Solomon Islands Aquatic Agricultural Systems Program design document

WorldFish is leading the CGIAR Research Program on Aquatic Agricultural Systems together with two other CGIAR Centers; the International Water Management Institute (IWMI) and Bioversity. In 2012 and 2013 the AAS Program rolled out in Solomon Islands, Zambia, Bangladesh, Cambodia and the Philippines. Aquatic Agricultural Systems are places where farming and fishing in freshwater and/or coastal ecosystems contribute significantly to household income and food security. The program goal is to improve the well-being of AAS-dependent people. A hub is a geographic location that provides a focus for learning, innovation and impact through participatory action research. In Solomon Islands AAS works in Malaita Hub (Malaita Province) and Western Hub (Western Province). In each hub we identify a ‘Development Challenge’ that the Program will address to give us focus and motivation.

Seafood consumption and supply sources in Hawaii, 2000-2009

Measures of consumption and supply sources of seafood can provide valuable input to research and policy planning of a viable food system. This article fills a gap in the existing literature by mapping the existing seafood supply flows from various sources (local, domestic U.S., and foreign) in Hawaii. The authors trace the seafood transshipment of foreign origin via the continental United States to Hawaii and update total and per capita consumption of seafood more accurately by including noncommercial catches into the analysis. Per capita seafood consumption in Hawaii from all commercial sources is estimated at an annual average of 29 edible pounds during the 10-year period from 2000 to 2009. This is significantly more than the 16 edible pounds for all U.S consumption in 2009. Including noncommercial catch, the same measure increases to 37 edible pounds. The eight-pound differential suggests that noncommercial fishing is an important source of seafood supply in Hawaii. Overall, fresh tuna (Thunnus spp.) is the single largest species group consumed, followed by Pacific and Atlantic salmon (Salmonidae). By edible weight, the majority of Hawaii’s commercial seafood supply comes from foreign sources (57%) vs. local sources (37%), and U.S. domestic sources (6%). The leading sources for Hawaii’s direct seafood imports from 2000 to 2009, were Taiwan, Japan, New Zealand, the Philippines, and the Marshall Islands. Local supply becomes the majority source once noncommercial catch is included with 51% of the total supply.

Dynamics of bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna in Hawaii’s pelagic fisheries: analysis of tagging data with a bulk transfer model incorporating size-specific attrition

Tag release and recapture data of bigeye (Thunnus obesus) and yellowfin tuna (T. albacares) from the Hawaii Tuna Tagging Project (HTTP) were analyzed with a bulk transfer model incorporating size-specific attrition to infer population dynamics and transfer rates between various fishery components. For both species, the transfer rate estimates from the offshore handline fishery areas to the longline fishery area were higher than the estimates of transfer from those same areas into the inshore fishery areas. Natural and fishing mortality rates were estimated over three size classes: yellowfin 20–45, 46–55, and ≥56 cm and bigeye 29–55, 56–70, and ≥71 cm. For both species, the estimates of natural mortality were highest in the smallest size class. For bigeye tuna, the estimates decreased with increasing size and for yellowfin tuna there was a slight increase in the largest size class. In the Cross Seamount fishery, the fishing mortality rate of bigeye tuna was similar for all three size classes and represented roughly 12% of the gross attrition rate (includes fishing and natural mortality and emigration rates). For yellowfin tuna, fishing mortality ranged between 7% and 30%, the highest being in the medium size class. For both species, the overall attrition rate from the entire fishery area was nearly the same. However, in the specific case of the Cross Seamount fishery, the attrition rate for yellowfin tuna was roughly twice that for bigeye. This result indicates that bigeye tuna are more resident at the Seamount than yellowfin tuna, and larger bigeye tunas tend to reside longer than smaller individuals. This may result in larger fish being more vulnerable to capture in the Seamount fishery. The relatively low level of exchange between the Sea-mount and the inshore and longline fisheries suggests that the fishing activity at the Seamount need not be of great management concern for either species. However, given that the current exploitation rates are considered moderate (10–30%), and that Seamount aggregations of yellowfin and bigeye tuna are highly vulnerable to low-cost gear types, it is recommended that further increases in fishing effort for these species be monitored at Cross Seamount.

