This study by Jónsdóttir et. al. (2013) showed that shrimp recruitment north of Iceland is strongly related to cod abundance and temperature in the area.
Influence of increased cod abundance and temperature on recruitment of northern shrimp (Pandalus borealis)
Ingibjörg G. Jónsdóttir, Árni Magnússon, Unnur Skúladóttir
Marine Biology 160:1203-1211 (May 2013)
Despite an increase in northern shrimp (Pandalus borealis) female biomass in the past years, the recruitment of the offshore population north and northeast of Iceland has remained very low. In this study, the influence of abiotic and biotic factors was studied in relation to shrimp recruitment. Two factors, cod (Gadus morhua) abundance and summer sea surface temperature (SST), were found to have a negative effect on offshore shrimp recruitment, explaining 71% of the observed variation. Both cod abundance and temperature on the offshore shrimp grounds have increased in the past years, while recruitment has decreased and been at historically low levels since 2005. No significant relationship was found between recruitment and spawning biomass, indicating that recruitment variability is mainly driven by other factors. Cod abundance and summer SST are likely to affect different life stages of shrimp, as SST influences shrimp during its planktonic phase while cod abundance influences the demersal stage.
The dataset used in the regression analysis is available for download. Alternatively, the dataset can be imported directly from the web server, using software like R:
shrimp <- read.csv("http://data.hafro.is/research/shrimp_recruitment/data.csv") plot(shrimp)