Traditional knowledge about natural history of fishes

Introduction

Gond people of the Mendha and Dhivar people of the Khursa are the biomass-dependent people. The life, culture, traditions, economy and livelihood of these people are directly linked with natural resources. In the subsequent pages of this chapter, an attempt has been made to collect the traditional knowledge of these two communities about the fish diversity. The knowledge about the fish diversity has been collected at the two levels viz. people's knowledge about the ‘fish as a class' (as one taxonomic group) and people's knowledge about the individual species. The themes adopted for the individual fish folk knowledge are value to people, abundance, on going changes in abundance, causes behind the change, use, food preference given to particular fish by local people, habitat of the occurrence, feeding behavior and seasonal abundance of the fish species etc. Whereas themes adopted for the fish as a class are migration behavior, breeding behavior, seasonal cycle and folk taxonomy of the fishes.

In earlier studies, it was found that fisherman's knowledge has been successfully used for the conservation of the fishes and to know the fish biology (John and Anders 2001). Local knowledge includes empirical and practical components that are fundamental to sustainable resource management. For example, among coastal marine fisher, regular catches and often long-term resource availability are ensured through the application of knowledge that encompasses empirical information on fish behavior, marine physical environments, fish habitats and the interactions among ecosystem components, as well as complex fish taxonomies (Ruddle 2001). There are various practical dimensions to folk knowledge about fish also, thus, Indigenous technical knowledge on pond construction and maintenance, fish seed transportation and fish health management in Assam hills is providing direct practical inputs in the fish farm management (Bhagaban 2004). Thus, it is very much essential to document the folk knowledge.

Material and Methods

Folk knowledge of the two communities, viz. Gond and Dhivar has been collected.

Type of traditional knowledge data collected

There were two categories of data about the fishes so far collected viz. people's knowledge about fish on species level and people's knowledge about fish on class level.

First category data – TK about fish at species level

Value of local relevance

Value is an anthropocentric concept as it depends upon the perception or judgment of the human society about the usefulness of something. The value ascribed by local people can provide important input in the conservation and management of a particular species. The value of local relevance has been asked on 3-point qualitative scale:
# Of great value
# Of some value and
# Of no significance

Current level of abundance

In natural community, some species are dominant than others. In no community examined would all species be equally common. It was found that few species were very abundant; some had medium abundance, while few individuals would represent most species. People's perception about the current level of abundance of fish species has been documented on 4-point scale:
# Absent
# Rare
# Moderately common and
# AbundantIn above scale the ‘absent' means the species that was present some time back in the ecosystem but since many years not noticed by the local people.

Ongoing changes in the abundance of fish species

Due to various human influenced and natural reasons, abundance of the species changes over a period. The changes have been documented on 6-point scale:
# Substantial increase
# Moderate increase
# No change
# Moderate decrease
# Substantial decrease and
# Now extinct

Reasons behind ongoing changes in the abundance of fish species

If any change happens in the population, then there must be some reason or motivation behind this, that reason or motivation was asked to the local people.

Use of fish species

Fishes provides cheap and nutritious food besides medicinal use of certain species. This ethenomedicinal study has been done.

Food preference given to fish species by local people

Species wise preferences to local people asked on 3-point scale:
# First preference.
# Second preference.
# Third preference.

Riverine habitat of occurrence of fish species

People's knowledge (only Dhivar people) on the occurrence of fish species in different habitat type such as pools, runs, rapids, riffles and cascades were recorded.

Food and feeding behavior of the fish species

In natural population, every species has its own tropical niche (tropic position, food level). This knowledge has been asked to local people (only Dhivar people). For the simplification and correlation with the existing scientific knowledge following three categories has been fixed for feeding habit viz. bottom feeder, column feeder and surface feeder and two categories for the food viz. carnivorous and herbivorous.

easonal abundance of the fish species

People's perception about the seasonal abundance of the individual fish species has been documented.

econd category data – TK about fish at class level

i. Migration behavior of the fishesii. Seasonal cycle of the migration of the fishesiii. Breeding behavior of the fishesiv. Folk taxonomy

Results and Discussion

Folk species richness

Dhivar people can tell 64 different species of fishes whereas Gond can tell 43. This difference is mainly due to the range of the resource gathering by the Dhivar people. Dhivar people's range of resource (Fish) gathering is wide as compared to Gond. Dhivar people fish in river as well as fish culture ponds and some time goes quite long distance for fishing (in Wainganga also).

First category data – TK about fish at species level

i. Value of local relevancePie graph 6.1 shows the species wise relevance to the Gond people on a scale of three, for 43 species. Out of 43 species spelt by Mendha villagers about half, 22 species (51 %) shown great value, 13 species (30 %) shows some value and 8 species (19 %) are of no significance to the local people.Pie graph 6.2 shows the species wise relevance to the Dhivar people on a scale of three, for 63 species. Out of 63 species spelt by villagers about half i.e. 31 (49 %) species shown great value, 19 species (30 %) shows some value and 13 (21 %) fish species with no relevance.

Food preference =>

ValueFirst preferenceSecond preferenceThird preferenceOf great value

Of some valueOf no significanceThere is a marked relationship between value ascribed to particular species and food preference given to it. Usually it is found that those species that score great value category preferred most. ii. Current level of abundance People's perception about this phenomenon is depicted in figure 6.3 for Gond people and 6.4 for Dhivar people. From these pie graphs it is clear that fishes known to Gond people are, 9 % absent, 12 % Rare, 28 % moderately common and 35 % abundant. Whereas for Dhivar people is, 8 % absent, 19 % Rare, 35 % moderately common, and 38 % abundant.

iii. Trend in the abundance of fish speciesOverall results for all species considered are shown in pie graph 6.5 and 6.6 for Gond and Dhivar people respectively. According to Gond people's perception, considering all fish species, about 72 % fish species are depleting whereas 21 % showing no change and 7 % species are moderately increasing.According to Dhivar people's perception, considering all fish species, about 69 % fish species are depleting whereas about 16 % showing no change and 15 % species are increasing also.It is found that those species, which are assigned by ‘substantially' and ‘moderately increase', are cultured species like Oriochromis mossambica, Ctenopharyngodon idellus, Hypophthalmichthys molitrix Cyprinus carpio etc. The locally extinct species according to Dhivar people are, Ghogar, Jarang, kudu, Pinjar and Tambu (Anguilla bengalensis bengalensis). The former four species in this series are not found in study collection (during sampling), that is why it was not possible to found out the scientific names of the same.iv. Reasons behind Ongoing changes in the abundance of fish speciesVarious responses regarding depletion of the fish fauna has been gathered and are summarized as follows:

a) Over fishingAs per people's perception, following are the reasons behind over fishing,
* Human population increaseAccording to local people, in last few decades, the human population has been substantially increased. This increased population exerting much pressure on river Kathani for food, resulting in over fishing.
* Depletion of terrestrial wild faunaSince from antiquity, tribal people of this area depends on the wild fauna for there protein need. In recent past abundance and availability of wild fauna has depleted seriously (and there is ban on hunting too) due to various reasons. According to local people, this is creating additional pressure on the river for food.
* Changing food habits of local people People's traditional food practices are changing day-by-day (Initially people used to eat NTFP like Mahua but now this practice is becoming outdated). According to local people, this might also indirectly affecting abundance of wild fish fauna by creating more pressure for food on the river.

* Poor culture fisheriesIn Mendha and adjoining villages t