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Although the theoretical importance of institutional designs for common-pool resource management, including lagoon fishery resources, is highlighted in many academic and research works, an actual and applicable framework in which such theory can be seen and tested in practice has not yet been available. Such a practical framework or guidance would be an innovative tool to help bridge the gap between theory and practice. Small-scale fishers would be able to achieve wise use of lagoon fishery resources sufficiently over time. In all of the case studies discussed, policy makers and practitioners are provided with guidance to enable the best conditions for integrated lagoon fisheries management and related sustainable livelihoods, with particular emphasis on issues of power, institutions, worldviews, and values among relevant stakeholders.The goal of this book is to create a framework for sound lagoon fisheries management, aiming to ensure sustainable livelihoods in fishing communities of lagoon areas.

Lagoon areas are among the most productive ecosystems in the world, where many migrating demersal nektonic species depend on shallow lagoon habitats as nursery areas for early development (Boynton, Hagy, Murray, & Stokes, 1996). With spatial and temporal changes in the lagoon environment, the unique ecotone is endowed with highly productive natural resources and valuable biodiversity, enabling a large number of people to make a living. In contrast, dynamic and complex lagoon areas are expected to be one of the most vulnerable environmental places. Their geographical location is highly exposed to environmental and climatic factors such as sea-level rise, increased level of inundation and storm flooding, seawater intrusion, coastal erosion, and water pollution. That is, the lagoon environment is physically rich in variation, but fishers have to coevolve with fishery resources and ecosystem dynamics to live with change and uncertainty.

Songkhla Lake is the largest lake in Thailand along the Bay of Thailand, situated at latitude 7°08′ and 7°50′ north and longitude 100°07′ and 100°37′ east (Fig. 4.1). The lake covers an area of approximately 1,042km², and consists of four interconnected lake ecosystems (Ratanachai & Sutiwipakorn, 2005): Thale Noi (approximately 27km²), Thale Luang (approximately 473km²), Thale Sap (approximately 360km²), and Thale Sap Songkhla (approximately 182km²).

Chilika Lagoon is the largest brackishwater lagoon in the Indian subcontinent, situated at latitude 19°28′ and 19°54′ north and longitude 85°05′ and 85°38′ east (Fig. 2.1). The lagoon extends from the southwest corner of Puri and Khurdra districts to the adjoining Ganjam district of Orissa state. The pear-shaped lagoon is around 64.3km long and its width varies from 18to 5km. It is connected to the sea through irregular water channels with several small sandy and usually ephemeral islands (CDA, 2008). The average lagoon area is 1,055km² which increases to 1,165km² during the rainy season and shrinks to 906km² during the summer season. Chilika Lagoon becomes less saline during the rainy season due to flood waters from 52 rivers and rivulets. It becomes more saline during the dry season as the supply of flood water is cut off when the south wind begins to blow and saline waters enter from the Bay of Bengal at high (Patro, 2001). The lagoon has three hydrologic subsystems (Mahanadi delta, western catchments, and the Bay of Bengal) influencing the hydrological regimes as shown in Fig. 2.1. The total inflow of freshwater from the Mahanadi delta has been estimated to be 4,912 million cubic meter, accounting for 80 percent of the total water flow. The maximum discharge of 3,182 million cubic meter comes from Makara River, followed by Bhargavi River (1,108 million cubic meter) and Luna River (428 million cubic meter) (CDA, 2008). Meanwhile, the western catchments account for 20 percent of the total fresh water flow.

From a historical viewpoint, decline of fishery resources were commonly identified in all three case studies. The reasons behind the decrease of fishery resources differ, depending on varying extent of socioeconomic and political features as well as of the natural environment. The book reviews the underlying causes learned from each case study experience, and put together a set of environmental issues for lagoon fisheries management that be addressed.

In line with climate variability such as extreme floods and cyclones, siltation is identified as among the most serious environmental problems posed to Chilika Lagoon fisheries. Exposure to silt accumulation reduced the water spread area and hindered the exchange of water between the sea and river, resulted in decreased salinity level and subsequent prolific growth of freshwater invasive species. As a result, fish landing quantities in Chilika Lagoon rapidly decreased until the year 2000, thereby leading to the poorer people not being effectively able to adapt to the ecological-social-economic system. The weed invasion also obstructed passages from boat jetties to fishing grounds, sometimes leading to boat clashes and the subsequent disputes among fishers.

Saroma Lake is the largest lagoon in Japan, situated at latitude 44°05′07″ and 44°11′58″ north and longitude 143°40′06″ and 143°58′14″ east (Fig. 3.1). It is located in the northeast of Hokkaido along the Okhotsk sea. The size and circumference of the lake area is around 151km² and 91km, respectively. The pear-shaped lagoon is around 25.7km long and around 9.5km wide. The lake has semiclosed estuaries with sea mouths between Okhotsk sea and lake. In the lake, two artificial sea mouths have been excavated, where the water exchange can be maintained. These are around 300 and 50m wide. Approximately 90 percent of the total inflow from the sea to the lake passes through the former mouth, which was opened in 1927. The salinity level in Saroma Lake is almost similar to that of the Okhotsk sea due to the active tidal water exchange through the two mouths. An average water depth in Saroma Lake is 14m, approximately 18m deep at the deepest point. The lake receives fresh water from 13 rivers, particularly two principal streams (i.e., River Saromabetsu and Baro), where a large quantity of freshwater and subsequent sediments and nutrients are supplied into the lake.

Our planet's essential goods and services emanate from the functions of biological diversity. An ecological sphere rich in variety and endowed with highly productive ecosystem services in which fishery resources are present provides attractive benefits. Fishery resource is the primary form of people's livelihood for survival, especially in coastal areas. It is a major source of food protein for human beings representing at least 15 percent of the average per capita animal protein intake of more than 2.9 billion people [Food and Agriculture Organization (FAO), 2009]. Significant demands for fishery resources create employment opportunities for many people around the world (FAO, 1995). Indeed, the number of fishers, including aquaculturists, has grown faster than the world's population and faster than employment in traditional agriculture during the past three decades (FAO, 2007a, 2009). In 2004, an estimated 51 million people were making their entire or partial living from fish production and capture (Pomeroy & Rivera-Guieb, 2006), the great majority of these in Asian countries (FAO, 2007a, 2009). According to FAO (2009), it has been estimated that for each person employed in the fishery primary sector, there could be four employed in the secondary sector (including fish processing, marketing, and related service industries). The estimated total population employed in the entire fish industry is approximately 204 million people. The total amounts of fish landing, including aquaculture, have maintained an upward trend, as shown in Fig. 1.1. To a large extent, advanced fishing technology that is efficiently and effectively capable of catching or harvesting fishery resources attracted a large number of fishers and has contributed to an increase in fish landing quantity.