Coral Reef Surveillance: Infrared-Sensitive Video Surveillance Technology as a New Tool for Diurnal and Nocturnal Long-Term Field Observations

Abstract

Direct field observations of fine-scaled biological processes and interactions of the benthic community of corals and associated reef organisms (e.g., feeding, reproduction, mutualistic or agonistic behavior, behavioral responses to changing abiotic factors) usually involve a disturbing intervention. Modern digital camcorders (without inflexible land-or ship-based cable connection) such as the GoPro camera enable undisturbed and unmanned, stationary close-up observations. Such observations, however, are also very time-limited (~3 h) and full 24 h-recordings throughout day and night, including nocturnal observations without artificial daylight illumination, are not possible. Herein we introduce the application of modern standard video surveillance technology with the main objective of providing a tool for monitoring coral reef or other sessile and mobile organisms for periods of 24 h and longer. This system includes nocturnal close-up observations with miniature infrared (IR)-sensitive cameras and separate high-power IR-LEDs. Integrating this easy-to-set up and portable remote-sensing equipment into coral reef research is expected to significantly advance our understanding of fine-scaled biotic processes on coral reefs. Rare events and long-lasting processes can easily be recorded, in situ-experiments can be monitored live on land, and nocturnal IR-observations reveal undisturbed behavior. The options and equipment choices in IR-sensitive surveillance technology are numerous and subject to a steadily increasing technical supply and quality at decreasing prices. Accompanied by short video examples, this report introduces a radio-transmission system for simultaneous recordings and real-time monitoring of multiple cameras with synchronized timestamps, and a surface-independent underwater-recording system.

Detecting Native Freshwater Fishes Using Novel Non-invasive Methods

“…To capture the whole community, both diurnal and nocturnal fishing, using visual observation methods, night-time sampling would be required. Ellender et al (2018) performed night snorkeling with a strong dive flashlight to observe the behavior of native eels, and other studies have used infrared cameras or light attachments on cameras for nocturnal-fish studies (Bassett and Montgomery, 2011;Dirnwoeber et al, 2012;Harvey et al, 2012). Night sampling would require additional personnel hours and extra safety precautions.…”

Hydrokinetic Turbine Effects on Fish Swimming Behaviour

“…Fish assemblage composition and spatial distribution of fish differ between night and day, and many of the species in this study are strictly diurnal [ 56 ]. Hence studies under dark conditions, and with adapted equipment [ 57 ], should be performed.…”

Quantifying the Foodscape for Stream‐Dwelling Cutthroat Trout Reveals Spatial and Temporal Ranges of Resource Exploitation and Energy Intake

“…To make nighttime observations, we used eight LED infrared lights (12 W, wavelength = 850 nm) powered by a 12 V battery and controlled with a programmable switch. Salmonid fishes, as well as invertebrates, are unable to see the infrared spectrum, making this method a suitable study tool to sample behavior during nighttime and low-light conditions (Heise 1992;Dirnwoeber et al 2012). We attached a HOBO Pendant Temperature/Light 8 K data logger (Onset, Cape Cod, Massachusetts) on the camera mount to record light and water temperature in the foraging area.…”