Despite occupying an area no greater than 8% of the earth’s surface, natural wetland ecosystems fulfill multiple ecological functions: 1. Soil formation and stabilization support, 2. Food, water, and plant biomass supply, 3. Cultural/recreational services, landscape, and ecological tourism, 4. Climate regulation, and 5. Carbon sequestration; with the last one being its most important function. They are subject to direct and indirect incident factors that affect plant productivity and the sequestration of carbon from the soil. Thus, the objective of this review was to identify the incident factors in the loss of area and carbon sequestration in marine, coastal, and continental wetlands that have had an impact on climate change in the last 14 years, globally. The methodology consisted of conducting a literature review in international databases, analyzing a sample of 134 research studies from 37 countries, organized in tables and figures supported by descriptive statistics and content analysis. Global results indicate that agriculture (25%), urbanization (16.8%), aquaculture (10.7%), and industry (7.6%) are incident factors that promote wetlands effective loss affecting continental wetlands more than coastal and marine ones. Regarding carbon sequestration, this is reduced by vegetation loss since GHG emissions raise because the soil is exposed to sun rays, increasing surface temperature and oxidation, and raising organic matter decomposition and the eutrophication phenomenon caused by the previous incident factors that generate wastewater rich in nutrients in their different activities, thus creating biomass and plant growth imbalances, either at the foliage or root levels and altering the accumulation of organic matter and carbon. It is possible to affirm in conclusion that the most affected types of wetlands are: mangroves (25.7%), lagoons (19.11%), and marine waters (11.7%). Furthermore, it was identified that agriculture has a greater incidence in the loss of wetlands, followed by urbanization and industry in a lower percentage.

Aquaculture uses large volumes of water, which is generally discharged without treatment, possibly causing scarcity and contamination. A sustainable aquaculture option is biofloc technology (BFT), which recycles food residues and toxic organic and inorganic compounds from the system through microorganisms, avoiding excessive use of water and serving as natural food for cultured aquatic organisms. The aim of this study was to identify the main factors that limit a Mexican aquaculture producer from adopting biofloc technology in their aquaculture production units (APUs). Strengths and weaknesses were methodologically analyzed through 248 questionnaires, applied to fish farmers in 16 states of the country with a mixed approach (quantitative and qualitative). Findings reveal that the main obstacles in the use of BFT are due to the following: low academic level, limited administrative capacity, scarce technological equipment in facilities, diversified productive activity, and obsolete regulations. Other factors that promote the adoption of BTFs for aquaculturists are production experience, favorable weather conditions, and abundant availability of water and energy. In conclusion, the use of BTF is a sustainable option for APUs despite the limiting factors identified in this research which slow down the growth of the sector. It is advisable to study Mexican producers with BFT, in order to spread their benefits to other APUs, and further evaluate the productivity of the aquaculture sector. This study considers production aspects, and also sustainable use of its resources, specifically, surface, energy, water, and food.

Sustainable development implies the proper use of natural resources, such as water resources, but the environmental, economic, and social benefits should also be considered. In the water sector, for example, sanitation is one of the challenges that arise in rural localities. However, issues related to it may be solved with the use of constructed wetlands (CWs), which may allow the cultivation of ornamental plants with phytoremediation properties. Through a content analysis, the environmental, economic, and social potential of ornamental species used in Mexico for phytoremediation in CWs is documented in this study. The environmental potential of the plants was considered based on their phytoremediation properties. The economic potential was determined from research articles and from the National Agri-Food Information System. The social potential was analyzed considering the ornamental and artisanal use of the plants. In total, 21 species of phytoremediation plants were identified. Anthurium andreanum and Zantedeschia aethiopica stand out for their commercial value, reported in 2018 to be 272,875 and 30,318 USD, respectively, at the national level. The social potential was identified by the ornamental or artisanal use for flower arrangements and weaving. This study reveals that the use of CWs with ornamental vegetation is a sustainable option to clean wastewater, reuse water, and generate economic incentives. Thus, it is essential to provide the community with adequate training for the management of CWs in those sites that lack treatment systems.

Conventional aquaculture (ACUA-C) in Mexico is an activity that maintains an annual growth rate of 6%. Tilapia (Oreochromis niloticus) aquaculture is the predominant aquaculture in the country with 4623 farms, most of which operate with semi-intensive (SIS) and extensive (ES) production systems, discharging untreated wastewater that negatively impacts the environment. To address this problem, new ecotechnologies such as biofloc (BFT), recirculation systems for aquaculture (RAS), constructed wetlands (CWs) for water treatment, and aquaponics (AS) have emerged to mitigate the environmental impacts of untreated wastewater. The objective of this work is to evaluate the feasibility of tilapia farming with BFT, RAS, CW, and AS ecotechnologies through an economic and financial feasibility analysis, considering their environmental and social implications in a Mexican aquaculture farm located in the state of Veracruz. Open interviews, direct observation, and diagnosis of the semi-intensive tilapia system was carried out between 15 May 2019 and 15 February 2020 in order to calculate, design, and theoretically evaluate the four ecotechnological alternatives (TBF, RAS, CW, and AS). Economic (13), environmental (10), and social (5) variables were applied, making use of the same facilities. The results reveal that the four ecotechnologies implemented in an SIS are economically viable and environmentally acceptable, especially in water management, in addition to being socially feasible. It is concluded that BFT offers an alternative to the producer by having a lower additional cost to improve problems, despite the possible complexity of operation and energy requirements to manage wastewater treatment. The technological transition to BFT is recommended to solve the problem of sustainable water management.

The latest FAO report indicates that aquaculture accounts for 51% of the global production volume of fish and seafood. However, despite the continuous growth of this activity, there is evidence of the excessive use of groundwater in its production processes, as well as pollution caused by nutrient discharges into surface waters due to the water exchange required to maintain water quality in fishponds. Given this context, the objectives of this study were as follows: (1) to review which emergent and floating plant species are used in constructed wetlands (CWs) for the bioremediation of aquaculture wastewater; (2) to identify the aquaculture species whose wastewater has been treated with CW systems; and (3) to examine the integration of CWs with recirculating aquaculture systems (RASs) for water reuse. A systematic literature review was conducted, selecting 70 scientific articles published between 2003 and 2023. The results show that the most used plant species in CW systems were Phragmites australis, Typha latifolia, Canna indica, Eichhornia crassipes, and Arundo donax, out of a total of 43 identified species. These plants treated wastewater generated by 25 aquaculture species, including Oreochromis niloticus, Litopenaeus vannamei, Ictalurus punctatus, Clarias gariepinus, Tachysurus fulvidraco, and Cyprinus carpio, However, only 40% of the reviewed studies addressed aspects related to the incorporation of RAS elements in their designs. In conclusion, the use of plants for wastewater treatment in CW systems is feasible; however, its application remains largely at the experimental scale. Evidence indicates that there are limited real-scale applications and few studies focused on the reuse of treated water for agricultural purposes. This highlights the need for future research aimed at production systems that integrate circular economy principles in this sector, through RAS–CW systems. Additionally, there is a wide variety of plant species that remain unexplored for these purposes.