Oceanic The adaption of each species is determined
Oceanic waters are generally far saltier than inland waters due to erosion of rocks causing more sodium and chloride enter the oceans waters, this extra sodium and chloride make the waters “salty.” The “salinity” (saltiness or amount of salt dissolved in a body of water) affects surrounding sea and plant life in a variety of harmful ways if the salinity levels are too low or too high. In ocean water salinity should be measured at frequent rates to prevent loss of sea life in the seas, to achieve this using the conductivity of ocean water can make recording the salinity levels far easier. Throughout this review the methods for how salinity and conductivity are recorded, the importance of such recording, current research being done, how salinity and conductivity are influenced and the connections to day to day life salinity may have. When scientists look to measure the conductivity of waters, they use probes which apply voltage (an electric force that causes free electrons to move from one atom to another) between two electrodes (a conductor through which electricity enters or leaves an object.) The drop in voltage is used to measure the resistance of the water, which is then converted to conductivity. Temperature also plays a role in affecting the conductivity of water, higher temperatures equate to higher electrical conductivities. Salinity is recorded using a hydrometer (an instrument for measuring the density of liquids.) The hydrometer measures gravity which can then be converted into salinity. Another method is the refractometer (a tool used to measure the ability of water to refract light.) Using a refractometer the light can be seen travelling slower if there is more salt present in the water. Salinity is important as it affects oxygen solubility. The higher the salinity level, the lower the oxygen concentration. Oxygen is less soluble in seawater than in freshwater at the same temperature. On average, seawater has a oxygen concentration than freshwater sources. Knowing this is very useful as most aquatic organisms only tolerate a specific salinity range. The adaption of each species is determined by the salinity of its surrounding environment. Most species of fish are stenohaline (exclusively freshwater or saltwater organisms.) Only a specific few sea life can adapt to a range of salinities, these organisms are euryhaline (tolerable to many levels of salinity.) If changes to salinity occur in bodies of water the sea life could suffer from major losses in population, which could be detrimental to the survival of the aquatic ecosystem present. Sudden changes in conductivity can indicate pollution. This occurs as runoff or leaks will increase or decrease conductivity due to the additional chloride, phosphate and nitrate ions. An oil spill would cause conductivity to drop as this compound does not break into ions. In both scenarios, measuring the conductivity of the water could warn us of possible changes in the system present allowing closer measures being taken to preserve the life in the system. Salinity affects water densities and these densities contribute to the major ocean convections on Earth. The higher the salt concentration, the higher the density of the water. The increase in density with salt levels is one of the driving forces behind the circulations of major currents. Knowing the levels of salinity in these convection areas is incredibly valuable as to know which direction the natural flow of oceanic waters is moving in. In future years, one of the main goals is to improve retrieving data closer to the coasts and poles. Land and ice emit very bright microwave emissions (waves read on an electromagnetic scale) that make the signal read by the satellite less accurate. At the poles, water requires very large changes in salt concentration to modify microwave signal. Launched June 10, 2011, aboard the Argentine spacecraft Aquarius/Satélite de Aplicaciones Científica, Aquarius is NASA’s first satellite specifically built to study the salt content of oceanic waters. Salinity variations, one of the main drivers of ocean circulation, are connected with the cycling of freshwater around the planet and provide scientists with information on how the changing climate on Earth is altering global rainfall patterns. Salinity is affected by a number of different variables. Rain in most environments has a conductivity equal to zero. Rain falling into a body of water can potentially lower the salinity and conductivity of the water. Soil and rocks release ions into the waters that flow through or over them. The landscape of an area will determines the amount and type of ions. Conductivity and Salinity can be influenced by sea spray (aerosol particles that are formed directly from the ocean) these sprays carry salts into the air, which then fall back into the rivers with rainfall. In flat areas, water at the river mouths are often salty because of saltwater intrusion (movement of saline water into freshwater) during high tides. The flow of rivers into estuaries (tidal mouth of a large river, where the tide meets the stream) can greatly affect salinity as well as the location of the estuarine mixing zone. This is very important to estuarine organisms. Lastly, evaporation and loss of fresh water will greatly increase conductivity and salinity of a waterbody. Warmer weather can even potentially increase ocean salinity. Saltwater intrusions can move into freshwater aquifers (a body of permeable rock that can contain or transmit groundwater,) which can lead to the contamination of drinking water sources. If salinity of aquatic sea life water is too high or low it can lead to a rapid decrease in the population of local living animals in that area, causing business reliant on those animals to close. Measuring and watching the salinity and conductivity levels in bodies of water around the globe can be very beneficial to surrounding countries looking to protect the waters near them and the water their people drink. Salinity in ocean water is measured at real time rates to prepare a proper response to a possible loss of aquatic sea life, using conductivity of ocean water as a means to measure salinity can make the process more accurate and simpler.