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Maritimes Ecosystem Indicator Catalogue

2 Surface Temperature (AZMP)

Data Type: Tabular Data

Spatial Scope: Scotian Shelf (4X, 4V, 4W)

Duration 1948-2024

Source: DFO Atlantic Zone Monitoring Program via azmpdata

2.1 Introduction to Indicator

AZMP Surface Temperature contains empirical temperature measurements at 0m depth, averaged across NAFO divisions (4V, 4X, 4W) and regional boundaries (Bay of Fundy + Gulf of Maine). Data from this indicator is not subdivided regionally, but see Chapter 1 for spatially-stratified surface temperature data.

Sea surface temperature is influenced by a variety of conditions spanning multiple spatial and temporal scales. In this region, long-term trends in SST are consistent with expectations of anthropogenic climate change (Greenan et al. 2019). At the same time, decadal-to-interannual regional SST trends are influenced by atmospheric indicators like those described in this book, and short-term local values can be influenced by many oceanographic and climate factors, such as freshwater input, ocean currents, and weather events.

2.2 View Data 

library(plotly)
plotly_df <- data@data %>%
  mutate( 
    smooth_10yr = zoo::rollapply(mean_value, mean, width = 10, partial = TRUE),
    overall_mean = mean(mean_value))

p <- plot_ly(plotly_df, x = ~year) %>%
  add_lines(y = ~mean_value,
            name = "Annual Mean",
            line = list(color = "grey"),
            hovertemplate = "Monthly anomaly: %{y:.2f}<extra></extra>"
           ) %>%
  add_lines(y = ~smooth_10yr,
            name = "10-yr Smooth",
            line = list(color = "blue", width = 2),
            hovertemplate = "10-yr smoothed: %{y:.2f}<extra></extra>",
            ) %>%
    add_lines(y = ~overall_mean,
            name = "Overall Mean",
            line = list(color = "black", width = 2, dash = "dash"),
            hovertemplate = "Overall Mean: %{y:.2f}<extra></extra>",
           ) %>%
  layout(
    title = "AZMP Surface Temperature for Scotian Shelf (4X, 4V, 4W)<br><sup>Source: DFO Atlantic Zone Monitoring Program via azmpdata</sup>",
    xaxis = list(title = "Year"),
    yaxis = list(title = "Surface Temperature (°C)",
                 fixedrange = TRUE),
    hovermode = "x unified",
    margin = list( t = 80)
    
  ) %>%
  config(displayModeBar = FALSE) 

p

Figure 2.1: AZMP Surface Temperature in Scotian Shelf; 1948-2024

2.4 Relevance to Research and Stock Assessments

Changes to sea surface temperature could have great impact on fisheries and stocks from both direct and indirect effects.

Sea surface temperatures can directly impact fisheries via changes to the distribution and phenology of key fisheries species (Hutchings et al. 2012). These changes are likely to result in the loss or decline of some commercially important species, but also the gain or increase of others. Atlantic Canada is projected to experience decreases in species and maximum catch in the Scotian Shelf and surrounding bioregions, but projected gains towards the Arctic (Cheung et al. 2010). These changes are consistent with expected poleward shifts if species track climatic envelopes towards the poles. Changes to surface temperature might also affect phenological processes of key species, including spawning times and predator/prey encounters.

Sea surface temperatures can also affect the physical and chemical properties of marine ecosystems, in turn, affecting species. Warming and freshening of surface waters can lead to increased stratification in coastal oceans, influencing primary productivity and nutrient cycling.

2.5 Variable Definitions

Table 2.2: Column names and definitions in the AZMP_surface_temperature dataset.
variable description unit
year Year of data observations
region Area over which observations were summarized (only one: scotian_shelf_box)
mean_value Averaged surface temperature in a given year °C

2.6 Additional Data

No additional data for AZMP Surface Temperature.

2.7 Get the Data 

library(marea)
data('azmp_surface_temperature')
plot(azmp_surface_temperature)

References

Cheung, William WL, Vicky WY Lam, Jorge L Sarmiento, Kelly Kearney, REG Watson, Dirk Zeller, and Daniel Pauly. 2010. “Large-Scale Redistribution of Maximum Fisheries Catch Potential in the Global Ocean Under Climate Change.” Global Change Biology 16 (1): 24–35.
Greenan, B. J. W., T. S. James, J. W. Loder, P. Pepin, K. Azetsu-Scott, D. Ianson, R. C. Hamme, et al. 2019. “Chapter 7: Changes in Oceans Surrounding Canada.” In Canada’s Changing Climate Report, edited by E. Bush and D. S. Lemmen, 343–423. Ottawa, ON: Government of Canada. https://changingclimate.ca/CCCR2019/chapter/7-0/.
Hutchings, Jeffrey A, Isabelle M Cote, Julian J Dodson, Ian A Fleming, S Jennings, Nathan J Mantua, Randall M Peterman, Brian E Riddell, and Andrew J Weaver. 2012. “Climate Change, Fisheries, and Aquaculture: Trends and Consequences for Canadian Marine Biodiversity.” Environmental Reviews 20 (4): 220–311.