Asserting rights, defining responsibilities: perspectives from small-scale fishing communities on coastal and fisheries management in Cambodia

In preparation for the Workshop and Symposium on “Asserting Rights, Defining Responsibilities: Perspectives from Small-scale Fishing Communities on Coastal and Fisheries Management in Asia”, held in Siem Reap Cambodia, from 3 to 8 May 2007, case studies were undertaken in six countries in Asia—Bangladesh, Cambodia, India, Indonesia, Philippines and Thailand. Among other things, the studies aimed to document and explore the understanding that fishing communities have about their rights to fisheries and coastal resources, as well as the obligations and responsibilities associated with these rights, and to document and discuss their initiatives to assert these rights and fulfill their responsibilities. The studies formed the basis for discussions at the Workshop and Symposium. This case study from Cambodia will be found useful by NGOs, regional and national organizations of artisanal fishworkers, and anyone interested in fisheries and fishing communities in Cambodia.

The propagation of the mud crab Scylla serrata (F.) de Haan

The mud crab Scylla serrata is an important commercial species found in many brackish areas in the Philippines. During spawning and hatching, the berried females migrate to the sea. Seeds for pond stocking are obtained from the wild. Because of the unpredictability of seed supply, there is a need to propagate the species artificially. Thus, spawning, larval rearing, maturation, and rematuration of the species are being studied. The first attempts at hatching S. serrata were successful with rates varying between 75% and 90%. Two out of three trials on larval rearing yielded a few megalops. The first zoeal stages were fed diatoms, rotifers, Artemia salina, and bread yeast. Overfeeding programs were implemented during the critical premolting periods to prevent weakening of the larvae and lessen cannibalism. Larval weakening during the premolt makes them susceptible to attacks by fungi like Lagenidium and ciliates like Vorticella. S. serrata larvae survived salinity levels as low as 15 ppt until the 14th day of rearing. Other larvae were able to survive in salinities of 30-32 ppt for 8 to 13 days. Zoeal molting was hastened by lowering the salinity to 25-27 ppt. Artificial broodstocking of juveniles and adult crabs has been made possible using a simple refuge system made of three-compartmented hollow blocks. This system has been helpful in minimizing fighting among crabs. Remarkable growth rates have been observed with feeds like mussel meat and trash fish. Average growth increments of 11 mm carapace length and 20 . 35 g body weight have been observed every fortnight. A newly spent spawner could gain additional weight of 22 . 5 g in only 6 days. Feeding rates of juveniles and adult crabs have been established based on the average body weight from an experiment using mussel meat. Crabs feed more at night. In another experiment, eyestalk ablation was found to be effective in inducing growth and mating. Aside from hastening the molting process, copulation is induced even among the small crabs (average carapace length = 55 mm). Natural mating lasts about 26 hr. A copulation which lasted for seven days with a break in between was observed.

Milkfish fry occurrence pattern in two localities along the Western Coast of Panay Island

The results are presented of a study of milkfish fry occurrence in the Philippines, namely at Magaba and at Tubog. There were 2 peaks of fry occurrence in the latter, one in May and another in October, whereas only one peak occurred in the former in May. The possible influence on light intensity on the fry seasons is examined.

Observations on the artificial fertilization of eggs and larval rearing of the grey mullet, Mugil cephalus L.

The results are presented of attempts to artificially fertilize Mugil cephalus eggs in the Philippines. Embryonic development is outlined and rearing of the larvae described. Mass mortality occurred during week 3 of rearing.

Selection and application of a suitable sampling method for quantitative and qualitative evaluation of lab-lab

Milkfish and prawn pond operation in the Philippines is often associated with lab-lab culture. Lab-lab is a biological complex of blue-green algae, diatoms, bacteria and various animals which form a mat at the bottom of nursery ponds or floating patches along the margins of ponds. This complex is considered the most favorable food of milkfish in brackishwater ponds. Variations in the quantity and quality of lab-lab between and within areas of a 1,000 sq. m. pond was determined over 2 culture periods (6 month duration) and the applicability and suitability of stratified random sampling as a method of sampling lab-lab was evaluated.

Mass production of Penaeus monodon Fabricius juveniles in earthen nursery ponds

Different culture techniques were tried for rearing larvae of Penaeus monodon, in order to obtain preliminary data on stocking density, water management, fertilization versus feeding and effect of different types of vertical substrate. The results of the experiments showed that: (1) older fry have greater chances of survival; (2) the traditional nursery pond designs and practices used for milkfish in the Philippines are applicable to prawn only at very low densities and give acceptable high survival rates only when used with the older postlarval stage.

