Seaweeds account for nearly 30% of global aquaculture production by volume, and their cultivation provides important opportunities for employment and wealth generation, particularly in rural coastal communities. Eucheumatoids (Kappaphycus and Eucheuma spp.) are tropical red algae commercially cultivated as raw material for production of carrageenans, particularly in South-East Asia and the Western Indian Ocean region. Diseases and pests are major limiting factors in eucheumatoid production, particularly a condition known as ‘ice-ice’ disease (IID). IID is characterized by bleaching of the thallus followed by the disintegration of affected tissues, leading to a loss of biomass and reduced carrageenan yield. IID has been associated with unfavourable changes in environmental conditions, particularly an increase in sea water temperature and a decrease in salinity, and infection by opportunistic or pathogenic bacteria. However, given that no single or combined causal agents have been definitely identified, IID may be considered a complex pathobiotic syndrome in which multiple factors contribute to the development of disease signs. Here, we review current knowledge of the abiotic and biotic factors associated with the development of IID, and the strategies employed to mitigate economic losses resulting from disease outbreaks. We discuss syndromic diseases in other marine holobionts, particularly other red algae and corals, in relation to their similarity to IID, and suggest the application of comprehensive and complementary methodologies, including high-throughput sequencing and high-quality microscopy, for enhancing our understanding of the pathological and microbiological processes associated with IID signs.

This paper reports the first use of thin flakes (310–315 μm thick) formulated diets as feed for the abalone Haliotis asinina. The study compared noodles and flakes prepared using refined and unrefined diets developed earlier for H. asinina (Bautista-Teruel et al., J. Shellfish Res., 35, 2016, 633). Four treatment diets in triplicates (refined flakes, MBTr-F; refined noodles, MBTr-N; unrefined flakes, MBTur-F; and unrefined noodles, MBTur-N) were used in a feeding experiment conducted in a tank facility. After three months, abalone fed MBTr-F had significantly higher mean shell length and body weight (35.92 ± 0.36 mm, 9.24 ± 0.29 g) compared with those fed MBTr-N (34.63 ± 0.37 mm, 8.22 ± 0.28 g) and MBTur-N (34.23 ± 0.36 mm, 7.66 ± 0.26 g), but did not significantly differ with those fed MBTur-F (35.40 ± 0.30 mm, 8.57 ± 0.24 g). Likewise, abalone fed MBTr-F had significantly higher mean growth rates (5.31 ± 0.08 mm, 2.59 ± 0.06 g/month), compared with those fed MBTr-N (4.90 ± 0.19 mm, 2.26 ± 0.12 g/month) and MBTur-N (4.71 ± 0.02 mm, 2.07 ± 0.06 g/month), but did not significantly differ with those fed MBTur-F (5.11 ± 0.06 mm, 2.37 ± 0.04 g/month). Survival (96.67–98.89%) and FCR (2.2–2.5) did not significantly differ among treatment diets. Between the flaked diets, MBTur-F is the cheaper option. However, the use of this unrefined diet resulted in distinct turquoise abalone shell colour, not observed in those fed MBTr-F.

COVID-19 pandemic is devastating the health, social, and economic well-being of citizens worldwide. The high rates of morbidity and mortality and the absence of vaccines cause fear among the people regardless of age, gender, or social status. People's fear is heightened by misinformation spread across all media types, especially on social media. Filipino college students are one of the top Internet users worldwide and are very active in social media. Hence they are very prone to misinformation. This paper aims to ascertain the levels of knowledge, precaution, and fear of COVID-19 of the college students in Iloilo, Philippines, and determine the effects of their information-seeking behavior on the variables above. This paper is a cross-sectional survey that used a qualitative-quantitative method and snowball sampling technique. Data were gathered among 228 college students using an online survey instrument a few months after the pandemic began. College students were knowledgeable of the basic facts about the highly infectious COVID-19. However, the majority were inclined to believe the myths and misinformation regarding the pandemic. Television was the primary, most believable, and preferred source when seeking information. The Internet as a preferred source of information was significantly associated with a high level of knowledge. In contrast, the information sourced from interpersonal channels were found to make college students very cautious. The local presence of COVID-19 cases had caused college students to fear, likely exacerbated by the plethora of information about the pandemic, mostly from Facebook. This is the first study conducted on the effects of the information-seeking behavior on the levels of knowledge, precaution, and fear of COVID-19 of the college students in Iloilo, Philippines.

