A fossil record of colonization and response of lacustrine fish populations to climate change

Abstract

To study fish species colonization and the response of populations to climate change, we reexamined a well-preserved late Pleistocene to early Holocene fossil fish assemblage from lake deposits on the Missouri Coteau, North Dakota. The fossil fishes in the assemblage include complete specimens of yellow perch (Perca flavescens), brassy minnow (Hybognathus hankinsoni), blacknose shiner (Notropis heterolepis), banded killifish (Fundulus diaphanus), and brook stickleback (Culaea inconstans). The sequence of colonization is explained by individual thermal and relative water velocity tolerances for each species. There are six peaks in fish abundance during approximately 1000 years, indicating a response to environmental perturbations. Charcoal deposition from fires is inferred to represent episodic droughts during which nutrient levels were reduced and fish abundance declined. The fluctuations follow an overall trend of increased fish abundance during a time when lake-marginal vegetation changed from a spruce to a deciduous forest in response to climatic warming. This study provides insight into the complex effects of a changing climate on fish populations and demonstrates the potential of using fossils to examine the long-term abundance patterns of contemporary fish species.