Preliminary trials in Artemia rearing and salt production in earthen salt ponds

The authors report on the production of Artemia obtained on a 0.5 ha pilot project with combined trials in Artemia rearing with solar salt production during the dry seasons and with production of milkfish (Chanos chanos) fingerlings and/or prawn (Penaeid sp.) juveniles during the rainy season in the Philippines.

Diel fluctuations in catch of the postlarval Penaeus japonicus group

Experiments were undertaken in order to measure the diel fluctuations in the catch of the post-larvae of P. japonicus in relation to the tidal cycles, light conditions and water temperature. The fluctuations are discussed comparing them with other post-larvae Penaeus species appearing along shore waters in the Philippines.

Identification of the postlarval Penaeus (Crustacea, Decapoda, Penaeidae) appearing along shore waters

Diagnostic characters for the identification of postlarval Penaeus appearing along the coastal waters of the Philippines are reviewed and categorized, based on materials from the wild and laboratory. Presently there are 7 adult known species belonging to the genus Penaeus around Panay Island and its adjacent waters, namely: P. monodon, P. semisulcatus, P. merguiensis, P. indicus, P. japonicus , P. canaliculatus, and P. latisulcatus.

The extraction of mimosine from ipil-ipil (Leucaena leucocephala) by soaking in water

The study aimed to find a cheap and practical method of extracting mimosine from Leucaena leucocephala, otherwise known as ipil-ipil in the Philippines. L. leucocephala leaves are used in cattle, poultry and swine feed and have been tried as a food ingredient in some fish diets. While it contains relatively high amount of protein, its use as feed has been limited because of the presence of toxic substance, mimosine. Findings revealed that soaking the leaves in water was highly efficient for the extraction of mimosine, the longer the duration of soaking the more mimosine was extracted. On the other hand, 87 % of the juveniles Penaeus monodon fed with diets containing L. leucocephala leaves soaked for 24 hours survived, much higher compared to those that were fed with unsoaked leaves for eight weeks.

Effect of stocking density on growth and yield of GIFT tilapia under rice-fish production system

The study was conducted at the Central Experimental Station, Philippine Rice Research Institute, Maligaya, Science City of Munoz, Nueva Ecija, Philippines during the wet season to determine the suitable stocking density(s) for better growth and yield of fish under rice-fish production systems. Recovery rate of GIFT tilapia in different stocking densities ranged from 75.74 to 83.47%. Among different treatments, rice +5,000 fingerlings/ha and rice +10,000 fingerlings/ha resulted in the highest recovery rate of 83.33% and 83.47%, respectively. The lowest recovery rate of 75.75% was obtained from rice +20,000 fingerlings/ha, but similar to that was obtained (78.56%) from rice +15,000 fingerlings/ha. Significantly higher rate of gain in body weight and that of specific growth rate were recorded in the treatment from rice +5,000 fingerlings/ha, while other treatments resulted in similar absolute and specific growth rate. Fish yield increased significantly with relatively higher stocking densities, but higher densities produced maximum number of smaller fishes and also lower recovery rate.

Lamproglena notopterai sp. nov.- a copepod parasite from a freshwater fish of Sindh, Pakistan

The study was conducted at the Central Experimental Station, Philippine Rice Research Institute, Maligaya, Science City of Munoz, Nueva Ecija, Philippines during the wet season to determine the suitable stocking density(s) for better growth and yield of fish under rice-fish production systems. Recovery rate of GIFT tilapia in different stocking densities ranged from 75.74 to 83.47%. Among different treatments, rice +5,000 fingerlings/ha and rice +10,000 fingerlings/ha resulted in the highest recovery rate of 83.33% and 83.47%, respectively. The lowest recovery rate of 75.75% was obtained from rice +20,000 fingerlings/ha, but similar to that was obtained (78.56%) from rice +15,000 fingerlings/ha. Significantly higher rate of gain in body weight and that of specific growth rate were recorded in the treatment from rice +5,000 fingerlings/ha, while other treatments resulted in similar absolute and specific growth rate. Fish yield increased significantly with relatively higher stocking densities, but higher densities produced maximum number of smaller fishes and also lower recovery rate.