Population Dynamics of Five Important Commercial Fish Species in the Sundarbans Ecosystem of Bangladesh: Recent Advancement | Chapter 3 | Current Research Trends in Biological Science Vol. 1
Aims:
To determine the population dynamics and assess the exploitation level of
Mystus gulio, Acanthopagrus latus, Chelon parsia, Otolithoides pama and Lates
calcarifer in the Sundarbans ecosystem of Bangladesh. Study Design: Monthly
length-frequency data of five fish species were collected from the Sundarbans
ecosystem. The lengths of five fish species were recorded to the nearest one cm
intervals in each month. Place and Duration of Study: The study was conducted
from January to December 2011 in the Sundarbans ecosystem in Bangladesh.
Methodology: The FAO-ICLARM Fish Stock Assessment Tools (FiSAT II) software was
used to estimate the von Bertalanffy growth parameters (L
and K), mortality coefficients (Z, M and F), probability of capture,
recruitment pattern and Yield/Biomass-per-recruit for five commercially
important fish
species caught by fishers in the Sundarbans ecosystem of Bangladesh. Results:
In the Sundarbans ecosystem of Bangladesh area the values of asymptotic length
(L)
for Mystus gulio, Acanthopagrus latus, Chelon parsia, Otolithoides pama and
Lates calcarifer were
found to be 23.0 cm, 33.6 cm, 30.0 cm, 32.5 cm and 55.0 cm respectively while
the growth co-efficient (K) were 0.75, 0.85, 1.1, 0.8 and 0.5 respectively. The
estimates for L (23.00 – 55.0 cm) and K (0.5-1.1 year-1)
obtained were consistent with those available in the literature. Relatively high K
and low L values, typical of short-lived tropical fishes, were obtained for
Mystus gulio, Acanthopagrus latus, Chelon parsia and Otolithoides pama. The
length growth performance index (’) of the Pauly and Munro’s
function was in the range of 2.599 – 3.180. Natural mortality, fishing
mortality and total mortality were in the range of 0.956-1.89, 0.55-1.58 and
1.52-3.3 respectively. Estimates for total mortality (Z) and natural mortality
(M) imply low annual rates of survival and high turnover rates. The recruitment
pattern suggested one main pulse of annual recruitment. The exploitation rate
was estimated to be between 27% and 47% and the length at first capture was
estimated to be approximately 19-54% of L. The
exploitation rate obtained for five fish species are relatively lower compared
to other available studies in the coastal areas of Bangladesh. The growth and
exploitation rates obtained were compared with available estimates to evaluate
the consistency of the results with current knowledge about the species in the
region. Conclusion: The study indicated that the length-at-first-capture/L
seem to be a simple parameter, which could be used to make a rapid assessment
of the status of the stocks. All together, the present study reveals that the
population of these five studied species attains acceptable sustainability
levels in the Sundarbans ecosystem and scope for a slight increase in catch
efforts.
Author(s) Details
Md. Golam Mustafa
Center for Resource Development Studies Ltd, 13C/8C Babar Road, Block B, Mohammadpur, Dhaka 1207, Bangladesh.
Imran Ahmed
Department of Forest, Bon Bhaban, Agargaon, Dhaka 1207, Bangladesh.
Mohammod Ilyas
WorldFish, South Asia, Level 5-7, House 2/B, Road 4, Block B, Banani, Dhaka 1213, Bangladesh.
View Book: - http://bp.bookpi.org/index.php/bpi/catalog/book/157
Author(s) Details
Md. Golam Mustafa
Center for Resource Development Studies Ltd, 13C/8C Babar Road, Block B, Mohammadpur, Dhaka 1207, Bangladesh.
Imran Ahmed
Department of Forest, Bon Bhaban, Agargaon, Dhaka 1207, Bangladesh.
Mohammod Ilyas
WorldFish, South Asia, Level 5-7, House 2/B, Road 4, Block B, Banani, Dhaka 1213, Bangladesh.
View Book: - http://bp.bookpi.org/index.php/bpi/catalog/book/157
Comments
Post a Comment