Global production of farmed fish and shellfish has more than doubled in the past 15 years. Many people believe that such growth relieves pressure on ocean fisheries, but the opposite is true for some types of aquaculture. Farming carnivorous species requires large inputs of wild fish for feed. Some aquaculture systems also reduce wild fish supplies through habitat modification, wild seedstock collection and other ecological impacts. On balance, global aquaculture production still adds to world fish supplies; however, if the growing aquaculture industry is to sustain its contribution to world fish supplies, it must reduce wild fish inputs in feed and adopt more ecologically sound management practices.

The response of grouper larvae to the thyroid hormones, thyroxine (T₄) and triiodothyronine (T₃), was examined. Two-, 3-, and 4-week-old grouper larvae were reared in seawater containing either T₄ or T₃ at 0.01, 0.1, and 1 ppm. T₄ or T₃ induced metamorphosis in all age groups in a dose-dependent manner. Regardless of the size of the larvae, metamorphosis was completed in 2 days in larvae treated with 1 ppm of either T₄ or T₃; 3–4 days in larvae exposed to 0.1 ppm; and 5–6 days in larvae immersed in 0.01 ppm. None of the fish in the control group completed metamorphosis during this period. Compared with the control fish, survival rates were higher in groups exposed to 0.01 ppm and lower in those exposed to 1 ppm of T₃. In 4-week-old larvae, T₄ treatment (0.01 to 1.0 ppm) resulted in higher survival compared to the control. These results suggest that a dose of 0.01 ppm is appropriate for acceleration of metamorphosis and improvement of survival in 3- and 4-week-old grouper larvae. A lower dose may be apropriate for earlier stages.

The effect of metaldehyde on brackish water pond snails, Cerithidea cingulata, was tested in 250 m2 ponds, and in semi-commercial and commercial milkfish ponds. The field trials were conducted at three locations, namely Luzon, Visayas, and Mindanao, Philippines. Three application rates (80, 100, 120 kg(ha) of 10% metaldehyde formulation, an untreated control and a reference standard 25% niclosamide EC (1.0 L/ha) were tested during the dry season in a pond with heavy snail infestation. Seven days after application (DAA), snail mortality rates (86-87%) did not differ significantly among the various metaldehyde treatments but were significantly higher than those in the control (6%) and the reference standard (29%). In the field trials, in heavily infested ponds (more than 2000 snails/m2), a dose of 120 kg/ha was effective under both dry and wet conditions. In moderately infested ponds (less than 2000 snails/m2), a dose of 80 kg/ha of a 10% metaldehyde formulation was effective under dry conditions but a dose of up to 120 kg/ha was needed under wet conditions. In a pond dosed with 120 kg/ha of the 10% metaldehyde formulation, the concentration increased in pond water, until 3 DAA relative to the initial level, indicating that the active ingredient had dissolved from the granules. From day 3, the concentration declined steadily to approx. 16% of the initially detected amount at 15 DAA. In the pond sediment, the metaldehyde concentration steadily declined to approx. 1% of the initially detected amount at 15 DAA. As metaldehyde is rapidly degraded in aquatic systems its efficacy in controlling brackish water pond snails depends on a high initial dosage.

Fishery cooperatives can co-manage coastal fishery resources, help improve the living conditions of small-scale fishers, and slow down the rapid depletion of these resources. Ten fisherfolk cooperatives in Capiz, central Philippines were assessed for their willingness to co-manage fishery resources. Seventeen members and three officers randomly selected from each of six mainland and four island-based cooperatives were interviewed using a pre-tested interview schedule. Statistical tools were employed to analyze field data. Specific factors related to origin and background, membership, management, and economic factors affect the success of cooperatives. Most cooperative members (74%) were willing to assume responsibility in managing fishery resources. Apathy and lack of advocacy and lobbying skills prevent the members from acquiring control and use rights over fishery resources. About 52% of them were aware of the 1991 Local Government Code and the provision on the participation of people's organization in local governance.

Juvenile Hippocampus barbouri were grown in illuminated cages with or without supplemental daytime feeding of thawed Acetes (a planktonic marine crustacean), or in non-illuminated cages with Acetes feeding, as a supplement to light-attracted zooplankton prey. After ten weeks, seahorses in illuminated cages fed Acetes had the highest mean body weight (2.24 g) and length (8.20 cm), but these did not significantly differ from seahorses in unfed illuminated cages (1.88 g; 7.25 cm), which did not significantly differ from those in fed non-illuminated cages (0.88 g; 6.32 cm). In all treatments, the mean instantaneous growth rate in body weight declined progressively throughout the test but the instantaneous growth rate in stretched length did not vary. Mean survival (76-100%) of seahorses in fed non-illuminated cages and in unfed illuminated cages did not vary significantly over the test period. The mean survival of seahorses in fed illuminated cages was lowest (54%), but did not significantly differ from the other treatments. Juvenile H. barbouri grown in illuminated cages had better growth than those in non-illuminated cages, but survival was reduced when seahorses in illuminated cages were fed Acetes.

Public consciousness about biodiversity and the environment, and their importance for sustainable development is not widespread in the Philippines. This article advocates nonformal environment education through nature recreation as a means toward 'greening, the mind and the spirit of the citizens. Information is provided about biodiversity, and the status and potential of nature parks, museums, gardens, and zoos in the country. Many of the 116 national parks and protected areas have been exploited for products and energy, and only some provide for recreation-cum-education. The Philippines has no national botanical garden, zoo, or aquarium, and the National Museum is not the proud institution that it should be. Some universities have small museums, botanical gardens, and other biodiversity exhibits for instruction and research, but these and the few zoos and wildlife centers are poorly funded or managed.

