Impact of climate change on potential habitat distribution of Sciaenidae in the coastal waters of China

Climate change has affected and will continue to affect the spatial distribution patterns of marine organisms.To understand the impact of climate change on the distribution patterns and species richness of the Sciaenidae in China’s coastal waters,the maximum entropy model was used to combine six environmental factors and predict the potential distribution of 12 major species of Sciaenidae by 2050s under Representative Concentration Pathways(RCPs)2.6 and 8.5.The results showed that the average area under the receiver operating characteristic curve of the model was 0.917,indicating that the model predictions were accurate and reliable.The main driving factors affecting the potential distribution of these fishes were dissolved oxygen,salinity,and sea surface temperature(SST).There was an overall northward shift in the potential habitat areas of these fishes under the two climate scenarios.The total potential habitat areas of Larimichthys polyactis,Pennahia argentata,and Pennahia pawak decreased under both climate scenarios,while the total habitat area of Johnius belengerii,Pennahia anea,Miichthys miiuy,Collichthys lucidus,and Collichthys niveatus increased,suggesting that these might be loser and winner species,respectively.The expansion rate,contraction rate,degree of centroid change,and species richness in the potential habitats were generally more significant under RCP8.5 than RCP2.6.The mean shift rates of the potential distribution were 41.50 km/(10 a) and 29.20 km/(10 a) under RCP8.5 and RCP2.6,respectively.The changes in Sciaenidae species richness under climate change were bounded by the Changjiang River Estuary waters,with obvious north-south differences.Some waters with increased species richness may become refuges for Sciaenidae fishes under climate change.The richness and habitat area change rate of some aquatic germplasm resources will decrease,meanings that these reserves are more sensitive to climate change,and more attention should be paid to the potential challenges and opportunities for fishery managers.This study may provide a scientific basis for the management and conservation of Sciaenidae in China under climate change.

Trends of Abundance of Salton Sea Fish: A Reversible Collapse or a Permanent Condition?

The Salton Sea is a closed-basin, 980 km2 salt lake in the Sonoran Desert of southern California. Three marine species, bairdiella (Bairdiella icistia), orangemouth corvina (Cynoscion xanthulus), and sargo (Anisotremus davidsoni), established from introductions of over 34 species beginning in 1929. During the late 1960s and early 1970s, a hybrid tilapia (Oreochromis mossambicus × O. urolepis hornorum) invaded the Salton Sea and became dominant by number and weight. Recent surveys show a precipitous decline of all four species above starting sometime between 2001 and 2002. Declines were more evident in nearshore than in estuarine habitats. Corvina has probably declined the soonest, followed by Gulf croaker. Tilapia declines were followed by more recent increases in population numbers. The tilapia rebound observed are probably only sustainable if a curb in Salton Sea salinity levels is realized. The marine species will likely need restocking to reach historic levels, if the salinity of the lake is managed at 40 g•L–1 or below. Restoration alternatives for the Salton Sea must take into consideration estuarine areas as essential fish habitats and fish refuge against high salinities.