It is generally accepted that coastal fisheries resources in the tsunami-affected countries were severely depleted even before the tsunami struck in 2004 (CONSRN 2005c; Sugiyama et al. 2004; WorldFish 2005). Although data are patchy, it has been estimated that resources may have been fished down to somewhere between 5 and 30 percent of their unexploited levels (Silvestre et al. 2003). The main reasons identified for these conditions have included direct effects from serious overcapacity and overfishing (WorldFish 2005) as well as indirect effects arising from losses or damage to the ecosystems that support fisheries (UNEP 2005). Human activities have led to removal of mangroves, siltation and pollution and the degradation of coastal habitats, making them less productive (Silvestre et al. 2003; UNEP 2005). These losses were already contributing to poverty in the region through the reduced contribution of coastal fisheries to employment, export revenue, food security and social stability (World Bank 2004).
The pre-tsunami fully or overexploited status of the region represents a dilemma for policy- and decision-makers. The fisheries sector was expected in many countries to contribute to an increase of GNP through an increase in total catches (Mous et al. 2005; NARA 2004).
Fisheries in Aceh Province have been mostly small-scale and traditional (Janssen 2005), though there were more motorized boats than in other parts of the country (Purnomohadi 2003). Levels of exploitation were higher on the east coast (the Malacca Strait) than on the western part of Sumatra. Fishing was focused on inshore demersal, and small to medium pelagic species. The fishing fleet consisted mostly of wooden boats 4 to 24 metres long that used trammel nets for shrimps, gillnets for fish and bottom set longlines for larger species. There were also small purse seiners (20 to 25 metres long) for small pelagic species. Most boats were "single-day" and operated in coastal waters, with only the purse seiners making extended trips of up to two weeks. Few locally registered vessels were active in deep sea fishing, and trawling was officially banned in 1980 (Dwiponggo et al. 1986; Janssen 2005). The main gear in use focused on nets, including trawl nets, seines, purse seines, gillnets, lift nets, cast nets and muro-ami (Tampubolon 2006).3 Hook and line methods, hand collecting and spearing were also commonly used.
Based on fish density analysis, the potential yield of the Strait of Malacca for large pelagic fish is about 25 560 tonnes/year, and for small pelagic species about 124 840 tonnes/year (Purnomohadi 2003). Bailey et al. (1987) concluded that in most parts of western Indonesia (including Aceh), demersal stocks were already strongly exploited, while there may have been at that time room for expansion for pelagic species. Matthews et al. (1995 in Matthews and Ghofar 2006) analysing data on pelagic fisheries (1977_1992) off the west coast of Sumatra, suggested the MSY might have been reached and large increases in landings were unlikely (see also Merta et al. 1995). Dwiponggo et al. (1986) considered that trawled demersal species were being optimally exploited between 1977 and 1979. Martosubroto et al. (1996) re-examined demersal fisheries of the 1970s and recalculated a sustainable yield for Aceh using provincial data and field reports. This gave a sustainable yield of 8 000 tonnes/year, from which they concluded that the stocks were already beginning to be overfished.
Over the past ten years, around 90 percent of the landed catch has comprised finfish, about 8.4 percent crustaceans and 0.6 percent molluscs, with the remainder constituting "others" such as sea cucumbers and seaweeds. In 2003 these capture fisheries totalled around 134 000 tonnes, with a value of 863 billion rupiah (US$86 million) and accounted for 3 percent of the provincial GDP (CONSRN 2005a; Janssen 2005). The fisheries sector employed around 89 300 people, or 16 percent of the total coastal population of 558 641 in the disaster-affected areas of Aceh Province and Nias Island (CONSRN 2005a).