To improve the production of Kappaphycus plantlets in tissue culture, optimum media concentrations of an Ascophyllum nodosum extract (Acadian Marine Plant Extract Powder, AMPEP), plant growth regulators (PGR), pH–temperature combinations, and explant density were determined. Kappaphycus alvarezii var. tambalang purple (PUR), kapilaran brown (KAP), vanguard brown (VAN), adik-adik (AA), tungawan green (TGR), and K. striatum var. sacol green (GS) were used as explants. Based on the shortest period for shoot emergence and the economical use of AMPEP, the optimum enriched media was 3.0 mg L⁻¹ AMPEP and 0.1 mg L⁻¹ AMPEP + PGR 1 mg L⁻¹ each phenylacetic acid (PAA) and zeatin for PUR, 1.0 mg L⁻¹ AMPEP + PGR for KAP and GS, 0.1 mg L⁻¹ AMPEP + PGR for VAN, and 3.0 mg L⁻¹ AMPEP and 0.001 mg L⁻¹ AMPEP + PGR for AA and TGR. Results showed that the addition of PGR to low concentrations of AMPEP hastened shoot formation. pH–temperature combinations for the most rapid shoot formation were determined for the brown (KAP) and purple (PUR) color morphotypes of K. alvarezii var. tambalang and the green morphotype of K. striatum var. sacol (GS) cultured in 1.0 mg L⁻¹ AMPEP + PGR. The brown morphotype produced the most number of shoots at pH 7.7 at 20°C after as little as 20 days. Purple K. alvarezii showed an increased shoot formation at pH 6.7 at 25°C and the green K. striatum morphotype at pH 8.7 at 25°C. The optimum number of explants added to the culture media was also determined for tungawan green (TGR), brown (KAP), and tambalang purple (PUR) varieties of K. alvarezii in 1.0 mg L⁻¹ AMPEP + PGR. The number of explants and the volume of the culture media combination were also tested. The highest average number of shoots formed occurred in two explants:1 mL culture media (2:1) for KAP and PUR (35.00% and 16.67%, respectively) and 1 explant: 2 mL culture media for the TGR (100.00%) with a range of 0.5–3.0 mm shoot length after 40 days in culture. The earliest shoot formation was observed after 21 days for the brown and 9 days for both the green and purple color morphotypes of Kappaphycus, in all densities investigated. This indicated that within the range tested, the density of explants did not have a significant effect on the rate of shoot formation but did influence the average number generated from the culture. The rate of production of new and improved Kappaphycus explants for a commercial nursery stock was improved through the use of AMPEP with optimized culture media pH, temperature, and density conditions.

Macrobrachium rosenbergii (de Man 1879) juveniles (0.4 g) were cultured in experimental cages (L × W × H: 2.5 × 1 × 1 m) in Laguna de Bay, the largest lake in the Philippines. The following stocking densities at four replicates each were used: 15, 30, 60 and 90 prawns m⁻² of cage bottom. The mean sizes at harvest after 5 months of culture ranged from 14.3 g for the highest stocking density to 26.3 g for the lowest. The mean size at harvest, daily growth rate and size class distribution were significantly influenced by stocking density, with those at the lowest stocking density showing significantly better growth and overall proportion of larger prawns. Heterogeneous individual growth (HIG) was fairly evident in all treatments. The percentage of blue-clawed males was not influenced by treatment but the mean weight was significantly higher in the lower stocking densities. Both the percentage and mean weight of berried females were significantly higher in the lowest stocking density. Survival was the highest in the lower stocking densities (55.3%, 54.0%, 52.7% and 36.9% for 15, 30, 60 and 90 prawns m⁻² respectively). Feed conversion ratio (FCR) improved with decreasing stocking density, ranging from 2.1 to 3. As expected, yield per cropping increased with stocking density and ranged from 450 to 1089 g m⁻² yr⁻¹ of actual cage area. Production values obtained in the cage cultured M. rosenbergii were comparable to or even higher than those reported from pond culture, given that the stocking densities used in this study were generally higher than in ponds. The results show that the farming of M. rosenbergii in cages in lakes is a viable alternative to pond culture and has the potential of improve aquaculture production in lakeshore fish farming communities.

Plants of Eucheuma denticulatum collected from Danajon Reef, Bohol, the Philippines were used to produce tissue cultures for the purpose of generating new strains. The plants were sectioned and grown in media encouraging callus growth. New shoots were produced after 3 months of in vitro culture. After another 3 months of laboratory growth, 5 plants were outplanted in the field. After 4 months growth at approximately 0.50 m depth, the five plants grew to biomasses that ranged from 354.9 to 1055.9 g wet weight. They demonstrated growth rates that ranged from 5.8 to 7.2% day⁻¹. The growth rates of the plants produced through tissue culture in this study suggest that such plants can grow at rates as good as, if not better than, those of 'seedlings' produced by the traditional method in the commercial cultivation of E. denticulatum.

Different biological films reportedly effective in larval settlement of other abalone species were tested on the tropical abalone Haliotis asinina to determine the most effective settlement inducers for the species. Larval attachment was significantly higher on mucus, Navicula, Navicula+mucus, and mixed diatoms+mucus than on mixed diatoms and the blank control. Metamorphosis was significantly higher on Navicula, Navicula+mucus. These results indicate the important contribution of mucus in larval settlement and the effectiveness of Navicula as a single species over mixed diatoms in larval settlement of the tropical abalone H. asinina.