Description of time series:
Between 2011 and 2015 the national average concentration of zooplankton biomass showed a significant upward trend.
Description of gauge:
The gauge value of 79 indicates that between 2011 and 2015 the average concentration of zooplankton biomass in the four US regions with data (Alaska, the California Current, the Gulf of Mexico, and the Northeast) was much higher than the median value of all zooplankton biomass concentration levels from 1986 through 2015.
Description of Zooplankton:
Zooplankton are a diverse group of animals found in oceans, bays, and estuaries. By eating phytoplankton, and each other, zooplankton play a significant role in the transfer of materials and energy up the oceanic food web (e.g., fish, birds, marine mammals, humans.) Like phytoplankton, environmental and oceanographic factors continuously influence the abundance, composition and spatial distribution of zooplankton. These include the abundance and type of phytoplankton present in the water, as well as the water’s temperature, salinity, oxygen, and pH. Zooplankton can rapidly react to changes in their environment. For this reason monitoring the status of zooplankton is essential for detecting changes in, and evaluating the status of ocean ecosystems. We present the annual average total biovolume of zooplankton in the Alaska, California Current, Gulf of Mexico and Northeast regions.
Overall Scores mean the following:
High values of zooplankton can be good (lots of lipid rich colder water species) or bad (lots of lipid poor warmer water species), depending on the region.
- 0 - 10: The five-year zooplankton biomass average is very low compared to the median value.
- 10 - 25: The five-year zooplankton biomass average is much lower than the median value.
- 25 - 50: The five-year zooplankton biomass average is lower than the median value.
- 50: The five-year zooplankton biomass average equals the median value.
- 50 - 75: The five-year zooplankton biomass average is higher than the median value.
- 75 - 90: The five-year zooplankton biomass average is much higher than the median value.
- 90 - 100: The five-year zooplankton biomass average is very high compared to the median value.
Zooplankton data for each region were obtained from the NOAA Fisheries Coastal & Oceanic Plankton Ecology, Production, & Observations Database, an integrated data set of quality-controlled, globally distributed plankton biomass and abundance data with common biomass units and served in a common electronic format with supporting documentation and access software. National numbers are spatially-weighted averages.