Asia-Pacific Fishery Commission

Managing tropical trawl fisheries

As in most parts of the world, industrial trawling in Asia began in the early part of the 20th Century when steamships and later diesel-powered vessels began to tow large nets (although, interestingly, there is some record of Japanese fishers towing beam trawls behind sailboats in Manila Bay prior to this). It was in the early  1970’s  that trawling  became a dominant form of  fishing in the region.  At this point,trawling in tropical Asian waters underwent a rapid expansion over a period of decades which led to massive increases in the total catches of shrimp and finfish, reaching around 2 million tonnes by 2002. By 2010 China and four other Asian countries accounted for 55 percent of the world’s total catch of shrimp. The  amount of   fish  caught in the region   using  trawl  gears is currently being  assessed. The rapid  increase in  tropical trawl fishing effort  has led to significant problems. This is  because,  the increasing  landings that occurred as trawlers fished new grounds has led to, serial depletion of stocks . As a result, catch rates and profits have declined, ecosystems have been  altered, and conflict  between trawl fishers and other users of the resources, especially small scale artisanal fishers are a common occurrence. These conflicts can be very significant and have even led to violent clashes.

The situation today sees a trawl sector throughout the region that catches enormous quantities and diversities of fish and shrimp to fulfil market demands, with very little discarding. Data which would allow the accurate partitioning of landings for various uses is widely unavailable and it is well known that a variety of markets rely heavily on the seafood produced by the trawl fisheries to provide a vital source of protein for human consumption in the region (of particular importance is a large and growing market in Surimi production which requires cheap white fish, usually the juveniles of commercially valuable and important species like threadfin bream, goatfish, etc (See APFIC Regional Overview  2012). Large quantities of fish are also converted into aquaculture feeds and animal feeds for other agriculture sectors. The trawl sector (which is partly subsidised by governments) therefore provides very significant incomes and economic well-being for many communities throughout Asia. It provides large numbers of jobs directly in the sector, and an even larger number in related industries such as canneries, processing plants, transport, refrigeration sectors, and supporting services.

However, these very positive aspects of the trawl sector in tropical Asia are tempered by several negative aspects. As seen above in its history, these negative aspects include overcapacity, excess fishing effort and, because trawls are poorly selective (usually by design) they can lead to the sub-optimal harvest of juveniles of many species. They also can adversely affect populations of commercially and biologically important target and non-target species, impact on threatened, endangered or protected species (ETPs), damage benthic habitats and disrupt normal ecosystem function. Further, as a mobile fishing method, trawling can also adversely affect benthic habitats. The non-selective nature of trawling is also well known for causing significant conflicts with other fleet segments that target the same species, especially those employing artisanal fishing methods. As described above, such conflicts have occasionally had fatal consequences in the region where there are often insufficient human and financial resources available for adequate enforcement of regulations, leading to significant illegal, unreported and/or unregulated (IUU) fishing.

So trawling in tropical Asian waters is a very important, yet complex human activity that interacts across many geographic scales and socio-economic bands. As a consequence, these fisheries, more than any other in the region, require careful management, underpinned by sound information and solid enforcement. In particular, with no more new fishing areas for trawlers to exploit, the current challenge for the region is to not only bring illegal fishing under control but, in parallel with this, to develop and implement strategies that will limit the region’s trawling effort to levels which will ensure long-term, sustainable demersal resources for all fleet segments.

The fourth  APFIC Regional Consultative Forum Meeting suggested that the Asia Pacific region should develop a regional  vision for more effective management of the trawl sector. This regional vision, would seek to balance the demand for fish for human consumption (e.g. fresh/frozen and surimi) and feeds for aquaculture, with the need to sustain ecosystem functions in the marine fishery and improve capture fishery quality.  This  was picked up  by the Asia-Pacific Fishery Commission,  which  at  it’s 32nd Session, strongly  highlighted these  issues  which are particularly  associated with  trawl fisheries in the region.  The Commission  agreed to use trawl fisheries  as a model through  which to  directly address the management of   trawling  and  indirectly to   build capacity in  fishery  and ecosystem   management approaches with  the  APFIC  member countries in  Asia.

