40 JUNE 2024 • WORLD AQUACULTURE • WWW.WAS.ORG salinity and pattern. Two different salts were used to create dilutions to evaluate which combinations created the best brown algae cultures. This algal strain tolerated a wide range of salinity in phototrophy, but 35 pptsalinity was optimal for algal growth in mixotrophy (Alkhamis 2013). Different salt mixes were evaluated with constant salinity at 35 ppt. Methods This study examined the success of culturing Isochrysis sp. using two commercial sea salt mixes. Isochrysis cultures were grown in 10,000 mL glass beakers using standard algal culture techniques and algal density microscopy. This process includes using a microscope to measure the Isochrysis sp. cells (Figure 2) and using a formula to calculate the volume. This is then calculated to the entire flask using cell density = e {[ln (absorbance_684) +16.439]/1.0219} (n=130; r2=0.9998). Isochrysis sp. cultures were subject to 2 different salt mixes, Instant Ocean®1. Other materials included a large light, a pump, tubes, pipettes, 1800 mL flasks, and a Carolina sample. A hemocytometer and a glass slide were used to place the samples onto a microscope. A counter was then used to help keep track of counting. Isochrysis sp. is a single-celled brown algae and a primary producer in oceanic ecosystems. Brown algae and brown seaweeds are the most dominant organisms in many of the world’s coastal regions (Cock 2011). As aquaculture becomes more commonly understood, the complexity of recreating an oceanic environment is also more widely known. Some sort of food chain is needed for successful cultures, and primary producers or their energy is used to help with this process. Algae, being a primary producer, is a perfect option for this necessity. Larval-staged organisms are most commonly fed algae, which provides a nutritious food source. Algae help with the survival and growth of many marine organisms, which is vital for the aquaculture industry. At The College of the Florida Keys’ (CFK) aquaculture lab, green algae are grown at a constant level to keep up with fish production. However, we miss out on key nutrients and energy that can be harnessed by not adding brown algae to larval diets. Although it is so abundant in the ocean our prior attempts to culture brown algae failed. In this project, the goal was to develop a brand-new culture of Isochrysis sp. at the CFK Aquaculture Lab. Starter populations were ordered and culture activities began once they were delivered (Figure 1). When the algal began reproducing, I observed the An Isochrysis Crisis Tiffany Clavijo FIGURE 1. A successful Isochrysis glabana culture including its light source and airflow. FIGURE 2. Isochrysis galbana on a hemocytometer slide under a microscope. The grid of the slide is shown, as well as algal cells that can resemble small oil globules.
RkJQdWJsaXNoZXIy MjExNDY=