Values indicate annual cumulative change in centroid across all species in a region in degrees N
Description of Time Series: Between 2013 and 2017 the average species latitudinal shift showed an increasing trend, indicating a northward shift in distribution.
Description of Gauge: The gauge value of 76 indicates that between 2013 and 2017 the average species latitudinal shift was much higher than the median average latitudinal shift between 1989 and 2017.
- 0 - 10: The five-year latitudinal shift is very low compared to the median value.
- 10 - 25: The five-year latitudinal shift is much lower than the median value.
- 25 - 50: The five-year latitudinal shift is lower than the median value.
- 50: The five-year latitudinal shift average equals the median value.
- 50 - 75: The five-year latitudinal shift is higher than the median value.
- 75 - 90: The five-year latitudinal shift is much higher than the median value.
- 90 - 100: The five-year latitudinal shift is very high compared to the median value
Indicator Source Information:
This data provides important information for fisheries management including which species are caught where and at what depth. The scientists at Ocean Adapt use this data to calculate each species’ centroid as the mean latitude and depth of catch in the survey, weighted by biomass. The centroid for each species is calculated for each year after standardizing the data to ensure that the measure is consistent over time despite changes in survey techniques and total area surveyed. A northern change in the centroid of latitude could result from the expansion of the northern edge of a species range, the contraction of the southern edge of a species range, or both.
Data Background and Caveats:
The regional and national marine species distributions shown here represent the average shift in the centroid of species caught in surveys conducted in each region. These species represent a wide range of habitats and species types. As species distributions respond to many environmental and biological factors, combining data from multiple diverse species allows for a more complete picture of the general trends in marine species distribution. In order to more easily track and display changes in these distributions, the first year is standardized to zero. Thus, the indicator represents relative change in distribution from the first survey year.