Aceh Province is bounded to the east by part of the Malacca Strait and to the west by the Indian Ocean (Purnomohadi 2003). Sumatra is 1 650 kilometres long and up to 350 kilometres wide; it has a mountain chain and associated volcanoes and is bordered to the east by a broad depositional lowland with extensive swamp areas. Off the west coast the Mentawai Islands constitute a "non-volcanic arc", consisting of uplifted and tilted areas with cliffed outer shores facing the predominant southwesterly swell transmitted across the Indonesian Ocean. The inner shores are typically lower and more indented, with embayments,
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3 Hauling a net across the ocean floor to trap fish.
and are fringed by mangroves. There are emerged coral reefs and beach ridges, especially on the outer shores and the possibility of continued tilting is supported by the disappearance of islets off the coast of Simeulue Isand even within the past century. The relatively high island of Nias (summit 886 metres) is encircled by emerged reef terraces. Coral reefs are rare along the central part of the southwest coast of Sumatra because of the large sediment yield from rivers draining the high hinterland, but to the south there are reef-fringed rocky promontories (Bird and Ongkosongo 1980).
The west coast is influenced by the presence of a pronounced thermocline between 100 to 125 metres, above which is a relatively homogenous mixed layer with temperatures of 28 to 29ºC — almost completely depleted in nutrients. In the Strait of Malacca, slightly higher surface temperatures of 28 to 30ºC occur during the south monsoon and lower temperatures of 26 to 27ºC during the north monsoon season. The southern shores of Sumatra receive a southwesterly ocean swell and relatively strong southeasterly wave action in the winter (Bird and Ongkosongo 1980).
Landings of Aceh fisheries generally increased from 1976 for total finfish, crustaceans and molluscs, peaking at 111 000 tonnes in 1998 and then falling to 92 000 tonnes in 2002. This pattern was followed by a sharp increase to 134 000 tonnes in 2003. Finfish dominated landings, peaking at 126 000 tonnes in 2003 and falling to 103 000 tonnes in 2004 for reasons not yet understood. Crustacean landings peaked at 18 500 tonnes in 1995 and then fell to around 5 000 tonnes in 2001 to 2002, rising to 10 000 tonnes in 2004. Four long-lived demersal fish (Indian halibut, red snappers, groupers and barramundi) showed a sharp fall in landings in 2003 to 2004, before the tsunami, and have probably been overfished for several decades (Martosubroto et al. 1996; Mathews and Ghofar 2006). These authors also considered goatfish and shrimps likely to be overfished and called for more comprehensive studies of other species. Although Matthews and Ghofar (2006) consider the Aceh Fisheries Statistics to be of generally good quality, no assessment of reliability has been undertaken and there are scant biological data to aid in assessing the status of stocks.
The examination of the Aceh provincial fisheries statistics revealed several patterns that would tend to support a trend of increasing fishing pressure prior to the tsunami. The first pattern concerns total catch production in kabupatens. While some show steady or slowly increasing production between 1995 and 2005, several show clear declines at some time after 1988 (Figure 1). The two kabupatens that show the greatest declines are also those that had the greatest yearly production, namely Aceh Selatan and Aceh Utara. The second pattern shows significant declines in prawn catches, particularly after 1998, and in longer-lived demersal fish as identified by Martosubroto (et al. 1996) (Figure 2). Barramundi may have been in decline as early as 1997. Finally, there was an apparent overall trend in replacement of small, mostly individually-owned, dugout and plank-built boats with small and larger inboard powered boats from 1994 to 2002, beginning to increase again after that period (Figure 3). Overall the number of fishing boats declined over that period but catch efficiency increased (as catch/boat/year) (Figure 4). It is difficult to assess whether or by how much overall effort changed as standard conversion factors (between boat types) are unreliable, but estimated that that the overall number of boats declined by about 25 percent, while catch per boat increased by 75 to 100 percent. Over the same period total catch fluctuated, but did not show any consistent trend upwards or downwards, though there were different responses in different kabupatens and/or target species. This suggests that changes in catch per unit of effort occurred over the past decade, mirroring the number of boats deployed.