Recommendations of the APFIC regional expert workshop on Tropical trawl fishery management

In 2013 the  Asia-Pacific Fishery Commission convened the APFIC Regional Expert Workshop on Tropical Trawl Fishery Management (30th September - 4th October 2013, Phuket, Thailand) to  develop "Regional  guidlelines for the  management of  tropical   trawl  fisheries". The APFIC Regional Expert Workshop  which  developed the  guidleines  made the following  summary  recommendations: 

MCS Recommendations

  • Clear, individual markings for all trawlers that are visible from a distance
  • Get effective MCS working – i.e. Satellite-based VMS on all larger vessels
  • Promote a fishers’ volunteer watch/reporting scheme, and integrate into existing MCS arrangements

Gear Recommendations

  • Regulate trawl specifications for lighter gear (e.g. net material, footropes, bobbins) to reduce the environmental impact of trawling
  • Regulations that provide an effective minimum of 40mm mesh size in the codend, recognising that larger mesh sizes than this are preferred
  • Promote gear designs that ensure correct selectivity in the codend
  • Develop and implement gear designs with industry (BRDs, JTEDs, TEDs, etc) that reduce impacts on at-risk and ETP species
  • Promote reduced duration of trawl tow to 2 hours to improve fish quality

Spatial/time/habitat management recommendations

  • Minimum 3nm trawl exclusion zone (noting that some countries currently have up to 8-10nm)
  • No trawling in critical habitats (e.g. on seagrass, corals), nursery grounds or in waters shallower than 10m
  • All trawl fisheries to have an annual seasonal closure of at least 1-3 months to coincide with peak spawning and nursery times

Fishing Capacity recommendations

  • Cap trawler numbers at existing levels
  • In fisheries with overcapacity, reduce vessel numbers by 30% by 2025
  • Limit effort shift into other areas and other fishery types
  • Maintain horsepower and headrope length at current levels to prevent effort creep (and reduce in cases of overcapacity)
  • Stop or reform the use of subsidies (especially fuel subsidies) for trawl fisheries
  • Ensure all financial incentives in trawl fisheries reward sustainable fishing practices

Institutional processes to  strengthen management

For countries with a significant trawl sector:

  • Establish a Steering Committee to implement these guidelines
  • Initiate the development of a draft fisheries management plan for an important trawl fishery, as a vehicle for capacity building
  • Establish consultative processes that engage with fishers, the fishing industry and other stakeholders for ALL steps in the above processes

Tropical Trawl Management Guidelines

Effective fishery management in Asia is more critical than ever, now that the region is passing from four decades of expansion and increased production to an era of overcapacity, overexploitation and unsustainable practices. The high growth in capture fishery production achieved during these past decades is due to increases in fishing effort, including gear modification and speed of...
Trawl fisheries are an important component of the capture fisheries sector in Malaysia. Although small in terms of percentage of licenses issued (11.79%), their significance is underlined by their contribution to the overall landings (48.19%), as shown in the table below for the year 2011.
The Western Bay of Bengal (WBoB) trawl fishery is typically a tropical multispecies mixed fishery with a history of commercial exploitation since early 1960s. The nature of fishing changed dramatically with the introduction of trawlers. In the last 50 years, trawlers have become immensely popular and have emerged as the most important fishing craft in the region. The trawl fishery...

Regional overviews and information on trawl fisheries and low value bycatch

"Assessment, Management and Future Directions for Coastal Fisheries in Asian Countries" [The collected papers of the the World Fishcenter/ADB "Trawlbase" programme on coastal fisheries are an excellent regional resource on the fisheries of the region and trawl fisheries in particular.]