Alamitos Bay Water Quality Data
Community scientists collect water quality samples throughout Alamitos Bay to help us understand how conditions change over time. This page brings that data together in one place, allowing you to explore patterns in temperature, salinity, dissolved oxygen, water clarity, and other indicators of bay health. Learn how to join the Water Quality Testing Team here.
Analyzing the Data
Navigate through each month using the box in the bottom right of the display to see how the data changes over the year.
Temperature
The temperature of the water can impact the other measurements you’ll take. It also can impact organisms if the temperature goes out of the normal range they are adapted to. The air temperature, amount of mixing of the water, and sunlight penetration can impact temperature.
Normal range: 58 -75 °F / 14 – 24 °C
Salinity
Alamitos Bay is an estuary where freshwater and saltwater systems connect. Organisms that live here are adapted to a certain range of salinity. Big or abrupt changes may impact those organisms. Rain and runoff of freshwater can decrease salinity, where as evaporation and increased ocean influx can decrease salinity.
Estuary Normal range: 0-35 ppt
Ocean Normal range: 33-37 ppt
pH
pH is a measure of free Hydrogen ions in a solution. The ocean has a stable pH of around 8.1, but ocean acidification, a side-effect of climate change, is the gradual change in ocean pH. pH is affected by any chemical processes going on in the ocean. In the bay, it is also connected to the salinity of the water (fresh water has a lower pH than ocean water). Sewage discharges can also impact pH.
Normal range: pH 7.5-8.5
Dissolved Oxygen
The dissolved oxygen in aquatic waterbodies is important because it is what marine animals use to breathe. Whether zooplankton, fish, or rays, animals that live in the water also need oxygen to survive. Warmer temperatures and algae or bacteria blooms can both result in reduced oxygen. Water mixing and waves can increase dissolved oxygen, which comes from the atmosphere.
Ranking Results:
90-100% – Excellent
70-89% – Good
50-70% – Fair
Less than 50% – Poor
Nitrate
Nitrate is a key nutrient for plant growth. Too much nitrate may lead to algae blooms, which when decaying use up too much oxygen, potentially causing fish die-offs. Sewage spills and fertilizer run-off can both lead to excess nitrate.
Ranking Results:
0-5 ppm – OK 20-40 ppm – Poor
Water Visibility / Turbidity
Water visibility is a measure of how far you can see through water. Turbidity is a measure of suspended solids in the water. Water visibility can be reduced when the bottom sediments are churned up, as well as microorganisms growing in the water. Low visibility/high turbidity is not always a bad thing, but a high sediment load may reduce sunlight penetration which can have a negative impact on plants and photosynthetic organisms.
Ranking Results:
0-5 feet – Low visibility
5-15 feet – Normal visibility