Figure 1: Catch production from 1994 to 2004 for kabupatens on the west and east coasts of Aceh Province
Data are from the Aceh Province Fisheries Statistics Yearbooks (1995_2005, see DKP 2005); there are missing data for some kabupatens, so trends cannot be discerned. Some kabupatens on both coasts showed steady or slowly increasing production over the period. They include Aceh Besar, Aceh Barat, Sabang and Pidie. For Aceh Selatan, Banda Aceh, Aceh Timur and Aceh Utara there are clear declines in catches.
Figure 2: Catch production from 1994 to 2004 for crustaceans and selected demersal fish landed in Aceh Province
Data are from the Aceh Province Fisheries Statistics Yearbooks (1995–2005, see DKP 2005). Prawns showed a decline after a peak in 1995, while crabs and lobsters were either steady or increasing slowly. The picture for some demersal fish is more complex. All of the four groups shown below declined in 2004, but before that production of Indian halibut was increasing.
Figure 3: Numbers of fishing boats in use per year between 1994 and 2004 in Aceh fisheries
Data are from the Aceh Province Fisheries Statistics Yearbooks (1995–2005, see DKP 2005). The overall decrease in the total number of boats was due to changeover. There was a general increase in the numbers of boats with inboard engines and a general decline in the numbers of dugout, outboard and plank-built boats from 1994 to 2002. Between 2002 and 2004 some of these boats started to increase again. So did the total number of boats.
Figure 4: Relationship between yearly total catch production, total number of vessels in use and catch/vessel/year in Aceh, 1994–2004
Data are from the Aceh Province Fisheries Statistics Yearbooks (1995–2005, see DKP 2005). There was a general decrease then an increase in the overall number of boats from 1994 to 2004, but part of this was attributable to switching from many small boats to a smaller number of larger boats with inboard engines. Using only data on total number of boats (and not details of their capacity) the catch per boat (right axis) increases from 4.4 tonnes/boat/year in 1994 to 8.4 tonnes/boat/year in 1998. Between 2002 and 2004 catch per boat decreased while the number of boats increased and production fluctuated. The number of vessels and the catch per vessel are almost mirror images and the best catches over the past decade tended to occur when the total number of boats was below 15 000.
Minimal provincial fisheries data are available for the period since the tsunami, but at Lampulo, Banda Aceh, it was possible to obtain some monthly data on catch, catch per boat, trips and number of boats between February 2004 and May 2006. These data show that catch per boat and total catch actually increased in 2005 and 2006 compared with 2004 (Figure 5). This is considered to be related to the reduced number of boats and fishing trips after the disaster.
Figure 5: Trends in purse seine landings at Lampulo, Banda Aceh from February 2004 to May 2006
Data are from Tampubolon (2006) and show that the number of boats and trips were reduced after the tsunami, but the total catch was back to within normal range by about May 2005. This was accompanied by far better catch rates per boat in 2005 compared with 2004.
The quantity and productivity of marine fish resources in Sri Lanka is driven by the presence of a narrow continental shelf and the lack of significant areas of upwelling (Joseph 1993). Between 1977 and 1980, acoustic surveys of coastal waters were undertaken4 to estimate a potential yield of about 250 000 tonnes/year (170 000 tonnes pelagic, 80 000 tonnes demersal resources). At that time it was thought that the demersal resources had little potential for expansion and that the pelagic species mostly sustained the inshore fishery (Blindheim and Foyn 1980). Preliminary estimates of potential yield from the offshore/deep sea areas varied between 29 000 and almost 99 000 tonnes, which at that time indicated a scope for increasing production. These estimates of potential yield have not been updated since that time (Hersoug and Munkejord 2003); if regional analyses of trawl survey data for the APFIC states, including Sri Lanka are any guide, there has been substantive degradation and overfishing of coastal stocks (Sugiyama et al. 2004) since then.
