Satellite and remote sensing technologies
Satellite tags: Attached to marine animals like sea turtles, sharks, and whales, these tags transmit data on animal movements, migration patterns, and diving behavior to orbiting satellites. This helps researchers correlate animal behavior with large-scale environmental features like currents, temperature, and eddies.
Satellite remote sensing: This technique allows scientists to observe vast expanses of the ocean from space. Instruments on satellites measure various parameters, including:
Sea surface temperature: Provides insights into ocean circulation patterns, climate changes, and how they impact marine species.
Ocean color: Measures the concentration of chlorophyll, an indicator of phytoplankton abundance, to assess ocean productivity and track harmful algal blooms.
Sea level change: Uses radar altimeters to measure long-term changes in sea level with high accuracy.
Acoustic technologies
Acoustic telemetry: Scientists tag individual marine animals with acoustic transmitters that emit unique high-frequency pulses. An array of underwater receivers detects these pulses, allowing researchers to track the movements of species like sharks, rays, and fish, especially those that do not frequently surface.
Passive acoustic monitoring: Hydrophones are deployed to listen to the ocean's soundscape and record the vocalizations of marine mammals, fish, and other sound-producing organisms. This helps researchers monitor species over long periods, study behavior, and assess the impact of human-made noise pollution.
Active acoustics (sonar): By sending out sound waves and analyzing their echoes, scientists can create detailed maps of the seafloor (multibeam sonar) and estimate the density and location of fish schools or plankton swarms.
Genomic and molecular technologies
Environmental DNA (eDNA): As marine organisms move through the water, they shed genetic material in the form of scales, mucus, and feces. By collecting and filtering water samples, marine biologists can analyze eDNA to detect species present in an area without direct observation or capture. This non-invasive method is particularly useful for detecting rare, elusive, or endangered species.
Molecular sequencing: Modern sequencing techniques allow scientists to analyze the genetic makeup of marine organisms. This helps identify new species, understand evolutionary relationships, and study the physiological adaptations of creatures living in extreme environments.