Growth and survival of the slipper oyster Crassostrea iredalei using traditional (tires and oyster shells) and new methods (pouches and trays) suspended from floating rafts were compared. After six months of grow-out culture, mean shell length (mm SL) and body weight (g BW) of oysters were significantly highest in those reared in pouches (89.32 ± 0.41 mm SL, 87.70 ± 0.70 g BW), followed by those in trays (83.16 ± 0.31 mm SL, 87.06 ± 0.72 g BW), then those harvested from oyster shells (76.42 ± 0.88 mm SL, 67.35 ± 1.03 g BW), and lastly from tires (72.30 ± 1.21 mm SL, 55.07 ± 1.49 g BW). Growth rates both for length and weight were almost comparable between oysters reared in pouches (6.05 ± 1.28 mm mo⁻¹, 10.98 ± 2.05 g mo⁻¹) and trays (5.01 ± 1.46 mm mo⁻¹, 10.77 ± 2.58 g mo⁻¹). Although 60.7% of the oysters harvested from pouches (n = 1071) were classified as large (85–100 mm SL) and jumbo (100–120 mm SL) and only 39.5% of those from trays (n = 1048), their meat yield did not significantly differ (pouches = 22.60 ± 0.86%; trays = 24.76 ± 0.93%). Survival in pouches (95.2 ± 0.77%) and trays (93.15 ± 2.10%) was almost parallel at harvest. Growing oysters using the new methods produced single, larger, meatier oysters of almost the same size at a shorter culture duration.

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.

The COVID-19 outbreak situation brought into focus not only the safety but also the mental wellbeing of nursing students. At present, the level of fear of COVID-19 and associated factors among nursing students in the Philippines is not well understood. This cross-sectional online survey determined the relationship between Internet use and eHealth literacy with fear of COVID-19. One thousand three hundred and sixty-seven (n=1,367) answered an online survey using the adopted eHealth Literacy Scale (eHEALS), and Fear of COVID-19 Scale (FCV-19S) administered from May 1 to 15, 2020. Descriptive statistics, tests for differences, and correlational analysis were performed. Results indicated that the composite score of the FCV-19S was 3.65, indicating moderate to high levels of fear. Fear of COVID-19 significantly differed based on sex, year level, and location. A significant inverse relationship was found between the average daily use of the Internet and fear of COVID-19. On the other hand, no significant association was noted between eHealth literacy and fear of COVID-19. The first wave of the COVID-19 outbreak has resulted in a far-reaching impact on nursing students' psychological wellbeing. This study highlights the value of the Internet and its use during the outbreak may not always lead to higher fear related to COVID-19. Nursing schools may need to create strategies to promote regulated and responsible Internet use, address students' mental health concerns and develop interventions to respond proactively to mitigate or reduce fear among nursing students during the pandemic.

Hatchery production of the tropical sea cucumber Holothuria scabra or sandfish has been successfully demonstrated in various countries, especially during the past decade. However, the main bottleneck in up-scaling production of larger sandfish juveniles is in the nursery phase where land-based facilities are limited in the Philippines compared to other countries. This has led to some promising pioneering research in ocean-based sandfish nurseries in the Philippines. However, site-specific and seasonal inconsistencies in production levels were observed. In this study, a comprehensive experiment comparing 17 replicated nursery culture operations of sandfish juveniles using floating hapas, was conducted across four sites with distinct geo-climatic zones in the Philippines and at different months from 2013 to 2016. We evaluated the performance of the ocean-based floating hapa nursery system by determining the effects of periphyton characteristics and broad-scale differences in meteorological variables to growth and survival of juvenile sandfish within different geo-climatic zones. Our data confirmed high spatial (across site) and temporal (among trials within site) variability in sandfish culture performances. Wind stress was the most significant driver of this variation, which negatively influenced growth and survival of juveniles especially during Cycle 1 (first 30 d). Sandfish growth was positively related to Chl-a and mean temperature, but was negatively impacted by Wind stress, Autotropic Index (AI), total rainfall (∑Rain), and sea-surface atmospheric pressure; while survival was positively affected by phaeophytin and Ash-Free Dry Weight (AFDW) content of the hapa biofilm. In Cycle 2 (succeeding 31–60 d), growth and survival was greatly influenced negatively by the re-stocked density (number of individuals surviving from Cycle 1), while survival was further affected negatively by ∑Rain and AFDW. Our results provide significant information on suitable ocean nursery conditions, periphyton/biofilm characteristics, and spatial-temporal considerations for optimizing production of H. scabra juveniles in floating hapas. We also highlight the negative effects of increasing biomass density when on-growing larger juveniles in this system. These insights are valuable in optimizing management and operation of ocean nurseries for sandfish, not only in various potential sites in the Philippines, but also in many developing tropical countries in the Indo-Pacific.

