In a coastal saltmarsh ecosystem, the primary producers are dominated by saltmarsh cordgrass (Spartina species).
Sunlight that can potentially be used in photosynthesis by green plants is called photosynthetically active radiation (PAR).
In one year, 7.34×109 kJ m−27.34 \times 10^9 \text{ kJ m}^{-2}7.34×109 kJ m−2 of PAR fell on an area of this saltmarsh. The cordgrass converted 8.56×107 kJ m−28.56 \times 10^7 \text{ kJ m}^{-2}8.56×107 kJ m−2 of this energy into biomass.
Calculate the energy in the PAR that the cordgrass plants did not convert into biomass. Give your answer in standard form to three significant figures.
A predatory bird in this ecosystem, the marsh harrier, has a current breeding population in a coastal wetland reserve estimated at 119 pairs. This represents 85%85\%85% of the estimated population thirty years ago.
Calculate the estimated breeding population of marsh harriers in the reserve thirty years ago, rounded to the nearest whole number.
