Investigate Behavioral Responses to Bioluminescence

Bioluminescence is the production of light by living organisms, commonly found in marine ecosystems. It occurs in various organisms such as fish, jellyfish, and crustaceans, particularly in the deep or polar sea where sunlight is scarce. The chemical reaction involves an enzyme (luciferase) and a light-emitting molecule (luciferin), which can vary among species. Most marine organisms emit light in the blue-green spectrum due to the properties of seawater. Bioluminescence plays a significant role in communication, predator-prey interactions, and the flow of energy in marine food webs. In the Arctic marine environments, especially during the polar night, bioluminescence is the primary source of light. The role of bioluminescence in interactions among Arctic species is therefore of particular interest. Studying behavioral responses to bioluminescence will contribute to enhancing our understanding of the ecological role of bioluminescence in marine ecosystems. Light responses of several zooplankton species representing diverse taxa were tested by conducting behavioral experiments in Kings Bay Marine Laboratory in Svalbard in January 2023, during the polar night. For some of these taxa further experiments with artificial light stimuli mimicking bioluminescent flashes were conducted in Trondheim. Plankton samples were collected from the study locations using nets, with species selected based on accessibility, ease of handling, and ecological significance. Artificial bioluminescent stimuli were created using LEDs, mimicking the duration, and wavelength of bioluminescent flashes of three different species. Behavioral experiments were conducted to assess the visual capabilities of target species through exposure to various light stimuli, and to figure out how bioluminescent and non-bioluminescent animals react to bioluminescence. The experimental setup included an aquarium tank equipped with controlled lighting, a camera, and infrared illumination for recording in darkness. Video recordings were analyzed to quantify behaviors such as swimming speed and proximity to the light source.