<div>Changes in the thermal structure of lake ecosystems have been documented
as a precursor of climate change, but the dynamics of biomass
distribution, which fundamentally determines species conservation, have
been less studied. An interdisciplinary approach was used to demonstrate
the influence of climate-driven changes on the biomass distribution of
two species (<i>Gymnogobius isaza</i> and <i>Palaemon paucidens</i>) in
Lake Biwa. In field surveys in 2016–2017 (full water circulation) and
2019 (partial water circulation), environmental DNA concentrations of
these species were used as proxies for biomass to measure 43 and 47
sites sampled at the lake bottom, respectively. A structural equation
model was used to estimate the correlation between species biomass and
environmental parameters. The species-environment relationship was
applied to species biomass distributions under existing and future
environments calculated by the model. Differences between the species
were found in their responses to climate change. The biomass
distribution of <i>G. isaza</i> will benefit in the future if full water
circulation occurs, although it appears to be independent of water
circulation at present. Partial water circulation enlarges the
distribution area of <i>P. paucidens</i>, but its biomass will be low in
the future, regardless of the extent of water circulation. These
findings advance the knowledge of how species respond to climate change
and suggest special attention should be given to species such as
<i>P. paucidens</i>, which is currently abundant but sensitive to
climate change. Furthermore, they emphasize the potential application of
interdisciplinary methodologies for improved species conservation.</div>