Table 2. Local ecological knowledge among groups of resource users, i.e., occupational categories, using different gear types and operating in distinct but overlapping subsystems of a coastal seascape in Kenya.
The knowledge is classified and related to the ecological principles defined by Dale et al. (2000a). Occupational category is based on main gear type used and groups are listed in this column according to the ecological knowledge they were found to possess. * groups exhibiting much less detailed understanding of links and processes 1 Differences in scale of the fish migrations acknowledged by different groups. Deep Sea, Gillnet fishermen and Middlemen all perceive migrations on a local and regional scale, whereas Seine net fishermen spoke only of fish migrations at a local scale in the bay.


Ecological principlea Knowledge of resource users reflecting each principle Groups possessing this knowledge
Time
Ecological processes function at different time scales, some long, some short; and ecosystems change over time.

A clear understanding of the effects of clear-cutting of mangroves on related systems


Shrimpers
Deep Sea
Speargun
Gillnet
Middlemen
Farmers*
Businessmen*
Notions among respondents that fish stocks migrate along the coast and that such patterns are affected by seasonal monsoons1 Deep Sea
Seine net
Gillnet
Middlemen
 
Species
Particular species and networks of interacting species have key, broadscale ecosystem-level effects.

Knowledge of the keystone function of mangroves in coastal biological, hydrological and geomorphologic processes in the form of nursery habitats, water filtration, and sediment stabilization.

All groups
Recognition of links between the ecosystems mangroves, seagrasses and reef Deep Sea
Notion of trophic cascades due to changes in abundance of sea urchins, leading to overgrazing of seagrasses with potential effects on inshore fisheries. Speargun*
Seine net
 
Place
Local climatic, hydrologic, edaphic, and geomorphologic factors as well as biotic interaction strongly affect ecological processes and the abundance and distribution of species at any one place.

Acknowledgement by respondents that seasonal climatic changes affect the distribution and abundance of shrimp and finfish in the area:

All groups
Seasonal monsoons and the resulting freshwater outflow attract juvenile shrimps into the mangrove system. All groups
Seasonal monsoon related wind patterns and currents affect fish migrations along the regional coastline. Deep Sea
Seine net
Middlemen
Gillnet
 
Disturbance
The type, intensity, and duration of disturbance shape the characteristics of populations, communities, and ecosystems.

Notion among some fishing groups that sea urchin aggregations can affect the dynamics of seagrass meadows and associated fauna.

Speargun*
Seine net
Acknowledgement that historical and present land-uses such as mangrove cutting will cause changes in the distribution and abundance of associated species, e.g., crabs, shrimp, fish, and ecosystem functions such as soil stabilization, water movement, nursery habitats, nesting areas, and wind breakers. Shrimpers
Deep Sea
Speargun
Seine net
Gillnet
Middlemen
Farmers*
Businessmen*
Notion among some fishing groups that changes in climate, e.g., timing of the monsoon rains and El Niņo phenomena, have occurred recently resulting in an effect on the artisanal shrimp fishery as well as mangrove coverage Shrimpers
Deep Sea
Speargun
Seine net
Gillnet
 
Landscape
The size, shape, and spatial relationship of land-cover types influence the dynamics of populations, communities, and ecosystems.

Awareness of the nursery function provided by mangroves for fish and shellfish residing part of their life outside of the mangrove habitat. Shows a notion of the positive spillover effect of such functions on coupled ecological subsystems such as seagrass beds and coral reefs.

Shrimpers
Deep Sea
Speargun
Seine net
Gillnet
Middlemen
Farmers*
Businessmen*