Abstract

Incorporating stratification by habitat type in the design of a reef fish survey is an obvious way to improve efficiency, optimize survey resources, and obtain more accurate abundance estimators for a given species. The issue becomes com-plex, however, in a multi-species survey covering a diversity of habitats. Post-stratification of collection records -- censoring some or many depending on the species -- may be necessary. It is no secret that the heavily exploited reef fishes (mostly serranids and lutjanids) in the northeastern Gulf of Mexico are closely tied to hard/live bottom habitat most or all of their lives. Cross-shelf mapping and video surveys conducted by NOAA Fisheries Service’s Panama City lab revealed that such habitat is not only widespread across the West Florida shelf, but also varies widely in relief, rugosity, morphology, density, area, and in density and composition of attached biota. Not surprisingly, these different forms of hard bottom often hold different suites and densities of reef fishes; and demographics within species may also vary. Variability related to depth, zoogeographic boundaries, species-specific patchiness, and behavior relative to survey gear is also common. All of these factors can result in species-specific effects on the precision and accuracy of survey indices; and must be considered in the design of, and analysis of data from, a multi-species reef fish survey. We present some species-habitat-location examples and compare frequency of occurrence and precision of abundance indices between trap and camera data for several species of reef fish from the NE Gulf.

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