Transfer of essential lipids from aquatic to terrestrial
ecosystems via emerging insects
Emerging aquatic insects (EAI) are important trophic vectors through which freshwater-derived organic matter can enter terrestrial food webs (Hoekman et
al.2010; Martin-Creuzburg et al.2017),and support terrestrial consumer fitness, especially via its polyunsaturated fatty acids (PUFA) that are otherwise
short in supply from terrestrial diet (Gladyshev et al.2009).
Considering qualitative aspects of resource subsidies is thus crucial for understanding energy and nutrient fluxes between ecosystems and for assessing
effects on food web processes in recipient habitats (Marcarelli et al. 2011; Twining et al.2016).
Quantify and qualify the transfer of dietary PUFA looking
at both altitudinal and lake depth gradients
Figure 1. Study lakes sampled from June to September 2019, with aquatic traps
presenting a depth gradient from 33 to 1 m.
oTaxa biomass oTotal lipid content
oδ13C of FA
Determine the origin of essential FA for riparian consumers
Figure 2. Map of the sampling sites of the three different ecosystems in Lake Lunz:
lake, stream, and terrestrial.
oBulk Stable Isotopes:
δ13C & δ15N
oδ2H of FA
oInsects & Riparian consumers
Figure 3. Relative contribution (%) of different insect groups to
the export of total insect biomass (mg.m-2)at different depths.
Figure 4. Biomass export (mg.m-2)
of Chironomidae and Microsema
insects from different depths
The effect of aquatic
subsidies on terrestrial
with distance to lake
PUFA-flux via EAI will decrease
with increasing lake depth and
oDifferent taxonomic contribution
as function of lake depth and time
Changes in quantity and quality
of PUFA exports
oBiomass export higher at shallow
Transfer of energy varies as
function of sampling sites
Margaux Mathieu-Resuge1, Tarn Preet PARMAR2, Dominik MARTIN-CREUZBURG2, Hannes H. HAGER1, Martin J. KAINZ1
1 WasserCluster Lunz - Inter-University Centre for Aquatic Ecosystem Research, Lunz am See, Austria
2 Limnological institute, University of Konstanz, Germany