Comparison of thermal niche model development methods for black sea bass

Physical processes in the coastal ocean are highly variable in space and time and play a critical role in structuring marine ecological systems. Defining pelagic habitat indicators for migratory fish, such as black sea bass, is particularly interesting and challenging due to the complex interaction between the marine food web and this physical variability. Generalized additive models (GAM) are frequently used to develop thermal niche models for ectothermic marine species. The response curves derived from these models are purely statistical relationships between the environmental features and fish catch used as input and vary depending on the specific data used to build the model. Thus, there is no inherent mechanistic or physiological basis to any resulting curves, making them difficult to extrapolate and easy to over-interpret. This presentation will compare thermal niche models for black sea bass along the east coast of the U.S. derived using GAMs that use various fisheries datasets as input, including the NOAA Northeast Fisheries Science Center spring and fall bottom trawl surveys, various inshore fisheries-independent trawl surveys, and fisheries-dependent observer data, as well as various sources of bottom temperature, including in situ measured and monthly-averaged modeled. The fishery data sources available vary greatly in the timing and depth of sampling as well as in the temperature-salinity space that is sampled and/or regionally available as potential habitat. These statistical model-derived niches are then compared to a physiologically-based thermal niche curve produced from laboratory aerobic scope measurements. We will discuss possible reasons and interpretations for differences between curves in an effort to create one wholistic relationship between black sea bass distribution and temperature in order to most effectively couple a thermal niche model to both physical hindcasts and climate projections.