Marine WP 2: Linking primary

producers to top predators: The role of capelin and sandeel in the

Godthåbsfjord area Peter Grønkjær (PI), Martin Blicher,

Rasmus Hedeholm, Malene Simon and Nathalie Danielsen

Small zooplanktivorous fishes

• Small zooplanktivorous fishes are the primary mediators of energy flow from low trophic levels to top-predators in many marine systems.

• These fishes are often fast-growing, short-lived and their condition & population dynamics respond quickly to environmental change.

Capelin & Sandeel

• In Greenlandic waters capelin is known as an important prey for a number of marine fishes, marine mammals and birds.

• In contrast, knowledge on the sandeel in Greenlandic waters is sparse, despite their privotal role in other north Atlantic ecosystems.

Sandeel lifecycle

Van Deurs, 2009

Aim

• To investigate how oceanographic conditions impact feeding, growth and energy accumulation in capelin and sandeel in the Fylla Bank & Godthaabsfjord area.

• To infer how changes in capelin and sandeel dynamics may influence their value as prey for higher trophic levels.

Gicacomo Nathalie

Sampling in May, August and September

Capelin

Sandeel

Analyses

• Age & growth - otoliths

• Diet

• Lipid content – muscle & total

• Energy density

• Stable isotope signatures

Diet

Zooplankton biomass strongly

influences growth of sandeel on the

Faroe Shelf

Eliasen 2012

Increasing winter temperatures decrease nutritional value of sandeel.

Eliasen 2012

Sandeel condition impact cod growth

Eliasen 2012

…and kittiwake breeding success

Eliasen 2012

Some perspectives

• Sandeel (and capelin) are sensitive indicator species for environmental change.

• Their growth and nutritional value can be used to gauge the productivity on the banks or fjords.

• The sandeel (and capelin) can be used to predict the productivity onhigher trophic levels.