Name of fishery Red ring trawl fishery   Priority-1 species

Target species Aristeus alcocki

Location INDIA-South west coast (Kollam) 

Fishing Area FAO51

Fishery history: (How long has the fishery been in operation? Describe changes in the fishery over time)

Researchers identified the prospects of a deep sea shrimp resources during the 1985 -1990s. 

Exploitory surveys conducted by FORV Sagar Sampada have given enough evidence of deep sea shrimp stocks. However active fishery started during 1999/2000 period. Kerala Govt. actively gave encouragement to the deep sea fishery by giving subsidized fuel for the operation. During 2000-2010 more fleets were interested in this fishery. Initial landing recorded massive quantities of red ring and other deep sea shrimps. But however landings showed a negative growth after 2010 to current year. Most of the fleet was from Tamil Nadu registration but operating along the Sakthikulangara harbor.

Aristeus alcocki commonly known as red ring was auctioned and marketed separately and showed a good demand because of its large size and good appearance. However currently this fishery showed a declining growth.

Stock biology : Stock size, structure, biomass, status, trends in population abundance, life cycle, growth, reproduction, schooling behavior, etc. 

The fishery and biology of Aristeus alcocki (Bate, 1888) from Sakthikulangara fishing harbour was studied for the period 2007-2016. The average annual catch was 1842 t, forming 22% of the total deepsea shrimp landing at Sakthikulangara. November to January was the most productive period in terms of catch and catch rate.

Females were sorted out and auctioned separately due to its large size, whereas males which are comparatively smaller in size were auctioned along with the other deep sea shrimps. Males having a size range of TL: 65-110 mm, W: 2.0-6.5 g and females TL: 85-200 mm, W: 2.5-26.0 g ranging from 85-200 mm. Only females were branded as red ring and have a market rate of 250 to 300 per Kg. 

According to the fisherman these red ring catches were avilabile from “kuzhi” in deep sea regions which means large pits. In these pits these shrimps are available in large quantities probably indication of schooling behavior.

Data on target species population:  What sort of stock assessment information exists for this fishery??? Is there a stock assessment? Is there catch per unit effort data? Landings data? Monitoring of biological indices?For how many years are data available? Who collects, manages, and stores the data? How are data collected?

The growth parameters L∞ and Kannual for males and females were 192 mm, 0.56 and 207 mm, 0.51 respectively. The growth performance index (φ’) and t0 were 4.315, -0.0023 and 4.340, -0.0024 for males and females, respectively with a longevity of 5-6 years. 

The length at recruitment (Lr) and length at 50% capture (Lc50) was 63, 156.7 mm (males) and 68, 154.9 mm (females), respectively which corresponded to an age (tc) of 2.2-2.5 years. The natural mortality, fishing mortality, total mortality, exploitation ratio, exploitation rate and Emax were 0.86, 1.22, 2.08, 0.59, 0.51, 1.00 and 0.78, 2.36, 3.14, 0.75, 0.72, 1.00 for males and females, respectively.  The rate of exploitation for A.alcocki was found to be lower than the Emax which indicates the sustainable utilization of the resource.

Catch  per unit effort data , landing data was available with CMFRI  FRAD division. Biological data were analyzed and recorded at Crustacean Fisheries Division CMFRI. Samples are collected fortnightly from Sakthikulangara harbor.

Fishing Activities : Methods, gear, size/sex/season fished

 The gear used for this fishery is bottom trawl nets. The mouth opening is achieved by otter boards. Bottom trawls were operated at a depth of more than 350 m, usually the nets were operated day and night. The nets were hauled 2-3 times per day, having a hauling speed of 2 knots for a period of 2-3 hrs. Catch quantities may vary but an average of 2-4 tons was landed from each trawl, the catch composition includes deep sea fin fishes,  red ring, deep sea prawns and lobsters.

Deep sea fishery of red ring is seasonal in nature and starts from September to May having a peak period during November to January.  The depth range is 200 m to 400 m. In monsoon period fishery may come to a suspension due to monsoon trawl ban and high seas which makes this venture at high risk.

On an average each vessel lands 2-4 tons of deep sea shrimps but red ring quantity may vary from 0.5-1.2 tons per landings.  Average duration for the voyage at Sakthikulangara fishing harbor is 5-7 days and at times it may extend till 10 days. 

Ecosystem Impacts: Describe how the fishery interacts with the ecosystem; including gear interactions (e.g. habitat disturbance), species interactions (e.g. bycatch, endangered species, and effects on the food web), etc. include what is found in literature as well as the local perception of the impacts

The environmental damage caused by bottom trawling can be substantial and irreversible, and trawling operations have ‘effects on the sea bottom that resemble forest clear-cutting, a terrestrial disturbance recognized as a major threat to biological diversity and economic sustainability. 

