Description of time series:
Trend analysis is not appropriate for Marine Mammal Unusual Mortality Event data.
Description of gauge:
The gauge value of 50 indicates that between 2015 and 2019 the average number of marine mammal unusual mortality events in the Hawaiian-Pacific Islands was 0. This is nearly identical to the median number of all unusual mortality events between 1991 and 2019, highlighting that unusual mortality events in this region are extremely rare.
Description of Unusual Mortality events:
Marine mammals are important parts of marine ecosystems. Sometimes we observe significant die-offs in a marine mammal population - also called unusual mortality events (UMEs). A UME is defined as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." UMEs are often caused by ecological factors (e.g. changes in ocean conditions or food sources), biotoxins, infectious disease, and human interactions, but in some cases the cause cannot be determined. Some unusual mortality events occur over a period of months and others last for years. Understanding and investigating marine mammal UMEs is crucial because they can be indicators of ocean health, giving insight into larger environmental issues, which may also have implications for human health. We present the number of unusual marine mammal mortality events in a given year in all the Alaska, Pacific Islands, California Current, Gulf of Mexico, Southeast, and Northeast regions.
Overall Scores mean the following:
High values for UME are bad, low values are good.
- 0 - 10: The five-year UME average is very low compared to the median value.
- 10 - 25: The five-year UME average is much lower than the median value.
- 25 - 50: The five-year UME average is lower than the median value.
- 50: The five-year UME average equals the median value.
- 50 - 75: The five-year UME average is higher than the median value.
- 75 - 90: The five-year UME average is much higher than the median value.
- 90 - 100: The five-year UME average is very high compared to the median value.
Unusual mortality event (UME) data for marine mammals were accessed from the NOAA Fisheries Active and Closed Unusual Mortality Events website (https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events). A value of 1 was assigned for each UME (open and closed) reported as occurring for any portion of a given year and the values were summed by year for each region. For UMEs where the date range was not indicated, a value of 1 was applied only for the year the UME was declared.