BACKGROUND AND OBJECTIVES: Choosing a location for Mariculture is very important because it affects water quality, while problems that affect cultivation and the environment can be avoided by choosing the right location. The objective of this study is to develop a methodological strategy for integrating and analyzing spatial data, which will facilitate the identification of optimal locations for Mariculture. In this context, the ecosystem approach to Mariculture is analyzed with an emphasis on evaluating water quality conditions and determining primary productivity values.METHODS: Water quality parameter data was analyzed using principal component analysis, values, and distribution of primary productivity using the kriging interpolation method using geographic information system. Spatial analysis employing Geographic Information System applications is used to evaluate the appropriateness of locations for Mariculture.FINDINGS: The distribution pattern of primary productivity is strongly influenced by the distribution of phytoplankton and the highest concentration values are located in coastal waters and small islands. The analysis identified three primary components that account for 79.64 percent of the results. The most influential factors include suspended particulate matters, nitrate, temperature, salinity, ammonia, current, and water transparency. According to the study results, the principal component values indicate that the most affected regions by pollutant pressure are agricultural lands that drain into rivers and watersheds, along with coastal residential neighborhoods.CONCLUSION: The status of water quality is the main limiting factor in determining the location of Mariculture, therefore it is necessary to relocate existing Mariculture, improve agricultural cultivation techniques, and/or regulate the use of pesticides that not carried out during the rainy season. These findings may assist the appropriate authorities in the selection and oversight of Mariculture sites. The innovative aspect of this study lies in its focus on adaptive management of sustainable marine cultivation, designed to align with regional conditions and promote ecological health alongside the socio-economic prosperity of local communities.

An investigative field survey was performed from October to November 2023 at nine villages within five districts in four selected regions, aimed to assess the status, challenges, and future perspectives of coastal Mariculture development along the coastline in Mainland Tanzania. During this study, both purposive and snowball sampling techniques were used. A structured questionnaire forms were used as an assessment tool to gather fish farmers’s information, followed by a focussed group discussion and key informants’ interviews with government officials. A total of 162 fish farmers, government officials and animal feed sellers were assessed. Demographic data indicated that most farmers were male accounting for 67.9% and females (32.5), aged between between 20 and 40 years old (56.8%), with primary education level, accounted for 82.7%. On the other hand, milkfish were mostly stocked at 2-3 fish/m2 in an earthen pond system, and under monoculture were mostly fed local feed ingredients (88%). The study showed that three major income-generating activities: Milkfish (85%), crab fattening (12%), tilapia (2%), and sea cucumber (1%) were practiced along the coast to support blue economy initiatives. Additionally, the results indicated that government subsidies (89), farm inputs (81%), and capital investment were the major challenges that constrained milkfish development along the coastline of mainland Tanzania. Further, current data indicated that milkfish farming is solely practiced at the subsistence level and needs a scale-up to sustain the blue economy. The present study highlighted the status, challenges, and plan for the future development of coastal Mariculture in Tanzania.

Viral Nervous Necrosis (VNN) also known as Viral Encephalopathy and Retinopathy (VER), is a hazardous and devastating disease of many species of cultured and marine fish worldwide. It is caused by Betanodaviruses, a serious concern especially in larvae and juvenile fish. This virus infects most of the cultured fish causing severe mortality. Our current review focuses chiefly on recent studies performed on VNN disease. Recent outbreaks have been reported in China, Indonesia, Singapore and India, affecting the Mariculture and aquaculture industries. It has also led to the dramatical decline of mullet stocks in the Caspian Sea. The four main genotypes of Betanodaviruses were found in all continents except South America. The economic loss due to the virus is mainly due to mortality and spread of infection both vertically and horizontally. More research and epidemiological surveys should be conducted, especially in critical areas, where Mariculture farms are planned to be established. Therefore, finding new rapid diagnostic tools, monitoring and surveillance programs, and effective vaccines, for the control, prevention and eradication of this disease should be considered globally.

Using Mariculture data from China’ s nine coastal provinces from 2003 to 2015, this paper first evaluates the technical efficiency through data envelopment analysis (DEA). Then, this paper analyses the spatial spillover effect of technical efficiency and its influencing factors with a spatial panel Durbin model (SDM). The results indicate that there are obvious regional differences in the technical efficiency of China’ s Mariculture, and there is a great room for improvements in the technical efficiency of most areas. The results evidence a significant positive spatial correlation in the technical efficiency of China's Mariculture. The technology promotion factor is beneficial for improving technical efficiency, and at the same time, this factor can produce a positive spatial spillover effect on the surrounding areas. The level of economic development clearly has a positive effect on the technical efficiency of the region, and the surrounding area has a negative spatial spillover effect. Moreover, the labor input has a negative effect on technology efficiency. The negative impact of the degree of disaster on technical efficiency is not significant.

The growing demands for nanotechnology in recent years have resulted in the environmental release of nanomaterials. The aim of the present study was to synthesize graphene oxide-based nanoparticles using an aqueous extract of green macroalgae and evaluate their toxicity against Chaetoceros muelleri microalgae as an important live feed in Mariculture. In a laboratory study, first, the biosynthesis process of graphene nanoparticles was performed using the aqueous extract of the green alga Ulva flexuosa and then the anti-algae activity was evaluated and the content of photosynthetic pigments and microalgae protein was determined. The results of characterization analyses of graphene oxide reduction with the aqueous extract of the green alga U. flexuosa and its conversion to graphene were confirmed. Evaluation of the anti-algae activity of the studied samples showed that the reduced graphene oxide has a higher anti-algae activity than graphene oxide. The results also showed that with increasing the concentration of synthesized nanoparticles, the content of photosynthetic pigments and proteins decreased. The toxic effects of the released nanoparticles can damage the stocks of C. muelleri as an important live feed in Mariculture.