Integrated multitrophic aquaculture (IMTA) as an environmentally friendly system for sustainable aquaculture: functionality, species, and application of biofloc technology (BFT)

Ocean warming and increased salinity threaten Bostrychia (Rhodophyta) species from genetically divergent populations.

In this review, it is discussed the prominent effect generated from aquaculture wastewater considered as the major water polluting crisis in the entire world. The cause rose due to intense development and improvement in aquaculture by the aquatic habitat species triggering quite a challenge in the environment. Scrutinizing this problem, researchers have found a way to tackle it by cultivating algal species in aquaculture wastewater in order to remove its high content of organic and inorganic pollutants. The theory proves wastewater serves as a nutrient source for algal growth and development such as phosphorous, nitrogen, and other trace elements. Besides harvesting the algal biomass from aquaculture wastewater, the extraction of lipid is also processed for biofuel production. Hence, the discussion includes conversion of wastewater into organic and inorganic pollutant-free water with low cost-effective method via algal cultivation in wastewater and high lipid yield for biofuel with a carbon-free and sustainable environment.

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Phycoremediation of aquaculture wastewater and algal lipid extraction for fuel conversion

Photobiological and biochemical responses of mangrove-associated red macroalgae Bostrychia calliptera and Bostrychia montagnei to short-term salinity stress related to climate change

With the growth in the number of people searching for ways to improve personal care, the consumer finds the solution in cosmetic products. However, this demand is currently made concomitantly with the demand for products of natural origin, including seaweed. Algae, in their composition, are full of bioactive compounds with several applications. Therefore, their insertion in cosmetics is evidenced in the high number of scientific studies, which makes this natural resource potentially useful for the cosmetic industry. From this, a review was conducted with the aim of highlighting some of these active compounds and the latent applicability and versatility of others. In addition, the best way to add to the production of these substances while staying in alignment with green consumption, the design of biorefineries, and the promising production of macroalgae on a large scale using green technologies was sought.

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Macroalgae Biorefinery for the Cosmetic Industry: Basic Concept, Green Technology, and Safety Guidelines

This study aimed to evaluate the performance of the red alga Gracilariopsis tenuifrons as a biofilter in a multi-trophic cultivation system with Litopenaeus vannamei, using recirculation by zero water exchange. The species were cultivated for 4 weeks, while measurements were taken of the chemical and physical characteristics of water, the development of the cultivated organisms (biomass and growth rate), and the carbon, nitrogen, and phosphorus content assimilated by the seaweeds. The water enrichment produced by shrimp farming favored the seaweed development, which increased on average by 2.6 % day-1 ± 0.24 (0.4 to 4.08 % day-1). The seaweed species was able to remove up to 35.1% of the ammonium ion and increased its tissue nitrogen by about 4.8 times by the end of the experiment (1.2–4.8%). The shrimp presented an increase in biomass (8.0 to 12.7 g), with an average growth rate of 1.7% day-1 ± 0.1 and a survival of 100% at the end of the experiment. Based on these results, the cultivation of L. vannamei in a recirculating water system using Gp. tenuifrons as a biofilter can be an advantageous alternative, helping to reduce water usage and remove the main metabolites produced by shrimp cultivation.

Performance of the agarophyte Gracilariopsis tenuifrons in a multi-trophic aquaculture system with Litopenaeus vannamei using water recirculation

Food source or refuge: What is behind amphipod choices for seaweeds?

Marine herbivores may alter their behavior regarding habitat and food source choice according to the presence or absence of chemical cues from predators. To assess whether an amphipod species can detect and react to different water-soluble cues, individuals of Ampithoe marcuzzii were tested through a 2-current choice flume. Dual-response choice experiments were conducted in which the animals selected water flowing from one of 2 different sources. Comparisons among sources were tested using seawater (control), water with cues from different seaweeds (Dictyopteris delicatula , Gracilaria cervicornis or Gelidium coarctatum) , water with cues from potential predators (Abudefduf saxatilis , Sparisoma sp., Haemulon plumieri , H. aurolineatum and Holocentrus adscensionis) and water mixtures with seaweed and predator cues. The amphipods were able to avoid predator cues and to distinguish and actively choose between the water-soluble cues of different seaweeds. The animals preferred D. delicatula cues over those of G. cervicornis and G. coarctatum . The amphipods also selected more G. cervicornis cues than those of G. coarctatum . When predator cues were mixed with D. delicatula cues, amphipods changed their initial choice for G. cervicornis . However, when predator cues were added to G. cervicornis , the animals maintained their preference for this seaweed’s cues over those of G. coarctatum . Our findings demonstrate that A. marcuzzii exhibits a preference for brown seaweeds that draw fewer predators. The choice of seaweed changes according to predation risk perception based on water-soluble chemical cues. This ability to distinguish water-soluble chemical cues and base their habitat decisions on them is a fundamental adaptive behavior for this group. 

Amphipod choice for seaweeds under predator cues: Should I stay or should I go?

Projecting environmental suitability areas for the seaweed Gracilaria birdiae (Rhodophyta) in Brazil: Implications for the aquaculture pertaining to five environmentally crucial parameters

Marcelle Stephanne Barbosa-Silva

Papers

Performance of the agarophyte Gracilariopsis tenuifrons in a multi-trophic aquaculture system with Litopenaeus vannamei using water recirculation

Ocean warming and increased salinity threaten Bostrychia (Rhodophyta) species from genetically divergent populations.

Food source or refuge: What is behind amphipod choices for seaweeds?

Amphipod choice for seaweeds under predator cues: Should I stay or should I go?

Projecting environmental suitability areas for the seaweed Gracilaria birdiae (Rhodophyta) in Brazil: Implications for the aquaculture pertaining to five environmentally crucial parameters