Local ecological knowledge

6.3.3.1 Knowledge of coastal biological processes

Ecosystem health indicators were linked to knowledge about the wider function of mangrove forests in coastal biological processes. For example, both younger and older generations recognised that mangrove forests provide nursery habitat for juvenile marine animals that reside part of their life outside of the mangroves, as the following statement shows, “you can find some marine animals in the forests, crabs, fish,

shellfish, and shrimps, but the sizes are smaller than the ones you catch from the sea. The mangrove forests are like their shelters to hide themselves before they are strong enough to go into the sea. It’s not safe for them to go out in the sea if they are not strong enough. Every mangrove forest is like a safe home to all marine animals” (V1,

ER, <35). Elder fishers from village 3 also show an understanding of ecosystem functioning. They understand that the coral reefs are habitat for marine animals. For example, when discussing changes arising from the 2004 Indian Ocean tsunami, one participant stated, “underwater the seabed was destroyed and there was less smaller

fish. The coral was turned upside down. That used to be fish habitat. 60-70% of the coral was destroyed” (V3, ER, >35).

6.3.3.2 Knowledge of spatial and temporal trends in species

Table 6.2 summarises the local ecological knowledge of the 8 different user groups. All groups held knowledge of relatively simple information, such as knowledge of different species and their habitats. Whereas, knowledge of more complex ecological processes, such as knowledge about the wider function of mangrove forests in coastal biological processes and understanding of how ecosystems change on temporal scales (daily, seasonally, or in response to disturbance), was less evenly distributed across groups.

Table 6.2. Summary of the local ecological knowledge among groups of different age (>35 years/<35 years), occupation (ecosystem related (ER)/ non-ecosystem related (NER)), and from different villages (village 1 (V1)/ village 3 (V3)) on the island of Koh Klang, Krabi. The ‘number of observations’ shown in parenthesis refers to the number of times the type of knowledge was discussed by each group.

Type of knowledge Example of local ecological knowledge among groups Group Number of

observations in group

Knowledge of species and their habitats Understanding that mangroves are habitat for marine animals, birds, reptiles etc. V3 Younger ER V1 Younger NER V1 Older NER V1 Younger ER V3 Younger NER V3 Older NER V1 Older ER V3 Older ER 8 7 5 5 4 3 3 2 Understanding that coral reefs are habitat for marine animals. V3 Older ER 1 Understanding that the beach/sea is habitat for marine animals and birds. V1 Younger ER

V1 Older ER V3 Younger NER V3 Older ER V3 Older NER V3 Younger ER V1 Older NER V1 Younger NER 8 6 3 2 2 2 2 1 Knowledge about the wider function of

mangrove forests in coastal biological processes.

Holistic perception of the seascape and their ecological processes.

Understanding that mangrove forests support nursery habitat for juvenile marine animals that spend part of their life outside of the mangroves.

V1 Younger ER V3 Older ER V3 Younger ER V3 Younger NER V1 Younger NER 5 4 3 3 1

Understanding that ecosystems change over time

Notions that different tidal stages provide a different diversity of shellfish species in the mangrove forests.

V1 Younger ER 1

Understanding of seasonal shifts in species abundance (related to the monsoon onset) V3 Younger NER V1 Older ER V1 Younger NER 1 1 1 Disturbance - knowledge that historic land

use change changes the abundance of marine animals, and ecosystem functions.

Knowledge that species of fish and shrimp that had once disappeared have started to come back (related to improved environmental health).

V3 Older ER 3

Loss of mangrove forests affects fisheries productivity/species abundance. V1 Younger ER V1 Older ER V1 Older NER

3 2 1 The tsunami negatively affected fisheries productivity in the sea and

mangrove forests. V3 Younger ER V3 Older ER V3 Older NER V1 Older ER V1 Younger ER V1 Younger NER V3 Younger NER 4 3 2 2 2 2 1 Water contamination caused by shrimp farming resulted in coral bleaching. V3 Older ER 2

Changes in water quality affects fisheries productivity. V3 Older ER V1 Older NER

1 1 Disturbance - Notion that changes in climate

have occurred recently resulting in a negative effect on fisheries.

Recent changes in seasonal temperature and precipitation - the seasons have been ‘unstable’ (cooler weather in summer, shifts in the timing of the monsoon onset, rain in summer and hardly in the rainy season).

V3 Older ER V3 Older NER V1 Older NER 3 3 2

Many participants held ecological knowledge useful for finding and harvesting marine resources, such as detailed knowledge about the location of important species. While the four key groups of animals (shrimp, shellfish, crab and fish) were clearly important across user groups, participants from village 3 held greater knowledge about the

location and abundance of fish species, whereas participants from village 1 were mostly concerned with shellfish productivity and harvesting. An elder from village 1 said, “Polymesoda proxima (clam), horn shell, and cone shell are dominant shell species.

Cockles are found at village 1, and this is where the greatest number of shells are found. Babylonia areolate and cone shell are at village 3, and root clam are at village 2” (V1, NER, >35). Similarly, younger groups from village 1 were specific when

describing species of importance and their location, and also described how different tidal stages provide a different diversity of shellfish species in the mangrove forests, “Periwinkles, babylonia, tegillarca grasosa, and mangrove snail are found in the

mangrove forest. Root clams and horse mussels are from the beach. In the mangroves, people go collecting periwinkles at high tide and babylonia at low tide” (V1, ER, <35).

Some elder fishers predicted short-term changes in fish productivity based on the colour and turbidity of the seawater, a type of ‘folk oceanography’, “If the water is

clear, we can collect more fish but if the water is unclear we collect less fish. When the water is unclear we don’t catch enough to cover the cost of the fuel” (W1, V3, >35).

Other participants held specific knowledge about the seasonal shifts in species

abundance. For instance, one younger group from village 3 associated changing species diversity with changing seasons, and stated that a healthy ecosystem is one that

functions in a way so to provide a variety of marine resources for each season, “there

are abundant marine resources for each season, stable seasons for animals, stable seasonal productivity in the sea. For example, jellyfish can be found in its own season, which is November-February. If in November the ecosystem is healthy, we can find these species”. This suggests greater local knowledge of biodiversity and temporal

patterns in productivity.