Which of the following is a sampling method in marine science?

Frame quadrats are indeed a recognized sampling method in marine science. This technique involves the use of a defined area, usually in the shape of a square or rectangle, that researchers can use to study the abundance and distribution of marine organisms within that specific space. By placing these frames at various locations and counting the organisms inside, scientists can gather quantitative data that helps in understanding population dynamics, community structure, and the health of marine ecosystems.

Other methods listed, while useful for marine science, serve different purposes. Hydrographic profiling is typically focused on measuring physical properties of the water column, such as temperature and salinity, which provides critical environmental context but does not involve direct sampling of organisms. Satellite imaging is an advanced tool for observing and monitoring large areas of the ocean and can be instrumental for remote sensing but is not a direct sampling technique. Water quality testing assesses the chemical and biological parameters of water, providing vital information about habitat health but again does not sample organisms directly. Therefore, frame quadrats represent a direct method of sampling and assessing biological communities in marine environments.