Long before the COVID-19 pandemic, the Broodstock Facility and Shrimp Hatchery Complex of SEAFDEC Aquaculture Department (AQD) in Tigbauan, Iloilo, Philippines, has already been practicing the best quarantine protocols. The gold standards to ensure the production of diseasefree and high-quality shrimp are being developed by AQD under the program “OPLAN Balik Sugpo” or Operation Plan for Black Tiger Prawn Revival. Initiated in 2017, this Program generally aims to bring back the Penaeus monodon industry of the Philippines and help farmers revive their hopes and venture again into shrimp culture. Under the Program, the disease prevention scheme is currently undergoing verification for responsible management of shrimp broodstock obtained from the natural environment at AQD’s Broodstock Facility, and for the care of the postlarval stage at AQD’s Shrimp Hatchery Complex.

We monitored the abundance of a non-native (Rhinogobius sp. OR) and two native stream gobies (R. fluviatilis and R. nagoyae) over a decade, from 1995 to 2004, in a fixed reach of a tributary of the Kamo River, southwestern Japan. The non-native Rhinogobius sp. OR appeared and reproduced in 1997, when an increased deposition of fine sediments occurred. However, after a severe spate in 1999, the non-native goby almost completely disappeared from the study reach, while the density of the native R. fluviatilis increased. The severe spate is likely to have prevented the establishment of the non-native goby. Our results provide an example of abiotic barriers to invasion.

Different microalgae as larval food for Holothuria scabra, a high-value sea cucumber species with hatchery technology continually being refined to improve production, were studied. Two experiments were conducted to determine the performance of the larvae—first, the use of single-algal diet of either Chaetoceros calcitrans, Rhodomonas sp., or Tetraselmis tetrathele as feed; and second, the use of a combination of two algal species, C. calcitrans + Rhodomonas sp., C. calcitrans + T. tetrathele, or Rhodomonas sp. + T. tetrathele as feed. For both experiments, hatched larvae at 2 days post-fertilization (DPF) were used for initial stocking at a density of 200 larvae L⁻¹. Growth, development, and survival were monitored until more than 50% of the larval population were considered as competent larvae (late auricularia). In the first experiment, during the early stage of development (early aricularia), larvae fed Rhodomonas sp. were larger compared to other treatments. However, when the larvae reached middle and late auricularia, they performed better when fed with C. calcitrans. Those larvae fed with C. calcitrans were significantly larger and showed faster development to competent larvae. In the second experiment, larvae fed mixed C. calcitrans + Rhodomonas sp. showed better performance in growth, development, and survival. The present study showed that C. calcitrans, when used solely as feed or in combination with Rhodomonas sp., promoted better growth, development, and survival of H. scabra larvae.

This study examined the effects of early weaning strategies on growth and survival of the silver therapon Leiopotherapon plumbeus larvae. In Trial 1, four larval age groups (8, 14, 20 and 26 days post‐hatch (dph)) were abruptly weaned to commercial powdered tilapia diet and compared with wild copepod‐fed group as the control. In Trial 2, another batch of three weaning age groups were subjected to gradual weaning (8 dph larvae with 8 days co‐feeding, 14 dph larvae with 6 days co‐feeding and 20 dph larvae with 4 days co‐feeding) with Artemia nauplii prior to weaning on commercial powdered prawn diet and compared with a control group consisted of larvae fed exclusively on Artemia nauplii. Both weaning trials were conducted for 21 days. A gradual weaning strategy promoted better survival (22.2%–40.0%) among weaning age groups than the abrupt weaning strategy (2.2%–36.7%). Except for those weaned at 26 dph, abrupt weaning resulted in significantly poor growth and survival among all weaning age groups compared with the wild copepod‐fed control group. The highest survival and growth were observed in 20 dph larvae with 4 days live food co‐feeding, although the values were significantly lower than the Artemia‐fed control group. These results suggest that abrupt weaning at 26 dph, and gradual weaning for 4 days from 20 dph promote successful rearing of silver therapon larvae and that a microparticulate diet specifically formulated for this species needs to be developed.

Farmed eucheumatoids are the top aquaculture commodity in the Philippines, contributing more than 60% of total national aquaculture production by volume. Despite significant production losses observed in recent years due to pests and diseases, data relating to the temporal and spatial geographic distribution, seasonality, prevalence, and etiology of these critical problems at the farm level are lacking. Here, we assessed the prevalence of pests and diseases at 16 farm sites within several major seaweed growing areas, including Luzon (Palawan), Visayas (Bohol), and Mindanao (Zamboanga City, Davao del Norte, and Tawi-Tawi). Prevalence of pests and diseases were recorded by assessment of individual seaweed plants in situ, comprising ≥5% of the total number of seaweed plants on each farm. Results from this survey revealed “ice-ice” disease (IID) at all sites, albeit at low prevalence rates of below 25%, the exception being one site where prevalence was 100%. No significant difference in the prevalence of IID was found between farms in shallow (≈0.5 m during low tide) and deep water sites (depths exceeding 4 m during the lowest tide) (p>0.05). Moderate prevalence (26–50%) of the macro-epiphyte pests Sargassum and Ulva was reported in Luzon. Further, epiphytic filamentous algae (EFA), black spots, and evidence of grazing were recorded in several farms with low prevalence (0.2–11.2%). The three farms with the highest prevalence of IID and EFA were evaluated to determine the severity of cover on the thallus of infected plants. A very high severity of IID (76–100% coverage) was observed on the secondary and primary branches, while for EFA, low severity (≤25%) was found in all regions of the thallus. Our results suggest the widespread occurrence of yield-limiting diseases and pests affecting eucheumatoid farms in the Philippines. Strategies for the diagnosis, surveillance, and management of yield-limiting pests and diseases are needed to ensure maintenance and sustainable expansion of this important aquaculture sector in the Philippines.

The study was conducted to compare four different culture containers [cage, recycled oil container, tray (control), and tube] in the nursery and grow-out culture of the abalone Haliotis asinina on a reef flat. For nursery culture, early juvenile abalone with mean shell length (SL) of 1.30 ± 0.006 cm and mean body weight (BW) of 0.45 ± 0.007 g were stocked in the containers at 100 ind m−2 and reared until they attained the 3 cm SL size required for grow-out culture in three of the four culture containers. For grow-out culture, juvenile abalone harvested from nursery culture with mean SL of 3.23 ± 0.018 cm and mean BW of 7.33 ± 0.131 g were stocked in the containers at 50 ind m−2 and reared until they were harvestable at 5 cm SL cocktail size in three of the four culture containers. The 3 cm SL grow-out size was attained at 90 days of culture (DOC) in recycled containers, trays, and tubes, while the 5 cm SL cocktail size at 180 DOC in the same containers. Abalone reared in tubes had the highest mean SL after 90 DOC in nursery culture (3.21 cm), while those in trays after 180 DOC in grow-out culture (5.30 cm). However, at the end of the nursery and grow-out culture, there were no significant differences in mean SL among the abalone reared in these three culture containers. In both culture phases, abalone reared in cages had the lowest mean SL, 2.88 and 4.44 cm, respectively. Survival was highest in trays (98.64%) during nursery culture and in tubes (96.57%) during grow-out culture. With comparable results in recycled containers, trays, and tubes for both growth and survival at the nursery and grow-out phases, tubes are recommended for use when culture is to be done on reef flats. Tubes are the most stable and durable among the four culture containers tested. They can withstand strong winds and waves and may be reused for several culture runs.