Most of Sri Lanka's fisheries are small-scale with relatively recent increases in privately owned larger scale enterprises (BOBP 1984; Maldeniya and Amarasooriya 1998; Preston 1988). The main areas in which fisheries are focused are: (i) inland fisheries and aquaculture; (ii) coastal fisheries, including those in lagoons, swamps and estuaries and diverse activities and species; and (iii) offshore fisheries focusing on
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4 Norwegian research vessel,
Dr Fridtjof Nansen.
shark and tuna, mostly for the domestic market (IOTC 2004; Preston 1988). For purposes of data collection and management the most important fisheries are organized in the six groupings given in Table 1; for the purposes of this study, the most important of these will be the coastal fisheries focused on small and medium pelagic fish, demersal fish and crustaceans. The area defined as the coastal region comprises all 74 administrative divisions with a maritime boundary; it extends about 50 kilometres inland and contains about 23 percent of the islands, 65 610 km2 of the land area and is home to one-quarter of the population (Joseph 2005).
According to the Department of Census and Statistics, fish contributes about 65 percent of the animal protein consumed in Sri Lanka. Total annual fish production in 1996 was 228 550 tonnes, around 65 percent of which was landed by coastal fisheries, 25 percent by offshore or deep sea fisheries and 10 percent by inland fisheries. By 1997 small pelagic fish contributed 70 percent of the catch from coastal waters with an estimated production of 152 752 tonnes (Samaranayake 2003). From 1999 to 2004, production of all commercial groups of marine fisheries climbed from 238 400 to 253 190 tonnes (NARA 2004). In 2003 coastal and offshore fishing produced 284 960 tonnes of fish providing 83 percent of the total quantity consumed in the country (CONSRN 2005b). Around 1 million people were dependent on fisheries and 250 000 people were employed in the sector (Sydnes and Normann 2003). The fishing industry contributed 2.6 percent to the GDP in 2003 in addition to foreign exchange earnings through exports of fish and marine products of 9.5 billion rupees5 (CONSRN 2005b).
Demersal species included fish, squid, prawns, crabs and lobsters of around 215 species belonging to 55 families (Samaranayake 2003). The most common families were the emperors, snappers, jacks and trevallies, groupers, grunts, sweet lips and pony fish. The smaller short-lived species such as pony fish predominated in the north and northwest while the larger longer-lived species such as emperors, snappers and groupers were predominant in the other areas of the continental shelf. The demersal trawl catch rates in the northwest and north were higher than in other areas. Small pelagic species such as sardines, herrings, anchovies and mackerel in the inshore waters were exploited primarily by gillnets (80 percent of production, Samaranayake 2003).
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5 US$1.00 = 112.76 Rupees (October 2007).
Large pelagic fish such as tuna, marlin, sharks and billfish contributed about 30 000 tonnes to total annual production. The larger species, particularly skipjack, yellowfin and big-eye tuna, billfish and pelagic sharks were mainly exploited in offshore areas and oceanic ranges. The smaller tuna species such as frigate, bullet and eastern little tuna (mackerel tuna or kawakawa) and seerfish (Spanish mackerel) were concentrated on the continental shelf (Samaranayake 2003). In recent years, tuna fisheries in Sri Lanka have developed rapidly. By 1998 there were more than 3 000 boats engaged in tuna fishing, with 1 700 greater than 10 metres in length and operating in offshore areas, some into international waters. Fishing efforts through multiday operations jumped from 11 percent to 57 percent in just two years (1994–1996). The total production of large pelagic fish in 1998 was in the range of 100 000 to 110 000 tonnes, but evidenced a decreasing trend for the industrial longline fleet. All species of tuna together now contribute about 50 percent of the catch of large pelagics from both coastal and offshore fishing, with skipjack dominating catches (Maldeniya and Amarasooriya 1998).
Other commercially important resources consisted mainly of prawns, lobsters, crabs, squid, cuttlefish, bêche-de-mer, oysters and chanks. There were about 33 species of prawns — eight of importance mainly from the Palk Bay area, between Colombo and Udappu, off Mullaitivu and in Batticaloa. About five species of lobsters were present. Sea cucumbers were found primarily in the muddy bottom off the shores of the northwest coast at Palk Bay, Gulf of Mannar and Kalpitiya. Molluscs have in the past included edible oysters, window-pane oysters and pearl oysters, which dwindled in the 1970s, in addition to chanks which are now reviving and are collected for export from Palk Bay (Samaranayake 2003). Squid and cuttlefish came from the prawn grounds as incidental catch.
