Climate-induced habitat suitability changes intensify fishing impacts on
the life history of large yellow croaker (Larimichthys crocea)
Abstract
Intense fishing pressure and climate change are major threats to fish
populations and coastal fisheries. Larimichthys crocea (large
yellow croaker) is a long-lived fish, which performs seasonal migrations
from its spawning and nursery grounds along the coast of the East China
Sea (ECS) to overwintering grounds offshore. This study used
length-based analysis and habitat suitability index (HSI) model to
evaluate current life-history parameters and overwintering habitat
suitability of L. crocea, respectively. We compared recent (2019)
and historical (1971-1982) life-history parameters and overwintering HSI
to analyze the fishing pressure and climate change effects on the
overall population and overwintering phase of L. crocea. The
length-based analysis indicated serious overfishing of L. crocea,
characterized by reduced catch yield, size truncation, constrained
distribution, and advanced maturation causing a recruitment bottleneck.
The overwintering HSI modeling results indicated that climate change has
led to decreased sea surface temperature during L. crocea
overwintering phase over the last half-century, which in turn led to
area decrease and an offshore-oriented shifting of optimal overwintering
habitat of L. crocea. The fishing-caused size truncation may have
constrained the migratory ability and distribution of L. crocea
subsequently leading to the mismatch of the optimal overwintering
habitat against climate change background, namely habitat bottleneck.
Hence, while heavily fishing was the major cause of L. crocea
collapse, climate-induced overwintering habitat suitability may have
intensified the fishery collapse of L. crocea population. It is
important for management to take both overfishing and climate change
issues into consideration when developing stock enhancement activities
and policy regulations, particularly for migratory long-lived fish that
share a similar life history to L. crocea. Combined with China’s
current restocking and stock enhancement initiatives, we propose
recommendations for future restocking of L. crocea in China.