Monthly sampling technique is used to analyze catch and value of inland fisheries production from large human-made freshwater bodies, such as dams, and also large freshwater reservoirs. The sampling sites are freshwater landing places of the fishing boats that operate in those reservoirs. The survey is divided into two steps as follows:
The equations for analysis are as follows:
| = |
| |
| = |
| |
When |
| = | production landed at fishing places in month h |
| = | value of production landed at fishing places in month h | |
Nh | = | number of total boats at fishing places in month h | |
nh | = | number to sample boats at fishing places in month h | |
Xhij | = | catch of species i of sample boat j in month h | |
h | = | month 1, 2,…, 12 | |
i | = | species 1, 2,…, m | |
j | = | sample boat 1, 2,…, n | |
Phij | = | average price of species i of sample boat j in month h | |
So |
| = |
|
| = |
| |
When |
| = | total catch of all year |
| = | value of total catch all year |
The survey is yearly conducted to obtain the annual catch production of natural reservoirs, in all provinces by sampling technique. The natural reservoirs are divided into three groups as follows:
The equations for catch analysis by province are as follows:
Xhij | = |
| |
When | Xhijk | = | catch of species h, natural reservoir group i, area j, sample reservoir k |
Xhij | = | catch of species h, natural reservoir group i, and area j | |
Aij | = | area of natural reservoir group i, area j | |
aijk | = | area of sample reservoir k, natural reservoir group i, area j | |
h | = | species type (1, 2, …, n) | |
i | = | group of natural reservoirs (1, 2, 3) | |
j | = | area (1, 2, 3, 4, 5) | |
k | = | sample reservoir (1, 2,…l, nij) |
Then, the catch of all species in each group of natural reservoirs and areas by province is
Xji | = |
|
The catch of all species in all areas of each group of natural reservoirs by province is
Xi | = |
|
The value of species h in natural reservoir group i, area j is
Vhij | = |
|
The value of species h in all areas of natural reservoir group i is
Vhi | = |
|
The value of all species in natural reservoir group i is
Vhi | = |
| |
When | Phij | = | average price of species h in natural reservoir group i, area j |
Vhij | = | value of species h in natural reservoir group i, area j |
The survey is yearly conducted to obtain the annual catch production of pond traps, which are personal or public properties, in all provinces by sampling technique. Pond traps are made for capture fisheries purpose. The one, who wants to harvest the catch production in any pond traps, has to inform the local district office.
The equations for catch, value, and price analysis of each species by province are as follows:
| = |
| |
When |
| = | catch of species j in province i |
Aij | = | total area of pond traps, which have production, in province i | |
aij | = | total area of sample pond traps for species j in province i | |
Xijk | = | catch of sample pond trap k, species j in province i | |
i | = | province (i = 1, 2,…, n) | |
j | = | species (j = 1, 2,…, m) | |
k | = | sample pond trap (k = 1, 2,…, l) | |
| = |
| |
When |
| = | value of species j in province i |
Aij | = | total area of pond traps, which have production, in province i | |
aij | = | total area of sample pond traps for species j in province i | |
Vijk | = | value of sample pond trap k, species j in province i | |
i | = | province (i = 1, 2,…, n) | |
j | = | species (j = 1, 2,…, m) | |
k | = | sample pond trap (k = 1, 2,…, l) | |
Pij | = |
| |
When | Pij | = | average price of species j in province i |
Vij | = | value of species j in province i | |
Qij | = | catch of species j in province i |
57 (DoF, 2005b).
58 (DoF, 2006d).
59 (DoF, 2005c).
