin-on, frozen in 10 kg blocks. Other value added products are possible (mashed cartilage, meat pulp, skin, gut).

A demersal living fish, distributed along the east coast of the Pacific Ocean from Nicaragua to Valdivia in southern Chile.
 

Average fish yield recorded during the project was 1.13 kg/tube-trap, equal to 3.17 individuals/tube-trap.
 

Sizes ranged from 25 to 92 cm total length (56.8 average), weighing from 11.8 to 1,160 g (with an average of 255.4 g).
 

Average price on beach was $350-450/kg.
 

Snake eel is exported to Japan H+G, frozen in 10 kg block. Industrial yield is 71% (H+G), with FOB prices from US$4,000 to US$5,000. Fish must reach the plant live to be processed in a state of lethargy caused by the cold.
 

Projasus bahamondei) Spiny lobster
 

Decapod crustaceans found off the Juan Fernández Archipelago, Islas Desventuradas and the Nazca Range, at depths of 175 to 550 m. Spiny lobster was caught during the project from 220 to 480 m in Area V.

AVERAGE CATCH YIELD OBTAINED WITH FATHOMS PLUS TRAPS ® WAS 0.84 KG/TRAP. AVERAGE CEPHALOTHORACIC LENGTH WAS 51.5 MM, EQUAL TO 140.4 MM TOTAL LENGTH AND AN AVERAGE WEIGHT OF 69.3 G.

Production yield for whole frozen lobster shell-on lobster tail and shell-off lobster tail was 90%, 30% and 20% respectively.
 

Spiny lobster's gastronomic characteristics include texture, taste, aroma, the artistic features of the shell and a tail ideally suited for haute cuisine.
 

Cancer porteri Lemon crab
 

A decapod crustacean found from Panama to Area VIII off Chile, within a known bathymetric depth range of 0 to 500 m.
 

Frequently appears as an accompanying species in the prawn trawler and shrimp fisheries in central-south Chile.

AVERAGE LENGTH RECORDED IN THE CATCH EXPERIENCES WITH FATHOMS PLUS TRAPS® WAS 64.2 MM CEPHALOTORACIC LENGTH, WITH AN AVERAGE WEIGHT OF 160.3 G. CATCH YIELD WAS 4.3 KG/TRAP. PRICE ON BEACH PER LEG WAS $20 AND THE END PRODUCT ARE WHOLE FROZEN CLAW SHELL-ON, WITH A 31% YIELD ON TOTAL WEIGHT.

Eel-form fish described for the Southern Atlantic off Namibia, common in South Africa and South America. Recorded off the Chilean coast, through the project, from Valparaíso to Valdivia, at depths ranging from 150 to 500m.

IN CATCH EXPERIENCES WITH "ESPINEL" LINES, SIZES AVERAGED AT 85.6 CM TOTAL LENGTH, WITH AVERAGE WEIGHT AT 1.514 G. AVERAGE CATCH YIELD WAS 1.06 KG/100 "ESPINELES" AND 1.52 KG/TRAP, WITH FATHOMS PLUS TRAP®.

Fish handling on board involved immediate gutting and storing on ice until offloaded into the plant.
 

Raw material yield was very good, as follows: H+G - 86%, skin-on fillet - 64% and skin-off fillet - 53%.
 

Outstanding characteristics of the meat are: pleasant colour, odour, taste and texture. The domestic fresh market is initially confined to resident Asian colonies and companies which process the meat to obtain pulp and value added products (e.g., hamburgers, medallion, meatballs). On the foreign market, it is possible to target the eastern market as an eel substitute.