Seaweed cultivation is the fastest‐growing aquaculture sector, with a demonstrable potential to drive development in some of the poorest coastal populations worldwide. However, sustainable exploitation, fair access and equitable benefits from marine genetic resources, such as seaweeds have yet to be fully realised. Patchy fundamental knowledge on the genetic diversity and metabolic potential of algae limits their exploitation; scant practical skills and low investment in breeding restricts germplasm availability and the Nagoya protocol has only partially remediated insufficient governance. Further developments and the addressing of knowledge gaps in relation to biosecurity, breeders’ rights and conservation of genetic resources are needed for progress.

An innovative microalgae harvesting technique was carried out under various anode/cathode (2/2, 4/4 and 6/6) configuration and at different voltage treatment (3, 6 and 10 V) to efficiently electroflocculate Chaetoceros calcitrans. This study was conducted to determine the optimal configuration of electrode units (Pb and Al) and voltage settings that could improve the quality of harvested paste in terms of nutritional value and metal contamination for its later use in aquaculture. The use of 6/6 electrodes achieved the shortest harvest time of 48 ± 1 min and the lowest Pb content (83.7 ± 0.3 ppm). In terms of voltage treatment, harvest time was inversely proportional to the voltage used. However, Pb content was significantly lowest in the paste produced using 3 V (41.78 ± 0.12 ppm), when compared to those harvested under 6 V (304.35 ± 0.79 ppm) and 10 V (343.90 ± 0.91 ppm) treatment. Likewise, Pb residues in the resulting effluent are also lowest (0.245 ± 0 ppm) with 3 V treatments. C. calcitrans paste can be resuspended ≤6 months but with a lag phase of 3–4 days for use as starter culture. A 97% reduction in Pb content of C. calcitrans paste and 77% reduction in Pb content were obtained in Artemia (7.8%) fed C. calcitrans paste.

The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation, are having major impacts on diverse sectors of society. Notably, these impacts are occurring in the context of other anthropogenic-driven threats including global climate change. Both anthropogenic stressors and the COVID-19 pandemic represent significant economic challenges to aquaculture systems across the globe, threatening the supply chain of one of the most important sources of animal protein, with potential disproportionate impacts on vulnerable communities. A web survey was conducted in 47 countries in the midst of the COVID-19 pandemic to assess how aquaculture activities have been affected by the pandemic, and to explore how these impacts compare to those from climate change. A positive correlation between the effects of the two categories of drivers was detected, but analysis suggests that the pandemic and the anthropogenic stressors affect different parts of the supply chain. The immediate measurable reported losses varied with aquaculture typology (land vs. marine, and intensive vs. extensive). A comparably lower impact on farmers reporting the use of integrated multitrophic aquaculture (IMTA) methods suggests that IMTA might enhance resilience to multiple stressors by providing different market options under the COVID-19 pandemic. Results emphasize the importance of assessing detrimental effects of COVID-19 under a multiple stressor lens, focusing on areas that have already locally experienced economic loss due to anthropogenic stressors in the last decade. Holistic policies that simultaneously address other ongoing anthropogenic stressors, rather than focusing solely on the acute impacts of COVID-19, are needed to maximize the long-term resilience of the aquaculture sector.