Variation in Temperature, Change in Barometric Pressure, and Salinity Explain Trends in the Acoustic Backscatter of Fishes Within a Large Ship Channel Inlet in the Gulf of Mexico

Human-fortified ship channel inlets can represent the only connection between estuarine and coastal waters for tens of kilometers in some areas Northern Gulf Mexico, making them bottlenecks fish movement. A variety fishes associate with jetties that fortify inlets, deep depths relative to surrounding may provide a unique type habitat. To understand variability biomass these vital areas, 49 hydroacoustic surveys Aransas Channel Inlet, Texas were conducted paired environmental (e.g., temperature) meteorological barometric pressure) data January 2018 February 2020. Fishery-independent fishery-dependent from area employed context backscatter (i.e., volume backscattering strength, sv, proxy biomass). Generalized additive models indicated variation was best explained by temperature, change pressure, salinity (adj.-R2 = 0.71). There two dimensions effects. In first, temperature tracked seasonal shifts abundance pelagic fishes, which well sampled acoustic technologies demersal fishes. second, episodic cold fronts high pressure systems) associated values — likely because Inlet is far deeper than protected jetties, it less affected physical disturbances rapidly changing air temperatures or precipitation. Thus, dredging construction, shipping traffic) are be most impactful non-demersal when low (< c.a. 15 °C < 28 psu) frontal systems affect (barometric increase > 3 mb decrease 7 over 24 h).