Main Menu
The importance of mangroves to prawn fisheries, particularly banana prawns (Udang Putih)
Project ID
FIS/1992/018
Inactive project countries
Malaysia
Commissioned Organisation
CSIRO Marine Research, Australia
Project Leader
Professor Neil Loneragan
n.loneragan@murdoch.edu.au
Phone:
08 9360 6453
Fax:
08 9360 6303
Project Budget
$531,368.00
Start Date
01/07/1997
Finish Date
30/06/2000
Extension Start Date
01/07/2000
Extension Finish Date
31/10/2001
ACIAR Research Program Manager
Mr Barney Smith
Related publications
Overview Objectives
The main purpose of this project was to study the effects of mangrove removal on the productivity of estuaries in Malaysia, and in particular the consequences for prawn fisheries.
Project Background and Objectives
Policy-makers in Malaysia and elsewhere long regarded mangroves as unproductive, and extensive areas were therefore cleared for agriculture, aquaculture, industry or residential purposes. However, mangroves and seagrasses are important as nursery habitats for the young of many fish and invertebrates, and prawns in particular are dependent on their nursery areas. Catches of many prawn species in Malaysia and of the banana prawn in Australia are known to be larger in areas with greater mangrove growth.
There was a need to investigate the commercial catch statistics for prawns in Malaysia and to examine the relationship between prawn catches and the extent of mangroves. Some of the prawn species caught in Malaysia did not depend on mangroves and it was not known whether the size of the prawn catch was a good representation of prawn numbers in a region.
The project topic was important because prawn fisheries are among the most valuable fisheries in Australia and Southeast Asia. On the west coast of peninsular Malaysia they account for 40% of the value (although only 5% of the biomass) of the total marine catch.
Project Outcomes
The project provided information beneficial to fisheries managers in both countries on the actual and potential impacts to fisheries resulting from mangrove loss on a large scale.
The study found a positive relationship between commercial banana prawn catch and extent of mangrove in all states of Malaysia. Loss of mangroves could be expected to lead to a reduction in prawn catch. It also found a relationship between the extent of shallow coastal water and commercial catch of white prawns, affirming that maintenance of the shallow fringes of estuaries is important to the fishery.
Researchers found little conclusive evidence that mangrove loss altered nutrient concentrations in mangrove waterways, but nitrogen pollution was evident near populated areas. They found no evidence that secondary production (fish, prawns and other biota) had been impacted in any major way, but populations of benthic organisms were lower, there were fewer species and changes in species composition in areas of total mangrove removal.
Project reviewers commented on some problems with the sampling designs for the fish and prawn studies and suggested alternative analytical approaches to help address these inadequacies. While the research did not find conclusive evidence that juvenile prawn abundance is influenced by certain levels of mangrove removal within estuaries, nevertheless scientists did establish a positive relationship between historical prawn catch and the extent of mangrove forest at State level.
An analysis of the commercial prawn fishery in Matung Estuary, undertaken as part of a linked PhD study, will provide valuable guidance to Malaysian fishery managers, particularly in relation to the design of appropriate catch monitoring systems. This study will also serve as a useful model for shrimp fisheries in Malaysia and elsewhere.
The establishment of a GIS database was considered a feature of the project outputs: this will provide a useful tool for explaining and presenting the project results to resource managers and the community at large in both Malaysia and Australia.
This project was included in an adoption study of projects completed in 2001-2002, which is available as an ACIAR publication.
Location
There are no project locations defined for this project.