Trawl nets are designed to catch economically valuable target species such as shrimps and are operated from mechanized boats called trawlers. As a mobile non-selective fishing gear, the bottom trawl net collects every organism in its path and the incidental capture of non-target species – by-catch – has become a major concern allied to trawling. The term ‘discarded catch’ or ‘discards’ denotes the portion of the catch which is returned to the sea and the term ‘by-catch’ means the incidental catch (retained catch) of non-target species plus the discarded catch. Intensive fishing activities, besides being detrimental to marine biodiversity, have started affecting the complex ecological processes of the oceans. 

The problem of discarding and by-catch has attracted substantial attention among researchers in the last three decades due to reports on the deleterious impact they have on the marine ecosystem, coupled with documented presence of a colossal amount of biodiversity in the by-catch, particularly eggs and young ones of commercially valuable species and endangered species such as sea turtles.

Nevertheless, trawling is considered as the most important source of human-induced physical disturbance on the seafloor throughout the world. Bottom-trawl nets can plow deep furrows in the seafloor, remove rock and coral, stir up sediments that smoother benthic organisms, and smooth out natural topography, thus resulting in the reduction of structural heterogeneity – an important factor contributing to the abundance of biodiversity at the sea bottom. A single passage of beam trawl has been reported to kill 5–65% of the resident fauna and mix the top few centimeters of sediment. 

Trawling activities may affect sediment community function, carbon mineralization and biogeochemical fluxes. The dragging of trawl nets may decrease dissolved oxygen, which may be due to the mixing of reduced products such as methane and hydrogen sulphide or the resuspended bacteria attached to sediments exerting an increase in oxygen demand in the water column. Formation of sediment clouds in the sea bottom may affect natural balance between physico-chemical parameters in the ocean, further depleting the availability of oxygen. Trawling was also found to flush out nutrients and contaminants, and there are possibilities of rise in lethal gases such as ammonia, methane and hydrogen sulphide, affecting the life of organisms in water. Increased temperature and nitrates and decrease in dissolved oxygen, organic matter and organic carbon due to the churning action of the trawl net on the sea bottom were noticed in Kerala coast. 

Organisms inhabiting the soft sediments, particularly the biogenic structure-forming creatures creating mounds, tubes and burrows, develop much of their habitat’s structure and play a critical role in many population, community and ecosystem processes. Intensive trawling has been recorded to decrease the density and abundance of sea grasses, polychaetes, molluscs and echinoderms. Depletion of polychaete fauna due to trawl fishing was observed in Kerala coast, India. Excessive trawling has also resulted in decline in the proportion of larger size groups of commercial species of shrimps in the Indian coast.

A variety of techniques have been developed in many parts of the world to improve the species selectivity and size selectivity of trawl nets and to reduce the by-catch levels, particularly aimed at bringing down the mortality of juveniles and young ones of commercially important species. One of the major issues associated with trawling is incidental capture of endangered sea turtles in the trawl net. Devices developed to eliminate sea turtle by-catch and reduce the non-target species and other unwanted catch in shrimp trawling are collectively known as by-catch reduction devices (BRDs) and those meant for excluding turtles are called turtle excluder devices (TEDs). In India, CIFT has developed indigenous square-type window attachment, radial-type escapement device, fish eye, grid with guiding funnel and escape opening, etc. to reduce by-catch of undersized shrimp and fish  in trawl nets. 

Some times, climatic aberrations affect coastal communities by causing cyclones, coastal erosion, and loss of mandays at sea and also has an impact on the availability of fish resources by affecting their abundance and distribution patterns.


Threats to Sustainability: Describe any additional threats to the sustainability of this fishery (e.g. outsider encroachment, coastal development, etc.). is there anything being done to address these threats?  

Not much threat

Fishers : Describe the group of fishers. Are they women or men? How many are there? How are they organized? To what extent do fishers profit from fishing? Are profits used to provide community infrastructure?

Only men are involved as active fishermen but women also show their involvement as secondary (peeling shrimp in the harbor area and selling it for the domestic market) and territory fisher folks in the processing and peeling plants finally exporting the product.

Management Agencies: Describe the roles that institutions, agencies, or local management bodies play in the management system and their interactions with each other

CMFRI devotes its research attention towards the estimations of fisheries landings, fishing effort and, taxonomy of deepsea shrimps.

Management regime:  Describe how the fishery is managed. Include information for both national and local levels about rules, regulations, closed areas/seasons, quotas, limited entry/licenses, conflict resolution, adaptability, coping strategy/mitigation, etc. how often do managers review rules and regulations? How would changes in the political regime affect management?

MLS  is in place (13 TL)

Regular Monsoon Ban is oberverd during June 15th to July  31st. Apart from this, because of rough seas fishermen willnot be able to venture into deeper waters till the middle or end of September .

Management compliance: Do fishers comply with the management regime? How do managers ensure compliance? Are regulations actively enforced? Do fishers comply with international regulations for species conservation?

Yes, fishers will comply if any management regime is enforced.

Only one regulation fishermen follow now is monsoon ban. But at times market driven management options were also followed.

 Example: If by going less deeper waters if they get lot of squid and cuttle fish which fetches better price than the deepsea shrimp, then fishermen avoid  venturing into deepsea.

Community participation in management: Describe how the community set its own rules and regulations? How does this happen? Are they active in the governmental management system?