Ornamental fish have been a significant reef resource in Sri Lanka since 1980 (BOBP 1984) and may have good potential for co-management arrangements with communities. There is, however, a substantial gap in the available information on the species and numbers of specimens exported (Wilhelmsson et al. 2005); overexploitation of the resource is likely to have contributed to the declining trends in ornamental fish abundance. Haputhantri et al. (2002) interviewed 12 ornamental fish suppliers who said that there was a declining trend in marine ornamental fish abundance over the previous five years. Reasons quoted for the decline included: effects of coral bleaching in 1998; increasing numbers of ornamental fish collectors; destructive fishing/collecting practices, coral mining and pollution.
Although a range of estimates of MSY has been provided through trawl, acoustic and productivity surveys since the early 1970s, they differ significantly. Samaranayake (2003) reviewed the existing data and estimated an aggregate MSY for demersal, pelagic and large pelagic species of about 172 000 tonnes/year, while higher estimates of total production of up to 500 000 tonnes/year have been proposed (Sydnes and Normann 2003). The number of boats required to attain the MSY discussed by Samaranayake (2003) for different categories are: 2 715 for inboard motorized craft; 7 839 for outboard motor craft; and 22 146 for artisanal craft.
Fishing activities occurred all around Sri Lanka's coastline, with landings made at 12 fishery harbour centres, several large and small fishery anchorages and as many as 700 village-level fish landing sites. In 2003 the fishing fleet comprised 29 694 fishing craft including multiday boats (34–50 feet long) powered by inboard engines, 3.5 tonnes single-day boats powered by inboard engines, fibreglass re-inforced plastic (FRP) boats 18-23 feet long powered by outboard engines and traditional craft (dugouts and log craft some of which had outboard engines) (CONSRN 2005b).
Sri Lanka and the southern tip of India stand on the same continental shelf and are separated by a shallow sea, the Palk Strait. There is a generally rocky continental shelf averaging 15 kilometres in width and 20 to 65 metres in depth, with the narrowest stretch at Kalpitiya, where the width is only 2.8 kilometres. The total area of the continental shelf is about 26 000 km2, occupying about 11 percent of the EEZ and providing about 70 percent of the annual fish production (Samaranayake 2003). Within the coastal zone are diverse ecosystems including lagoons, estuaries, coral reefs, mangrove forests, sea-grass beds, salt marshes, beaches and dune systems (Samaranayake 2003). Coral reefs in Sri Lanka can be found along only 23 percent of the total shoreline and they are mostly fringing reefs. Barrier reefs are found in Vanakali and Silvathurai in the north and are rare.
The lagoons and estuaries of Sri Lanka are some of the country's most prominent natural features and cover some 160 000 hectares in total (UNEP and MENR 2005; NARESA 1991). The lagoons are complexes of other wetland systems and often contain marshes, mangrove areas, sea-grass beds and mud flats. These ecosystems are valuable for their fish, shrimp and other products. Those that open to the sea also provide nursery functions, supporting estuarine and coastal fisheries. About 90 percent of commercially important organisms captured in estuaries and lagoons arrive as migrants from the sea (NARESA 1991). They also have socio-economic importance as major settlement sites for urban and rural communities and provide natural harbours and anchorages. The health of lagoons and estuaries is heavily dependent on the interplay of freshwater flowing from the interior and influxes from the sea. Closed lagoons may be periodically opened naturally or by humans; diversions may reduce waterflow resulting in siltation and changes in salinity and ecology (UNEP and MENR 2005). For example, Negombo Lagoon's effective water area was reduced by 791 hectares between 1956 and 1981 due to high siltation rates (NARESA 1991).
