Eco-efficiency assessment of shrimp aquaculture production in Mexico

Globally, human society faces the challenge of providing food to a growing population, at the same time that the effects of climate change and resource depletion must be addressed. Aquaculture allows to ensure a safe supply of different marine species and is a major technological and biological undertaking. Taking into account that in Sonora (Mexico), there are more than 200 aquaculture plants, the analysis of this sector implies a joint and harmonized assessment, considering not only life cycle assessment (LCA), but also data envelopment analysis (DEA). This study focuses on the application of LCA + DEA methodology to assess the ecoefficiency of 38 semi-intensive shrimp farms located in the state of Sonora. LCA results showed that feed management and electricity consumption are the main critical points in almost all the impact categories. Further improvement actions were evaluated, the replacement of wheat meal for Dried Distiller Grains with Solubles (DDGS) resulted in environmental impact reductions ranged from 2% to 57%, depending on the impact category. On the other hand, the installation of photovoltaic panels in the area was evaluated, looking for a shift towards a less carbon-intensive energy production. Overall, the implementation of these improvement measures will contribute to increased environmental protection and resource efficiencyThis research was supported by the Comité de Sanidad Acuícola del Estado de Sonora (COSAES). A. Cortés, C. Cambeses Franco, G. Feijoo and M.T. Moreira belong to CRETUS and the Galician Competitive Research Group GRC (ED431C 2017/29), co-founded by Xunta de Galicia and FEDER (EU)S

Silencing Pacific white shrimp Litopenaeus vannamei LvRab7 reduces mortality in brooders challenged with white spot syndrome virus

White spot syndrome virus (WSSV) is a major threat for farmed shrimp worldwide. RNA interference (RNAi) is the most recent tool against viral diseases. Rab7 silencing effectively inhibited virus infections in juvenile shrimp, but the antiviral effect in brooders remains unknown. This study found a homologue Penaeus monodon Rab7 gene in Litopenaeus vannamei brooders from Mexico. Sequence identity was >99% to a Thai LvRab7 sequence and >94% to Rab7 sequences from P. monodon or Marsupenaeus japonicus. Animals treated with a partial (494 bp) or a complete (618 bp) LvRab7 dsRNA sequences and challenged 48 h post treatment (hpt) with a high WSSV dose showed 80–88% mortality respectively. Shrimp treated with 4 or 20 μg LvRab7 dsRNA and challenged with a WSSV high dose had 80% mortality each, but it was reduced to 33% and 40%, respectively, with a low dose. Efficacy of dsRNA to reduce shrimp mortality was dependent on virus dose used regardless of dsRNA concentration. A significant reduction in LvRab7 mRNA levels was observed at 120 hpt. In conclusion, silencing LvRab7 in brooders showed a mild antiviral effect against a WSSV challenge at 48 h

The endemic region and infection regimes of the White Spot Syndrome virus (WSSV) in shrimp farms in northwestern México

Shrimp farming with a value annually of US$711 million approximately, is one of the most important primary activities in Mexico. However, shrimp farming has had to face various problems that have limited their development, within which the mortality caused by the white spot syndrome virus (WSSV) is the most important. To have scientific elements to focus on preventive health management actions is necessary to know, among other factors, aspects of the epidemiologyof white spot disease (WSD). Therefore this study focused on delimiting the endemic region for WSD and its temporal regimes of infection and discusses possible risk factors related to outbreaks of the disease in shrimp farms of northwestern Mexico. We analyzed information from the databases of the State Committees of Aquaculture Health of Baja California Sur, Sonora, Sinaloa and Nayarit, as well as data of Integrated Program on Shrimp Aquaculture Health (PISA 2007-2008) and the Strategic Alliance Network Aquaculture Industry Innovation (AERI-2008). Data analysis showed that, for the shrimp production cycles of 2007-2008, white spot syndrome virus (WSSV) was endemic to the region of Tuxpan, Nayarit in the south and to Agiabampo, Sonora in the north. Spring outbreaks of WSD in the fishfarms had a spatiotemporal distribution, indicating three infections regimes: (1) March-April in the southern shrimpfarming region (Local Aquaculture Health Boards [LAHBs] of Mazatlan, El Rosario, Escuinapa, Tecuala, and Tuxpan); 2) April-May in the central region (LAHBs of Navolato Norte, Navolato Sur, and El dorado); and (3) May-June in the northern region (LAHBs of Agiabampo-Sonora, Ahome, Guasave Norte and Sur). The WSD were consistent between 2007 and 2008, with slight variations among some LAHBs, with respect to the onset or presence of spring WSD outbreaks. It shows the association of infection regimes throughout the region endemic with the location of Mazatlan,Pescadero and Farallon oceanographic basins according to the increasing differential temperature within them, which may be a determinant factor for the presence of WSD outbreaks

<i>Salpianthus macrodontus</i> Extracts, a Novel Source of Phenolic Compounds with Antibacterial Activity against Potentially Pathogenic Bacteria Isolated from White Shrimp

This study aimed to evaluate the antibacterial activity in vitro of Salpianthus macrodontus and Azadirachta indica extracts against potentially pathogenic bacteria for Pacific white shrimp. Furthermore, the extracts with higher inhibitory activity were analyzed to identify compounds responsible for bacterial inhibition and evaluate their effect on motility and biofilm formation. S. macrodontus and A. indica extracts were prepared using methanol, acetone, and hexane by ultrasound. The minimum inhibitory concentration (MIC) of the extracts was determined against Vibrio parahaemolyticus, V. harveyi, Photobacterium damselae and P. leiognathi. The polyphenol profile of those extracts showing the highest bacterial inhibition were determined. Besides, the bacterial swimming and swarming motility and biofilm formation were determined. The highest inhibitory activity against the four pathogens was found with the acetonic extract of S. macrodontus leaf (MIC of 50 mg/mL for Vibrio spp. and 25 mg/mL for Photobacterium spp.) and the methanol extract of S. macrodontus flower (MIC of 50 mg/mL for all pathogens tested). Both extracts affected the swarming and swimming motility and the biofilm formation of the tested bacteria. The main phenolic compounds related to Vibrio bacteria inhibition were naringin, vanillic acid, and rosmarinic acid, whilst hesperidin, kaempferol pentosyl-rutinoside, and rhamnetin were related to Photobacterium bacteria inhibition