Not involved

In Kollam region deepsea fishery is not governed by the community. However in Tuticorin region it is governed by a single community which limits the number of boats. 

Processing and marketing Information: Once the product is landed, what happens to it? What is the chain from fishhook to consumer? Include how the product is processed and sold, and who processes and sells it. Where are the main markets for the fishery? Please also describe any buyers data that are available (e.g quantity sold or exported, overall value); who collects manages, and stores the data; how the data are collected; and the number of years for which data are available

85% of the resources have ended up in overseas markets as dried, frozen and individually quick frozen (IQF) products.

Export market : European union especially Spain

12X400 trays in one container  total 2000 trays

Exported as PUD (peiled and undeveined , 4200 tray  on each container )

Exported along with squids and cuttle fish 

Exported as ready to cook products marketed in oversees supermarkets and hotels

Export rate 8 USD/packet.

Container cost: 1750-2000 USD

Purchase count: 140-150 gm

Cost of production Rs. 50/Kg

Inspection scenario

500 gm from each 500 Kg was randomly taken and inspected for microbiological aspects

Area of raw material: Kollam 

Rate at which company purchase from fishermen: 200/Kg

Peeling loss    58%

Freezing lose  3%

Export: On an average 6-7 Container/year

Export history : During 2015,  5 containers and 7 containers in 2014 were exported. 

Maximum shelf life 2 years

A diagrammatic representation 

Boat owner – auctioner/middile man –private parties mainly peeling shed owners- processing companies –export markets.

 Boat owner – auctioneer/middle man- individuals/women –local market

Operational costs

Each trip costs an amount of Rs 2,000,00-2,50,000 as operational charges out of this fuel charge cost more, In early days deep sea vessels were using a subsidized fuels from govt. but currently Government completely withdraws the policy which makes fuel charges at a high end.

Average Profit margin is 1-2 lakh of which 65% goes to boat owner and 35% to crew.

Interest in certification: Describe the fishery’s interest in certification. Are they interested? Why or why not?

At present they did not show any interest in certification but it will be possible only when the demand comes from the buyer.

Stakeholders: who are the key stakeholders in this fishery (e.g. fishing organizations, processors, agents, buyers, researchers, NGOs, fisheries/natural resources management bodies, local authorities, etc.)? how many people are involved in the fishery (including fishers, processors, sellers, boat and gear manufacturers, managers, scientists, etc.)? what percentage of the human population within the coastal community depends on the fishery for their food or livelihood?

Fishermen, processors, agents, buyers, researchers.

Issues requiring special attention: Describe any local, regional or global controversies and/ or conservation concerns that impact or involve the fishery. 


Additional comments:  Include any additional information about this fishery or important to working with this fishery)


Overall view 

Gear :   Bottom trawl 

Mouth opening : otter boards

Area of operation :  south of Kollam mainly 8- 9 latitude & 75-76 longitude

Depth : 200- 350 m or more 

Gear size : codend 24-26mm

Head rope length : 40-60 m

Hauling speed : 2 knots

No .of hauls per day : 2-3 

Towing duration : 2 -3 hrs.

Catch /trawl : 250- 300 Kg 

Vessel length : 60-90 m

Operational cost: 2-2.5 Lakhs

Profit margin:  1-2 Lakhs

Voyage days: usually 5-7 days and at times gets extended to 10 days



Suseelan, C (1989) Taxonomic notes on a potentially commercial deep-sea prawn from the southwest coast of India. Journal of the Marine Biological Association of India, 31 (1&2). pp. 54-58.

Kurup, B.M., Radhika Rajasree and S. Venu. 2008. Distribution of deep-sea prawns off Kerala. J. Mar. Biol. Ass. India., 50 (2):122-126.

Venkataraman, K. and Wafar, M., Coastal and marine biodiversity of India. Indian J. Mar. Sci., 2005, 34, 57–75.

Rajan, K.N., Nandakumar, G., Chellappan, K., 2001. Innovative exploitation of deepsea crustaceans along the Kerala coast. Mar. Fish. Inf. Serv. 168, 1–11.

Suseelan, C and Nandakumar, G and Rajan, K N (1990)  In: Results of bottom trawling by FORV Sagar Sampada with special reference to catch and abundance of edible crustaceans. Proceedings of the first workshop on scientific results of FORV Sagar Sampada, 5-7 June 1989, Kochi.

Radhika, R. and B. M. Kurup. 2005. Fishery and biology of deep-sea prawns landed at the fishing harbours of Kerala. Fish. Tech., 42(2): 141-148.

Mohamed, K.H and C. Suseelan. 1973. Deep-sea prawn resources off the South-West Coast of India. Proc. Symp. Living Resources of the Seas around India, CMFRI., India, pp. 614-633.

Kurian, C.V. 1965. Deep water prawns and lobsters off the Kerala coast . Fish.Tech., 2(1):51-53.

Oommen, P. V. 1980. Results of the exploratory fishery of Quilon Bank and Gulf of Mannar. IFP Bulletin No. 4, 53 pp.