Conserving Black Bass Diversity

USGS Cooperative Research Unit Corner

Conserving Black Bass Diversity

Black bass (genus Micropterus) is the number one group of fish pursued by anglers in the United States since recreational fishing statistics have been gathered, but their true diversity has yet to be fully documented. Because of their status as sport-fish, their conservation receives priority attention by many state natural resource agencies. However, even among biologists there is disagreement about how many species of black bass exist; conservatively there are eight species, but possibly up to 17. The Oklahoma Cooperative Fish and Wildlife Research Unit (CRU) is researching black bass diversity and working to increase awareness of the variety of species.

Many are surprised to learn that black bass diversity extends beyond the three most widespread species: Largemouth Bass, Smallmouth Bass and Spotted Bass. While Alabama Bass, Redeye Bass, Shoal Bass, Guadalupe Bass, and Suwannee Bass are all generally recognized species, Florida Bass, Choctaw Bass, Bartram's Bass, Warrior Bass, Chattahoochee Bass, Tallapoosa Bass, Cahaba Bass, and Lobina Negra de Cuatro Ci?negas are all species that are either newly described, should be described, or are newly recognized from previous descriptions. While the populations of these lesser-known species are segregated into small watersheds, typically shared among only two or three states, one thing they share in common is that they all occur within the southern portion of the U.S or northern Mexico.

To highlight this diversity, CRU fisheries biologists in Oklahoma helped organize a set of symposia at meetings of the American Fisheries Society (AFS) and its divisions beginning in 2009. In 2010, the CRU helped develop a $30 million Keystone Initiative through the National Fish and Wildlife Foundation (NFWF) to deliver on-the-ground conservation and management for these southern endemic black basses. After the 2013 symposium, held at the Southern Division American Fisheries Society's annual meeting in Nashville, the AFS agreed to publish a book highlighting this diversity and the interest of biologists to conserve it. Titled Black Bass Diversity: Multidisciplinary Science for Conservation, this volume is slated for publication in late 2014 or early 2015 and will feature 46 contributions in four topic areas: 1) biology, ecology and life history; 2) conservation genetics; 3) habitat restoration and management, and; 4) fisheries management. Taken together, these endemic black bass species represent a diverse group, but because they each occupy a small area, it remains up to individual states to study and conserve the unique forms found in their borders.

For example, in Oklahoma, biologists with the CRU are actively engaged in studying the genetics of Neosho Smallmouth Bass, a sub-species restricted to tributaries of the Arkansas River in the Ozark Highlands, and the effect of impoundment. At Grand Lake O' the Cherokees, Smallmouth Bass are rare, but they naturally occur in abundance in tributary streams such as Honey Creek, Elk River and Spring River. One hypothesis being tested, using another native black bass species as a control, is whether the impoundment itself is a barrier to this sub-species, which is thought to be a stream-specialist. Spotted Bass do occur in these tributaries but are also found in the impoundment. The hypothesis is that Neosho Smallmouth Bass is a habitat-specialist and not able to traverse the slack water of the impoundment to any great degree whereas Spotted Bass are more generalists. If this is the case, it is expected that there would be a greater degree of variation among tributary streams for Neosho Smallmouth Bass compared to Spotted Bass. Because there is often a desire on the part of anglers to stock Smallmouth Bass in Grand Lake, this research should help guide management actions including whether to stock and identification of suitable brood sources.

Each month, the ONB features articles from Cooperative Fish and Wildlife Research Units across the country. Working with key cooperators, including WMI, Units are leading exciting, new fish and wildlife research projects that we believe our readers will appreciate reading about.

October 16, 2014