Synthetic Pattern of Fish Diversity in Alabama, USA

Abstract

The state of Alabama has a rich fish fauna. Analyzing the current distributional patterns of fish diversity by synthesizing information and integrating different spatial and temporal scales is important for understanding the underlying mechanisms of diversity and making strategies for fish conservation. Basing the study on long-term intensive samples (9,244 collections) of fish species at 3,716 field stations across Alabama from 1845 to 1994, I analyzed the general pattern of fish diversity in Alabama at the county level. The results indicate that more than half the area of Alabama has high fish diversity, including fish species endemic to the USA. Most of the counties with the highest fish diversity are in southwestern Alabama. Nonnative fish species occurred mainly in the southernmost counties, such as Mobile and Baldwin. Twelve counties have the rare species which has only one occurence location in each country, with Lauderdale County having the most (10 rare species); the counties with the rare species are generally distributed at the four corner areas of the state boundaries, particularly on the northern and southern boundaries. A high positive correlation exists between species diversity and endemic species, but there is no significant correlation between species diversity and diversification. Both Power-law and logarithmic relationships exist between class of species diversity and its frequency; counties with higher fish diversity tend to have low human-population densities, and are located at or nearby the Alluvial-deltaic Plain and Gulf Coast floodplain.