Sri Lanka has short rivers with low sediment yield and maximum tidal amplitude of only about 75 centimetres, so there are few locations suitable for the development of extensive stands of mangrove vegetation. There are limited mangroves in Puttalam District, with over 2 000 hectares, and Batticaloa and Trincomalee Districts, each with over 1 000 hectares. Elsewhere, mangroves occur only along the fringes of brackish-water lagoons, estuaries and inlets (UNEP and MENR 2005).
With the ongoing support of several international NGOs (e.g. IUCN) there are now several programmes aimed at protecting coastal ecosystems and resilience in the country such as a wetland sanctuary in Kalametiya (Bambaradeniya et al. 2006); others are in the pipeline, such as a turtle refuge at Rekawa (Sandun et al. 2006).
Marine fish production in the districts of Galle, Hambantota and Kalutara increased steadily from 1990 to 2000, tripling in that period and peaking at over 34 000 tonnes in Hambantota (Maldeniya and Jayamanne 2006) (Figure 6). This was followed by a decline to around 17 500 to 22 000 tonnes per district in 2004 and then a steep drop back to or below 1990 levels after the tsunami (6 220 to 11 560 tonnes). Almost 80 percent of the marine fish catch in these districts consisted of large pelagic species, with shore seine varieties contributing over 21 percent (demersal finfish and non-finfish prawns, lobsters and others). After the tsunami the contribution of shore seine varieties declined by up to 20 percent (Maldeniya and Jayamanne 2006).
A different picture emerges for Ampara and Batticaloa Districts. Data on total fish production are recorded by the district offices for a number of fisheries (FI) divisions. According to these data, annual catches in Batticaloa were increasing from 2001 to 2004, from a yearly total of about 4 200 to 7 600 tonnes (Figure 7). After the tsunami, the monthly catches at Ampara fell to nearly zero and increased by March 2005, but remained lower than the equivalent months in 2004. In Batticaloa after a lower catch in January 2005, catches were subsequently within the normal range seen from 2001 to 2004.
Landings' data for small pelagic species in seven districts using NARA's Small Pelagic Fisheries Database were examined (see examples in Figure 8). Chilaw, Kalmunai, Kalutara, Matara, Negombo, Tangalle and Trincomalee Districts had data from 2000 to early 2006. Five of the seven districts showed an overall trend of declining landings of small pelagic species from 2000 to 2004, with two districts (Kalutara and Chilaw) remaining relatively steady over the same period. In two of the districts showing an overall
Figure 6: Catch production of marine fisheries in three tsunami-affected districts in Sri Lanka (Maldeniya and Jayamanne 2006). Data are from MFAR, the red line marks the tsunami
Figure 7: Landed catches in Ampara and Batticaloa Districts. Data are from district administrations; the red line is the tsunami. (a) is total production per month and (b&c) is average production across all FI divisions +/-SE
decline in catches, the pattern was more complex. For Matara and Trincomalee, catches increased in 2000 and 2001, dropping abruptly in November and December of that year. Between 2002 and 2006 catches remained low and steady. Responses to the tsunami were very different in the seven districts. In Chilaw (Figure 8a), catches were greater in 2006 than at any time back to 2000. In Tangalle and Kalmunai (Figure 8b), catches were significantly lower after the tsunami and by May–June 2006 had not recovered to pre-tsunami levels. In all of the remaining districts, catches quickly recovered to pre-tsunami levels, including normal seasonal fluctuations (Figure 8c).
Figure 8: Landings per month of small pelagic fisheries in (a) Chilaw, (b) Kalmunai and (c) Kalutara. Data are from NARA's Small Pelagic Fisheries Database. The red line is the tsunami
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Figures 6, 7 and 8 cover different time frames and provide different information on the overall behaviour of the district fisheries and how they responded to the tsunami. The yearly data give a good picture of how the fisheries were behaving over longer time frames before the tsunami. The monthly catch data show significant seasonal patterns that tend to repeat over the years and different responses to the tsunami. The highlights are:
